Wednesday, April 28, 2010

Grains as Food: an Update

Improperly Prepared Grain Fiber can be Harmful

Last year, I published a post on the Diet and Reinfarction trial (DART), a controlled trial that increased grain fiber intake using whole wheat bread and wheat bran supplements, and reported long-term health outcomes in people who had previously suffered a heart attack (1). The initial paper found a trend toward increased heart attacks and deaths in the grain fiber-supplemented group at two years, which was not statistically significant.

What I didn't know at the time is that a follow-up study has been published. After mathematically "adjusting" for preexisting conditions and medication use, the result reached statistical significance: people who increased their grain fiber intake had more heart attacks than people who didn't during the two years of the controlled trial. Overall mortality was higher as well, but that didn't reach statistical significance. You have to get past the abstract of the paper to realize this, but fortunately it's free access (2).

Here's a description of what not to eat if you're a Westerner with established heart disease:
Those randomised to fibre advice were encouraged to eat at least six slices of wholemeal bread per day, or an equivalent amount of cereal fibre from a mixture of wholemeal bread, high-fibre breakfast cereals and wheat bran.
Characteristics of Grain Fiber

The term 'fiber' can refer to many different things. Dietary fiber is simply defined as an edible substance that doesn't get digested by the human body. It doesn't even necessarily come from plants. If you eat a shrimp with the shell on, and the shell comes out the other end (which it will), it was fiber.

Grain fiber is a particular class of dietary fiber that has specific characteristics. It's mostly cellulose (like wood; although some grains are rich in soluble fiber as well), and it contains a number of defensive substances and storage molecules that make it more difficult to eat. These may include phytic acid, protease inhibitors, amylase inhibitors, lectins, tannins, saponins, and goitrogens (3). Grain fiber is also a rich source of vitamins and minerals, although the minerals are mostly inaccessible due to grains' high phytic acid content (4, 5, 6).

Every plant food (and some animal foods) has its chemical defense strategy, and grains are no different*. It's just that grains are particularly good at it, and also happen to be one of our staple foods in the modern world. If you don't think grains are naturally inedible for humans, try eating a heaping bowl full of dry, raw whole wheat berries.

Human Ingenuity to the Rescue

Humans are clever creatures, and we've found ways to use grains as a food source, despite not being naturally adapted to eating them**. The most important is our ability to cook. Cooking deactivates many of the harmful substances found in grains and other plant foods. However, some are not deactivated by cooking. These require other strategies to remove or deactivate.

Healthy grain-based cultures don't prepare their grains haphazardly. Throughout the world, using a number of different grains, many have arrived at similar strategies for making grains edible and nutritious. The most common approach involves most or all of these steps:
  • Soaking
  • Grinding
  • Removing 50-75% of the bran
  • Sour fermentation
  • Cooking
But wait, didn't all healthy traditional cultures eat whole grains? The idea might make us feel warm and fuzzy inside, but it doesn't quite hit the mark. A recent conversation with Ramiel Nagel, author of the book Cure Tooth Decay, disabused me of that notion. He pointed out that in my favorite resource on grain preparation in traditional societies, the Food and Agriculture Organization publication Fermented Cereals: a Global Perspective, many of the recipes call for removing a portion of the bran (7). Some of these recipes probably haven't changed in thousands of years. It's my impression that some traditional cultures eat whole grains, while others eat them partially de-branned.

In the next post, I'll explain why these processing steps greatly improve the nutritional value of grains, and I'll describe recipes from around the world to illustrate the point.


* Including tubers. For example, sweet potatoes contain goitrogens, oxalic acid, and protease inhibitors. Potatoes contain toxic glycoalkaloids. Taro contains oxalic acid and protease inhibitors. Cassava contains highly toxic cyanogens. Some of these substances are deactivated by cooking, others are not. Each food has an associated preparation method that minimizes its toxic qualities. Potatoes are peeled, removing the majority of the glycoalkaloids. Cassava is grated and dried or fermented to inactivate cyanogens. Some cultures ferment taro.

** As opposed to mice, for example, which can survive on raw whole grains.

112 comments:

EL 66K said...

Wow, don't ya sleep?

Stephan, wouldn't we be better adapted to say, fruit, than to most sources of starches? Of course, we are very far away from our days climbing trees in the jungle (if you get my idea), but there's no reason that the ability to tolerate natural sugars would be selected against.

EL 66K said...

Oh lol, sorry, is the time zone differences...

Michael said...

But wait, didn't all healthy traditional cultures eat whole grains? The idea might make us feel warm and fuzzy inside, but it doesn't quite hit the mark. A recent conversation with Ramiel Nagel, author of the book Cure Tooth Decay, disabused me of that notion. He pointed out that in my favorite resource on grain preparation in traditional societies, the Food and Agriculture Organization publication Fermented Cereals: a Global Perspective, many of the recipes call for removing a portion of the bran (7).

That is pretty clear in Burkitt's work, which is cited by the WAPF website, though it seems to get buried in any recommendations they make regarding grains, unless the latest edition of Wise Traditions (which I have not read) says something different.

stephen said...

Err, my confidence is undermined by Nagel's website. "Energy medicine"? Nexus magazine? My fruit-loop radar is just about blown already. Your analysis has been pretty persuasive to me Stephan, but this seems like a name-dropping own goal to me.

thania said...

TRUE,true! I know of taditional indian food that soaking is always involved. Looking forward to your next post on the issue! I am not keen on grains and find it much better without them , but am very interested for general information aspect ...

Lindybill said...

Dr Davis, at the Heart Scan Blog, pulls all of his patients off wheat. He finds that this lowers their triglycerides and their small dense LDL.

I got off and it did both for me.

Wheat is a high-glycemic simple starch that can cause overweight, pot belly, high blood sugar, Type II Diabetes, and IBS.

Other than that, it's fine.

Riles said...

Bill, you have to consider what wheat here in America is almost always eaten with ie. refined sugar & refined veggie oils

Mavis said...

A quick question for now, but more on the way:

What is it about non-soluble fiber that increases the risk of heart disease? Any clues?

Anonymous said...

"Potatoes are peeled, removing the majority of the glycoalkaloids."

Interesting. So does that mean eating peeled potatoes is preferable as opposed to eating them unpeeled? I'm consuming great amounts of potatoes and most of them unpeeled, so this would be quite relevant for me to know. Any opinions?

Unknown said...

Bill,

Please stop spreading your FUD about wheat. Dr. Davis pulls his patients off of stale, highly refined white flour. That stuff is bad for you. Properly prepared wheat is fine.

To say all wheat is bad for you merely because Wonder Bread is bad for you is like saying fresh fruit and corn causes diabetes just because High-Fructose Corn Syrup does.

It's not even the same ball park.

jandro said...

Stephan,

great post, always enjoy reading your blog.

How do you think tubers compare to grains? It seems that a lot of tubers require less processing to make them safe to eat (e.g. sweet potato, yams). At the same time, I have not noticed any big differences between traditional societies that depend on tubers compared to those that depend on grains.

PS: do you include legumes in your definition of grains?

Elizabeth Walling said...

Very interesting post. I'm looking forward to hearing more about this.

madMUHHH: I'm wondering the same thing. I've actually noticed since we upped our potato consumption, the peel has suddenly become less desirable to me (whereas before I would enjoy eating it occasionally).

Emily said...

facinating info here, thx so much for doing the research into these articles.

@madmuuhh- my understanding about potato peels is that hunter gatherers of yore would have probably baked thier tubers in hot coals and the skin would have gotten inedibly charred so they would have peeled em.

Chris Kresser said...

