A Perk of Going Veggie: Improve Your Mood

A recent study published in the Nutrition Journal reports that eschewing animal products in favor of plant-based foods helps improve mood in just a few weeks.  This short-term study incorporated thirty-nine omnivores.  Each participant was randomly assigned to a control group consuming meat, fish and poultry daily, a group consuming fish 3-4 times per week but avoiding meat and poultry or a vegetarian group avoiding meat, fish and poultry.  At the outset of the study and after two weeks of making assigned dietary transitions, participants were asked to complete a Food Frequency Questionnaire, the Profile of Mood States questionnaire and the Depression Anxiety and Stress scales.  By the conclusion of the study, mood scores remained constant for the omnivore and fish eating group but several mood scores for vegetarian participants improved significantly.1  These findings might be surprising given that people who eat fish regularly increase their intake of healthy eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) fatty acids, fats that are critical for optimal brain health.  This is what makes the study’s results so surprising.

Vegetables. Flickr: Bruce Guenter

Research evidence has frequently linked long-chain omega-3 fatty acids, EPA and DHA, to mood- a substance primarily found in fish and shellfish.  Conversely, meat and poultry are high in arachidonic acid (AA), a potentially neuroinflammatory long-chain omega-6 fatty acid.  Omnivores who consume large amounts of meat and poultry and low amounts of fish, with their elevated AA to EPA/DHA ratio, have been known to be at increased risk of depression.2 Omnivorous diets rich in fish and low in meat and poultry have been linked to a lower risk of depression.3 Vegetarian and vegan diets tend to be low in both long-chain omega-3 and long-chain omega-6 fatty acids, but prior to this study, there has been limited research examining the effects of a vegetarian diet on mental well-being. 

Potential confounding variables such as a prior history of mental disorder, alcohol or substance abuse, BMI, age, gender and exercise frequency were accounted for and a general health history was completed at baseline.  After two-weeks, the vegetarian group’s levels of EPA, DHA and AA dropped to negligible amounts while the fish eating group exhibited a 95-100 percent rise in dietary EPA/DHA.  This evidence is indicative that manipulation of fatty acid concentrations in each of the participants was successful.  In every individual on the vegetarian plan, stress and anxiety scores decreased after the two weeks, indicative that those who eliminate meat, fish and poultry may be better able to cope with mental stress than omnivores.  The results of this study support another cross-sectional study which found that vegetarians report significantly better moods than non-vegetarians.4

While warranting further investigation, the results may be due to increased antioxidant consumption on the vegetarian plan leading to a reduction in oxidative stress on the brain.5 These findings are fascinating and while we might not completely understand the mechanisms involved in why a vegetarian diet likely leads to enhanced mood, the results are certainly worth pondering.  I know I feel good as I finish off my huge salad or green smoothie!   

I know my father gets excellent results with those suffering with depression by combining his nutritarian diet with added EPA and morning light therapy.  He always uses nutrition and lifestyle medicine as the primary intervention, not drugs, which can lead to dependency, side effects and long-term health problems.  It is good to know that the scientific literature is slowly catching up to Dr. Fuhrman (my dad).   Who knows, maybe next year some other study will show that combining green vegetables, onions and mushrooms prevent cancer (Ha Ha)!



1. Beezhold BL, Johnston CS. Restriction of meat, fish, and poultry in omnivores improves mood: A pilot randomized controlled trial. Nutr J. 2012 Feb 14;11:9.

2. Kiecolt-Glaser JK, Belury MA, Porter K, Beversdorf DQ, Lemeshow S, Glaser R: Depressive symptoms, omega-6:omega-3 fatty acids, and inflammation in older adults. Psychosom Med 2007, 69:217-224.

3. Colangelo LA, He K, Whooley MA, Daviglus ML, Liu K: Higher dietary intake of long-chain omega-3 polyunsaturated fatty acids is inversely associated with depressive symptoms in women. Nutrition 2009,25:1011-1019.

4. Beezhold BL, Johnston CS, Daigle DR: Vegetarian diets are associated with healthy mood states: a cross-sectional study in Seventh Day Adventist adults. Nutr J 2010, 9:26.

5. Szeto YT, Kwok TC, Benzie IF: Effects of a long-term vegetarian diet onbiomarkers of antioxidant status and cardiovascular disease risk. Nutrition 2004, 20:863-866


Vitamin D may elevate mood during the winter

The days are beginning to get shorter and we’re spending more time indoors as most of the day’s sunlit hours are occurring during the work day. For our bodies, this is a significant change to adjust to, especially for those of us who live in cooler climates. It’s common to experience some decline in mood during the winter – feelings of anxiety and depression are known to be more prevalent throughout the colder months. For some individuals, these seasonal mood changes along with fatigue, irritability, and appetite changes are especially pronounced, and this is called Seasonal Affective Disorder (SAD).[1] Incidence of SAD increases with distance from the equator, and light therapy is an effective treatment for many individuals with SAD. Reduced sunlight exposure, resulting in shifts in circadian rhythms and alterations in serotonin metabolism, is thought to underlie this condition.[2]

