They selected 27 studies that reduced saturated fat or total fat (in some cases along with increased PUFA), and fit several inclusion criteria. The results:
There was no significant effect on total mortality (rate ratio 0.98, 95% CI 0.86 to 1.12), a trend towards protection form cardiovascular mortality (rate ratio 0.91, 95% CI 0.77 to 1.07), and significant protection from cardiovascular events (rate ratio 0.84, 95% CI 0.72 to 0.99). The latter became non-significant on sensitivity analysis."Sensitivity analysis" is a statistical method that allows investigators to take into account the limitations of their model, in this case, the way in which they aggregated the studies' data. Another way of putting their findings is that they found no significant effect of fat modification on mortality or cardiovascular mortality, and they found a reduction in non-fatal "cardiovascular events" (more on this phrase later) only in a subset of the data.
Trials where participants were involved for more than 2 years showed significant reductions in the rate of cardiovascular events and a suggestion of protection from total mortality ["suggestion" = not statistically significant]. The degree of protection from cardiovascular events appeared similar in high and low risk groups, but was statistically significant only in the former.
I'll be the first to admit the meta-analysis isn't perfect. They cast too wide a net, not allowing them to distinguish the effect of reducing total fat from the effect of reducing saturated fat. They lumped both together, which from a practical standpoint isn't actually a problem because both sets of studies show essentially the same thing: zilch. But it's still not the best way to conduct a meta-analysis. They also omitted the Sydney Diet-Heart study for mysterious reasons, which was a five year randomized trial that found an increase in mortality in volunteers substituting vegetable oils for animal fat. Then there's the conclusion, which boggles the mind:
Lifestyle advice to all those at high risk of cardiovascular disease (especially where statins are unavailable or rationed), and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates.Are these the same people who wrote the results section? I don't understand how they arrived at that conclusion from their own results.
In any case, this brings me to my main point. There are two types of outcomes you can measure in these trials: "hard endpoints" and "soft endpoints". Hard endpoints are not subjective. The hardest endpoint is death. Either you're dead or you aren't; there's no room for interpretation there. A bit less hard is death from a particular cause, such as heart attack. In that case, you're definitely dead, but the physician has to guess what you died of. That involves some judgment on the part of the physician and can introduce bias, depending on the study design. The softest endpoints are non-fatal events like angina, bypasses and stents. These depend on the judgment of both the physician and the patient, and are the most susceptible to bias.
The gold standard for controlled trials is a design known as "double-blind", where neither the participant nor the physician knows which group the participant is in. This design eliminates bias from both the participant and the physician side, allowing correction for the placebo effect and subtle bias in diagnosis. This is easy to do for drug trials, where placebo pills look just like the drug. But it's more difficult to pull off in a diet trial, where the patient knows what foods he's eating. Still, it can be done by giving participants similar-looking margarines containing either saturated or polyunsaturated fats, or sometimes by controlling diets in an institutionalized setting.
There have been three double-blind trials comparing the incidence of heart attack and/or mortality in volunteers eating either saturated animal fat or polyunsaturated vegetable fat: the 1968 National Diet-Heart trial (2 years), the 1969 Los Angeles Veterans' Administration trial (8 years), and the 1989 Minnesota Coronary Survey trial (4.5 years). The two studies that reported total mortality found no significant difference between groups. Two out of three found no difference in heart attack deaths. Of the two that reported on non-fatal cardiovascular endpoints, one found a significant difference. The V.A. trial was the only one to find a significant difference in heart attack deaths (18% decrease) and non-fatal events. There were significantly more heavy smokers in the animal fat arm of the V.A. trial, which was an unfortunate consequence of the participant randomization process. So that result is difficult to interpret.
The three double-blind diet trials, with the least potential for bias, really give no support to the idea that saturated/animal fat contributes to cardiovascular disease. As the participants were already eating a diet high in omega-6 to begin with, there is also no detectable effect of increasing omega-6 on cardiovascular health.
