On Wednesday a new paper reported that higher levels of long-chain omega-3 fats (EPA, DPA, and DHA) in blood are associated with a 43% increased risk of prostate cancer and a 71% increased risk of aggressive prostate cancer. [1] This built on earlier work by the same group. [2] In a press release, the authors stated:
“We’ve shown once again that use of nutritional supplements may be harmful,” said Alan Kristal, Dr.P.H., the paper’s senior author …
“[W]e have confirmed that marine omega-3 fatty acids play a role in prostate cancer occurrence,” said corresponding author Theodore Brasky, Ph.D.
They sound confident! Is there anything to it, and should it affect our dietary advice?
Mechanisms Linking Omega-3 Fats to Cancer
In our book and on this blog, we’ve already discussed two mechanisms linking excessive omega-3 intake to cancer risk.
First, there is the issue of lipid peroxidation. Of all fatty acids, long-chain omega-3 fats are the most readily peroxidized:
Peroxidation of PUFA generates highly toxic compounds, such as aldehydes, which mutate DNA and turn proteins into advanced lipoxidation end products (ALEs). [3, 4] These lipid peroxidation products have been implicated as causal factors in cancer. [5]
Second, oxidation products of DHA promote angiogenesis – the creation of new blood vessels to feed tumors. These products make cancers grow rapidly. I’ve blogged about this (DHA and Angiogenesis: The Bottom Line, May 4, 2011; Omega-3s, Angiogenesis and Cancer: Part II, April 29, 2011; Omega-3 Fats, Angiogenesis, and Cancer: Part I, April 26, 2011).
So there are known mechanisms by which the long omega-3s in fish oil may promote cancer.
The Brasky et al Papers
The new study by Brasky et al measured omega-3 fat levels in plasma phospholipids. Thus, it doesn’t measure any omega-3s in cells, only omega-3s in serum particles like LDL, HDL, and VLDL; and even in those particles it excludes omega-3 fats found in triglycerides.
This is a very different biomarker than the Omega-3 Index of William Harris, which looks at the omega-3 phospholipids in red blood cell membranes. [6] This biomarker might behave quite differently than the Omega-3 Index.
The study measured plasma phospholipid omega-3s in a group of people, then followed them for 6 years or so to see who developed cancer. Here are the group averages [1]:
Statistically the most reliable data is in the no cancer vs total cancer comparison. There we find that subjects who went on to develop prostate cancer averaged 3% more DHA and 4% more EPA+DPA+DHA in plasma phospholipids than those who didn’t develop cancer.
Does This Variation Reflect Dietary Intake?
Chris Kresser kindly sent a link to an analysis of the study published at LecturePad by William Harris: “Omega-3 Fatty Acids and Risk for Prostate Cancer.” Harris tells us how to translate the plasma numbers to the corresponding Omega-3 Index numbers:
Based on experiments in our lab, the lowest quartile would correspond to an HS-Omega-3 Index of <3.16% and the highest to an Index of >4.77%).
Even the top quartile of the Brasky et al subjects had quite low omega-3 levels:
In Framingham, the mean Omega-3 Index of participants who were not taking fish oil supplements was 5.2% and for those taking supplements, it was 7.5% [7]. Both of these numbers are considerably higher than the values reported by Braskey et al., even in their highest quartile.
The trial asked its participants not to take supplements, and it looks like they drew a study population whose fish intake was much lower than that of Framingham, Massachusetts, residents.
If dietary omega-3 intake was low in all subjects and varied only slightly among participants, how do we know that this biomarker is related in any way to dietary intake? There could be other factors – genetics, oxidative environment, omega-6 fat intake, antioxidant intake, changes in the proportions of VLDL, LDL, and HDL, to name a few – that affect this biomarker.
Does High Dietary Intake Lead to More Cancer?
If high dietary intake of omega-3s caused more cancer, we would expect cultures that consume lots of fish oil to have higher prostate cancer rates. But epidemiological studies have found that high omega-3 intakes seem to be associated with low cancer rates. For instance, the Japanese eat eight times more omega-3 fatty acids than Americans and their blood levels are twice as high, yet the prostate cancer rates are only one-sixth the American rate.
