High levels of the amino acid homocysteine may increase the risk of developing Alzheimer's disease, according to a new study carried out at the Boston University School of Medicine, Massachusetts.
Dr Sudha Seshadri and colleagues made use of data from the ongoing, long-term Framingham Heart Study. In this US study, homocysteine levels were measured in 1092 men and women - with an average age of 75 - none of whom had dementia. Eight years later, 10 per cent had developed dementia, mostly due to Alzheimer's rather that stroke or other vascular disease.
The 30 per cent with the highest homocysteine levels had twice the risk of developing Alzheimer's compared with those who had average levels.
These findings suggest that taking more folic acid and vitamins B6 and B12 to lower homocysteine levels may help prevent dementia. However, there is no evidence that lowering homocysteine will prevent Alzheimer's disease.
Nevertheless, Dr Seshadri hopes these results will encourage further trials of the subject (N Engl J Med, 2002; 346: 466-8, 476-83).
* Keeping your brain stimulated cuts the risk of developing Alzheimer's by nearly half, according to a recent US study of 801 US nuns and priests. It is suggested that frequent mental activity may help the brain to process information more efficiently and aid perception. However, more studies are needed (JAMA, 2002; 287: 742-8).