Many of the trials of this nature have been "single-blinded", where the participant knows which group he's in, but the physician doesn't. In this case, all endpoints involving death will be unbiased, because the physician deciding the diagnosis is not influenced by knowing what group the patient is in. However, soft, non-fatal events such as angina are still highly susceptible to the placebo effect. This is because they depend on the subjective judgment of the patient, who knows which group he's in.
I think it's interesting to note that very few dietary fat modification trials have found reductions in total mortality, which is the hardest endpoint and the least susceptible to bias. This is reflected in the Cochrane collaboration's findings. However, a number of the non-blinded and single-blinded studies have found differences in non-fatal cardiovascular events, sometimes creating absurd results. For example, in the 1966 Anti-Coronary Club trial, participants in the vegetable oil group had a significant reduction in non-fatal cardiovascular events, but a massive increase in cardiovascular deaths and total mortality. The former result could result from a placebo effect, due to the non-blinded nature of the trial.
The fact that the Cochrane review found statistically significant benefits of fat modification in soft, non-fatal endpoints (for a portion of the data set), but not endpoints involving death, suggests to me that what we're seeing may actually be a placebo effect resulting from the fact that patients were not blinded in the majority of these trials.
The only "fat modification" intervention that consistently reduces total and cardiovascular mortality is omega-3 fat supplementation, ideally in combination with omega-6 restriction. This is supported by the results of the DART trial, the Lyon Diet-Heart trial, the ISIS trial and the the GISSI-prevenzione trial.
46 comments:
Is there any form of Omega-3 supplementation that doesn't involve fish oil? And/or is there any cooking oil heavily biased towards Omega-3 fats? I've noticed some oils at the grocery store have started to label themselves as high in Omega-3, but the best I saw had something like a ratio of 4:1 Omega-6:3...
I'm also curious what you think of canola oil, I read your entire blog since discovering it a few weeks ago and don't recall seeing anything about it.
Anyway, back to my original reason for commenting, my mom made us take cod liver oil as kids, and I really can't stand the stuff.
Whatever benefit might be associated with saturated fat restriction is most likely due to the corresponding lowering of carb intake.
Typically, people who go on so-called Heart Healthy diets drop the fries, the hamburger bun, the ice cream sundae, the 6 slices of pizza, even if they continue to eat a lot of "low fat" starchy foods.
Of course, the older I get, and the more I watch what happens to the "old old" in my circle of acquaintance, the more I personally welcome heart disease.
None of us lives forever, and if you don't exit with a swift heart attack, you can choose from a slow, humiliating death via alzheimers, a slow painful death from cancer, choking to death from COPD, or perhaps slow poisoning renal failure.
Regarding omega-3 fatty acids. What do you think of Ray Peat's take on them?
He say's things like the following...
"In declaring EPA and DHA to be safe, the FDA neglected to evaluate their antithyroid, immunosuppressive, lipid peroxidative (Song et al., 2000), light sensitizing, and antimitochondrial effects, their depression of glucose oxidation (Delarue et al., 2003), and their contribution to metastatic cancer (Klieveri, et al., 2000), lipofuscinosis and liver damage, among other problems."
Kinda makes a person wonder if omega-3 is such a great idea after all.
Jenny - I agree! I'd much rather go from a sudden heart attack or stroke than most of the other options! In my sleep of course.
I would like to nominate Max Gerson to the nutrition Hall of Fame. It was mainly his daughter's book, "The Gerson Therapy" and Weston Price's book that finally set me straight on what a healthy diet truly consists of i.e. whole, fresh, unprocessed foods. There is nothing wrong with meat as long as the animal had a healthy diet.
Honorable mention should also go to Victoria Boutenko for introducing me to green smoothies and Loren Cordain for probably summing it all up best and putting it all in the proper context and perspective.
daniel the smith...
Your mom had it best: cod liver oil should be your first choice with regards to omega-3 supplementation (not to mention vitamin A and D, and a whole host of other nutrients, especially if you choose the fermented stuff)...
