This month in the Nutrition Journal, researchers published a randomized controlled trial entitled “Restriction of Meat, Fish, and Poultry in Omnivores Improves Mood.” An earlier cross-sectional study (which I detailed in my 3-minute video Plant-based Diet & Mood) found that vegetarians reported better mood than omnivores, but without doing an interventional study, you never know which came firstómaybe they were eating healthier because they felt better, rather than the other way around. And so researchers randomized omnivores into three groups: a control group (eating their regular diets), a fish group (eating fish but no other meat), and a vegetarian diet without eggs. I detail the results in my NutritionFacts.org video pick shown above.
The reason the researchers had the vegetarian group avoid eggs is because they think it may be the arachidonic acid in animal products that’s to blame for the brain inflammation implicated in the mood disturbances found in omnivores. Arachidonic acid is a long-chain omega-6 fatty acid that produces inflammatory compounds in the body, and the top sources in the American diet are chicken and eggs (see my 1-minute video Chicken, eggs, and inflammation). In fact, the egg industry is trying to make eggs less pro-inflammatory by feeding hens blubber from the Canadian harp seal hunt. You have to see it to believe it: watch my 2-minute video Chickenís fate is sealed.
Quoting from the new study: “[Arachidonic acid] raises the risk for inflammation-based chronic diseases including depression since these metabolites are associated with altering mood-regulating mechanisms.” The other diseases alluded to include cancer, asthma, inflammatory bowel disease, rheumatoid arthritis, and other autoimmune disorders. For more, see my 2-minute video Inflammatory remarks about arachidonic acid.
Michael Greger, M.D.
Image credit: gautsch. / Flickr