Saturday, February 21, 2009

How to Eat Grains

Our story begins in East Africa in 1935, with two Bantu tribes called the Kikuyu and the Wakamba. Their traditional diets were mostly vegetarian and consisted of sweet potatoes, corn, beans, plantains, millet, sorghum, wild mushrooms and small amounts of dairy, small animals and insects. Their food was agricultural, high in carbohydrate and low in fat.

Dr. Weston Price found them in good health, with well-formed faces and dental arches, and a dental cavity rate of roughly 6% of teeth. Although not as robust or as resistant to tooth decay as their more carnivorous neighbors, the "diseases of civilization" such as cardiovascular disease and obesity were nevertheless rare among them. South African Bantu eating a similar diet have a low prevalence of atherosclerosis, and a measurable but low incidence of death from coronary heart disease, even in old age.

How do we reconcile this with the archaeological data showing a general decline in human health upon the adoption of agriculture? Humans did not evolve to tolerate the toxins, anti-nutrients and large amounts of fiber in grains and legumes. Our digestive system is designed to handle a high-quality omnivorous diet. By high-quality, I mean one that has a high ratio of calories to indigestible material (fiber). Our species is very good at skimming off the highest quality food in nearly any ecological niche. Animals that are accustomed to high-fiber diets, such as cows and gorillas, have much larger, more robust and more fermentative digestive systems.

One factor that reconciles the Bantu data with the archaeological data is that much of the Kikuyu and Wakamba diet came from non-grain sources. Sweet potatoes and plantains are similar to the starchy wild plants our ancestors have been eating for nearly two million years, since the invention of fire (the time frame is debated but I think everyone agrees it's been a long time). Root vegetables and starchy fruit ted to have a higher nutrient bioavailibility than grains and legumes due to their lower content of anti-nutrients.

The second factor that's often overlooked is food preparation techniques. These tribes did not eat their grains and legumes haphazardly! This is a factor that was overlooked by Dr. Price himself, but has been emphasized by Sally Fallon. Healthy grain-based African cultures often soaked, ground and fermented their grains before cooking, creating a porridge that's nutritionally superior to unfermented grains. The bran was removed from corn and millet during processing, if possible. Legumes were always soaked prior to cooking.

These traditional food processing techniques have a very important effect on grains and legumes that brings them closer in line with the "paleolithic" foods our bodies are designed to digest. They reduce or eliminate toxins such as lectins and tannins, greatly reduce anti-nutrients such as phytic acid and protease inhibitors, and improve vitamin content and amino acid profile. Fermentation is particularly effective in this regard. One has to wonder how long it took the first agriculturalists to discover fermentation, and whether poor food preparation techniques or the exclusion of animal foods could account for their poor health.

I recently discovered a paper that illustrates these principles: "Influence of Germination and Fermentation on Bioaccessibility of Zinc and Iron from Food Grains". It's published by Indian researchers who wanted to study the nutritional qualities of traditional fermented foods. One of the foods they studied was idli, a South Indian steamed "muffin" made from rice and beans. 

The amount of minerals your digestive system can extract from a food depends in part on the food's phytic acid content. Phytic acid is a molecule that traps certain minerals (iron, zinc, magnesium, calcium), preventing their absorption. Raw grains and legumes contain a lot of it, meaning you can only absorb a fraction of the minerals present in them.

In this study, soaking had a modest effect on the phytic acid content of the grains and legumes examined. Fermentation, on the other hand, completely broke down the phytic acid in the idli batter, resulting in 71% more bioavailable zinc and 277% more bioavailable iron. It's safe to assume that fermentation also increased the bioavailability of magnesium, calcium and other phytic acid-bound minerals.

Fermenting the idli batter also completely eliminated its tannin content. Tannins are a class of molecules found in many plants that are sometimes toxins and anti-nutrients. In sufficient quantity, they reduce feed efficiency and growth rate in a variety of species.

Lectins are another toxin that's frequently mentioned in the paleolithic diet community. They are blamed for everything from digestive problems to autoimmune disease. One of the things people like to overlook in this community is that traditional processing techniques such as soaking, sprouting, fermentation and cooking, greatly reduce or eliminate lectins from grains and legumes. One notable exception is gluten, which survives all but the longest fermentation and is not broken down by cooking.

Soaking, sprouting, fermenting, grinding and cooking are the techniques by which traditional cultures have been making the most of grain and legume-based diets for thousands of years. We ignore these time-honored traditions at our own peril.


Anonymous said...

My daughter likes to eat black beans out of the can, which has some water in it. Does anyone know whether this water serve to soak the beans and remove anti-nutrients? Are there additional steps I should take before giving these to her? Thanks.