Regarding cooking oils, I, like many others, choose to stay away from them, at least the ones people normally refer to as "cooking oils". Fats of animal origin (from pastured animals of course) are definitely preferable for cooking (lard, tallow, butter, ghee, goose and chicken fat...) as they are more stable at high temperatures, not to mention more flavorful! Their fatty acid profile is actually quite different from what you might imagine (Stephan wrote a good article on this previously) and once you understand that saturated fats are good for you, there will be no going back! Coconut and palm oil can also be used, although their smoke point is not quite as high as say ghee or lard.
As for canola oil, my personal opinion, based on readings over many years, would be to stay away from it. The Weston A. Price Foundation actually goes into great depths at explaining some of their reasons why in this article http://www.westonaprice.org/knowyourfats/conola.html.
As far as 'liquid oils' go, emphasize extra-virgin cold-pressed olive oil and flax seed oil, but never submit these to heat. Drizzle it on salads or on warm food after cooking only...
Hope this helps,
Eric
Daniel the smith:
Fish oil is by far and away the best (flax being the only real alternative) since a lot of studies show that it's the EPA/DHA from animal sources that are particularly useful, not just omega 3 per se. You can get fish-based but heavily flavoured supplements: I've seen "Barlean's Omega Swirl Fish Oil Supplement" here in the UK and that's apparantly "the taste and texture of a fruit smoothie." (But I can't testify as to what else they put in it.
Alternative there's capsules you could just swallow, you can easily get some that don't leave you with a fishy taste. If you just can't stand fish then flax is useful for balancing out your O-6 at least, but it's not much tastier. (Although I did used to love it ground in yogurt before I gave up nuts/seeds...).
I'd avoid the flax, as the varieties of fatty acids it contains can actually be pro-inflammatory, which is not what you're going for. If you want more omega 3's, eat grass fed and free range meats/poultry and take a flavorless fish oil capsule. Animal sources are what it's all about.
Steven, as usual, a great article.
daniel the smith.
Modern refined oils don't taste of anything. They are a million miles away from products of 10-15 years ago which were with you all day.
In the US Carlsons
In the UK Boots own brand
Are both pretty tasteless and DO NOT REPEAT AT ALL !!!
There are algal based supplements but they only contain DHA and EPA and are a lot more expensive if you are on a budget.
Bryce
Re flax.
The problem we have in the west is that many do not have access to farm reared animals, true free range eggs, cattle that do not get at least some grain etc.
So we eat high amounts of Omega 6 LA and it is prudent to get an equivalent amount of plant based Omega 3 too.
Plant based Omega 3 ALA is used in body processes, incorporated into membranes and important in the skin. It also competes for enzyme pathways.
High Omega 3 seeds are probably a better choice as they contain minerals etc (but then there is the anti nutrient issue and the need for soaking sprouting etc.
For those with poor digestion, lack of access to grass fed products etc a small amount of flax/ flax oil may have a useful place in the diet.
There is no guarantee the body can convert the plant fats to the longer fats. Many are very poor converters. Many men only convert tiny amounts of the plant fats. - which is why it makes sense to get some long chain Omega 3.
Fish has to be the first choice and a complete package, fish oil is the next option and a good insurance policy.
Diabetes and age are two of several factors that reduce the ability to convert plant fats to long chain fats.
Grain fed free range poultry is high in Omega 6.
Author Omega Sis The Devils Fat
www.omegasixthedevilsfat.com
Rewritten new version with new material on its way, and getting closer.
Hey I've got a practical question:
Is supermarket red meat/ground beef safe to eat?
It isn't easy to find grass fed only meat and I question whether there is any here in TX.
I know people that have cattle and they tell me everyone they know supplements with grain.
Even at wholefoods market a guy who supplies "grass-fed beef" admitted to me they use "small amounts of grain" after I questioned him on it.
And what about mad cow/CVJ? Is that a concern with grocery store beef?
daniel
Re fish oil
Nordic Naturals have an exellent reputation in quality terms and sell fish oils.
They also do a lot of work to get the message about the importance of Omega 3 to a wider market
http://www.nordicnaturals.com/en/Products/Product_Details/98/?ProdID=1425
Glenn,
There's plenty of grass-fed meat in TX, but "everyone" won't necessarily know about it. Check www.eatwild.com or www.localharvest.org for vendors. There might be one closer than you think.
