Two new studies indicate that low folic acid levels play a strong role in depression, and other research suggests that nutritional deficiencies are common in depressed patients.
Tommi Tolmunen and colleagues assessed depressive symptoms in more than 2,600 men between the ages of 42 and 60, and then divided them into three groups according to their dietary intake of folic acid.
The researchers report, "Those in the lowest third of energy-adjusted folate intake had a higher risk of being depressed than those in the highest folate intake third," a finding that remained true after the researchers adjusted for a wide range of other lifestyle and socioeconomic factors. "These results," Tolmunen et al. say, "indicate that nutrition may have a role in the prevention of depression."
In a related study, M. S. Morris and colleagues examined the relationship between depression and folic acid levels in a multi-ethnic group of nearly 3,000 subjects between the ages of 15 and 39. After adjusting for other factors, the researchers found that "subjects who met criteria for a lifetime diagnosis of major depression had folate concentrations in serum and red blood cells that were lower than those of subjects who had never been depressed." Low folic acid levels were most common in subjects who had recently recovered from depressive episodes, leading the researchers to suggest that "folate supplementation may be indicated during the year following a depressive episode."
Deficiencies of other nutrients also are linked to the development or exacerbation of depression. Physician Rebecca Kirby recently conducted a chart review of 12 randomly selected patients with depression, and reports finding "overtly deficient plasma vitamin C levels in 25 percent." In addition, levels of riboflavin, niacin, and vitamin B6 were low in many depressed patients, and half had low levels of magnesium. Levels of zinc and chromium were reduced in one quarter of depressed patients, and 40 percent had low levels of the omega-3 fatty acid eicosapentaenoic acid (EPA). (see related articles, Crime Times, 1999, Vol. 5, No. 1, Page 1; and Crime Times, 1999, Vol. 5, No. 1, Page 2.)
Kirby concludes that an out-of-balance biochemistry caused by nutritional deficiencies "can cause mood swings and depression to become so extreme that they interfere with normal activities."
"Dietary folate and depressive symptoms are associated in middle- aged Finnish men," T. Tolmunen, S. Voutilainen, J. Hintikka, T. Rissanen, A. Tanskanen, H. Viinamaki, G. A. Kaplan, and J. T. Salonen, Journal of Nutrition, Vol. 133, Number 10, October 2003, 3233-6. Address: Jukka T. Salonen, Inner Savo Health Centre, Suonenjoki, Finland.
"Depression and folate status in the U.S. population," M. S. Morris, M. Fava, P. F. Jacques, J. Selhub, and I. H. Rosenberg, Psychotherapy and Psychosomatics, Vol. 72, No. 2, March-April 2003, 80-7. Address: M. S. Morris, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, 711 Washington Street, Boston, MA 02111.
"Mood swings and depression: let's get to the bottom of it," Rebecca K. Kirby, Health Hunter, Vol. 17, No. 9, October 2003, page 1. Address: Rebecca Kirby, Center for the Improvement of Human Functioning International, 3100 North Hillside Avenue, Wichita, KS 67219.