A recently published study in the British Journal of Nutrition reports that increased antioxidant status is associated with a lower risk of depressive symptoms. Approximately 20.9 million American adults—or about 9.5 percent of the U.S. population age 18 and older—have a mood disorder in a given year. This includes 14.8 million American adults with major depressive disorder, as well as 3.3 million American adults with dysthymic disorder, a milder form of depression.
The researchers evaluated data on 1,798 U.S. adults aged 20-85 years from the National Health and Nutrition Examination Surveys 2005-2006. The investigators assessed depressive symptoms using the Patient Health Questionnaire and measured serum levels of carotenoids, retinol, vitamin C and vitamin E to evaluate serum antioxidant status.
The investigators found that a higher total serum carotenoid level was associated with a lower likelihood of elevated depressive symptoms. More specifically, the data showed a 37 percent reduction in the likelihood of elevated depressive symptoms overall with each standard deviation increase in serum carotenoids. The subjects with the highest serum carotenoids had a 59 percent decrease in the odds of elevated depressive symptoms compared to the subjects with the lowest serum carotenoids.
Among carotenoids, beta-carotene in both men and women and lutein plus zeaxanthin in women had an independent inverse association with elevated depressive symptoms among US adults, meaning that as levels of these carotenoids increased, the risk of elevated depressive symptoms decreased. No association was found between the other antioxidants and depressive symptoms.
The researchers stated, “In conclusion, total carotenoids (mainly beta-carotene and lutein plus zeaxanthin) in serum were associated with reduced levels of depressive symptoms among community-dwelling U.S. adults.”
Beydoun MA, et al. Br J Nutr. 2012 Aug 31:1-16.