Bryan - oz4caster said...

Stephan, of course these groups eating a high carb diet also didn't get much fructose or omega-6 fat either I suspect. That could also be part of the key to their success.

Monica said...

Nice post! I've gone from a WAPFy type of diet a year ago to low carb and now, based in part on the readings on your blog, a bit more toward WAPFy again. In short, many of your posts have once again made me think that certain foods are not the spawn of the devil (just made a lentil soup tonight). I don't yet eat sprouted bread and may tolerate it in the future but for now I'm not eating it because I'm afraid I'll gain weight.

This has nothing to do with your post, but if you can indulge a question I wonder whether you have any opinions on the (un)healthfulness of coffee?

Stephan Guyenet said...

Hi Todd,

I believe canned beans are actually pretty low in anti-nutrients. But I reflexively don't trust canned foods because of preservatives, BPA-containing plastic liners, and the potentially long storage time from canning to eating. I still eat canned foods sometimes, but I think fresh is probably better.


Good point, they weren't eating modern crap food either.


Keep us filled in on how you're feeling. I'm interested to know how your body will react to re-introducing WAPF-type carbs,

I tend to see coffee and tea as pretty harmless, but I'm open to being convinced otherwise. I personally feel better overall when I don't drink caffeine regularly.

Bryan said...

Do bean sprouts have a low lectin content? Do they come from soy or what?

I'm in Asia and looking for something to replace the rice that meals are served with. This blog is fairly rice friendly, but Cordain says to boot it out in his acne book, and in my experience with acne, I do better without it.

Stephan Guyenet said...


Lectins are mostly destroyed during sprouting. If you don't tolerate rice but you still want something starchy, I'd suggest starchy root vegetables (potatoes, sweet potatoes, taro, etc). I don't think sprouted beans would be a good substitute for rice. The typical Asian bean sprouts you see in the U.S. come from mung beans.

Half Navajo said...

hey stephen!

so soaking didn't have quite the effect as fermentation. What is the difference? When i make oatmeal, i usually soak it in water and yogurt for 24 this fermentation, because i use yogurt, or is this just soaking? Would you give me some examples of how to ferment grains.


Anna said...

Perfect timing. I've been wondering if I needed to do more than long soaking. It had occurred to me I might need to do something to enhance fermentation in the mixture of half steel cut oats/half almond meal porridge I make for my son (wish he'd eat eggs for breakfast, like I do, but ....).

Typically I soak the oat/ground almond combination in a glass jar for a day or so with filtered water and a spoonful of yogurt, then I store the jar in the fridge, taking out big spoonfuls during the week to make a bowl of porridge (adding enough water before cooking to get the right consistency). Even with a soaking that can last a week, it never takes on a "sour" odor.

Know any "sour" porridge recipes or techniques? Perhaps a "sourdough" starter, but without wheat?

Daniel said...

Soaking and cooking grains more may increase the glycemic index of the food, with the result that such processing may end up having insulin and inflammation implications. Of course, you are right that such processing makes grains edible in the first place. Perhaps, instead of trying to calibrate the amount of processing needed to reduce grain toxins without increasing glycemic index too much one coudl bypass the whle conundrum by avoiding grains in the first place. Such a diet would aid in weight loss and doesn't appear to have very many negative health implcations, given what we know know about fat consumption (which is very different than what we knew a few years ago).

Anonymous said...

Are you implying that phytic acid is all bad and we should cut it out completely?

Anonymous said...

re: steel cut oats, I'm now cooking them (used to eat them raw until Stephan advised me otherwise) - I take it that it's necessary to soak them too?

Also, what about rice - just cooking rice normally, is this sufficient? Or does rice also need to be soaked/fermented?

Stephan Guyenet said...


Yeah that study didn't see much of an effect of soaking on phytic acid, but other studies have shown that it's pretty effective for beans and certain grains. The other thing is that soaking did reduce the tannin content quite a bit, so it wasn't a lost cause. It probably also reduced other toxins and anti-nutrients as well.

The difference between soaking and fermentation is that in soaking, you're activating the seeds themselves to break down their own toxins. It's part of the natural sprouting process. Soaking also passively leaches out certain chemicals like tannins.

With fermentation, you're cultivating microorganisms that secrete enzymes that break those same chemicals down. They probably secrete them to break down the anti-nutrients so they can use the nutrients themselves. But we eat them before they can get that far! Your example of using yogurt is fermentation, because the yogurt contains microorganisms that partially digest the oats.