Many grass-feeding ranchers sell direct to the public, but you might need to make your purchases in bulk, rather than in individual retail cuts. Often you can reduce the per pound price quite a bit this way, but you will need freezer capacity. Many people find it worth while to buy a decent sized freezer.
Thank you everyone for your responses :)
One followup question for Eric (or anyone): Do you have an explanation/link/reference for the not heating olive oil thing? I cook with olive oil all the time, I thought it was vastly preferable to other oils?
Coconut oil is great to cook with because it is 93% saturated. The concern with olive oil and other polyunsaturated fats is that high heat can damage the fragile double bond and create a damaged fat more prone to toxicity. Olive oil is less risky than omega-6 oils because it is monounsaturated, but the risk is still present.
Hi Daniel,
PaleoRD said it well: olive oil isn't quite as fragile as other oils, but it's still worth noting that a lot of the actual value in olive oil comes from different compounds and phenols present in the oil (rather than the actual fatty acid profile, as some might have theorized). Extra-virgin cold-pressed olive oil, by its very nature, tends to contain a higher proportion of these, the latter of which are also quite fragile to high heat.
Another point you might notice if you do some research... With oils, and especially with oils you are considering using for cooking, it's important to look at smoking points. For olive oil, this number seems to be all over the place, depending at what source you look at, and the reason is quite simple: the more processed the oil is, the higher it's smoking point will be (due to it having already been subject to heat).
In essence then, if you pick the healthiest olive oil out there (generally more expensive), it is also bound the be the most fragile, and probably not ideal for cooking applications. So save your money (and the nutrients) and don't expose your good olive oil to high heat.
Preferable choices, as mentioned earlier, would be ghee (very high smoke point), butter, lard, tallow and even palm and coconut oil (smoking point not as high here...).
Some notable liquide vegetable oils with high smoking points also inclue macadamia nut and avocado oil...
Cheers,
Eric
Olive oil contains 10% Omega 6 and almost no 3.
As Eric points out the benefits in olive may also be due to the plant antioxidants it contains which will be damaged by heat.
The nutrients have been stripped out of industrial lard and the Omega 3 it contains may be hydrogenated.
The cholesterol in animal fats is susceptible to oxidation.
So better to add olive or other fats at the end of cooking.
@Robert--
Something has to be wrong, as unless I've misunderstood you, what you're saying seems to preclude any cooking with any fats? ...I have to sizzle the garlic in something!
Daniel
There is not perfect solution and death is guaranteed.
Logically highly saturated vegetable oils carry the lowest risk, but I have never tried garlic and coconut! (-:
And that opens up the cooked v raw debate, and there again there are advantages and disadvantages.
It is all about moderation.
Hi,
I keep coming across information that coconut oil is good since it contain saturated fat. Fair enough. But the smoking point of unrefined coconut oil is 350°F (177°C). While that of other oils including Olive oil is higher.
Inspite of the low smoking point of coconut oil, how do people say that it is better that other oil? In fact they also say that coconut oil will remain stable even when heated etc. After seeing the smoking point data of coconut and other oils, I am skeptical about coconut oil for cooking...
Can you some one throw light on coconut oil stability while cooking?
Thanks
Venkat
Did someone replied to Coach Jeff on EPA and DHA's usefulness?
Thanks
Venkat
~Jenny
trust me. you don't want heart disease.
suggestion? go backpacking. as much as possible. you can avoid so much future grief and will feel like a healthy animal. there are so many positives, i can't fit them all here.
...and it's as addictive as a drug.
@daniel the smith
yes you can get organic algae oil from companies like v-pure. This is what the fish and krill use to produce dha/epa. Research into equivalency to other epa/dha forms looks good so ya you can go vegan with algae oil and stay well :)
mc
@ dave moss
with respect to algae oil, on the contrary, the bioavailability of epa/dha has been compared in a few studies and it's at least equivalent with fish and with fish oil.
at this point other questions come into play as to optimal amounts - if there's any difference with fish oil amounts for instance
here's two great overviews:
Am J Ther. 2009 Mar-Apr;16(2):183-92. Links
Clinical overview of algal-docosahexaenoic acid: effects on triglyceride levels and other cardiovascular risk factors.