Of course, there are many confounders in epidemiological studies. Harris helpfully provides a summary of clinical trials in which fish oil was provided as part of the study and cancer outcomes measured:
Although none of these studies produced a statistically significant link between omega-3 intake and cancer, incidence of cancer diagnosis or death was increased in every one of the clinical trials except the GISSI-Heart Failure study and perhaps the Origin study. A meta-analysis might find a small cancer promoting effect of omega-3s.
UPDATE: Vladimir Heiskanen points me to an interesting paper in which the effect of dietary fatty acids on cancer metastasis was examined. Colon carcinoma cells were injected into the portal vein (which leads from intestine to liver) of rats and 3 weeks later rats were sacrificed and their livers were examined for metastases. The rats were on three diets — low-fat, high omega-6 (safflower oil), high omega-3 (fish oil). The results:
At 3 weeks after tumor transplantation, the fish oil diet and the safflower oil diet had induced, respectively, 10- and 4-fold more metastases (number) and over 1000- and 500-fold more metastases (size) than were found in the livers of rats on the low-fat diet. [7]
I wish they’d used a saturated fat or monounsaturated fat diet, rather than a low-fat diet, as the control, as this would have clarified that polyunsaturates specifically promote metastasis; in the study the rats’ food was mixed with fish oil or safflower oil, greatly increasing the fat fraction and decreasing the carbohydrate, protein, and micronutrient fractions, so the control diet deviates in many respects from the high-PUFA diets. However, the results are consistent with the idea that fish oil is more cancer-promoting than the less peroxidizable safflower oil, perhaps because of the unique pro-angiogenic effects of DHA products.
Conclusion
There might be biological contexts in which omega-3 fats promote cancer.
This doesn’t mean we should refrain from eating omega-3 fats. Cardiovascular disease causes more deaths than cancer, and omega-3 fats are protective against CVD.
However, I think these studies support the PHD advice:
- Eat enough oily marine fish to achieve omega-6 and omega-3 balance;
- Minimize omega-6 intake so that omega-6 and omega-3 balance is achieved at the lowest possible intake of polyunsaturated fats.
All nutrients can be eaten in excess, and omega-3 fats surely fall into this category. The right amount of oily fish is probably about one to two meals per week.
References
[1] Brasky TM et al. Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial. J Natl Cancer Inst. 2013 Jul 10. [Epub ahead of print] http://pmid.us/23843441.
[2] Brasky TM et al. Serum phospholipid fatty acids and prostate cancer risk: results from the prostate cancer prevention trial. Am J Epidemiol. 2011 Jun 15;173(12):1429-39. http://pmid.us/21518693.
[3] Hulbert AJ et al. Life and death: metabolic rate, membrane composition, and life span of animals. Physiological Reviews 2007 Oct;87(4):1175–213, http://pmid.us/17928583.
[4] Hulbert AJ. Metabolism and longevity: is there a role for membrane fatty acids? Integretive and Comparative Biology 2010 Nov;50(5):808–17, http://pmid.us/21558243.
[5] Nair U, Bartsch H, Nair J. Lipid peroxidation-induced DNA damage in cancer-prone inflammatory diseases: a review of published adduct types and levels in humans. Free Radic Biol Med. 2007 Oct 15;43(8):1109-20. http://pmid.us/17854706.
[6] Harris WS, Von Schacky C. The Omega-3 Index: a new risk factor for death from coronary heart disease? Prev Med. 2004 Jul;39(1):212-20. http://pmid.us/15208005.
[7] Griffini P et al. Dietary omega-3 polyunsaturated fatty acids promote colon carcinoma metastasis in rat liver. Cancer Res. 1998 Aug 1;58(15):3312-9. http://pmid.us/9699661.
via this link:
I was looking at a recent few epidemiological papers on prostate cancer risk and diet, and there are no correlations with any fats. For example, http://www.ncbi.nlm.nih.gov/pubmed/9398038
“No association was found between energy-adjusted intake of total fat, saturated fat, mono-unsaturated fat or poly-unsaturated fat and the incidence of prostate cancer.
Significant positive associations were found for body mass index (BMI) and consumption of hamburgers/meatballs, while no association was found with consumption of frankfurters/sausages and a significant negative association with the weekly number of main meals with meat. A significantly increased risk of prostate cancer was associated with skim milk as compared to whole milk [I think this was by far the largest correlation in the study]. Milk preference (skim vs. whole) was associated significantly positively with BMI.”