These days I'm feeling like grains really aren't worth the effort. I read Nagel's articles in the recent WAPF journal about the preparation needed for various grains in order to neutralize the various toxic or inhibitory substances.

The upshot is this: if I want to have a bowl of oatmeal on Friday, I better start getting it ready on Tuesday or Wednesday. Soaking oats overnight, even with whey, doesn't cut it at all. The same is true for most other grains.

I'm far from lazy when it comes to food preparation. I spend a lot of time on it. Which is why I'm resistant to adding even more time intensive preparation methods for grains.

I don't love them and they don't make me feel that well anyhow. It's probably easier to just abandon them entirely.

And if this is true for me, as someone who is willing to spend a lot of time on food prep, I imagine it's even more true for the person who isn't (which is most people).

So advising people not to eat grains at all (unless they're willing to do the extensive prep, which most aren't) is probably a good idea.

Dave said...

@Chris Kresser

I'm with you. What's the upside to eating grains? They're a pain to prepare properly, not really that high in any nutrient compared with other foods, and for my money not particularly flavorful. Does anybody out there really find plain gruel appetizing, compared to jazzing it up with cream or butter, sugar, etc?

BTW, I don't suggest anybody take up Stephan's challenge to eat a bowl of raw wheat berries. I suspect you'd end up with a pretty bad stomach-ache.

Simon said...

Steven,

Out of curiosity, why do you extrapolate that the increased mortality and coronary heart disease risk during the first two time periods are do the the anti-nutrient properties of whole grains rather than increased carbohydrate content? Also, it seems that the overall mortality was not only higher during the controlled time period as you said, but also for the two years after and then dropped to below that of the control group. I just think its a little too early to establish causation, perhaps you would agree.

-Simon

carcissist said...

Cusick, I believe corn IS bad for you ...

Chris Kresser said...

Dave,

The only reason I can think of is that grains are cheap relative to meat and veggies. This is why they're a staple in developing countries, and here in this country as well. Refined flour and sugar are CHEAP.

(Of course if you include the cost of the diseases they cause and the consequent burden on the health care system, they don't look so cheap anymore.)

Apolloswabbie said...

Simon, would you agree that it confirms that there's no health benefit to a high fiber diet? There has been no study to my knowledge that does show a benefit to fiber. This one at least shows there isn't.

Whether it's due to the wheat or just the massive amounts of fiber and the impact on the intestinal linings probably cannot be determined from this study - many variables.

I agree w Dave: "What's the upside to eating grains?" There's no nutritional case to be made for them, and a strong case to made against them, and a doubly strong case to made against the wheat you and I can get without self processing the stuff.

Why eat grain at all?

carcissist said...

@ Apolloswabbie - the lack of a diet high in fibre can cause issues like diverticulitis. My husband was diagnosed with this last year and his lack of fibre intake, as well as stress, was pinpointed as the cause. We are livin' la vida lo-carb right now and off grains completely (including rice and corn), so he is getting fibre from fruits, nuts and veggies. He misses his bread, though. Oddly, HAD he kept eating bread, he would have had to avoid bread with seeds in it because that can irritate the bowel and cause a flare-up of diverticulitis.

Anonymous said...

"@madmuuhh- my understanding about potato peels is that hunter gatherers of yore would have probably baked thier tubers in hot coals and the skin would have gotten inedibly charred so they would have peeled em. "

Yeah, I have already heard of this and I think looking to our ancestor's eating habit would be the wisest thing to do first. However, that alone does not make a good argument in this case in my opinion. I mean, what choice did hunter/gatherers have? Did hunter gatheres possess the necessary tools to boild potatoes? Should we stop steaming vegetables, or cooking sous-vide because hunter gatherers didn't have access to such fancy cooking methods?

What I wanna say with all this is that I think hunter gatherer's did not not eat the peel because they felt it was bad for them, but because they simply couldn't. I may be wrong here though. So I am looking for an argument based on (anti-)nutritional contents of unpeeled vs peeled potatoes.

Derek S. said...

Cusick said, "Dr. Davis pulls his patients off of stale, highly refined white flour."

Wrong. He pulls them off ALL wheat. Just ask him. In his view it seems there's no such thing as "properly prepared" wheat. It doesn't exist and therefore is not worthy of attention.

All wheat is toxic to the human body, whether whole grain or not, unless it is painstakingly prepared in a traditional method.

Who in our modern society has the time or inclination to put forth so much effort into a substandard food source? If finances are an issue you can take all that extra effort you're putting into making a toxic substance edible and put it towards making more income so that you can afford to buy real food.

Dan Good said...

Like some other readers, I was struck by your footnote on tubers. I for one would be very appreciative of best practices for preparing tubers, particularly sweet potatoes.

BJ said...

carcissist said... "the lack of a diet high in fibre can cause issues like diverticulitis."

My mom has the same and was told the same thing. I don't believe that a diet lack in fiber is the cause. That sounds a lot like conventional wisdom to me. In fact I think that fiber can irritate the intestines. She's taking fiber supplements, etc. I need to find some time to look into it.

Jen said...

Madmuhhh and Elizabeth - At the last Western A Price conference in Chicago, Garrett L. Smith gave a talk called, "Nightshades: The Inflammatory Scientific Evidence". He also stated that we should be peeling our potatoes.

carcissist said...

Joseph, I agree 100%. There are all sorts of opinions about what to eat and not to eat when you have diverticulitis. He was told, besides seedy bread, not to eat brocolli because the little knobs can get stuck in the bowel ... WHAT? ... Also, he is not supposed to eat nuts. I say nuts to that. The biggest change we have made is to his stress level and he seems to be getting better.

Sorry to deviate from the topic here, BTW.

Simon said...
This comment has been removed by the author.
Simon said...

No I wouldnt say that. 1, I don't tend to think much of single epidemiological studies. I have to read it over but I also would have to know what the whole wheat was displacing. I don't eat wheat because I do think there is good evidence that it can cause some problems, but much of these comments seem to me to be evidence of food neuroses. Call me a flamer, but The inflamatory evidence of nightshades? Peeling potatoes? We're all mortal, eat healthy, whole foods (important as Steven would agree), exercise, stop worrying so much. Probably avoid wheat ;).

Tucker Goodrich said...

@ carissist

I had acute diverticulitis, and had surgery to remove part of my colon. I also got the "not-enough-fiber" news.

There is no scientific evidence to support that hypothesis, however. It's a bit of medical conjecture about the fact that only people in industrialized countries get diverticulitis.

My problem with the fiber/diverticulitis diagnosis is that I had been eating a high-fiber diet for the 20 years prior to my attack, with lots of fruits, vegetables, whole grains, and I diligently avoided processed starches and sugar. I got diverticulitis anyway.

Thanks to Steven's work, I've eliminated the lingering symptoms of what would more accurately been diagnosed as "diverticular colitis" by eliminating vegetable oils and wheat from my diet. I think vegetable oils were the primary cause, as both of my acute attacks were after weekends eating lots of restaurant and processed food (high in vegetable oils).

Hopefully this will help you out.

carcissist said...

@ Tuck

Thanks for the info and good to hear that your condition is improving.

I think processed foods in general are to blame for most of humans' medical problems, including the increase in allergies, obesity, diabetes, heart disease, you name it.

We have adopted a new rule of thumb in our house since my husband's illnes: "if it's processed, don't eat it. If it's grain, don't eat it." (This includes rice, bread, corn, etc.) So that pretty much eliminates 80% of what we can buy at Safeway. :-)

We already see the results in weight management, overall health and energy levels.

The toughest thing to eliminate is the alcohol ... now we stick to red wine exclusively.

