Natural Food Folate and Late-Life Depression

Abstract

Low folate status has been linked to depression, but findings have been inconsistent. The authors sought to examine the association between folate intake and late-life depression. This cross-sectional study included individuals age 60 and older (n = 111 depression, n = 136 comparison). Depression participants received psychiatric care. Folate and kilocalorie intakes were assessed with a Block 1998 food frequency questionnaire. Naturally occurring food folate was inversely associated with depression after controlling for age, sex, race, education, and total energy (P = 0.0047). All other folate variables including total dietary folate and folic acid were non-significant for depression. These findings may indicate that the naturally occurring form of folate is uniquely protective for depression and perhaps brain health. Alternatively, natural folate may be a surrogate for other nutrients or overall dietary quality.

KEYWORDS:

• depression
• folate
• folic acid
• nutrition
• older adults

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Corrigendum

We dedicate this paper to the late Dr. Marcy Speer (1959–2007), a valued and much-missed colleague.

We thank the participants of this research project for their dedication to furthering knowledge of late-life depression. We also acknowledge Cortnee W. Pierce for subject recruitment, Andrew Shiloh and Douglas R. McQuoid for data management, and Maragatha Kuchibhatla for statistical assistance.

Notes

∗P value for difference between groups (chi-squared test used to compare proportions; t-test used to compare means).

†Education ≥ 12 years (yes/no).

‡Four conditions were included in the vascular comorbidity score: diabetes mellitus, hypertension, arteriosclerosis, and heart trouble. Each condition was assigned a score of 1 if the condition was not reported, and 2–4 indicating the condition was reported as present and interfered not at all (code 2), interfered a little (code 3), or interfered a lot (code 4) with their activities. The comorbidity score thus had a possible range from 4 to 16.

∗Mean (standard deviation).

†P value for difference between groups (t-test).

‡DFEs (dietary folate equivalents) = folate (µg) + [1.7∗folic acid(µg)] (15).