Depression in the elderly population may be prevented by higher intakes of certain B vitamins but not folate, a large population study reveals.
Published in the American Journal of Clinical Nutrition, the study followed more than 3,000 people aged 65 and older, and found that higher intakes of vitamins B-12 and B-6 were both associated with a slightly reduced risk of depression over 12 years of follow-up.
Approximately 13 per cent of participants reported depressive symptoms during three of the four interview cycles.
However, each 10 additional milligrams of vitamin B-6 and 10 additional micrograms of vitamin B-12 were associated with two per cent lower odds of depressive symptoms per year.
"In the assessment and treatment of depressive symptoms in older adults, clinicians and other healthcare professionals should be mindful of the patient's nutritional status in general, and whether there are vitamin insufficiencies in these nutrients before treatment," researchers from Rush University in Chicago said.
Data provided by the authors showed that six per cent of older people are deficient in vitamin B-12, which results in a neurologic syndrome that includes cognitive and depressive symptoms.
Marginal depletion in vitamin B-12 was noted as occurring among 20 per cent of the population, while the prevalence of depression in later life ranged from seven per cent to 49 per cent.
Due to vitamin B insufficiency among older people potentially being caused by reduced absorption, diets were assessed via food-frequency questionnaire and depression was measured by the Center for Epidemiologic Studies Depression scale, which has shown reasonable specificity and sensitivity for detecting major depression among older adults.
But authors discovered there was no association between depressive symptoms and food intakes of these vitamins or folate, while intake of vitamin B-6 from dietary sources wasn't significantly associated with depressive symptoms.
“It is possible that the association with total intake is due to partial confounding by vitamin B12 contained in multivitamin supplements," said researchers.