Lindybill said...

I quit eating all sugar, wheat the cornstarch. And use only olive oil and butter.

The effect of wheat on Trigs and sdLDL is separate from the others.

Lindybill said...

Cusick, the "whole grain" argument is that it's better than white bread. But nobody has ran studies on whole grain vs none.

Davis pulled his patients off wheat to lower their Blood Sugar, and found the other effects from tests.

Going from white bread to whole grain for a heart patient is like going from full strength poison to diluted. Better to get completely off.

The other benefit you are getting here is all three are high glycemic.

Beulah said...
This comment has been removed by the author.
Mavis said...

Simon,

The inflammatory properties of nightshades are real, and some are more susceptible to them than others. Remember, deadly nightshade is a poison. Other members of the nightshade family have this poison, solanine, but in lesser amounts. http://en.wikipedia.org/wiki/Solanine

Some people cannot break it down easily.

Most solanine in potatoes is found in the skin. Cooking breaks down some, but not the majority, of it. It can cause joint pain in some people (and, reportedly, in cattle who graze on nightshade greens). I am one of those people.

If potatoes with skin don't bother you, I think it's okay to eat them. I have problems even with peeled potatoes, but I eat them a couple times a week anyway.

Brandy Vencel said...

Okay, so you are saying that many cultures removed 50-75% of the bran. I am curious about this on a practical level. I have lately found a number of purported "compromise" recipes for sourdough bread. The starters and loaves themselves are part whole-wheat and part white unbleached flours, with a 1-3 day fermentation period for the loaves. The idea is more a culinary one--the breads are a bit more desirable to most people as far as taste and texture go. Would this have an effect similar to "removing the bran"? Or is white flour just so horrible that this is a bad idea?

I don't know how many mothers read your blog, but we like details like this. ;)

Simon said...
This comment has been removed by the author.
Simon said...

@ Helen

How do you know the association between potatoes and joint pain isnt in your head. From all the research I've done the connection between solanaine and other compounds in nightshades and pain is speculation. Do you think people in traditional societies complain about joint pain in response to whole foods?

Ryan said...

I've been around the potato storage industry and I wouldn't eat the skins simply because of the sheer volume of chemicals sprayed on the potatoes to allow them to make it through long term storage - anti-blight, anti-fungals, sprout inhibitors, etc.

carcissist said...

... and, ironically, people order potato skins as appetizers.

Unknown said...

What about sprouted breads?

I've read that sprouting removes the phytates

Mavis said...
This comment has been removed by the author.
Mavis said...

Well, Simon, it's hard to tell with any dietary change that makes people feel "worse" or "better" if it's all in their head, don't you think?

Here's the story that's in my head. I thought I'd noticed potatoes giving me joint pain in the past, but didn't think much of it. Didn't eat potatoes frequently anyway, since I was a little concerned about their being high glycemic (another debatable concern).

But in cutting out most grains lately, my family started eating a lot of potatoes. I was leaving the skins on for more iron, protein, etc. Over time, I noticed I was getting more and more pain in my feet and ankles when jogging, which was new. I decided to lay off the potatoes for a while and it got better. I ate a potato and it happened again. In fact, a couple of weeks ago, I ate a potato and got cramps and muscle pains throughout and thought I might have mild solanine poisoning. Individual potatoes can have particularly high levels of solanine. Like I said, I still eat them, but less often, and without the skin.

Doesn't it make sense that something that is deadly at high doses would be slightly toxic at lower ones? At least to people who either can't break down the substance or have some other condition that sensitizes them to it?

As for traditional societies, I believe it's traditional to peel and cook the potatoes, which probably reduces the solanine to a tolerable level for most people.

I think that's part of the point of Stephan's post - that some "healthy" whole foods need to be processed by traditional methods to be good for us. The traditions came about for a reason, through trial and error, including as data subjective experiences of feeling better or worse, since there weren't scientific studies to confirm these experiences.

He was focusing on grains, of course.

Anna said...

No wheat in my household anymore, for a variety of reasons including BG management, several + tests for gluten intolerance, and weight management. My son and I are strict about avoiding all wheat/gluten, though my husband will still have a some small amount when he dines out if it is really "good stuff" (not Wonderbread). I can always tell when he's eaten some bread at a dinner because within a couple hours he gets gas and sleeps fitfully with more snoring (we both notice nearly complete absence of intestinal gas when eating no wheat and low carb - a nice benefit).

I used to loooove wheat-based foods, esp artisan style bread. I grew up eating homebaked bread and dense whole wheat store-bought bread, NOT Wonderbread or much white flour. My mother was an Adele Davis reader and tried to feed us well on a budget and my dad was/still is a Rodale organic garden aficionado, so I had a better diet than probably most kids of the 60s and 70s (though she did feed us margerine instead of butter, and skimmed milk - yuck). My diet definitely went downhill when I left home at age 20 because I added too many of the things my friends ate, but it wasn't as awful it could have been; I liked to cook and made a lot of my own meals. Almost a decade ago I gained 20 pounds when I began baking bread and pizza after acquiring a bread machine (most bread machine recipes also call for added wheat gluten and high gluten flours to boost dough performance, btw).

For the meals I prepare for my family (we dont' eat out nearly as much now and I'm very selective about where), I can see no upside to any kind of wheat foods anymore, no matter what the preparation, esp since my son and I have positive antibody and genetic tests for gluten intolerance and/or celiac. My husband has to have at least one celiac gene because my son has one copy that I don't. So we have at least some degree of gluten problems from several branches of our families (a variety of northern European/Celtic heritages), so we are much better off without wheat.

My gestational diabetes diagnosis 12 years ago was a real shock to everyone in the family, because no there wasn't any diabetic family history at that time. Now my mother, her brother, and his son are T2 diabetics. Something is expressing this tendency at an even earlier age in my generation - be it over-consumption of fructose & industrial seed oils, environmental contaminates, or a toxic combination of all the possible factors. It's been hard to get answers as to why.

So I don't think it's just cheap refined white flour that is a problem.

Anna said...

Regarding diverticulitis, I suspect its cause isn't a result of lack of fiber, and from what I am able to find out, the conventional advice to increase fiber, avoid seeds, etc. is not based on good evidence. We eat plenty of fiber from the local produce in our CSA box. Both of us have generally improved GI function now that our dietary fiber source is primarily from vegetables and fruits, and not grains. I used to purchase a LOT of Alka Seltzer for my husband and Maalox for myself in past years when we were eating a high carb/high grain diet. I can't remember the last time I bought any GI remedy of any sort for either of us other than magnesium or probiotic supplements for travel.

About 2 years ago, out of the blue, my husband had an attack of acute diverticulitis, which was compounded by acute appendicitis. This began the evening after a dinner at a local Brazilian-style churrascaria (all-you-can-eat meat & buffet), resulting an emergency appendectomy. The pain began as diverticulitis in one area, then spread across to the appendix area, so we think the appendicitis was secondary to the diverticulitis.

He had another diverticulitis flare-up last year after steak dinner at an out-of-town TGIFridays, resulting in another trip to urgent care and antibiotic therapy. The pattern of pain after the meal occurred with the same time frame.

His earlier colonoscopy report does not note diverticula, though it does note the location of the two benign polyps that were excised. My sister, a nurse, used to work in a colonoscopy clinic. She said diverticula probably would have been noted on the report if they were seen. She also said by age age 50+ patients asymptomatic diverticula is very common.

I can't prove this, but my theory is that his diverticulitis (or perhaps they are simply inflamed colon flare-ups) resulted from eating (too much?) cheap antibiotic-tainted meat or something else which killed off gut flora. At home, we eat a fair amount of meat well as organic veggies, but I prepare only meat that is raised without antibiotics or added hormones.