Timing of exposure of the retina to light affects the sleep-wake cycle, and inadequate light exposure during the winter disrupts this cycle. Light therapy independent of vitamin D production (ultraviolet light is filtered out), especially in the morning hours, is known to be effective for treating SAD and major depression. SAD has been successfully treated with light therapy since the early 1980s. For depression, a meta-analysis in 2005 revealed that the effectiveness of light therapy was comparable to that reported in many trials of anti-depressant drugs.[3] Light entry into the retina inhibits production of melatonin, a hormone that promotes sleep. Light therapy helps to restore melatonin, the neurotransmitter serotonin, and other mood-regulating molecules to their normal time cycles and levels of production; consequently depressive symptoms are reduced.[4]

Reduced exposure to sunlight during the winter also means less natural vitamin D production by the skin, , and vitamin D itself may also regulate mood. There is still much unknown about how vitamin D works in the brain, but there are plenty of vitamin D receptors in the brain, and it is thought to affect daily biorhythms and production of neurotransmitters, including serotonin.[1] Also, low circulating vitamin D is associated with SAD and major depression.[5] So far, only a handful trials of vitamin D supplementation for seasonal depressive symptoms have been performed, and some of these used doses that were likely too low to have any measurable effect (400 IU; currently many experts believe that 2000 IU/day or more may be necessary for most people to maintain adequate blood 25(OH)D levels [6]). A dose of 800 IU improved mood of healthy subjects during winter in one trial [7], but had no effect in another trial.[8] A third trial used a dose of 4000 IU/day for six months starting in the summer, and then evaluated feelings of wellbeing during the December-February time period. The 4000 IU dose of vitamin D produced an average 25(OH)D level of 45 ng/ml and improved wellbeing scores compared to a 600 IU dose (average 25(OH)D level of 32 ng/ml). [9]

Current research is investigating the connection between depression and diabetes with a focus on vitamin D. Because depression is associated with insulin resistance, and vitamin D is thought to affect insulin secretion by the pancreas, ongoing studies are evaluating whether vitamin D supplementation can help to prevent diabetes. [10] In fact, healthy adults with low vitamin D levels were more likely to develop diabetes within 10 years compared those with adequate levels, according to a recent study. [11]

Vitamin D is active in essentially every cell and tissue in the human body. It is crucial (for everyone, not just sufferers of SAD ) to maintain adequate 25(OH)D levels (Dr. Fuhrman recommends 35-55 ng/ml) with supplementation. Especially if you note mood or sleep issues during the winter, be sure to accompany vitamin D supplementation with plenty of morning light.



1. Bertone-Johnson, E.R., Vitamin D and the occurrence of depression: causal association or circumstantial evidence? Nutr Rev, 2009. 67(8): p. 481-92.
2. Lurie, S.J., et al., Seasonal affective disorder. Am Fam Physician, 2006. 74(9): p. 1521-4.
3. Golden, R.N., et al., The efficacy of light therapy in the treatment of mood disorders: a review and meta-analysis of the evidence. Am J Psychiatry, 2005. 162(4): p. 656-62.
4. Miller, A.L., Epidemiology, etiology, and natural treatment of seasonal affective disorder. Altern Med Rev, 2005. 10(1): p. 5-13.
5. Murphy, P.K. and C.L. Wagner, Vitamin D and mood disorders among women: an integrative review. J Midwifery Womens Health, 2008. 53(5): p. 440-6.
6. University of California - Riverside (2010, July 19). More than half the world's population gets insufficient vitamin D, says biochemist. ScienceDaily July 28, 2010]; Available from: http://www.sciencedaily.com/releases/2010/07/100715172042.htm.
7. Lansdowne, A.T. and S.C. Provost, Vitamin D3 enhances mood in healthy subjects during winter. Psychopharmacology (Berl), 1998. 135(4): p. 319-23.
8. Dumville, J.C., et al., Can vitamin D supplementation prevent winter-time blues? A randomised trial among older women. J Nutr Health Aging, 2006. 10(2): p. 151-3.
9. Vieth, R., et al., Randomized comparison of the effects of the vitamin D3 adequate intake versus 100 mcg (4000 IU) per day on biochemical responses and the wellbeing of patients. Nutr J, 2004. 3: p. 8.
10. Loyola University Health System (2010, March 8). Vitamin D lifts mood during cold weather months, researchers say. ScienceDaily. . November 9, 2010]; Available from: http://www.sciencedaily.com/releases/2010/03/100303162854.htm.
11. Valencia, W., Abstract 125: Prospective risk of hyperglycemia in a South Florida population with low levels of vitamin D, in World Congress on Insulin Resistance, Diabetes and Cardiovascular Disease 2010.


Chocolate Craving, Walk it Off...

Chocolate is my weakness. Sometimes I need it! But next time a craving hits, I’ll try walking it off. A new study in Appetite claims a brisk 15-minute walk can halt chocolate cravings. And short spurts of exercise, like walking, might help improve mood and alertness too; Reuters reports.

For a healthier chocolate alternative, give my chocolate pudding a try!