Lipids. 2007 Nov;42(11):1011-24. Epub 2007 Aug 23.Links
Bioequivalence of Docosahexaenoic acid from different algal oils in capsules and in a DHA-fortified food.
@ daniel the smith: olive oil
you can heat olive oil but only a bit:)
these temps have to do with the smoke point of oils where heating them destroys them and they go all carcinogenic.
here's a link on various oil smoke points.
best
@ Coach Jeff
Sir, ya gotta consider the source of these supposed bad things about epa/dha.
for instance "their depression of glucose oxidation "
That's FABULOUS. if that helps glucose sparing for fuel, and foregrounds oxidation of fat instead (which it does) that's a REALLY GOOD THING.
mc
Can anyone comment further on the issue of too much omega 3 and immunity? If the source is questionable, it would still be helpful to understand why the claim is unfounded. I have also wondered if too much omega 3 could supress the immune system... I have a list of other good reasons to get extra omega 3, so I would like to discount this worry if possible.
Also, does the heat generated in the canning process damage omega 3 in sardines and salmon. I'd like to get omega 3 from natural sources, can I count these items?
Sandra,
Omega-3 definitely suppresses the immune system when taken in excess. That's because it outcompetes omega-6 derived eicosanoids which are important in immunity.
Immunity.
It is complex.
The eicosanoids are only one of a number of ways that Omega 3 and 6 impact on immune function. They work in different way through different mechanisms.
Omega 3 supplementation in our western Omega 6 world has been shown to assist in conditions such as "sepsis,trauma abdominal SIRS and peritonitis", "reduced infections and complications in postoperateive patients", and reduced ICU stay lengths.
Ref - "Omega 3 Fatty Acids in Clinical Nutrition Heller" Stehr and Koch ( a recommended read for those in the medical profession.)
The Kitavans has an Omega 6 intake of 1/2% of calories and a high intake of fish and so eat more Omega 3 than 6 10:1? and excluding diseases of poverty were very healthy. (thanks Stephan who found this data)
Eskimos were also pretty healthy (but died of different things to us) had slightly higher TB rates (I read somewhere) but they also may have had less Vitamin D, and Vit D is a factor in the risk of TB - so these things are complex.
Author Omega Six The Devils fat
www.omegasixthedevilsfat.com
(Rewrite and expansion on the way)
Canning.
You can look up the Omega 3:6 content on nutrition data.
http://www.nutritiondata.com/facts/finfish-and-shellfish-products/4110/2
I recall reading some fish is de oiled before canning.
Heat will damage food but it is all about balance and pragmatism.
Stephan >> Omega-3 definitely suppresses the immune system when taken in excess. That's because it outcompetes omega-6 derived eicosanoids which are important in immunity.
It's my understanding that this is true of both omega-3 & omega-6s, when taken in excess, correct?
Robert Andrew Brown >> The Kitavans has an Omega 6 intake of 1/2% of calories and a high intake of fish and so eat more Omega 3 than 6 10:1?
Do we really suspect the ratio was so off-kilter? I'm under the impression that fish have varying levels of omega-3s-to-6s depending on climate/species; compare bluefin tuna at 25:1 versus tilapia at 1:1.
After an (admittedly) brief search for the composition of the Kitavan diet, all I was able to come up with was "fish" (i.e., nothing specific on which species are consumed); as such, isn't it better to assume that their geographical location makes it unlikely "fish" encompasses cold-water varieties?
I know that Stephan mentioned in a previous post that the Kitavans consume an avg of one tsp of fish fat per day--is data available on the composition of this fat?
Yes, excess omega-6 can do the same thing because it inhibits conversion pathways that lead to eicosanoids.
The Kitavans eat about 4g of fish fat per day, with a total PUFA intake of 2%, so their omega-6 to 3 is probably not too far off from 1:1. They don't eat much omega-6 or even that much omega-3.
Chandler
>>"Stephan >> Omega-3 definitely suppresses the immune system when taken in excess. That's because it outcompetes omega-6 derived eicosanoids which are important in immunity.