Hi George,
There are a lot of papers with inconsistent results. I believe that polyunsaturates can promote cancer somewhat. The effect may be hard to detect in epidemiological studies.
Excellent and in-depth article.
Hi Paul-
If I remember correctly, in the book, you state that most fish oil supplements are rancid due to their exposure to heat. Is that a factor in these studies?
In the Brasky study they asked people not to take any supplements, including fish oil supplements, so I doubt that was a factor.
Thanks for sharing Paul.
Being a case control study, I’m surprised the authors had the cojones to say “[W]e have confirmed that marine omega-3 fatty acids play a role in prostate cancer occurrence”.
Pick a different set of controls or data-mine for other variables, and the statement could be quite different.
Also, I wonder how just much of a role the slow natural history of prostate cancer plays into this. Maybe a study could say “[W]e have confirmed that marine omega-3 fatty acids play a role in death in old age by natural causes”.
Of course, they only have cojones in the media, not in the paper. I wonder why academics think it’s OK to mislead the public. A certain contempt for the public, which is odd considering the public is the ultimate source of their funding.
It’s not surprising that Brasky et al would exaggerate, given their claims during SNL in the 90s…
http://www.veoh.com/watch/v16999067EdNYzmw8?h1=Bill+Brasky-Stock+Broker
I am a retired physician (horribly weak as a statistician) and unable to follow the stats. What I do know is that taking 4 capsules of fish oil a day has cut my PVCs from “constant” to “once in a blue moon”. I’ll take the rest of the risks. Then, I’m old.
TJ – would you mind emailing me at akman2012@live.com, I’d like to ask you a few questions about PVCs.
Thanks
As a long time PVC sufferer, I’d like to hear more about this.
Good points regarding dietary intake vs. supplementation Paul. In the study, they use geometric means, which is laudable given that the results are normalized. But the differences between means are so small that the only reason they are significant is the relatively large sample size. For example, .86 and .90 on the DPA row for NC and TC, respectively, yielding a P < .001. The effect sizes are minute. Ignoring effect sizes seems to be a statistical “trick” that is very commonly used in epidemiological studies.
Yes. In economics Dierdre McCloskey has often made the point that “statistically significant” and “significant” are two totally distinct concepts.
An old boss of mine wrote this cool paper on p-values and Bayesian stats. There don’t seem to be many papers that take a nuanced view of their results in the discussion though.
http://annals.org/article.aspx?articleid=712762
Paul – Is there anything in the study (flaws and all) that says what n3:n6 ratio is predictive of cancer?
You say, “•Eat enough oily marine fish to achieve omega-6 and omega-3 balance” Is there any way to determine this ratio without periodic testing? I have yet to find a doc who will order these labs and I have heard that mail-order labs have a huge margin-of-error in this lab.
Thanks for the timely review of this alarmist study!
Hi tater, one to two meals of fatty fish a week should achieve balance.
What’s your thought on cod liver oil then because by nature it doesn’t have a lot of the omega 3 fats if you were to take a tsp a day. Of course you’d be getting a decent dose of vitamin A and other co-factors <— especially important if you can't tolerate liver.
Also, would you say there is a higher chance of fish oils in capsules to be less rancid than eating whole fish?
I also wanted to comment there hasn’t been much said on the levels of fat soluble vitamins in the study. I’m sure vitamin D and K2 sufficiency would lower the rate of aggressive prostate cancers. It’s probably why Japanese people can eat so much fish and get the benefits of consuming natto.
Hi Paul,
Interesting post. One point in your conclusion stood out against some data I’m trying to reconcile. Specifically that CHD is rapidly trending to zero:
http://qjmed.oxfordjournals.org/content/105/6/509.full.pdf+html
Interested in your thoughts on this.
Kevin
Hi Kevin, That’s a good paper, and I basically agree with its main points. It seems that coronary heart disease, and cardiovascular disease generally, is a chronic infectious disease caused by microbes that had previously been more virulent and generated fatal acute diseases, but by the 20th century began to generate chronic milder disease.
I don’t think CVD is going to zero because I think microbes are still evolving for more virulent chronic infections. But it may take decades before we start to see a rise in CVD mortality.
Omega-6/omega-3 imbalances distort immune function so the infectious disease explanation is not inconsistent with omega-3 fats having a protective effect.