I think treating oats like that is a good idea, because oats are toasted when you buy them so simply soaking them in water doesn't do anything. That's because the toasting process destroys the enzymes that would otherwise break down phytic acid etc when they're soaked.


I wouldn't worry about it not getting a sour odor, I think that's a good way to treat oats, as I mentioned above. I've tried a couple of different fermented porridges. The first just involves cooking rice, oats or millet, adding raw miso and letting it sit for a day. The second is ogi (in Nourishing Traditions), which was a disaster when I tried to make it.

I also make idli, which are thoroughly fermented.


They do increase the glycemic index, but I can't say I'm convinced that's a problem. I agree with you that grains are not necessary in the diet and you can circumvent all these nuances by avoiding them altogether.


I'm not ready to make any unequivocal statements about phytic acid. In any case, it's very difficult to avoid it completely unless you're a carnivore. Even root vegetables contain some. But I do think it's worthwhile to keep it low. I know some people ascribe benefits to it, for example because it can help prevent iron overload in older folks. But I tend to think that for most people, not absorbing the minerals in food is a bigger problem.


I don't want to say it's necessary, but I do think it's beneficial. Troy and Anna's method of soaking them for 24 hrs in raw yogurt water (make sure the water isn't chlorinated) or whey is a good one. Raw miso is another option.

Aaron Blaisdell said...


I suppose your recipe would work with just steal cut oats without the almond meal? And when fermenting in the glass jar, is the lid on or does the process require access to air?

Anna said...

What I've been doing with the oats/almond soaking is either sitting a small plate on top to keep out the odd fruit fly, dust, etc., or placing the jar lid on top very loosely, not tightened down. Then when it goes into the fridge, I tighten down the lid.

I also make sure to leave some extra room at the top for expansion. Several times the contents have expanded more than I expected and spilled over. A plate under the jar is also useful for poor estimates and easier clean-up ;-).

I add the ground almonds to the oats to "cut" the starch content of the oats and bump up the fat, protein, and minerals. Might be playing mind games with myself, but it seems like this mixture "sticks to his ribs" longer and he isn't back before the next meal looking for a "top-up".

I'd really rather not feed him oats at all (even if properly prepared, grains are unnecessary), but he doesn't like protein and fat for breakfast as often as I'd like, and this is a concession on my part, in a way that seems the least likely to do harm (compared to conventional industrial cereal foods).

Robert M. said...

As a coeliac, I can eat corn gluten if it's been lime processed, or some varieties of yogurt, especially if I leave it in the fridge for a couple of weeks. I generally don't, however, because I gain weight on corn whereas I don't on animals and sub-10 % carb vegetables.

Wheat gluten is an exception, as you say.

I think quinoa is the fastest sprouting grain I've ever seen. 24-36 hours will generally do it.

We've talked about this before, but I'm not sure that omega-6 PUFAs are all that low on a high-carbohydrate diet. What matters, the ratio of omega-3 to omega-6 (due to brain needs) or the ultimate quantity of omega-6 ingested? Probably a bit of both.

Also, on the topic of tannins, I really like naked red wines (i.e. those that have not been aged in oak barrels). They lack the pucker power of regular reds so you can better taste the wine. This, IMO, is a good example of traditions that lead us in the wrong direction.

JMC said...

Hi Stephan,

I've been studying lectins as part of the diet-auto-immunity connection and although these traditional methods may reduce lectins, the papers I've checked show that they don't eliminate them completly (and in people with auto-immune disease, just a very tinny antigen or something that can bring antigens from the gut, like lectins, even in small amounts, can trigger a massive immune reaction - I've experienced a worsen in symptoms - I have RA - with capsules that contain tinny amounts of a legume, which name I can't remember right now). If you have references showing that soaking, sprouting, fermentation and cooking ELIMINATE lectins, I would love to see it.


jensgb said...

Hi Stephan.

I have read everything ever posted on your blog, and would like to express my gratitude for your tireless researching and sharing of valuable information, that matters in peoples lives.

With regards to phytic acid content in oats: I soak my oats overnight before cooking to get rid of the phytic acid. Since the oats themselves are low in phytase which is required to break down the phytic acid, I include a little buckwheat (1 part buckwheat to 6 parts oats). I also add a dash of vinegar to the soaking mix. Buckwheat is high in phytase, and has more than enough to facilitate the breakdown of the phytic acid in the oats - especially since the enzymatic activity of the phytase is higher in the slightly acidic medium that the vinegar

Reference:"Phytic Acid Degradation in Complementary Foods Using Phytase Naturally Occurring in Whole Grain Cereals" -

Keep up the great work Stephan!