Seeds and nuts have not caused him any diverticulitis problems ever and he doesn't avoid them at all. His diet hasn't changed because of the diverticulitis though now he is much more careful about avoiding cheap meat from chain restaurants (and he carries Rx for antibiotics and takes probiotics/magnesium when he travels).

My husband's family history includes acute appendicitis. His mother's appendix was removed out as a young woman when she lived in South Africa, but my SIL had her appendix out the same year as my husband (she lives in a Scandinavian country, is a chef/foodie, and only eats high quality food, but has been overweight her entire life). Her appendix was determined to be "encapsulated" and "watched" while treated with heavy antibiotics, but later that year it flared up again and was eventually removed via major abdominal surgery along with bowel resection. My understanding is that acute appendicitis doesn't occur as much in middle aged adults, but rather tends to occur in childhood, the teen years, or young adulthood.

I frequently include naturally probiotic condiment foods in our meals, like raw sauerkraut/fermented pickles or salad dressing made with sauerkraut juice (not Activia or similar products).

I think acute and chronic gut dysbiosis is too often overlooked in GI tract disorders.

carcissist said...

Wow, great post, Anna! Thanks for sharing - and I am glad to hear about the nuts and seeds. He was told to avoid those but he has raw almonds on occasion. He was also told to avoid strawberries because of the small seeds, and brocolli, as I mentioned earlier. (He got conflicting advice from several doctors on which foods to abandon.)

What about yogurt? I know it's very good for digestion but because it's a processed food I have been avoiding it lately. I assume that if one ate it, it would be best to look for full-cream, plain, organic yogurt? Any thoughts?

Mavis said...

Simon -

On inflammation and potatoes.

(1) Dig Dis Sci. 2010 Mar 3. [Epub ahead of print]

Naturally Occurring Glycoalkaloids in Potatoes Aggravate Intestinal Inflammation in Two Mouse Models of Inflammatory Bowel Disease.

http://www.ncbi.nlm.nih.gov/pubmed/20198430

(2) Inflamm Bowel Dis. 2002 Sep;8(5):340-6.

Potato glycoalkaloids adversely affect intestinal permeability and aggravate inflammatory bowel disease.

http://www.ncbi.nlm.nih.gov/pubmed/12479649

Unknown said...

"Remember, deadly nightshade is a poison. Other members of the nightshade family have this poison, solanine, but in lesser amounts."

This is misleading. The principal active agents in deadly nightshade (atropa belladonna) are atropine, scopolamine, and hyoscyamine, none of which are found in potatoes. Solanine may be present in deadly nightshade but it is not the primary or even secondary cause for nightshade's "deadliness."

Solanine may be an issue, but it is inaccurate to suggest that potatoes share the same poison as deadly nightshade.

Mavis said...

Wow! I didn't know I'd be getting into a heated debate over potatoes.

BizJ - I wasn't aware of those chemical breakdowns and did not intend to be misleading. I'd assumed it was all the same poison - my bad.

Still, solanine is a toxin, and a potentially deadly one. People have died (but very rarely) from eating potatoes that were too high in solanine.

Here's what I've found in a quick search:

"Solanine is a glycoalkaloid poison found in species of the nightshade family (Solanaceae), such as the Potato (Solanum tuberosum). It can occur naturally in any part of the plant, including the leaves, fruit, and tubers. It is very toxic even in small quantities. Solanine has fungicidal and pesticidal properties, and it is one of the plant's natural defenses. Solanine was first isolated in 1820 by Desfosses from the berries of the European Black Nightshade (Solanum nigrum), after which it was named.[1]

...

"Solanine occurs naturally in many species of the genus Solanum, including the Potato (Solanum tuberosum), Tomato (Solanum lycopersicum), Eggplant (Solanum melongena), and Bittersweet Nightshade (Solanum dulcamara).
Potatoes naturally produce solanine and chaconine, a related glycoalkaloid, as a defense mechanism against insects, disease, and predators. Potato leaves, stems and shoots are naturally high in glycoalkaloids."

http://en.wikipedia.org/wiki/Solanine


"Solanine Poisoning from Supermarket Potatoes

"While death from potato poisoning is rare, eight ounces of a green potato can contain high enough levels of solanine to affect a 50 pound person, and 16 ounces could impact a 100 pound person. Symptoms of glycoalkaloid poisoning include gastrointestinal upset, headache, fever, convulsions, drowsiness, rapid breathing, delirium, and coma. Three to six milligrams of solanine per kilogram of body mass can be fatal.

"Green potatoes often taste bitter, which is caused by the presence of solanine. However, toxic potatoes may not taste bitter, and bitter potatoes may not be toxic."

http://www.promolux.com/english/retail_produce_greening.html

Now I have to get back to cooking dinner. Ironically, on the menu tonight is mashed potatoes.

Simon said...

@ Helen: Your first point re: subjective feeling in traditional cultures is well said. I would be hypocritical if I said I didn't use subjective feelings as a judge, but I think its wise to be cautious about focusing on what we eat too much. It can easily make us more worried and attentive than we need to be. With regard to the second research, the test was done on murine lines in culture, so I'm cautious on it.

The other problem re: your comment about traditional prep methods. How does a student on a tiny budget working 60 hours a week eat a traditional foods diet with no one to help him with the prep methods. Seems pretty impossible to me.

Tucker Goodrich said...

@ Anna

Your husband's experience would be consistent with mine. Grain-finished beef contains linoleic acid, the primary chemical component of seed oils.

I was never too fond of steak, or any food with a noticable linoleic acid content (except peanuts, for some reason). Food fried in corn oil was particularly unappealing. I always used olive oil for cooking, even though my wife insisted veggie oil was better (and she used it).

I never put 2 and 2 together until finding Stephen's blog, however.

Tucker Goodrich said...

@ Simon

"How does a student on a tiny budget working 60 hours a week eat a traditional foods diet with no one to help him with the prep methods. Seems pretty impossible to me."

You're right. It's too hard.

Just get sick. That's what I did. :)

Half Navajo said...

on the potato peeling debate... i always peel my potatoes, the skins give me a shortness of breath when i eat them... without them, they just give me energy and increase my circulation. I think the skins get bound up in my esophagus/stomach area, putting pressure on my diaphram... because its not digesting... hell... i don't know... i just make sure not to eat the skins.

troy

Jeffrey of Troy said...

Hi Stephan,

I don't know if I'm being too technical, but:

I see everywhere dietary fiber defined as "carbohydrate humans can't digest"; it seems to me like we must digest it. If you try eating something a human really can't digest - like a matchbox car - you would be actually damaged by that.

Wouldn't fiber be "carbohydrate humans digest but cannot absorb"? Please correct me if I am wrong...

Derek S. said...

@Tuck

Grass finished beef has just as much linoleic acid as grain finished. Stephan actually gives a reference for this in one of his posts. I've personally seen the research as far as the fatty acid composition of grass finished vs grain finished beef.

There is a small difference, however, in the omega-3 content with grass finished having more. This is why many people who eat a lot of grain finished beef supplement with fish oil. This brings the ratio of n-6 to n-3 back to acceptable levels.

It seems pretty clear that in the "paleo" community, and even the "organic" community, that the differences between commodity beef and grass finished beef have been somewhat overstated.

Chris Kresser said...

Tuck,

I've heard similar things re: the overstated difference in n-3 levels between grass-fed and conventional meats.

I'd love to look at the original research you refer to. Could you post a link or two?