Thanks Paul, so root cause is microbial but diet can be protective. However, the CHD rate is rapidly decreasing irrespective (or perhaps despite of) diet.
This may suggest dietary focus on cancer protection as optimal (per your post http://perfecthealthdiet.com/2011/09/an-anti-cancer-diet/)
Kevin
Isn’t it possible that the CHD death rate trend over the years (graph on page 510) can be partially explained by the use of hydrogenated vegetable oils (aka trans fats)? Crisco was brought to market in 1911 and margarine use spiked during WWII(at least in the US) as butter was rationed. This lines up pretty well with increasing portion of the graph. On the other hand, trans fat use did not start declining until after 1990 so this does not directly explain the CHD death rate decrease beginning in 1970. But it certainly could have been a contributing factor.
Hi Paul,
I’m concerned about the “single avenue thinking” aspect of this study. There’s a lot more to life than Prostate Cancer (PCa). It’s similar thinking by dermatologists that have resulted in an “epidemic” of Vitamin D insufficiency/deficiency.
There are mental health benefits from eating oily fish, as per http://www.ncbi.nlm.nih.gov/pmc/articles/PMC533861/
There are cardiac health benefits from eating oily fish, as per http://www.ncbi.nlm.nih.gov/pmc/articles/PMC99405/ I’m not convinced by Dr Grimes’ extrapolation of CHD mortality data, linked in Kevin’s comment.
Having had prostatitis (now O.K.), I feel that n-3 fats’ anti-inflammatory effects are more important than a slight increase in the risk factor of getting PCa.
Cheers, Nige
Hi Nigel,
Yes, one negative effect, even if it should be validated, doesn’t eliminate other positive effects. It does direct our attention toward the context of the rest of the diet, to see how we can enjoy the positive effects of omega-3 without getting the negatives.
Hi Paul,
Your Spam filter appears to allow no more than 1 link per comment. Can you retrieve the following comment from it? http://perfecthealthdiet.com/2013/07/omega-3-fats-and-cancer/comment-page-1/#comment-205138 You can then delete this comment.
Cheers, Nige
No way am I ditching my daily can of salmon with bones or sardines with bones. These foods give me calcium and are convenient sources of protein. Ok ok — I also think they taste great. 🙂
thanks for a level headed analysis.
i agree with Kamal. XD
do you know how long the study is?
regards,
It went about 6 years.
This was a case-cohort study, so it’s impossible to establish causality.
There was no dose response, so the high omega-3 levels were probably a consequence of people with enlarged prostate taking fish oil supplements.
This is an example of good science ruined by the overreach in the conclusion, and showboating on the part of the authors.
Would you please email me the link to the studies that document the statement that you have made about high doses of Tuna supplements and prostate cancer.
Thanks so much,
Frank Wolfe
The difference in the low and high omega 3 groups was the difference between 1 or 2 servings of fish per week, according to the study–how that translates into ‘fish oil supplements are bad’ is beyond me. Maybe the guys with higher levels ate a lot of breaded and deep fried fish, or lots of flax seed.
I don’t get it. Chemistry is very confusing to me, and in this article I can’t even see what the bottom line is. The study is wrong? They didn’t take into account the way omega-3’s interact with certain underlying health situations related to various dietary habits? They didn’t consider the ratio of 3s to 6s?
Hi S, The bottom line is we don’t know. There are known mechanisms by which omega-3s might promote cancer but also known mechanisms by which they might suppress it. It is likely that omega-3s can either promote or suppress cancer depending on the context of the rest of the diet and the infectious disease burden. Which way it more commonly goes is an empirical question and we have dueling studies on that point. The weight of the evidence may slightly favor an increased cancer risk, at least in older people eating SAD, but there is similar evidence that it reduces cardiovascular disease (also not entirely certain), so omega-3s may reduce total mortality. Another bottom line is, biology is complex. They didn’t have dietary data, only serum phospholipid data at the time of enrollment in the study, so though they considered the ratio of omega-3 to omega-6 in serum, they didn’t consider dietary ratios.
Okay. That helps. So they didn’t consider pre-existing dietary habits? And did they even neglect dietary habits the participants followed throughout the study?
Wow…that might be the most rational concise comment made on the internet this year. This type of even handed thinking that doesn’t rush to protect whatever diet dogma de jour has allowed me to truly invest in PHD as the best diet science has to offer in 2013.
