By Greg Arnold, DC, CSCS, January 29, 2010, abstracted from “Serum folate and homocysteine and depressive symptoms among Japanese men and women” published online in the European Journal of Clinical Nutrition
Folic acid is a B-Complex vitamin found in highest amounts in leafy green vegetables, fruits, dried beans, peas, and nuts (in the form of folate). It is best-known to benefit a healthy pregnancy in helping prevent spinal cord defects and helping reduce neural tube defects by 23% in the 1990’s (1). The current folic acid fortification guidelines are 0.14 mg (140 micrograms, or mcg) of folic acid per 100 grams of cereal grain and are designed to produce an increased intake of 0.2 mg (200 mcg) of folic acid per day (2). Research has suggested that 5 mg (5,000 mcg) of folic acid per day can decrease the risk of neural-tube defects by 85% in women. Current recommendations by the National Institutes of Health range from 0.15 mg (150 mcg) per day in infants to 0.5 mg (500 mcg) per day in lactating women (3).
But folic acid’s benefits also extend to other areas of health, including digestive health (4), heart health (5), and breast cell health (6). Regarding mental health, a 2005 study (7) found that folic acid helps maintain mental health by slowing cognitive decline. A 2007 study (8) showed folic acid to maintain mental health and performance on tests of psychomotor speed.
Now a new study (9) has found that folic acid may help mental health in men by helping maintain healthy levels of homocysteine, a natural metabolite of the amino acid methionine. Elevated levels of homocysteine can indicate B-vitamin deficiencies and convey an increased cardiovascular risk. In the study, 530 patients aged 21 to 67 provided data at their periodic checkup on their depressive symptoms via the Center for Epidemiologic Studies Depression (CES-D) scale (10). The CES-D consists of 20 questions addressing six symptoms of depression. The frequency of each symptom was scored on a scale of 0–3, with the total possible CES-D score ranging from 0 to 60. The patients also filled out a food questionnaire (11) providing data on 56 foods and beverages.
The researchers found higher blood levels of folic acid to be associated with a decreased prevalence of depressive symptoms in men. Specifically, those with the highest 25% of folic acid blood levels had a 49% reduced risk of depression compared to those with the lowest blood levels of folic acid (more than 6.0 vs. less than 2.0 nanograms/milliliter). What’s more, the data suggested a positive association between serum homocysteine and depressive symptoms in men. Those with the highest 25% of homocysteine levels had a 60% increased risk of depression compared to those with the lowest 25% of homocysteine levels (more than 16.0 vs. less than 9.3 nmol/mL). In women, however, neither folic acid blood levels nor homocysteine levels were associated with depressive symptoms.
For the researchers, “Low [folic acid blood levels] may be related to an increased prevalence of depressive symptoms in Japanese men.”
Greg Arnold is a Chiropractic Physician practicing in Danville, CA. You can contact Dr. Arnold directly by emailing him at mailto:PitchingDoc@msn.com or visiting his web site at www.PitchingDoc.com
1. Wald NJ. Folic Acid and the Prevention of Neural-Tube Defects. NJEM 2004; 350(2):101-103
2. Shaw GM. Choline and risk of neural tube defects in a folate-fortified population. Epidemiology. 2009 Sep;20(5):714-9.
3. “Dietary Supplement Fact Sheet: Folate” posted on http://dietary-supplements.info.nih.gov/factsheets/folate.asp
4. “Inflammatory Bowel Disease” posted on the www.Emedicine.com website June 9, 2004
5. Wang X. Efficacy of folic acid supplementation in stroke prevention: a meta-analysis. The Lancet 2007; 369(9576):1876-1882
6. Ericson U. High folate intake is associated with lower breast cancer incidence in postmenopausal women in the Malmö Diet and Cancer cohort Am. J. Clinical Nutrition, Aug 2007; 86: 434 – 443
7. “The First Ever Dementia Conference Opens In Washington, DC” posted on the Alzheimer’s Association Website
8. Ericson U. High folate intake is associated with lower breast cancer incidence in postmenopausal women in the Malmö Diet and Cancer cohort Am. J. Clinical Nutrition, Aug 2007; 86: 434 – 443
9. Nanri A. Serum folate and homocysteine and depressive symptoms among Japanese men and women. Eur Jou Clin Nutri 2010. Published online ahead of print, doi: 10.1038/ejcn.2009.143
10. Radloff LS (1977). The CES-D scale: a self-report depression scale for research in the general population. Appl Psychol Meas 1, 385–401.
11. Sasaki S (2004). Development and evaluation of dietary assessment methods using biomarkers and diet history questionnaires for individuals (in Japanese). In: Research for Evaluation Methods of Nutrition and Dietary Lifestyle Programs held on Healthy Japan 21 (Head Investigator: Tanaka H). Summary Report, ed. Ministry of Health Welfare, and Labour: Japan. pp 10–44. Tokyo.