Chris Kresser said...

Oops, that last comment was for Derek not Tuck.

Anna said...

carcissist,

Thanks.

I either buy whole milk yogurt (with as many bacteria varieties as possible and NO added non-fat milk solids or thickeners added, such as Strauss or Fage Greeek Yogurt) or I culture yogurt at home. However, while I do think yogurt is a fine food, I don't think it has enough CFUs to keep good gut bacteria going all the time if it's the only probiotic food consumed. Other probiotic foods (lacto-fermented veggies, etc.) and good prebiotic foods are necessary, too.

While traveling, we now take along some blister packs of high CFU probiotic capsules that don't require refrigeration and take those instead.

Anna said...

carcissistic,

Just reread your comment mentioning full cream yogurt and had this thought to share: one of my favorite "decadent" yogurts is homemade yogurt, but made with heavy 40% butterfat cream instead of milk! With a touch of vanilla and a bowl of the many strawberries we receive in our CSA box, it's an incredible dessert. Sometimes I lightly puree berries to flavor it, but usually I like the tartness to show through.

Derek S. said...

@Chris Kresser

Here's an abstract that states, "Concentrations of PUFA, trans fatty acids, n-6 fatty acids, and cholesterol did not differ between grass-fed and control ground beef.":

http://www.ncbi.nlm.nih.gov/pubmed/18641180?ordinalpos=1&itool=PPMCLayout.PPMCAppController.PPMCArticlePage.PPMCPubmedRA&linkpos=2

And here is a free full text study on the fatty acid profiles of grain vs grass fed beef where you'll find the statement that there is, "...no significant change to the overall concentration of n-6 FAs between feeding regimens, although grass-fed beef consistently shows a higher concentrations of n-3...":

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2846864/?tool=pmcentrez

Michael said...

It seems pretty clear that in the "paleo" community, and even the "organic" community, that the differences between commodity beef and grass finished beef have been somewhat overstated.

It terms of the superiority of EFA's absolutely. The difference is so marginal is it not even worth mentioning, especially in the context of a nutritious diet.

Carole Eilertson said...

What about the role of degraded carrageenan in dairy products, such as whipping cream? In Germany, where I live, carrageenan is even in organic dairy products.

http://en.wikipedia.org/wiki/Carrageenan#Health_concerns

Robert Andrew Brown said...
This comment has been removed by the author.
Robert Andrew Brown said...

Derek S

Thanks for the links.

The first paper makes no mention the control cattle were grain fed, so they could have been primarily grass fed, or grass finished.

The second seems to be about grass finished cattle. The rate of fat turnover of fatty tissue is probably too slow for grass finishing to remove the accumulated Omega 6.

I do not think the above papers can reasonably be cited as evidence of no Omega 6 fat content difference between a true free ranged animal and a stock yard animal.

Robert Andrew Brown said...

Derek S

The second of the trials you cite concluded

"Research spanning three decades supports the argument that grass-fed beef (on a g/g fat basis), has a more desirable SFA lipid profile (more C18:0 cholesterol neutral SFA and less C14:0 & C16:0 cholesterol elevating SFAs) as compared to grain-fed beef. Grass-finished beef is also higher in total CLA (C18:2) isomers, TVA (C18:1 t11) and n-3 FAs on a g/g fat basis. This results in a better n-6:n-3 ratio that is preferred by the nutritional community. Grass-fed beef is also higher in precursors for Vitamin A and E and cancer fighting antioxidants such as GT and SOD activity as compared to grain-fed contemporaries.
Grass-fed beef tends to be lower in overall fat content, an important consideration for those consumers interested in decreasing overall fat consumption. Because of these differences in FA content, grass-fed beef also possesses a distinct grass flavor and unique cooking qualities that should be considered when making the transition from grain-fed beef. To maximize the favorable lipid profile and to guarantee the elevated antioxidant content, animals should be finished on 100% grass or pasture-based diets."

Mavis said...

Hi Simon,

Regarding food neurosis. Yes, you can really drive yourself bonkers with this stuff. You can make your friends and family crazy, too! Welcome to my world.

At the same time, my interest in this stuff is driven by wanting to recover from some chronic health problems (mainly allergy and autoimmune) and prevent some, as well (elevated risk for diabetes). Dietary changes have helped a lot with the allergies, though I've been down the garden path more than once. The traditional foods approach seems the most helpful so far.

About expense and prep time. I hear you. Some things aren't so arduous or expensive, like peeling and boiling potatoes. Some things just take some lead time, but not much more work, like soaking beans and grains. I haven't tried a purely paleo diet, but people on those blogs often remark on how cooking is much easier. I doubt it's cheaper, though! Mark Sisson has some tips on cutting expenses (Mark's Daily Apple), and Nora Gegaudas (Primal Body, Primal Mind) (sp?) claims you can eat healthfully for less money than you thought possible!, though I haven't read her plan of how.

Mavis said...

P.S. Sweet potatoes work well in the microwave. Goitrogens are destroyed by heat, though I don't know about protease inhibitors and all that.

Ned Kock said...
This comment has been removed by the author.
Ned Kock said...
This comment has been removed by the author.
Ned Kock said...

Grains prepared in the ways suggested by Stephan are one thing, refined grain products are another. The latter usually have a much higher glycemic load, a better measure of blood glucose elevation potential than the glycemic index:

http://healthcorrelator.blogspot.com/2010/04/huge-gap-between-glycemic-loads-of.html

Apart from that, many grains are seeds, and the plants do not want animals to eat their seeds. It seems reasonable to me that the toxins may lead animal species that consistently eat seeds to extinction, in the slow timeframe of evolution.

That is, if the toxins are not enough for the animals to avoid the seeds in the first place.

Unknown said...

According to some, grains in Australia are good for us:
http://www.lef.org/news/LefDailyNews.htm?NewsID=9615&Section=NUTRITION&source=DHB_100429&key=Body+Title

Dan Good said...

I'm wondering now if nuts also possess these anti-nutrients.

Stephan Guyenet said...

Hi Garry,

I can't resist chiming in on this. Basically, that story was about some researcher who decided to make a random press release about whole grains. It wasn't even based on a study he did, it was based on an industry-sponsored "research report" promoting the whole grains they sell:

"His comments coincide with the release of a research report, compiled by the industry body GoGrains, which also said Australians eat about half the daily recommended amount of wholegrains."

The fellow stated:

"Published research shows eating two to four serves of wholegrain foods a day can reduce the risk of heart disease by as much as 40 percent - equal to the effect of cholesterol lowering drugs."

That's not at all what the research shows, and he's making an amateur mistake of interpretation. The research shows that whole grain consumption is associated with reductions in heart disease risk, that can be up to 40% in some groups. Key word: associated. These data are from observational studies, not controlled trials in which researchers randomize people and ask one group to eat more whole grains. If he had been quoting the only controlled trial that has addressed the question, DART, his conclusion would have been the opposite.

Derek S. said...

@Robert Andrew Brown

I wasn't advocating a general position that grass finished beef doesn't have it's advantages over grain finished. It certainly has a more favorable omega 6:3 ratio as well as higher levels of CLA.

My point was that the levels of n-6 are pretty much identical between the two and that this ratio can be restored by supplementing with fish oil for people who either cannot afford or cannot obtain grass finished beef. And if one wanted to supplement with CLA in addition, it would pretty much wipe out any significant shortages of the most important nutrients in the grain finished beef as compared to the grass finished.

