Maintaining high levels of HDL is an effective strategy for reducing risk of Alzheimer’s disease in women. Data from an ongoing study indicate that women in the highest quintile of HDL — ranging from 60 to 75 mg/dL — reduce their risk for developing Alzheimer’s disease by about 50%.
Lead investigator Elizabeth Devore, a graduate student at the Channing Laboratory at Harvard Medical School in Boston said HDL was the most significant cholesterol fraction in terms of assessing AD risk. Those with the highest LDL levels had a slight increase in risk of AD but “clearly HDL is the more important in determining a woman’s risk.”
From 1992-95, the Women’s Health Study — an ongoing longitudinal study of cardiovascular risk factors — collected baseline health and lifestyle data from 39,000 female health professionals. Blood samples were collected from 75% of the cohort. During the 1998-2000 evaluations, cognitive assessments were conducted on 4,081 subjects aged 65 or older.
The cognitive testing used a validated telephone interview. This included five tests measuring general function, verbal memory, and category fluency. Multivariate-adjusted mean differences in cognitive performance across quintiles of baseline plasma cholesterol levels were then calculated.
The findings are “good news because we know how to modify HDL,” Devore said at a press conference. She noted that exercise, weight loss and moderate alcohol intake — one to two drinks a day — have all been shown to increase HDL levels. “But exercise is the most important element, even more important than diet.”