Stephan Guyenet said...


My opinion is that both the ratio and the absolute quantity of n-6 and n-3 matter. Did you get my latest e-mail a few days ago? I sent it in plain text but it bounced back again.


I don't know if they can eliminate lectins completely. There are some Italian papers floating around where they succeed in reducing wheat gluten to undetectable levels by fermentation. They even fed it to celiacs and they didn't react. I think most people can handle a little bit of lectins in their food, but if you're very sensitive then it's probably a good idea to avoid those foods altogether.


Thanks for the encouragement. I'm going to look up the paper you cited and possibly post on it.

Stephan Guyenet said...


I just read that paper. It's interesting but everything in it was done with flours rather than whole seeds. I wonder if throwing buckwheat flour in with soaking whole brown rice would have any effect? Do you know?

Unknown said...

The Bantu tribes' consumption of starchy and fermented foods naturally reminded me of Hawaiian poi, which I haven't had for a long time but would like to revisit.

marco said...


maybe this ...

Anonymous said...

A source for sprouted flours:

JMC said...

Thanks Stephan and Marco. Although the studies you pointed out are applicable to prolamins in gluten grains (wheat, rye, barley and oats), it raises the possibility that it may possible to gratly reduce or eliminate lectins and other anti-nutrientes in foods.

I remember Dr. Cordain saying in a lecture that soaking and long cooking would greatly reduce lectin activity in legumes. I'll try to look for studies that looked at that and if I find anything, I'll let you know.


Senta said...

That is so interesting that it can be possible for even celiacs to eat wheat if it is treated correctly!

I have heard very good things about bread from Bezians Bakery in Los Angeles. The breads are fermented for two weeks, some as long as 3-4 weeks.

Check out the comments, one person says he is allergic to wheat but can eat the bread and another comment quotes from the brochure that tells how the breads are made.

I've called the bakery but they do not ship. They can be purchased at farmer's markets in the area, wish I lived closer.

The owner also has a blog and conducts workshops.

Robert M. said...


I read through the review published by the author's after that article you linked. It looks like the 120 hour fermentation cuts the gliaden fraction down by a factor of six. That's not sufficient for coeliac disease patients to be symptom free. It's not even as good as 'gluten-free' flours, IIRC.

mongander said...

I've been eating unsoaked whole intact grains (primarily barley and oats)for years. Probably better than 1/2 my calories are from these grains. Also eat about 2oz daily of cold ocean fish. I'll be 70 in two months and I feel great...better than I did 25 years ago. I walk/sprint 3 miles most days. When are the lectins and phytins going to get me? Why should I worry about phytins when I supplement with IP6? Have never had a broken bone and have zero joint pain.

All this soaking business sounds like religious ritual.

Stephan Guyenet said...


I'm glad that's working well for you, and I hope it continues to.

I don't think it's religious ritual. Why would healthy cultures around the world nearly all adopt such labor-intensive processes to prepare their grains if it was pointless?

Anonymous said...

Found this:

Dietary Lectins as Disease Causing Toxicants.
Rabia Hamid and Akbar Masood.
Pakistan Journal of Nutrition 8 (3): 293-303, 2009.

Full text:

There's a table of different foods presented in the article containing lectins. Among them is coconut, cocoa, rice, potatoes and bananas...
It's getting harder eating paleo...

I'm very impressed by the way you investigate and search for the haste to draw conclusions. No ego involved.
Thanks for this great blog...probably the best there is!

Stephan Guyenet said...


That looks interesting, I'll look forward to reading it. I don't think it's necessary to avoid all lectins. Every living cell contains lectins, it's just a question of whether they're the type that are harmful to humans. In my opinion, that has to be determined empirically for each food.

AlanL said...

I wonder what you think about the south Indian practice of roasting pulses? I share your admiration of idli/dosa, although I personally find idlis a little bland and prefer dosas (fried in a little coconut oil, if available). I have also been familiar for years with the south Indian way of using small amounts of various dals, roasted and ground, as a masala ingredient (flavouring).

Then a couple of years ago I discovered this fantastic mung dal recipe, in which one roasts a full pan of beans prior to boiling them. It's a really delicious recipe and I recommend it very highly, but I wonder if roasting the beans is doing anything other than "just" (sic) improving the flavour

Stephan Guyenet said...


I love South Indian food, but they aren't role models when it comes to health. Roasting does make seeds more digestible, but it doesn't break down phytic acid. That's not a problem when you're just using it as a flavoring, but a whole dish made from roasted unsoaked beans is probably not very nutritious in my opinion.

But you know what, as long as you aren't eating it every day I don't think it's anything to worry about. There's something to be said for flavor after all!