As a result of finances and/or access, some people who eat a paleo type diet are pretty much forced to consume a substantial amount of grain finished beef. I believe that those people still have options and can obtain all of the same powerful nutrition benefits by simply supplementing with fish oil and CLA. The differences in all the other nutrients are negligible. Grain finished beef, as pointed out in the studies, is still considered to be a nutrient-dense food as compared to most others.

Tucker Goodrich said...

@Derek S.

Fascinating studies. The point is not to entirely avoid linoleic acid, the point is to eat it at a ratio in a range dictated by our evolution.

This table puts the whole thing in perspective:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2846864/table/T2/

For grass-fed the n-6/n-3 ratios range from 1.44 to 3.72. For grain-fed the range is 3 to 13.6.

From what little I've read on this, the n-6/n-3 ratio in the human diet should be from 1:1 to 3:1. Grass-fed is whithin that ratio, grain-fed is outside of it.

So as Mr. Brown points out, your links seem to reinforce the point that grass-fed is better.

Chris Kresser said...

Derek,

What about the hormones and antibiotics in factory-farmed meat? The safety issues (i.e. higher risk of e. coli and other infections from conventional meats)? The environmental issues?

I understand that grass-fed meat may be out of reach financially for some, but let's not pretend that the only difference between grass-fed meat is the n-6:n-3 ratio.

BTW, I get 100% grass-fed meat from a local farmer for between $5-$7/lb average (this includes very expensive cuts like rib-eyes and filet mignon). Would be even cheaper if I didn't get those cuts.

Derek S. said...

I still stand by my assertion that grain finished beef has been a whipping boy in the paleo and organic communities to a far greater extent than it should be. I think the differences are overstated and overemphasized, causing many people (such as Tuck, whose comment got me to post in the first place) to have a certain amount of misunderstanding as to the real differences between the two.

Here are a couple of relevant statements from the free full text study for which I posted the link:

"It is also noted that grain-fed beef consumers may achieve similar intakes of both n-3 and CLA through the consumption of higher fat grain-fed portions."

In other words if you must consume grain finished beef and want to have the same levels of n-3 and CLA as you would obtain by consuming grass finished, you simply need to choose fattier cuts of grain finished beef to achieve the desired result.

And:

"Red meat, regardless of feeding regimen, is nutrient dense and regarded as an important source of essential amino acids, vitamins A, B6, B12, D, E, and minerals, including iron, zinc and selenium. Along with these important nutrients, meat consumers also ingest a number of fats which are an important source of energy and facilitate the absorption of fat-soluble vitamins including A, D, E and K."

Derek S. said...

Sorry for the continued posts, but this is a subject near to my heart as beef is by far my preferred food and I eat both grain and grass finished. I consume an average of a pound per day, and living in Texas allows me ample opportunity to eat both grain and grass finished.

As for hormone levels, that is also vastly overstated. For example, even if you consume hormone treated beef (which is becoming less and less common, by the way) you will take in about 3.8ng (that's nanograms, not milli- or micrograms) of estrogen in a 6 oz portion. Non-treated beef would still contain 2.6ng of estrogen in the same 6 oz portion.

Sound significant? It's not...because guess how much estrogen an adult male will endogenously produce in a single day? 136,000ng. The extra 1.2ng of estrogen you would take in from hormone treated beef as opposed to non-treated beef is miniscule compared to the 136,000ng you already produce in a day. It is completely, totally biologically insignificant in such tiny levels as your body already produces 36,000 times the amount of estrogen you are consuming. It is less than insignificant.

Guess how much estrogen 4 oz of cabbage contains? 2700ng. That's 2250 times as much estrogen as the difference between hormone-treated vs untreated beef in a 6oz portion.

Are you starting to see how the differences between commodity beef and grass finished beef have been vastly overstated? It almost reaches the level of fear mongering in certain circles. The truth is much less extreme.

Chris Kresser said...

Derek,

I agree that some of the risks may be overstated. But some are understated. Chronic, sub-therapeutic use of antibiotics in food animals create drug resistance in those animals. If someone gets infected with that resistant bacteria via improperly cooked meat, they'll be in big trouble.

Europe and Canada have recognized this danger and have banned the use of sub-therapeutic antibiotics. But they're still permitted here.

In one study published in the New England Journal of Medicine on February 6, 2002, researchers found links that strongly suggested that the people who developed Cipro-resistant bacteria had acquired them by eating pork that were contaminated with salmonella. The report concluded that salmonella resistant to the antibiotic flouroquine can be spread from swine to humans, and, therefore, the use of flouroquinolones in food animals should be prohibited.

Another NEJM study from Oct. 18, 2001, found that 20 percent of ground meat obtained in supermarkets contained salmonella. Of that 20 percent that was contaminated with salmonella, 84 percent was resistant to at least one form of antibiotic.

There's a movement even within the meat industry to stop using antibiotics to fatten cattle. But most producers still do.

Riles said...

I regards to hormones

Dr. Wong -

"First off, animal hormones degrade (lose their structure and ability to work) in 5 min. or less at temperatures above 58 to 67 degrees C (136 to 152 degrees F). The higher the temp the faster the degradation. Unless you are eating steak tartar, you are going to be cooking your meat for more than 5 minuets at temperatures above 200 degrees F (93 degrees C). So bye-bye hormones, they are no longer a problem."

http://www.totalityofbeing.com/FramelessPages/Articles/anti_milk_meat.html

Gwen said...

Derek S.,

Thanks for your comments - so helpful (as in reassuring) when trying to plan healthy meals on a budget.

If I remember correctly, Peter at Hyperlipid also did not think the difference between grass-fed and commodity beef was significant. And again if I'm remembering correctly it's because it's more difficult to buy grass-fed beef in the UK.

Anyway, thanks for your comment.

Gwen

Derek S. said...

@Gwen

You're welcome. I thoroughly enjoy tipping sacred cows (pun intended)!

Robert McLeod said...

I think Table 3 is probably the most interesting. As usually we see a small but not statistically significant decrease in coronary heart disease in substituting polyunsaturated fats for saturated fats. This is much like what Krauss' meta-analysis found. However, the stroke risk is doubled, although there were only 35 stroke deaths in the advice group so the confidence intervals are quite broad. Krauss only found about a 20 % difference for stroke risk, in comparison.

Rancid vegetable oil is bad for your brain.

Robert McLeod said...

Stephan:

After mathematically "adjusting" for preexisting conditions and medication use, the result reached statistical significance: people who increased their grain fiber intake had more heart attacks than people who didn't during the two years of the controlled trial.

Although this is technically true it's personally not something I would feel comfortable claiming. The p-value here is 0.04665 which is still really quite high, and the association goes negative in the 5-10 year period when the majority of the deaths in both groups occur. Perhaps the fibre advice pushed some gluten-sensitive individuals over the edge?

st111 said...

I really recommend going to www.diverticulitis.info.com as it is so educational and informative. It discusses diet and other helpul ways to help treat various bowel disorders. A homeopath, who runs the website, has devised these great kits that are drug-free and are aimed at helping digestive disorders. It's helped me so I want to recommed it :)

Markus said...

Robert,

You said, "I think Table 3 is probably the most interesting." Would you please point out which table/study you were talking about?

Tucker Goodrich said...

@Derek S.

"Are you starting to see how the differences between commodity beef and grass finished beef have been vastly overstated?"

I'd never tried grass-fed beef until a few weeks ago. I was stunned. It's like the meat of a different animal. I've never been a big fan of beef, but I am now a big fan of grass-fed beef.

Typically one should follow your cravings in nutrition (aside from sugar). Everyone in my family had the same reaction.

There's clearly a big difference somewhere, between the two. You can taste it.

Robert Andrew Brown said...

Derek S

I understand what it is to be on a budget. I try and select meats that are more likely to be grazed like lamb and mutton.

