B vitamins intake may reduce risk of disabling dementia

Dietary intakes of folate, riboflavin, and vitamins B6 and B12 appear to lower the risk of disabling dementia, suggests a study involving Japanese individuals.

A total of 4,171 Japanese participants aged 40‒69 years were included in this community-based prospective study, as part of the Circulatory Risk in Communities Study. Overall, 887 cases of disabling dementia occurred over a median follow-up of 15.4 years.

An inverse association was noted between intake of riboflavin and the risk of disabling dementia, with a multivariable hazard ratio (HR) of 0.51 (95 percent confidence interval [CI], 0.42‒0.63; p_trend<0.001) for the highest vs lowest quartiles.

Likewise, intakes of folate (HR, 0.80, 95 percent CI, 0.66‒0.97; p_trend=0.01) and vitamin B6 (HR, 0.79, 95 percent CI, 0.65‒0.96; p_trend<0.001) showed an inverse association with incident dementia.

In this study, the researchers estimated dietary intakes of B vitamins using a single 24-h dietary recall method and calculated HRs of disabling dementia using area-stratified Cox proportional hazard models. Disabling dementia was defined by the daily living disability status related to dementia based on the long-term care insurance system of Japan.

Low levels of B vitamins have been shown to increase dementia, but epidemiological evidence is lacking, according to the researchers, who then examined the relationship between dietary intakes of B vitamins and the incidence of disabling dementia over a 15-year observation period.