Friday, July 22, 2011

Friday fun: Food and mood

We all know that coffee is energizing, oysters are an aphrodisiac (maybe), and turkey makes us sleepy, especially when combined with gravy and stuffing. But there are many other important - and less obvious - links between food and mood. Here are a few of them:

1. Carbs are calming.  I always like to have a piece of toast before bed, and I recently discovered why that might be: carbohydrates like bread, pasta, and potatoes increase a brain chemical called tryptophan, which is converted to serotonin, a calming "feel good" neurotransmitter. This link may be one reason why many so-called comfort foods are carb-heavy, and why depressed people, who many researchers believe have deficits related to serotonin production and regulation, are more likely to crave carbs. Unfortunately, a high-carb diet is no substitute for therapy and medication, and can lead to obesity and other health problems. Drastically restricting carbs, however, has been found to increase depressive symptoms - so beware of Atkins and similar diets if you're prone to moodiness. The healthiest approach seems to be to consume moderate portions of complex carbs, like brown rice and whole grains.

2. Asparagus might do more than just make your pee smell weird. Apparently it can also boost your libido due to its high content of vitamin E, which increases the production of sex hormones like testosterone. Other unexpected aphrodisiacs include watermelon, especially the rind (through an indirect chemical process it increases nitric oxide, which in turn increases blood flow), chili peppers, garlic, and ginger, which also increase circulation and arousal. Whether eating normal quantities of these foods produce noticeable changes in sex drive is debatable, but one should never underestimate the power of the placebo effect. And what about anti-libido foods? If you're male and a vegan or lactose-intolerant, be careful not to consume too many soy products. Though soy has some health benefits, especially for post-menopausal women, there is initial evidence that it may contribute to erectile dysfunction in men. Alcohol is another known culprit: it may reduce your inhibitions, but it can kill the mood.

3. Your brain needs fat. Foods rich in omega-3 fatty-acids, such as fish and flax seeds, have been shown to boost moodimprove memory and cognitive performance, and even potentially reduce aggression. In one study, participants with higher levels of omega-3s in their bloodstream had a more positive outlook on life and were less impulsive than participants with lower levels, and another study showed an association with increased grey matter in areas of the brain responsible for emotion regulation, suggesting a mechanism for improved functioning in these areas. Complementary treatment with omega-3 supplements has been found to be effective in reducing symptoms for a number of psychiatric disorders, including bipolar disorder and suicidal behavior. Omega-3 fatty acids are not to be confused with omega-6s, which are found in many processed foods and are over-consumed in the U.S. Whereas omega-3s decrease inflammation, omega-6s tend to increase it, contributing to health problems. Rather than simply categorizing the two as "good fats" and "bad fats," however, most nutrition experts recommend consuming a proper balance between the two.

There are countless other interesting studies - and untested hypotheses - on the complex interactions between food and mood. Although some findings are well-established, many remain controversial and require further research. In the meantime, there is no harm in doing some experimenting of your own (just make sure to talk to your doctor before making any major dietary changes).

Further reading:

Food & Mood: The Complete Guide to Eating Well and Feeling your Best, by Elizabeth Somer. There is also a cookbook.

Your Brain on Food: How Chemicals Control Your Thoughts and Feelings, by Gary Wenk

Brain foods: The effects of nutrients on brain function. Neuroscientist Fernando Gomez-Pinilla reviews research on the brain mechanisms linking diet to mental function.

Conklin, S., Gianaros, P., Brown, S., Yao, J., Hariri, A., Manuck, S., & Muldoon, M. (2007). Long-chain omega-3 fatty acid intake is associated positively with corticolimbic gray matter volume in healthy adults Neuroscience Letters, 421 (3), 209-212 DOI: 10.1016/j.neulet.2007.04.086

Siepmann, T., Roofeh, J., Kiefer, F., & Edelson, D. (2011). Hypogonadism and erectile dysfunction associated with soy product consumption Nutrition, 27 (7-8), 859-862 DOI: 10.1016/j.nut.2010.10.018

Wurtman RJ, & Wurtman JJ (1996). Brain Serotonin, Carbohydrate-craving, obesity and depression. Advances in experimental medicine and biology, 398, 35-41 PMID: 9045545


  1. Awesome post!!! This information can really help us make healthier choices while negotiating those days where we need extra energy and mood stabilization.

    Thank you. I'm going to circulate this one at work.


  2. So excited to find another blog relating Psychology to everyday life. I'm at researcher at the Stanford Psychophysiology Lab and always eager to hear about new findings and fascinating people!

  3. Daniel, I'm so glad you found the info helpful.

    FluffsEnough, it's great to meet you! We'd love to hear your thoughts on the posts, and we'll be sure to check out your psych blog as well.

  4. We can all do with more Omega-3s. I feel this calls for a salmon bagel - a calming, depression busting meal? :)

  5. A salmon bagel sounds perfect :)

  6. Carbohydrates might well increase tryptophan, the pre-cursor of serotonin. However, tryptophan has to compete with other molecules to enter the brain through the blood brain barrier so there is not a simple relationship between available tryptophan and mood. Brain levels of tryptophan only increase after carbohydrate consumption when the diet is also low in protein, thus lowering the levels of large nucleic acids that saturate the blood brain barrier.

  7. Anonymous, thank you for drawing attention to the complexity of the relationship between carbs and serotonin. As you said, tryptophan appears to work best in isolation, when it is not competing with other animo acids. I've also read that the insulin produced by a high-carbohydrate meal can block competing amino acids, letting more tryptophan into the brain. Too much insulin, however, can be dangerous, so eating protein along with carbs may be a good idea, as it can help stabilize blood sugar levels and prevent mood swings.

    Tryptophan can also be taken as a supplement, though there is some controversy about the safety and effectiveness of this approach.

    As a caveat, I'm by no means an expert in nutritional science, so I welcome other comments regarding complexities I may have overlooked in the post, or additional research on this topic.