I am just trying to make the point that the evidence suggests that products from wholly grass fed animals are more nutrient dense, have greater antioxidant levels, and a much better 3:6 ratio.

"However, the n6:n-3 ratio was much less desirable in the bulls,(fed cereal concentrates) 15.6–20.1 compared with 2.0–2.3 in the steers fed grass."

"Fatty acid content and composition of UK beef and lamb muscle in relation to production system and implications for human nutrition"

http://cat.inist.fr/?aModele=afficheN&cpsidt=2311990

Anna said...

I have additional reasons for choosing the meat I do (in this case it's grass-fed bison from Montana via a co-op purchase). I like doing business with a ranch run by a family (a hug comes with my order). My side of bison is prepared by a small state-licensed meat processor who custom-cuts and wraps the meat to my specifications. The white butcher paper wrapping is stamped with my name on it. This might seem like a small thing, but I'm a actual customer, no, a real person, to the butcher when my order is prepared, not a nameless nobody. I feel confident making carpaccio or steak tartar with this meat, but I wouldn't with grass-fed meat from a retail market (usually sourced from another continent).

Some of this discussion reminds me a bit of Michael Pollan's writing about "nutritionism" whereby the value of a food is simply based on its nutrient constituents. There's far more to food than simply its nutrients.

Chris Kresser said...

I completely agree with you Anna.

Michael said...

I don't really have time to get involved in this discussion, and while I think there is some value to eating grass fed meat, its EFA content and/or ratio is not among them.

Essentially this is what I have seen in the literature, that grass-fed beef is much higher in n-3 content, as a proportion of total fat and total mass. It is roughly equivalent to or somewhat higher in n-6 content as a proportion of total fat, while significantly leaner when it comes to total fat.

Most studies I have seen people interpreting as an argument against grain fed on this issue, well... they are not doing the math right.

Derek S. said...

@Tuck

I also enjoy the taste of grass fed more so than grain fed beef. I purchase grass fed whenever possible. However, when I do eat grain fed beef in no way whatsoever do I feel like I compromised or missed out on anything. I simply feel like I didn't get to have my absolute favorite but that I still ate something nutritious and tasty.

water said...

When we eat away from home, we choose beef based on the idea that grain fed beef is overall more nutritious than conventional pork or poultry.

Tend to get grass fed beef at home, but occasionally some nice prime steaks from Costco.

The argument seems to be that there's less difference between grass and grain than you would think, given the hype. Ok, I can see that for the muscle cuts, but what about the offal "fifth quarter" cuts?

Anonymous said...

I was eating a bar of quality plain chocolate the other day, and looked at t nutritional info and was amazed to see that in the 100g bar, there were 11g of fibre! That's more than in 3 bowls of high fibre cereal!

Tucker Goodrich said...

@Derek S.

The study you posted says this:
"It is also noted that grain-fed beef consumers may achieve similar intakes of both n-3 and CLA through the consumption of higher fat grain-fed portions."

They don't provide any evidence to support this statement, however.

Which cuts of the animal retain high levels of n-3 despite a high n-6 diet?

Anonymous said...

I wonder if Chia should be roasted or processed in some form, too. Anybody know?

sandra said...

Since tubers have antinutrients and lectins too, why wouldn't wheat (properly prepared as in real sourdough) be OK for folks w/o celiac?

Mavis said...

Sandra,

I've recently learned that sourdough bread works better for me for potatoes. Gluten is nearly eliminated with proper sourdough preparation, while the solanine in potatoes can't fully be eliminated.

In a comment above in this string, I posted links to two studies I found suggesting that solanine causes inflammation and hyperpermeability in the gut wall of mice.

I feel like I found this in the nick of time. I was eating potatoes instead of gluten grains to try to minimize "leaky gut," and I think I did myself some harm, since I've recently been getting some new, pretty pronounced rheumatoid arthritis symptoms (which I'm getting checked out soon). (I already have an autoimmune disease so it's not unlikely.)

Come to find out, there's a strong connection between leaky gut and rheumatoid arthritis, or at least that's the theory of much of the alternative health community. In any case, the potatoes have been worse to me, experientially, than the sourdough.

Mavis said...

And, sourdough fermentation also significantly reduces phytic acid.

Stephan Guyenet said...

Hi Sandra,

All lectins aren't the same. Gluten is sort of a lectin, but the real problem is it irritates the immune system in many if not most people. The degree varies greatly depending on the individual. Whole wheat also contains the nasty lectin WGA, which is heat resistant. It's also low in fermentable fiber, as opposed to rye and barley.

Hi Helen,

You're right about the phytic acid, but typical sourdough fermentation leaves most of the gluten intact. Only prolonged fermentation with special strains of bacteria and yeast degrades gluten completely. If your bread has a nice (light, chewy) texture, rather than being a brick, it contains plenty of gluten, because gluten is what gives bread that nice texture.

I'm not a fan of wheat, but I understand that everyone is different. Sourdough should be significantly better than wheat bread made with the typical quick-rise yeast. I'm open to the possibility that some people have no problem with wheat. It's always important to pay attention to what your body is telling you. I do think sourdough rye is probably superior to wheat bread though.

Mavis said...

Hi Stephan,

I did a little Googling on the subject to try to find what convinced me before that sourdough degraded gluten. You're right about the process needed to degrade it to a point at which most celiac patients don't react to it.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC348803/

But it looks to me as though, generally, sourdough fermentation using lactobacilli does hydrolyze gliadin and make it less immunoreactive. (Perhaps still allowing for chewiness?) Maybe that accounts for why I feel so much better eating it than non-sourdough bread.

(1) Agrarian diet and diseases of affluence – Do evolutionary novel dietary lectins cause leptin resistance?

“Sourdough lactic acid bacteria hydrolyse gliadin peptides and inhibit their lectin-like behaviour, which perhaps explains some of the unexplained health effects of probiotics.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1326203/pdf/1472-6823-5-10.pdf/?tool=pmcentrez

(2) Use of selected sourdough lactic acid bacteria to hydrolyze wheat and rye proteins responsible for cereal allergy

http://www.springerlink.com/content/y16x5331g5858770/

(3) Proteolytic activity and reduction of gliadin-like fractions by sourdough lactobacilli

http://www.ncbi.nlm.nih.gov/pubmed/16313422

(4) Proteolysis by sourdough lactic acid bacteria: effects on wheat flour protein fractions and gliadin peptides involved in human cereal intolerance.

http://www.ncbi.nlm.nih.gov/pubmed/11823200

Still, I'm trying to largely avoid gluten-containing grains, even fermented, but it seems that if a person is tolerating it well, sourdough breads are not a bad choice.

Stephan Guyenet said...

Hi Helen,

Yes, that Italian group has done some nice research on sourdough fermentation and gluten hydrolysis.

There's no doubt that sourdough fermentation breaks down a portion of the gluten. It's also possible that the partially digested gluten that remains is more susceptible to digestion by human enzymes, but that's speculation.

However, there is still a fair amount of gluten remaining in typical sourdough bread. I found a nice review article by Gobbetti's group:

http://cat.inist.fr/?aModele=afficheN&cpsidt=20862616

Here are a few relevant quotes:

"LMW glutenins are partially hydrolysed during fermentation and the degradation of HMW glutenins is virtually quantitative..."

"Gliadins are degraded to a lesser extent than glutenins and their sensitivity to proteolysis decreases in the order g-, a, and u-gliadins, which was attributed to the high content of proline in u-gliadins..."

