Homocysteine is an amino acid believed to be toxic to blood vessels. Several studies have linked high blood levels of it to increased heart attack risk. This study found that homocysteine levels in patients with stroke, Alzheimer's disease or vascular dementia were consistently higher than homocysteine levels in age-matched healthy volunteers.
"Since B vitamins and foods fortified with folate can reduce homocysteine levels, this study suggests that B vitamin supplementation may be appropriate for most adults. It warrants a large placebo-controlled study of folate, and vitamins B6 and B12 in people at risk from dementia and stroke," says lead author Stephen P. McIlroy, Ph.D., a lecturer in geriatric medicine at Queen's University in Belfast, Ireland.
McIlroy and his colleagues studied 83 Alzheimer's patients (average age 77); 78 patients with dementia caused by poor blood flow to the brain, a condition called vascular dementia (average age 77); 64 stroke patients (average age 74) and 71 healthy volunteers (average age 74).
There is some disagreement among scientists about what constitutes an elevated homocysteine level. Here, researchers designated the upper quartile of homocysteine levels of the healthy volunteers 13.3 micromoles per liter (mol/L) or higher as an elevated level.
They also collected data on education, diet, blood pressure, cholesterol, and smoking history. Several of these factors are associated with the risk for Alzheimer's disease, and smoking directly affects homocysteine levels, he says.
The researchers also used DNA testing to determine if any of the subjects had a variation in the gene methylenetetrahydrofolate (MTHFR), which can adver
Contact: Carole Bullock
American Heart Association