Be sure to listen to this interview if you take DHA/Omega 3 supplements or are considering doing so. Also read Dr. Fuhrman's description below of the dangerous trial-and-error method of discovering supplements thought to be helpful can turn out to be quite harmful.
The talk is below is a link to a recent 11-minute interview with the lead researcher on the new DHA study that showed those with higher blood levels of DHA had a whopping 70% higher risk of aggressive prostate cancer.
This fellow has been at this research for 25 years. If you are taking or considering DHA supplements, from fish oil or the vegan kind, you should definitely take note. It appears that excess DHA above what you consume may crowd out other nutrients and set the stage for serious, lethal disease. Here is the interview:
The interview has some bad news not only for taking Omega 3 pills, but for a variety of other supplements. Bottom line: supplement at your own risk, and the risk is considerable.
You should also check out this letter from some of the biggest hitters in Cancer Prevention, published in the British Journal of Nutrition, late last year. In it, the researchers very seriously call into question the idea of supplementing with these DHA/EPA fish oil type supplements, and that increasing food or supplements that raise blood levels of DHA can not be seen as uniformly safe -- there are risks to trying to raise your DHA levels. See:
I also want to bring attention to an interesting piece by Dr. Joel Fuhrman about the hazards of supplements and how theories about supplements may sound reasonable at first -- but often they turn out to be wrong and have deadly consequences for those who took the supplements.
Disclaimer: As a vegan for 18 years and veg for 23, I personally only take B-12 and otherwise stay away from the supplement aisle.
In the excerpt below from his site, Dr. Fhurman talks about beta-cartone (Vitamin A). The story he tells is a story which is increasingly showing up for a number of other vitamins and supplements. Something that may be found to be low in the blood of unhealthy people -- when you try to raise that level in a healthy person with a pill, generally it doesn't promote health but in more and more cases it can actually promote cancer the subject would not otherwise have gotten if they hadn't taken the pills.
Quoting from Dr. Fuhrman:
"Why did researchers think that beta-carotene (Vitamin A) had such a powerful anti-cancer effect? They had found that populations with high levels of beta-carotene in their bloodstream had exceedingly low rates of cancer. Recently, it was discovered that the reason these people were protected against cancer was because of hundreds of carotenoids and phytochemicals in the fruits and vegetables they were consuming. It wasn't that beta-carotene alone was responsible for the benefit; it was merely that it had served as a flag or marker for those populations with a high fruit and vegetable intake. Unfortunately, many scientists confused the flag for the ship.
"In Finnish trials, those using beta-carotene supplements failed to prevent lung cancer, and there was actually an increase in cancer in those who took the supplement. 2 This study was halted when the physician researchers discovered the death rate from lung cancer was 28 percent higher among participants who had taken the high amounts of beta-carotene and vitamin A. Furthermore, the death rate from heart disease was 17 percent higher in those who had taken the supplements compared to those just given a placebo. 3 Another recent study showed similar results, correlating beta-carotene supplementation with an increased occurrence of prostate cancer.
"As a result of these European studies, as well as similar studies conducted here in the United States, 4 articles in the Journal of the National Cancer Institute, 5 the Lancet, 6 and the New England Journal of Medicine all advise people to stop taking beta-carotene supplements.
"How have supplement manufacturers responded? As a result of these studies, I expected many manufacturers to drop beta-carotene from their vitamins and substitute plant-derived carotenoids, but it never happened."
- - - end of excerpt from http://www.diseaseproof.com/archives/supplements-dr-fuhrman-discusses-vitamins-and-supplements.html
This is the same progression for recent studies on DHA/omega 3. The most common form is from fish oil, which experts are now advising people to avoid or minimize. But just like Vitamin A, sellers of DHA pills show no signs of slowing down or dropping a potentially problematic substance. Some vegan supplement sellers say it is probably the fish origin, and not the higher DHA levels, that is causing the cancer. But there is currently no research to back that up, so you have to take it on faith.
If you are vegan and believe you have "low" DHA/omega 3 levels, are you actually at any increased risk of disease? Studies of people eating the SAD with low DHA levels may have increased risks of some chronic illnesses if they have low DHA. But what about people who have switched to a plant-based diet?
Well actually this question was looked at in a study in 2009:
A review of "DHA status in vegetarians" noted that "Dietary analyses show that vegan diets are devoid of DHA and vegetarian diets that included dairy food and eggs only provide about 0.02 g DHA/d." It went through all of the presumptive problems in bioconversion, and the resulting low levels of DHA observed in body fluids of average veg(etari)ans, but still concluded that: "There is no evidence of adverse effects on health or cognitive function with lower DHA intake in vegetarians. " It also stated, "In the absence of convincing evidence for the deleterious effects resulting from the lack of DHA from the diet of vegetarians, it must be concluded that needs for omega-3 fatty acids can be met by dietary ALA. "
Sanders TA. DHA status of vegetarians. Prostaglandins Leukot Essent Fatty Acids. 2009 Aug-Sep;81(2-3):137-41. Epub 2009 Jun 4. Review. PubMed PMID: 19500961.
Most important, there have been zero studies showing that supplementing with DHA -- whether from fish oil or vegan sources -- confers any actual health benefit, or that raising your blood levels of DHA through supplementation does anything actually health-promoting. Again, I am talking about research, not hyperbole, puffery or conjecture.
So if there's no proven benefit, but it is shown an elevated DHA may seriously increase your cancer risk, why would anyone do it?
Perhaps a low DHA level in people eating a SAD is simply a flag for something bigger, as Dr. Fuhrman noted a low beta-cartone level turned out to be. More likely, if you are eating a healthy diet like Fuhrman and McDougall teach, you simply don't need to obsess about your omega-3's to the point of taking expensive supplements. To repeat: the study above notes that expected low levels of omega-3's in the blood of vegetarians and vegans didn't actually translate to any health problems in the real world.
In any event, all of this is probably why experts like Neal Barnard MD (expert on Alzheimer's), John McDougall MD, Caldwell Esselstyn MD, Jeff Novick MS RD and others are opposed to DHA pills and many other supplements. Don't be scaremongered into doing something potentially risky, without at least some research to back up potential benefits against known risks of any pills you may take.