It's my understanding that this is true of both omega-3 & omega-6s, when taken in excess, correct?"<
Omega 3 and 6 downstream products have very different roles and effects.
So blocking Omega 3s or 6s will have very different outcomes.
http://www.ncbi.nlm.nih.gov/pubmed/17965751
So excess Omega 6 will suppress the anti-inflammatory effects of Omega 3 by overwhelming the eicosanoid pathway which as discussed increases inflammatory aspects of immune function.
Chandler
Thanks for challenging me on this
>>Robert Andrew Brown >> The Kitavans has an Omega 6 intake of 1/2% of calories and a high intake of fish and so eat more Omega 3 than 6 10:1?<<
I need to receheck the paper but I am sure this figure came out of the paper, as I was surprised to.
I will refind the paper and come back.
Tilapia is a fresh water fish. Fresh water fish generally all have lower 3:6 ratios. I presume due to the food chain.
Swordfish a marine tropical fish has a 10 +:1 ratio. Tuna are tropical. I have not checked on the values of reef fish.
As far as I am aware marine algae contain high levels of DHA so I would expect that in general terms to go through the marine food chain. My impression is that generally marine animals have much higher Omega 3 than Omega 6 in their body fat, and I do not recall anything that contradicts that generality.
>Do we really suspect the ratio was so off-kilter? <
As shoreline dwellers we may well have had more Omega 3 than 6 overall in our diet, and I suspect we did.
This is a bit hard to follow for me... if both omega 3 and 6 can hinder the immune system when consumed in excess shouldn't we eat them in equal amounts? I realize that most Americans eat way too much omega 6 so need to balance...but if you minimize omega 6 foods already it sounds like it could actually be harmful to take even a little CLO or fish oil (or to try to get extra omega 3 by eating lots of fish for that matter). Do we need to be calculating exactly how much omega 6 we get with food intake daily and strictly balance with supplements only if needed to make our ratio correct?
Robert:
What are "inflammatory aspects" vs. "non-inflammatory" aspects of immune function? Are some parts of the immune response unaffected by excessive omega 6? Would excessive omega 3 (excessive maybe being small amounts if omega 6 intake is low) affect only the "inflammatory aspects" and leave other parts of the immune response alone?
And thanks for your response on canning- could you give me more info on that... I realize food nutrients are lost in canning, but I'm wondering about omegas in canned fish specifically. I read here that PUFAs are unstable when heated and become oxidized (and should be avoided). Do you know if the omega 3 fats in salmon and sardines become denatured in the canning process?
Chandler
Kitavans.
Thank you for questioning my figures and making me revisit it.
1:10 is very probably to high but it looks as if they were eating more Omega 3 than Omega 6 and probably by a significant margin.
Figures below might suggest an Omega a 3:6 ratio of maybe 4:1. Stephan at a previous point in time suggested 2:1
I think the answer as to the exact Omega 3:6 ratio is open but a diet for marine shore dwellers that contains significantly more Omega 3 than 6 should not be discounted.
http://www.ajcn.org/cgi/reprint/66/4/845.pdf
Stephan said on wed 13th Aug "They have an omega-6 : omega-3 ratio of 0.11. " which is where this started, although the context was not entirely clear. I cannot find my copy of the paper that came from but do recall reading it.
Their calorie intake was about 2200cals
Table 2 of the above paper
% of energy
Omega 3 intake 2%
Omega 6 intake <1%
Based on USDA figures which are at best only indicative of the type of food, and figures might be species dependent;
Table 1
Kitavan Food intake
Yam 1200 Omega 6 per 100g 60mg
Fruit
Fish
Coconut 110 Omega 6 per 100g 366mg
Other veg
The Omega 6 in fruit veg and fish is generally small
So very roughly on the above basis we are looking at a gram a day of Omega 6 which would be about 1/2% of cals.
Assuming the Omega 3 figure of 2% of cals is accurate in ball park terms that would give us a Omega 3:6 ratio of 4:1
But the fish fat figure in table 1 is 4 grams, and only a proportion would be Omega 3 so that leaves a question. But under 4 oz a day of fish does not seem a lot for marine dependent island dwellers.
