B Vitamins Slow Memory Loss

Daily supplements of B vitamins slow the decline in mental function in people with mild cognitive impairment, says a new clinical trial. A daily combination of folic acid and vitamins B6 and B12 was associated with a 30 percent reduction in levels of the amino acid homocysteine and improvements in a range of mental tests.

"One interpretation of the data is that lowing homocysteine concentrations by administering B vitamins slows brain atrophy, which in turn slows both cognitive and clinical decline," wrote researchers from the University of Oxford and the Unviersity of Oslo. "Such an interpretation is consistent with several studies showing that whole brain atrophy rate is strongly correlated with decline in various cognitive measures. Wasting in the brain, or atrophy, is a common symptom of mild cognitive impairment (MCI) and can be an early warning to signs of dementia. One important factor determining the rate of atrophy appears to be raised concentations of the amino acid homocysteine. Previously, epidemiological studies have reported that high levels of homocyseine are associated with suspected or confirmed dementia. The farmingham study reported that people with homocysteine levels above 14 micromoles per liter of serum had twice the risk of dementia. Tissue and plasma concentrations of homocysteine are know to be determined by viamin B levels, as they are cofactors for enzymes involved in homocysteine metabolism. The new study investigated the links between vitamin B supplementation, homocysteine levels and cognitive function. The Vitacog study involved 266 people over the age of 70 with diagnosed mild cognitive impairment. Participants were randomly assigned to receive either a placebo or a B vitamin supplement providing 0.8 mg per day of folic acid, 0.5 mg of vitamin B12 and 20 mg of vitamin B6 for two years. At the end of the study the researchers report that homocysteine levels decreased by an average of 30 percent in the B vitamin group compared with the placebo. In addition, executive mental function was stablized in the B vitamin group compared with the placebo. When the Oxford and Oslo based scientist looked specifically at people with high homocysteine levels (greater than 11.3 micromoles per liter) they found that vitamin B supplementation was associated with significant improvements in global cognition, episodic memory and semantic memory.