Charles R. said...

"A lactic acid-fermented oat gruel increases non-haem iron absorption from a phytate-rich meal in healthy women of childbearing age"

Unknown said...

Hey Stephen,
I don't know if you still monitor old posts or not but I came across Muesli this morning at the work cafeteria and it was really good. I looked it up and it's just oats, milk, and apples that are mixed together (no cooking) and allowed to sit overnight. Do you think if I let this mixture sit in my fridge overnight that I'd be helping the whole lectin thing? I don't know if oats even have that much gluten in them. In the grand scheme of things it's probably nothing to worry about since it will only be about a 1/2 cup of uncooked oats per day. Thanks for your time, this blog is one of the best out there. -Mark

Stephan Guyenet said...

Hi Mark,

My opinion is that something like that is fine but not every day. That soaking method won't eliminate anti-nutrients because oats are cooked prior to sale, eliminating their phytase activity. So soaking them won't break down their phytic acid. The fact that you eat them with milk (animal protein) and apples (vitamin C) will help you absorb the minerals however.

David said...

Grains also contain complex sugars that are difficult to break down as well as allergenic proteins like gluten. Again, soaking grains does aid in their digestion, so if you do eat grains it is very important to properly prepare them.

Unknown said...

Read: African Population and Capitalism: Historical Perspectives
By Joel W. Gregor page 210.
According to this book, the Kikuyu ate meat and milk until they had their land holdings reduced around 1910-1920. The resulting decline in health of the Kikuyu is documented in this book.

Stephan Guyenet said...

Hi Matt,

Very interesting. So they were eating meat and milk just a decade before Price visited them.

Olga said...

Hi Stephan:

Does the action of phytic acid occur in the digestive system, or is it absorbed into the blood stream, and chelating minerals there? This isn't clear from the litterature.

Unknown said...

hi stephen,
I am in the middle of researching just what you are talking about and have always been interested in the old traditions of fermentation, and semi germination prior to cooking. You are right we do need to get back to some lost wisdom. certonally I find that to eat legumes successfully you need to rince, steep for 24 hours and then semi germinate under a damp towle. just at the point of germination then cook your legumes with a small piece of seedweed in the water which will futher increase their bio availability. kumbu works well. also in regard to the damaging effects of lectins you can always compinsate with the addition of sacrificial sugars which bind with the lectins and they are removed harmless. so sugars with in the like of seaweeds in particular bladderwrack , ( fucoidin) and Okra which is rich in binding muciage. apart from all the other health giving benifits of these food you can reduce the lectins possible problems. Once again its amazing the synergetic effects, in the combinations of foods.
all the best

Unknown said...

Yes,I am interested in fermenting cereal grains to improve digestion.I've googled the subject many times and find alot of info saying why you should do it.But nothing on how-to do it.One thing I wondered are things like what bacteria's to use(I'm sure there's more to it than just what bacteria to use. If anyone can point me to some info on how to get started, Thanks.

VitalbodySue said...

Dan, I agree completely. My health is amazing - at 55 I feel better than I did at 15, 25, 35 or 45. And the biggest change that facilitated that was my giving up grains! I eat potatoes and root veggies now and then, but mostly it's meats, fish, seafood, dairy, veggies and fruits, nuts and seeds, and chocolate. For those interested in losing weight, I went down 4 sizes right away, and have keept the weight off for eight years effortlessly.

Carolyn said...


The Muesli I was learned about in Switzerland (where Muesli was invented) used yogurt instead of, or in addition to, milk. Sometimes other ingredients were added - dried fruits, fresh berries or currants in season, bananas, nuts, etc. If you mixed the oat with yogurt and maybe some milk first and allowed for some fermentation, then added the fresh fruits later, you might have a more appealing, and healthier, dish.

gg said...

As far as I have read there is no particular deficiency of Zinc or Iron in the USA fact there is thought to be possibly a bit too much of both these days due to multivitamin/mineral supplementation etc. Any calcium lack can be solved by increasing dairy product intake of milk, yogurt or cheese. Therefore I see no compelling reason to go to inordinate lengths to prepare grains and legumes by special fermentation methods. I like brown rice cooked in a pan or microwave with just enough water to absorb into the grains. It has much more flavor, fiber and vitamins than white rice and as long as you are getting enough minerals from other sources it is not harmful.
Some phytate may actually be good as an antioxidant and act against certain cancers(see wiki), an effect possibly linked to mopping up excess iron on the intestine.
Why not get your levels of these minerals checked out to see if you are deficient before embarking on a major change of food preparation?

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