AJCN.org - A new study of older adults has linked increased intakes of vitamin B6 and vitamin B12 - especially through dietary supplements - with less risk of developing depression over time. Using data gathered on older adult residents living in neighborhoods located in Chicago’s south side, researchers at Rush University have discovered that inadequate consumption of these B vitamins may be related to depression in this at-risk population. Results of their study, as well as an editorial written by scientists at Bangor University (United Kingdom), have been published in the August 2010 issue of The American Journal of Clinical Nutrition.
Folate (or folic acid), vitamin B6, and vitamin B12 are nutrients that orchestrate the synthesis of compounds needed for brain development and neuronal activity. For decades, researchers have documented associations between these vitamins and neurological outcomes such as depression. Moreover, the recent fortification of the US cereal grain supply with folate to reduce the risk of neural tube defects has re-energized scientific interest in this often debated relation.
Study Design: The investigation involved 3,503 biracial adults (59 percent African American; mean age: 74 years old) enrolled in the Chicago Health and Aging Project, an ongoing study initiated in 1993. At the beginning of the study and then every 3 years thereafter, information was collected concerning dietary intake (including nutrient supplements), symptoms of depression, sociodemographic variables, and overall health status. The researchers then statistically evaluated whether, after controlling for possible confounding factors, differences in vitamin intake were predictive of onset of depression over the course of the study.
Results: The data indicated that individuals consuming the lowest amounts of vitamin B6 and vitamin B12 (but not folate) were also those most likely to be classified as depressed. Specifically, each additional 10 mg of vitamin B-6 or 10 µg (micrograms) of vitamin B-12 consumed was associated with a 2 percent decrease in risk of developing depression in a given year. Use of dietary supplements of vitamin B12 and vitamin B6 appeared to be especially important.
The authors conclude that their results support the idea that high intakes of vitamins B6 and B12 may protect against depression in older individuals. Of course, rigorously controlled intervention trials will need to be done to confirm this. In their accompanying piece, Seren Roberts and colleagues provide additional comments concerning the possibility that further fortification of flour may be beneficial to health, especially in this growing and at-risk population.
Skarupski KA, et al. Longitudinal association of vitamin B-6, folate, and vitamin B-12 with depressive symptoms among older adults over time. American Journal of Clinical Nutrition 2010;92:330–5.
Roberts SH, et al. Half-baked? B vitamins and depression. American Journal of Clinical Nutrition 2010;92:269–70.