Transcript: Should We Take EPA and DHA Omega-3 For Our Heart?
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
According to two of perhaps the most credible nutrition authorities, the World Health Organization and the European Food Safety Authority, we should get at least a half a percent of our calories from the essential short-chain omega-3 ALA; which is easy—just like a tablespoon a day of chia seeds or ground flax seeds, and you’re all set.
Our body can then take the short-chain ALA from our diet, and elongate it into the long chain omega-3s, EPA and DHA. But, the question has long been, can our bodies make enough for optimal health? How would you determine that?
Take fiber, for example. A convincing body of literature showed an increased heart disease risk when diets were low in fiber. So, the Institute of Medicine came up with a recommendation for about 30 grams a day, which is an intake observed to protect against coronary heart disease and reduce constipation. Thus, just as cardiovascular disease was used to help establish an adequate intake for dietary fiber, it was used as a way to develop a recommendation for EPA and DHA.
So, with reviews published as late as 2009 suggesting fish oil capsules may help with heart disease, nutrition authorities recommended an additional 250mg a day of preformed EPA and DHA, since evidently we were not making enough on our own, if taking more helped. So, in addition to the one or two grams of ALA, it was suggested that we should take 250mg of preformed DHA/EPA, which can be gotten from fish, or algae.
Fish is a toughie, because, on one hand, fish has the preformed DHA and EPA. But, on the other hand, our oceans have become so polluted that fish may contain various pollutants, including dioxins, PCBs, pesticides like DDT, flame retardant chemicals and heavy metals—including mercury, lead, and cadmium—that can negatively affect human health.
This was an editorial comment on a recent study of women that found that dietary exposure to PCBs was associated with increased risk of stroke, and an almost three times higher risk of hemorrhagic stroke. Unless you live next to a toxic waste dump, the main source of exposure to PCBs is fish consumption—of which perhaps salmon is the worst, though PCBs can also be found in lesser quantities in other meat sources.
This may explain why studies in the U.S. have shown that just a single serving of fish a week may significantly increase one’s risk of diabetes, emphasizing that even levels of these pollutants once considered safe may completely counteract the potential benefits of the omega-3s and other nutrients present in fish, leading to the type of metabolic disturbances that often precede type 2 diabetes.
Now, one could get their 250mg a day from algae oil, rather than fish oil. Algae oil is free of toxic contaminants, because it never comes in contact with anything from the ocean.
Then, one could get the best of both worlds—the beneficial nutrients, without the harmful contaminants. But, recently, it was demonstrated that these long-chain omega-3s don’t seem to help with preventing or treating heart disease after all. And since that’s the main reason we thought people should get that extra 250mg of preformed EPA and DHA, why do I still recommend following the guidelines? Because the recommendations were not just based on heart health, but brain health as well. To be continued…
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