Twitter is a black hole for time spitting out information like Hawking radiation. (I may have achieved the geekiest simile ever!) I've been a bit busy, as the applications for preschool are pretty detailed, asking for medical records, descriptions of my culture, and different ways we help the little one settle down or take her nap (bribery and threats, mostly. Oh, wait, the correct answer is "routine.") And sure, she's allergic to sunscreen. Well, with all that going on the blogging and reading has gone by the wayside a little. Also, most papers come out as a preview in the last week of the month, so there tends to be a rush of exciting new information all at once. Then a dry spell. If I'm fired up, I'll actually look into a topic in depth and do a nearly proper literature review. But not having had the time to do that... there's always twitter (and Jamie Scott, who is sending me a slew of papers about mitochondria, histamine, and sleep because he is awesome that way. I'm hoping to settle down and look at them sometime over the next couple of weeks).
Twitter! The be-ripped Martin Berkhan tweeted up a paper earlier today that is a new review of Omega 3s and 6s. The article, Evolutionary Aspects of Diet: The Omega-6/Omega-3 Ratio and the Brain, is a tidy look at omega-3 and omega -6 biochemistry detailing all the conversions and enzymes along the way for the biochem geeks. In the end, it describes the more interesting stuff about the evidence that omega 3s, in fact, do have an important role in the brain, and that one would be a sad and foolish monkey indeed to consume the modern 25:1 6:3 ratio (just say no to corn and safflower and soybean oil...) Another interesting fact - the review is written by Artemis P Simopoulos, who pretty much first popularized the Mediterranean diet with her book The Omega Diet: The Lifesaving Nutritional Program Based on the Diet of the Island of Crete. Guess she knows what she's talking about with respect to the omegas.
Let's dig in. Hmmm... "psychologic stress in humans induces the production of pro-inflammatory cytokines such as IFN gamma, TNF alpha, IL-6, and IL-1." Yup. Too much omega-6 compared to omega 3 can lead to the overproduction of inflammatory cytokines, which for various reasons is Not Good. Theoretically, changes in PUFA ratios can alter the function and structure of the serotonin receptors (for example, essential fatty acids in the plasma predict the CSF metabolites of serotonin and dopamine)(1). Treatment with DHA and EPA can be useful in major depressive disorder and bipolar disorder. Other researchers note that as the dietary ratio of omega-6/omega-3 increases, depression symptoms, TNF-alpha, IL-6, and the IL-6 soluble receptor increases. Another group studied brains of people suffering from depression when they died vs. controls. A decrease in AA/DHA ratios were negatively correlated with age in depressed people, but not in controls. All these lines of evidence, including the randomized controlled trials of omega-3 supplementation, seem to support the idea that our brain needs omega-3s to work well and keep the mood stable.
Now onto the studies of cognition and omega-3 PUFAs. Turns out that when the neurons are stimulated with neurotransmitters, the PUFAs in the cell membrane can be released to become all sorts of different inflammatory and anti-inflammatory or signaling molecules. The PUFAs also seem to influence cell migration and cell self-destruction (called apoptosis) - they even influence the length of telomeres, which are known to decrease with age, cancer, and cardiovascular disease. A lot of neurochemistry has been elucidated in this area - the details are nicely summarized by Simopolous. Suffice it to say that brain inflammation is part of the pathology of schizophrenia, dementia, and likely autism, and that omega 6/3 ratios could be important, and omega 3 supplementation (if done early on), can possibly be helpful. There is some controversy as to the best ratio with which to supplement (2:1 EPA to DHA is recommended by Simopolous), and in these unknowns I prefer to fall back to the primary sources - fatty fish themselves.
A study of prisoners showed many violent incarcerated young folks have deficiency ("0% intake") in omega 3 fatty acids from fish and selenium in the Table 5 of the paper, called "Diet of disaffection: nutrient intakes from a sample of disadvantaged young people." Only 17% of them get adequate intake of magnesium too. Interesting.
When one looks at studies of substance abusers, one also finds deficiencies of omega 3s. Alcoholics, for example, are a known population rife with nutrient deficiencies (a med school professor used to call it the BBB diet - "beer, bread, and bologna.") A group of researchers carried out a small double-blind randomized controlled trial of 3g EPA and DHA vs soybean oil control in substance abusers. After three months, the treatment arm had significantly reduced feelings of anger, anxiety, and cravings. The increase in plasma EPA strongly correlated with the reduced anxiety, and the effects persisted for 3 months after the end of the treatment.
Putting it all together - the overall evidence suggests that if you want to be anxious, moody, depressed, violent, and craving addictive substances, by all means slurp down those omega 6 PUFAs. If you want more control over your brain and urges, maybe look into avoiding any extra 6 (the animal fats will have all that is necessary) and be sure to get the omega 3s you need via fish a few times a week or properly sourced beef or other grassfed ruminant meat. This brain chemistry thing ain't so hard after all.