"The use of sourdough in bread making requires a limited extent of proteolysis in order to prevent extensive gluten degradation while ensuring a sufficient liberation of amino acids for flavour precursors."

Otherwise stated, sourdough fermentation breaks down some types of gluten pretty well, others not very well, and gluten is required for the chewy texture of bread. If the bread has a normal bread texture, it contains a significant amount of gluten.

These authors have been able to make wheat bread where all the gluten is gone, but it requires special strains of bacteria, yeast and long fermentation times. And the resulting bread doesn't have a light chewy texture, it's denser and more cake-like. Kind of like what you'd get i you baked bread with cake flour (low gluten) instead of bread flour (high gluten).

sandra said...

Thanks Stephan and Helen...

We use a sourdough rye sometimes- slices are very dense, but kinda chewy (esp. when toasted). Hopefully that is low gluten. It doesn't work too well for sandwiches or dipping in pastured egg yolks though...

I eat my eggs with veggies or fried sweet potato, but this is sacrilegious to my husband. For him, and occasional sandwiches for school lunches would it be better to use white sourdough rather than whole wheat if it is the light, "bready" sourdough bread? Or does refined wheat still retain the gluten and other lectins?

Helen, were you eating the skins of the potatoes when you were affected by them?

Mavis said...
This comment has been removed by the author.
Stephan Guyenet said...

Hi Sandra,

I wouldn't worry about a slice of sourdough every now and then if he isn't showing symptoms of wheat intolerance. The dose makes the poison.

Mavis said...

Hi Sandra,

We went through a few weeks of unpeeled, when my symptoms peaked. We started eating fewer potatoes, and peeled, but I still experienced increased symptoms. I'm now avoiding them completely, along with other nightshades. So far, less joint pain... we'll see what happens.

White sourdough would have as much gluten as whole grain, while whole grain would have more wheat germ agglutinin and phytic acid, I believe. But it also has more nutrients. I agree with Stephan that the dose makes the poison and that everyone is individual in their sensitivity. I'm pretty sure the same is true for potatoes.

Sara said...

I'd like to jump into the nightshade debate. At 38 I was diagnosed with osteoarthritis in my hip. It was very painful, and, although the hip was the only part x-rayed, I had the same pain in my neck, knees and lower back. As an experiment I stopped eating all nightshades. Seeing as it's not that hard to do I've kept it up for nearly two years now and have virtually no joint pain and vastly increased mobility. In fact, I never think about my arthritis, maybe I don't even have it anymore.

I know.. it's anecdotal, perhaps the improvement was caused by something else, maybe it was ALL IN MY HEAD (and x-ray), I don't care. I'm just glad that the pain in gone and that I seem to be able to drink lots of espresso with no joint aggravation. ;) I was so worried that it was coffee causing my creakiness. That would have been a real sacrifice!

Interesting about sweet potatoes. I eat them nearly every day. It would be great to know how to best prepare them.

Stephan, your blog is wonderful and I appreciate so much the effort you put in and the information you make available.

Anonymous said...

From the previous thread

"So it seems we've really got this perfect storm of factors: refined carbohydrates causing insulin resistance, refined grains damaging gut flora, increased wheat consumption increasing gut permeability causing more inflammation, industrial oils causing inflammation, over-consumption of fructose contributing to inflammation and insulin resistance.

And probably all of these factors have tipping points. We could take some amount of all of them, and function. But with all of them acting at the same time, an increasing segment of the population is going to develop the problems we're seeing. "

That's so good I think I'll steal it

The dietician who told me I was eating too much fat and even banned avocados and nuts, replacing them with more carbs (Healthy Whole Grains, natch) and encouraged me to drink more orange juice (No Added Sugar, of course) did me considerable harm.

Yet she was cute and very fit so obviously her diet worked for her. Whether it would have continued to work when she reached my age I'm less certain

http://heartscanblog.blogspot.com/2008/12/flat-tummy-or-why-your-dietitian-is-fat.html

Personally I need to avoid wheat (probably the WGA as I can tolerate sufficiently small quantities of other gluten grains) and citrus, but I can eat berries without harm. Many diabetics have significantly differing responses to the same foods and can eat things which will cause a severe glucose spike in others.

Likewise for the nightshades and for others lactose intolerance: some individuals appear to have adapted to eating things which are still toxic to others, all of which makes it especially hard to determine general recommendations.

Then there are other considerations: my local grass-fed beef actually *tastes* like beef, unlike some of the tough tasteless shoeleather from those double-miscled Eurobeasts stuffed with grain, antibiotics and hormones. That counts for a lot even if its fat balance isn't as much better than expected.

Unknown said...

Ouch
Whole grains are getting a very bad reputation on this blog.

Then why did Weston A. Price find that cultures who lived almost exclusively on sourdough bread and dairy products to be in excellent health?
If people develop very healthy bodies from eating lots of whole grains then why can't we?

Unknown said...

There are many "independent" studies all around the world about health. What I've found interesting is that they all contradict each other in one way or another. For example, every study that shows that a particular diet causes harm, there's another that shows the opposite. If you look, you'll find real world examples that fit into all of these different camps.

Good health and well-being does not come from the outside-in, it comes from the inside-out.

Joe said...

Is there any way to ferment brown rice without grinding it? I always soak my rice and I like to sprout it too to increase the nutrients in it (including GABA) but I'd prefer not to have to grind it into mush too...is there any way?

JoAnne said...

Stephan, I just read this post more than 2 years after it was written. However, I wanted to comment that what you said about cultures around the world de-branning grains rang true to my experience. I know for a fact that people in Eritrea, Ethiopia, and India do this. (I have traveled to the horn of Africa, and have a friend from there who has taught me to prepare some of their cuisine.) I live in India now with my husband, and his mother has been a wealth of interesting info about how life was in the village where she was raised in north India.

She eats chapati every day for every meal. It is made with relatively freshly ground soft white wheat berries. Her teeth are very straight, and evenly spaced, although they are very stained now from some kind of breath freshener that is popular here (and undoubtedly very bad for her). When making the chapati, she sifts about 70-80% of the bran out of it. Mixes it with water, some oil, and salt, and kneads it, and lets it rest for about an hour. So, as you see, there is probably plenty of phytic acid in the chapatis, but that doesn't seem to have negatively affected their health. They do, however, get a lot of vitamin D in their diet from eating organ meats--mainly goat brain, liver, and kidney.

What is interesting is that I find the chapati hard to digest, although no one else in the household seems to. Maybe I just don't have the same kind or as many enzymes as all of my housemates who grew up here. (I'm American) I am going to try making some version of Ethiopian injera here with the fresh whole wheat flour so that I have a fermented flat bread to eat at meals with the family in place of chapati.

I also wanted to mention that I appreciate all your posts on phytic acid, and your discussion of such foods as idli and brown rice.

Keep up the good work, and know that you are making a difference for people like me.

Saleha Seedat said...

Hi Stephen,
I'm so glad I stumbled onto your blog. Thanks for sharing all the info you do.
I've read a few posts but I can't seem to find definitive info or steps to soak and ferment grains. I'm new to this so I have a few questions please.
I live in a very hot climate with temperatures reaching 50C plus sometimes. How do I soak and ferment grains for 24 hours in this temperature without it turning rancid and alcoholic?
I'm feeding my 1 year old quinoa and amaranth daily as she has been suffering with constipation since 3 months old. Feeding her these grains have solved her constipation problem but now I'm concerned about the PA content and possibly hurting her more than helping her in the long run. Do I need to soak and ferment the quinoa and amaranth before cooking it?
I'd appreciate clear steps on exactly how to ferment grains.
Thank you for your generosity in time and info!
God bless you!