fish oil improves working memory in healthy young adults

Omega-3′s, especially DHA research, just keeps confirming what our grandmother’s said about fish being ‘brain food’. Research headed by Rajesh Narendran at the University of Pittsburgh was published in the on line journal PLOS one in early October 2012, (you can read the rather technically written abstract here). This clinical trial tested working memory in 11 young men and women between the ages of 18 and 25, before and after 6 months of supplementation with 930 mg of EPA and 750 mg DHA per day.

Working memory is the memory that we use to hold a number of different tasks in mind–such as when we ask our kids to ‘go upstairs, put on your pajamas, wash your face, brush your teeth, then get get a book, get in bed, and then I’ll come up and read to you”. Until this becomes a routine, it requires working memory to keep all those steps in mind. We need it a lot working with computers, to follow a set of complex sequential tasks–the better our working memory, the less often we have to refer back to the directions.

There were a number of very surprising things about this study. First, they found that baseline working memory correlated rather well with the level of DHA found in each participant’s red blood cell membranes (a convenient place to test, since DHA and EPA are taken up in cell membranes). Further, at the end of the study, all 11 subjects had an improvement in working memory, which again correlated with the increase in DHA content of their red blood cell membranes.Researchers were a bit disappointed that the sophisticated brain imaging that they also did could not discern the mechanism by which this improvement in working memory occurred.

Researcher Bita Moghaddam commented “Before seeing this data, I would have said it was impossible to move young healthy individuals above their cognitive best. We found that members of this population can enhance their working memory performance even further, despite their already being at the top of their cognitive game.” Coauthor Matthew Muldoon noted “So many of the previous studies have been done with the elderly or people with medical conditions, leaving this unique population of young adults unaddressed. But what about our highest-functioning periods? Can we help the brain achieve its full potential by adapting our healthy behaviors in our young adult life? We found that we absolutely can.”

These levels of EPA and DHA can be achieved with 2 capsules of any high quality fish oil that is concentrated to at least 2/3 EPA+DHA (standard fish oil is 1/3 EPA+DHA). Be sure that it is from small ocean fish, such as sardines, which have lower levels of environmental contaminants to begin with, is protected from oxidation during processing, which should include molecular distillation to remove residual contaminants such as PCBs, and dioxins, and is preserved with potent antioxidants. So if you or your kids want to do well in school, 2 capsules a day of high quality fish oil appears to definitely provide a benefit.

fish, mercury, omega 3s, and heart disease

An intriguing new study published in the American Journal of Clinical Nutrition, took a look at fish consumption, mercury levels, and blood levels of long chain omega 3 fatty acids from fish, in relationship to heart disease in Scandanavian men. You can read the abstract (and the full paper) here . Basically what they found was that eating more fish raised both blood levels of EPA and DHA, but also increased measured mercury levels. Those with the highest levels of omega-3s and the lowest levels of mercury, compared with those with the highest mercury levels and lowest levels of omega-3s had a greater than 3 fold difference in diagnosis of heart and vascular disease. The authors noted: “Our model indicated that even a small change in fish consumption (ie, by increasing S-PUFA by 1%–blood levels of EPA+DHA–) would prevent 7% of MIs (heart attacks), despite a small increase in mercury exposure. However, at a high hair-mercury content, the modeled beneficial effect of PUFA on MI risk was counteracted by methylmercury.”

Although not stated in the paper, it still seems to me like the safest way to get your EPA and DHA is from high quality fish oils–those that have been molecularly distilled to remove environmental contaminants, such as PCBs and dioxins–mercury is never an issue, even in low quality fish oils, as it stays in the fish protein, and does not come out in the oil. But many low quality fish oils are also oxidized (rancid), which can increase oxidative stress in the body significantly. As noted in a recent post about the meta-analysis (desk research) which stated that fish oils supplements were of ‘no value’–see that post for all the reasons that this was a very poor ‘study of studies’–not the least of which reasons is that many of those studies used over the counter fish oils and didn’t analyze them for content, rancidity, or toxins. Not all fish oils are created equal. When you do eat fish, choose small fish, like sardines, herring (pickled is fine if you like them), anchovies, mackerel. And NEVER farmed fish–unless the are certified organic, with a natural food chain established, rather then feeding them pellets of grain (which are often GMO corn and soy). Virtually all tilapia (a marketing term for perch) are farm raised, and their fatty acid profile is closer to that of bacon than to that of fish. Caveat Emptor!

Omega-3 Kills Cancer Cells

Medical News today reported the results of a study showing DHA’s role in reducing tumor size:

Docosahexanoic acid (DHA), an omega-3 fatty acid found in fish oils, has been shown to reduce the size of tumours and enhance the positive effects of the chemotherapy drug cisplatin, while limiting its harmful side effects.

Ever since a case report was published in the journal Nutrition and Cancer in 2005 in which an elderly man with a large and inoperable lung sarcoma went into complete remission with high dose fish oils, predominantly DHA, I’ve been emphasizing DHA (and vitamin D) in my nutritional recommendations for people facing cancer challenges.

In the case report, the intake of EPA+DHA was in the range of 15-18 grams per day, about the amount that the Innuit on their traditional diet of seal, fish, and whale blubber used to consume. That’s a lot of omega 3, and should be supervised by a nutritionally knowledgeable physician, but even 4-6 grams per day, especially with a high DHA product can be a big help.