Great post/comments Paul – well said Evan. What sets Paul’s work (and some of the other smarties in the Ancestral Health/etc community) is a more solid epistemology to build upon. It involves saying “we don’t know” when we don’t know and then seeking firmer grounds for best guesses and building from there.
E.g. Science hypothesizes that cholesterol/saturated fat are bad for you, but has very weak evidence for hypothesis. On other hand, human breast milk has a lot of Cholesterol/saturated fat.
The burden of proof is on the new hypothesis to show very, very strong evidence before we withhold breast milk from babies and put little kids on statins.
We don’t have perfect conclusive knowledge/evidence either way. BUT, in the face of ignorance, not all hypotheses are of equal weight.
I think that is something of immense value we get from the paleo/primal/PHD/Ancestral perspectives: a proper epistemology with which to admit ignorance, analyze/organize our assumptions, build a foundational framework, and begin to sort through and evaluate data from modern science. As Paul pointed out (somewhere), you’ll never be able to read all the scientific studies and thus disprove every errant hypothesis. You have to start with a rational foundation and build up.
http://www.wellnessresources.com/health/articles/fish_oil_prostate_cancer/
The other point of view: fraud.
Byron went into it in the 4/17 weekly health podcast too around 20 min: http://www.wellnessresources.com/audio/podcast/2013/podcast_071713.mp3
I think studies like this where there iss no direct correlation between omega 3 and cancer do more harm than good. The benefits of fish oil far outweigh the risks. This article proves my point – http://www.topfishoilbenefits.com/fish-oil-benefits/
I think the key word here is supplement. It would no doubt be a better practice to include clean foods that contain omega 3 as opposed to manufactured pills.
I think the subjects from the clinical studies were getting their omega 3 from fish, not supplements.
It’s a little hard to reconcile with the Inuit people who arguably have the highest fish consumption in the world and virtually no cancer on their native diet.
It seems the key point here is that the study measured plasma phospholipid omega-3 levels but did not measure ingestion of omega-3s. It’s possible that the observed plasma phospholipid omega-3 levels in this study have no connection to omega-3 dietary intake and have everything to do with how the body distributes and retains omega-3s under various conditions (including the presence of cancer-causing agents).
Thank you for sharing Paul, very excellent information.
what is the maximum level of DHA in supplement form do you consider safe? Or at what level do you feel that the benefits outweigh any potential risks?
Testing, testing.
I left 2 comments to this post. Neither of them appeared.
Cheers, Nige
Out of the spam filter now. Sorry about that Nigel.
Thanks, Paul! I’ll restrict the number of links in future comments to 1.
Dr.mercola just wrote an article on this study which seems to pretty thoroughly refute it – http://articles.mercola.com/sites/articles/archive/2013/07/31/omega-3-fats.aspx?e_cid=20130731_DNL_art_1&utm_source=dnl&utm_medium=email&utm_content=art1&utm_campaign=20130731
What do you think paul?
“…omega-3 fats are protective against CVD.”
Is absolutely certain? Brian Peskin is vehemently against supplementing with fish oil, claiming that they are deleterious for our health.
Here’s another piece of info. http://www.highbeam.com/doc/1P2-1577846.html:
“The finding, from a study of 200 patients with implanted defibrillators that shock the heart back to a normal rhythm, surprised researchers who expected to find that fish oil guards against rhythm abnormalities in patients who need protection most.
… Four previous studies have shown that fish oils cut the risk of fatal heart rhythm problems, called arrhythmias, in patients who had had standard heart attacks.
…The research team chose to test fish oil in patients who were prone to arrhythmias because any benefits probably would be obvious and apply to a lot of people. About 150,000 people each year receive implanted defibrillators.
“Our initial thought was that this was a great population in which to show that fish oil is anti-arrhythmic,” says study leader Merritt Raitt of the Portland VA Medical Center. His team’s report appears in today’s Journal of the American Medical Association.
The research was carried out at six major medical centers from 1999 to 2003. Half of the patients were given fish oil. The rest were given olive oil, a placebo.
Researchers found that 65 percent of the patients who took fish oil supplements developed rhythm disturbances over the next six months, compared with 36 percent of those in the placebo group.”
http://hopefulgeranium.blogspot.com/2013/08/linoleic-acid-omega-6-pufa-promotes.html?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+TheHigh-fatHepCDietBlog+%28The+High-fat+Hep+C+Diet+Blog%29
From the hep c diet blog. About high PUFA diets etc.
