Elevated levels of the amino acid homocysteine in the blood can lead to a higher risk of dementia, including Alzheimer's-related dementia, according to the 14 February issue of The New England Journal of Medicine.
The journal published the research findings of a team from Boston University School of Medicine led by Dr Philip A. Wolf. The researchers evaluated the development of dementia in 1,092 adults who participated in the Framingham Study. None of the subjects had dementia at study entry. The participants homocysteine levels had been measured eight years before and and were re-evaluated at study entry.
During the study period, 111 subjects developed dementia, including 83 who were diagnosed with Alzheimer's disease, Dr Wolf said. For each increase in the homocysteine level of 5 micromol/L, the Alzheimer's disease risk increased by 40 per cent (p less than 0.001). Levels greater than 14 micromol/L were associated with a near doubling of the Alzheimer's disease risk.
"The results of our prospective, observational study indicate that there is a strong, graded association between plasma total homocysteine levels and the risk of dementia and Alzheimer's disease," the researchers said in the journal. They stressed that further studies, including controlled clinical trials, were needed to confirm the current findings.
Dr Joseph Loscalzo from Boston University Medical Center commented in an accompanying editorial to the research that the findings had suggested potential means of treating dementia. He said that folate, vitamin B12 and betaine were known to reduce plasma homocysteine levels, and that it was intriguing to contemplate the possibility that consumption of these vitamins might prevent the development of Alzheimer's disease and other dementias.