Elderly people could gain some protection against cognitive decline by taking B vitamins to reduce levels of homocysteine, an independent predictor of cognitive function, report researchers in the American Journal of Clinical Nutrition this month.
In a trial on almost 1800 elderly Latinos, the team from University of California, Davis, and the University of Michigan, Ann Arbor (MNH) found modest inverse associations between homocysteine concentrations and several indexes of cognitive function.
They said that while demographic variables, particularly age and education, were more strongly associated with cognitive function scores than homocysteine, B vitamins may offer some protection of mental health in old age.
The trial compared total plasma homocysteine concentration and cognitive function in a population of 60 years old participating in the Sacramento Area Latino Study on Aging.
The researchers assessed global cognitive function using the Modified Mini-Mental State Examination, and other tests to evaluate specific cognitive functions.
Modest inverse associations were found between homocysteine concentrations and several indexes of cognitive function, including the global Modified Mini-Mental State Examination assessment and the picture-association, verbal attention-span, and pattern-recognition tests.
The findings fit with previous evidence showing homocysteine to be a marker for deficiency of vitamin B12 and folic acid. Homocysteine is also a well-documented risk factor for cardiovascular disease, related to both vascular dementia and Alzheimer's disease.
Vitamin B12 plays an important role in the central nervous system, however it is also poorly absorbed when consumed in foods.
"Reducing plasma homocysteine concentrations by administering B-vitamin supplements may provide some protection against cognitive decline in this and other elderly populations, but the effect may be limited," concluded the researchers.