Try the Naturally Splendid’s omega rich plant based product line. Great natural source of omega 3s.
Nick, most plant-based sources of omega-3s lack DHA and EPA, and the human body is inefficient at producing them from a-linolenic acid (ALA).
Roger, Brian Peskin states that the human body produces enough DHA and EPA when it needs it, provided that it is supplied enough *fresh* “parent EFAs”.
The question is really if omega-3 fatty acids «work» only because they reduce inflammation. Because if that´s the case, then other strategies could be implemented instead, such as supplementing with anti-inflammatory spices like especially turmeric, and also ginger, thyme, garlic, maybe vitamin D etc. Even aspirin may be a better option.
The problem is also that excessive intake of these fragile unsaturated fatty acids is that they could oxidize and that itself could cause inflammation and accelerate the ageing process (and promote cancer) and thus cause the very problems they are supposed to fix.
Now if N3 is supplemented in smaller quantities together with liberal use of natural antioxidants, then there could probably be a benefit (the body needs small quantities of especially DHA), but if large quantities of N3 without these antioxidants are used, perhaps the problem worsens, the oxidative process gets out of control. As people gets older they also produce less of their own antioxidants, again worsening the problem with excess omega-3.
I like to think that high fish consumption is associated with a healthier diet with less sugar, more antioxidant rich plant foods and even less smoking. So studies of healthy populations eating lots of fish should not automatically be translated into omega-3 in itself in the form of some capsule filled with rancid fish oil being beneficial.
At the same time it is possible that some people with poor diets try as a quick solution to supplement rancid fish oil capsules and vitamin tablets as an alternative to getting their diet and lifestyle in order. Now what would the effect be for an individual eating a refined diet with lots of refined rancid and deodorized vegetable oils, a diet stripped of antioxidants, will this individual experience any «improvements» by adding omega-3 supplements to «balance» the omega-6 in the vegetable oils? I am not so sure.
Perhaps it is also worth pointing out that arachidonic acid (AA) is the major fatty acid for land animals, especially humans. Even grass fed animals would as a whole end up with more AA than DHA in their bodies and also their milk have more AA than DHA (unless they are fed fish meal – very unnatural for these animals), even as grass has 4 times more omega-3 (LNA) than omega-6 (LA). An analysis of meat of wild squirrel suggest 40 times more LA than LNA in their meat, for boar 20 times more LA than LNA. And yet these animals have well functioning eyes and brain that has DHA in it. They preserve the DHA very well.
I do not eat much fish since my family won’t touch it so I take Barlean’s Fish oil each day. It is a liquid so I know it is fresh, I order it direct and keep it refrigerated. I take a tsp. each day. Is this okay? My husband is a vegan (I know, I have tried to convince him of his mistakes. He is a very intelligent dentist but won’t budge)and takes about 3 TBSP of ground flaxseed a day in orange juice. He has an enlarged prostate but his numbers are fine. Is this safe for him? He says he feels better since he started taking it. He started eating chicken twice a week (finally!) but just read an article saying you should not eat chicken to avoid prostate cancer (written by a Harvard oncologist). He wants to avoid Prostate cancer. I have convinced him to stop eating wheat and many grains, but his phobia of meats and eggs is huge. He feels better since going vegan, but he has the emaciated vegan look even though he works out daily. (self-cannibalism?)Being vegan for 2 years has not eliminated the BPH or improved his interstitial cystitis. Any advice? ❓
Great article. One question, if a non-food supplement were chosen to balance omega 3 intake, in capsule form, which would you recommend?
How about liquid refrigerated cod liver oil? Why capsules?
Very thorough analysis of some overstated claims. However, I wonder why you conclude that “[t]he right amount of oily fish is probably about one to two meals per week,” given the high intake of fatty fish yet low cancer rate of the Japanese?
Hi everybody!
I had a revelation today. (I suppose this should be “a given” for knowledgeable people though?)
Isn´t the per oxidative qualities of PUFAs mostly the effect that we need from them. And isn´t the pro inflammatory property one of the most important roles of omega-6 fatty acids? As the anti inflammatory property is an important function of the omega-3 FAs?
