Role of Homocysteine and B Vitamins in Predicting Cognitive Decline

Category: Aging , Conditions of the Brain , Men's Health

Homocysteine is a known inflammatory mediator in the body. It increases the risk of oxidative damage and can contribute to several chronic diseases such as heart disease and diabetes. Homocysteine can become elevated due to deficiencies in B vitamins (B6 and B12) and folate. Recent studies have shown that homocysteine may contribute to cognitive decline and may also increase risk of developing Alzheimer's disease.

The relationship between cognitive decline and homocysteine is not fully understood. Researchers do not know if homocysteine is acting alone as an independent risk factor, or if the risk actually due to a deficiency in B vitamins (and elevated homocysteine just a by-product). Scientists speculate that both may play a role in cognitive decline.

Researchers at Boston University conducted a study of 321 men over a 3-year period. The men were assessed for cognitive function using the Mini-Mental State Examination. Verbal fluency, memory, constructional praxis was measured using a revision of the Wechsler Adult Intelligence Scale. Tests to assess Alzheimer's disease were also given. Food questionnaires were used to assess dietary intake of B vitamins and baseline serum concentrations of homocysteine. B-compound vitamins were also administered.

Results after the 3-year period were compared to baseline statistics. Elevated homocysteine and decreased levels of folate, Vitamin B12, and Vitamin B6 were associated with increased cognitive decline as measured by constructional praxis. Elevated homocysteine was an independent marker for a decline in recall memory, while dietary folate was an independent factor against the decline in verbal fluency. Spatial copying function was protected by folate when adjusting for changes in the other B vitamins and homocysteine.

In conclusion, cognitive decline is affected by both the elevation of homocysteine in the blood and by decreased dietary intake and blood concentrations of folate, Vitamin B6, and Vitamin B12. Homocysteine acts independently on decline in recall memory. Folate is independently protective against cognitive decline, specifically in verbal fluency and spatial copying.

Posted by Kristopher Foster on January 23, 2006 09:00 AM