In one of my videos last year, I reported on the finding that vegetarian men and women had significantly better scores on the Depression, Anxiety, Stress scale. Why were vegetarians significantly less depressed, anxious, and stressed than even healthy meateaters in this study? “Negligable arachidonic acid intake may help explain the favorable mood profile observed with vegetarian diets. As I talked about last year, this arachidonic acid stuff in our diet produces inflammatory compounds which may inflame our brain.
The omnivores ate 9 times as much arachidonic acid than the vegetarians, which is not surprising, given that arachidonic acid is not found in plants. That’s why vegetarians and vegans, have significantly lower levels of arachidonic acid flowing though their bloodstream. In fact you can even measure it right out of saliva. They found significantly lower levels of arachidonic acid in vegetarian drool.
This was a landmark study, but it was also just a cross-sectional study, a snapshot in time. What you need to do to prove cause and effect is do an interventional study. So in a follow-up study presented at the annual American Public Health Association conference they took a bunch of meateaters and split them up into three groups. The control group maintained regular intake of flesh foods The second group ate fish, but no other meat, and the third was put on a vegetarian diet with no eggs. The whole study only lasted two weeks, but what do you think they found?
If it was primarily the saturated fat inflaming the omnivores’ brain, then the moods of both the veg and fish groups would presumably improve. If arachidonic acid was the culprit then presumably only the veg group would feel significantly better.
This is the amount of arachidonic acid in blue consumed per day by the end of the study. The fish eaters, though, were eating a lot more of those long chain omega 3’s, though, EPA and DHA, so maybe they were protected? Or, more like nothing would happen in such a short time frame—just two weeks.
In terms of psychological benefits, the egg-free vegetarian group significantly improved, meaning greater reductions in both the depression, anxiety, stress scale and the Profile of Mood States a measurement of mood disturbances. Though the no-poultry fish group did marginally better than the control group, the difference was not statistically significant.
Conclusion: “The complete restriction of flesh foods significantly reduced mood variability in omnivores…. Our results suggest that a vegetarian diet can reduce mood variability in omnivores. Perhaps eating less meat can help protect mood in omnivores, particularly important in those susceptible to mood disorders.
Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. For information on the role that plant-based diets can play in improving mood, check out my other video Plant-Based Diet & Mood. Also, there are 1,449 subjects covered in my other videos–please feel free to explore them!
Also, be sure to check out my associated blog posts: Harvard’s Meat and Mortality Studies, Inflammation, Diet, and “Vitamin S”, The Most Anti-Inflammatory Mushroom, How To Boost Serotonin Naturally, Treating Crohn’s Disease With Diet, Top 10 Most Popular Videos of the Year, Saffron vs. Prozac for Depression, The Science of Acai Berries, Raspberries Reverse Precancerous Lesions, and How Probiotics Affect Mental Health
About Michael Greger M.D.Michael Greger, M.D., is a physician, author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United States.