Do the omega-3s achieve their anti inflammatory effect through per oxidation? I mean that if the per oxidation is only the mechanism for communication between cells? I guess this sounds counter intuitive, but I´m just wondering.
I mean that of course the properties, like high per oxidation and pro inflammation, must be just as wanted effects per say as the stability of SAFAs but they must be in the right proportions.
Sakari, it took me a while do understand that by “per oxidation” you meant peroxidation. Please don’t split the word into two.
Sorry. My bad 😳
Hi again!
I assume that high supplementation of omega-3 in order to balance out the omega-6 would have some negative effects since the amount of the omega-6 that we are trying to match is pretty stupendous.
Two wrongs won’t make one right. Right?
We must lower the intake of omega-6s and a lot!
Hi Paul,
I wanted to thank you for writing in your book about the beginning toxicity level of “3 grams long-chain omega-3s per day”. I had never heard of that prior.
Like everyone else who eventually found you, I am the type of personality who has always read (and tried) everything (ironically, to be “healthy).
In my case, it wasn’t so much the weight loss gurus as the performance oriented systems and advice I sought out. Many of these books, systems, and/or advice told me to take large amounts of omega 3, which lead me to bruise quite easily.
In in effort to be healthy without the bruising, I lowered the dose a few years ago to two “triple strength” capsules daily (each capsule supplying 950mg omega-3 as “Ethyl Esters” and 869mg of DHA/EPA. Daily DHA/EPA total from capsules 1,738mg). I keep them in the freezer originally to prevent dreaded “fish burps” but in hindsight, I guess a good side effect was the lessening of the chance they would become rancid.
I have enjoyed a good HDL to LDL ratio, low Triglycerides, and great BP which at this point (years) I attribute, at least partially, to the fish oil. However, I do not want to risk prostate cancer, so it looks as if I’ll begrudgingly give up my capsules in favor of 1 pound a week of salmon (for the 1.5g/day average).
This recommendation still stands, correct?
By the way, I feel like a horrible parent since we have had my 5 year old taking a DHA gummy supplement twice daily for some time.
Sorry, one more follow up:
I looked up Atlantic farmed salmon on http://nutritiondata.self.com/facts/finfish-and-shellfish-products/4259/2 and it says 1oz has 633mg omega 3.
So, a 4.7oz serving would equal the 3g omega-3 toxicity threshold. Assuming I am trying to get 1 pound weekly, is it better to eat a 2.4oz (1.5g omega-3 serving daily versus eating fish 1-2/week which would put my over the daily 3g limit?
There is no daily limit, only an average daily level that can be harmful. Go ahead and eat fish once a week in the appropriate amount.
Perfect, thank you! I was thinking what a pain that was going to be:)
Does anyone have a method to extrapolate the blood serum levels of Omega-3 and Omega-6 found in a test like MetaMetrix ION panel to the approximate implied daily intake in one’s diet?
Having to reverse engineer total O3 and O6 food intakes from breakdown of every food you eat is extremely tedious and time consuming. It’s also not necessarily accurate since it doesn’t show absorption of those fats.
I read that all fish has plastic “molecules” in tissue. What to do? I have decided not to eat any fish.
In the book page 128 there’s the table showing us optimal ratio 1:3 omega-6 to omega-3, 4.8g LA to 1.8 EPA + DPA + DHA. Isn’t it a mistake? Because 4.8:1.8 != 1:3. Also, how we can achieve balance eating 3 egg yolks (2g omega-6) plus 0.6 omega-6 from 1lb salmon and only 1.8g omega-3. It seems like 2.6:1.8 ratio, far from ideal 1:3 ratio. One would wonder, if it might be more beneficial to remove egg yolks and take choline and other egg yolk nutrients as supplements without omega-6 burden? Thank you
Hi Denis,
The proper dietary ratio of omega-6 to omega-3 is 3:1, 3 g omega-6 to 1 g omega-3. The proper tissue ratio (usually measured by the lipid content of red blood cell membranes) is about 28% omega-6 to 72% omega-3. These ratios are not the same because they are measuring different things.
Best, Paul
Hello Paul!
What do you think, is 5-6 gram of daily intake EPA+DHA is too much which is just from mackerel and cod liver? Even if the all PUFA intake is below 3,5% of the daily calorie and the omega6:omega3 ratio is about 1,5:1? The increased amount is beacuse of the intense resistance training and beacuse of the increased daily stress.