RE fat content.
I realised after making the previous post that you may have been thinking of fat content rather than fat ratios. The fat content of warm water fish is reported as being lower than the content of fish from colder waters.
But is that based on whole fish content because once you start looking at bits figures vary considerable e.g. cod flesh v cod liver.
Sandra
Canning this link might help
http://www.vitalchoice.com.au/24.html#anc5
Fish canned in veg oil oil will suffer from high 6 from the veg oil
Intake
You said
"Do we need to be calculating exactly how much omega 6 we get with food intake daily and strictly balance with supplements only if needed to make our ratio correct?"
Yes we do need to keep an eye on our intake.
Marine products are a better choice than oil, but modest fish oil intake as insurance is prudent for most.
Some do not convert plant fats to long chain fats so that means marine foods fish oil or other supplementation.
This paper may help with some of your questions. It is on the web and available in full for free.
Healthy intakes of n-3 and n-6 fatty acids: estimations considering
worldwide diversity
Joseph R Hibbeln, Levi RG Nieminen, Tanya L Blasbalg, Jessica A Riggs, and William EM Lands
You said
"What are "inflammatory aspects" vs. "non-inflammatory" aspects of immune function? "
My feeling is that there is less risk from excess Omega 3 than Omega 6.
Peoples that eat a lot of fish are generally healthy.
Excess Omega 6 is the biggest factor in the western diet.
sandra,
My logic, when it comes to things like this, is to eat within the ballpark and let the homeostatic tendencies of my body do the "calculating."
In this particular case, my thinking is that as long as I'm not flooding my system with either vegetable oils or fish oils, my body will be able to process what it needs from the food I eat (regardless of my actual ratio). Unfortunately, I don't have any authoritative study (or authority figure...) I can point to in support of this.
On the other hand, for example, if you're consuming too much omega-6 PUFA, supplementing with omega-3s will be relatively beneficial, as omega-3s are required for tasks other than immunity.
What I'm curious about is which studies support causation between PUFA intake and immunosuppression (Eric Newsholme's comments aside), and how this change was measured.
Robert,
Thanks for looking into this further, the numbers you provide are clarifying (and thanks for the link to the study).
Also, looking back at my original comment, it wasn't very clear whether I was talking about ratios or absolute values, mainly because I was jumping back and forth between the two, for the reasons described above.
Popular Fish, Tilapia, Contains Potentially Dangerous Fatty Acid CombinationFarmed Tilapia Tilapia has higher levels of potentially detrimental long-chain omega-6 fatty acids than 80-percent-lean hamburger, doughnuts and even pork bacon.
Chandler
You said
"In this particular case, my thinking is that as long as I'm not flooding my system with either vegetable oils or fish oils, my body will be able to process what it needs from the food I eat (regardless of my actual ratio)."
I do not think this applies to Omega 6.
Crawford and Marsh in "The Driving Force" suggested that Omega 6 allowed the development of land based life and the vascular system.
My theory expanding the work of Crawford, Marsh, Cunnane and others is that Omega 6 is natures control mechanisms of breeding, metabolism, immune function etc and behaviour.
Arguably Omega 6 connects our ability to breed directly to the fertility of the environment.
Omega Six in QUANTITY is only found in quantity on land in plant reproductive material which is weather dependent and seasonal.
If Omega 6 is plentiful so is the food chain.
The availability of Omega 6 ultimately controls most (if not all)the enzymes that produce the sex hormones.
In combination with Omega 3acting as moderator it is arguably the key external controlling factor in the fertility cycle and the age of puberty.
It also has big influences on behaviour through a variety of mechanisms.
Omega 3 is available year round in quantity in the oceans so is not a controlling variable.
Omega 6 is totally weather / environment dependent.
This fact is the core of my book and a simple but seminal observation of huge significance.
Author Omega Six The Devils Fat
www.Omegasixthedevilsfat.com
(A total rewrite, with new material hopefully better edited is getting closer)
July 19, 2009 2:35 PM
Sandra
Canned fish
Please excuse the shout but this is something people should know about -
TUNA IN VEGETABLE OIL (drained)-
YOU MAY BE BETTER OFF EATING BREAST OF GRAIN FED CHICKEN !
In the bizarre way life works, whilst looking for information on lipids in fish skin I have just accidentally found a book that gives very useful information on the effect of cooking including microwaving and canning.
[The effects of cooking on fish is a subject I have searched quite a lot on but never found this book (-:]].
http://books.google.com/books?id=d8l3LOyBrc8C&pg=PA87&lpg=PA87&dq=DHA+content+skin+fish&source=bl&ots=gbMxz1onKq&sig=_BqZNqbdtVn9vdtC-Ypy9Fo_5U0&hl=en&ei=_JpjSv-KKdShjAf95YkE&sa=X&oi=book_result&ct=result&resnum=2
see Page 95 onwards
CANNED FISH
WE NEED BETTER LABELLING !!!
Tuna is one of the most popular fishes in the US.
We are overfishing a precious resource which has a medium mercury pollution risk. We are taking out the Omega 3 with vegetable oil, throwing the Omega 3 with the vegetable oil down the sink, and leaving the Omega 6 from the vegetable oil in the tuna.
We then tell people to eat canned tuna (in oil)to get more Omega 3, but we have removed the Omega 3 and replaced it with Omega 6, (how ironic is that,) and then just for good measure we warn people about the mercury content of tuna (A medium risk fish).
Here is a thread on the impact of excess Omega 6 and a lack of Omega 3 on THE RISK OF BREAST CANCER and the situation is similar for PROSTATE CANCER.
http://her2support.org/vbulletin/showthread.php?t=24410
AND I have checked on Nutrition Data -
SPEECHLESS.
What a travesty at every level.
**!!!** ****!!!***!*!**!*!**!
Canned Tuna in Oil
100 gram serving drained
http://www.nutritiondata.com/facts/finfish-and-shellfish-products/4145/2
Total Omega-3 fatty acids
202
mg
Total Omega-6 fatty acids
2683
mg
Tuna now has a worse Omega 6 profile than breast and skin of industrial grain raised chicken.
Chicken breast with skin
http://www.nutritiondata.com/facts/poultry-products/696/2
Total Omega-3 fatty acids
120
mg
Total Omega-6 fatty acids
1740
mg
Tuna canned in water (drained) at least has a positive 3:6 balance
http://www.nutritiondata.com/facts/finfish-and-shellfish-products/4146/2
Total Omega-3 fatty acids
281
mg
Total Omega-6 fatty acids
9.0
mg
And fresh is better(depending on variety)
Skipjack
http://www.nutritiondata.com/facts/finfish-and-shellfish-products/4143/2
Total Omega-3 fatty acids
1298
mg
Total Omega-6 fatty acids
53.0
mg
Yellowfin
http://www.nutritiondata.com/facts/finfish-and-shellfish-products/4143/2
Total Omega-3 fatty acids
243
mg
Total Omega-6 fatty acids
8.0
mg
The Book
Getting back to the very useful paper in the book "Omega 3 fatty acid research" By M. C. Teale
They Anna Kolakowska, Zdzislaw Domiszewski and Grzegorz Bienkiewicz say:
Canning can reduce DHA by up to 40%.
Canning in oil can transfer a significant portion of Omega 3s to the oil ( which we often throw away, and most vegetable oils used will be high in Omega 6. - so only buy tuna in good quality olive oil and use the oil.)
Commercially caned tuna may have almost NO Omega 3, which is evidenced above.
In contrast sardines in olive oil may have as much as fresh fish, (presumably that included the oil.)
It is easiest if you read it yourself.
Author Omega Six The Devils Fat
www.OmegaSixTheDevilsFat.com
(Total rewrite with new material on the way)
Dietary Fats Omega-6 and Omega-3: Impact Your Inflammation Gene Machine
Attention to the background diet is often a missing design element in supplementation studies, which is necessary to observe consistent changes in cellular fatty acid distribution.
A tangential comment: don't you have the concept of single-blind trial backwards? In a single-blind study, it is the subjects who are unaware of which group they are in, not the researchers.
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