Statins may protect against memory loss
People at high risk for dementia who took cholesterol-lowering statins are half as likely to develop dementia as those who do not take statins, a new study shows.
The study consisted of older Mexican-Americans in Sacramento, Calif., who suffered from metabolic conditions that put them at risk for developing dementia, Alzheimer’s or cognitive impairment without dementia, says Mary Haan, epidemiology professor at the School of Public Health (SPH) and lead author of the study. Some of the risk factors for dementia include high cholesterol, Type 2 diabetes, obesity and hypertension.
“The bottom line is that if a person takes statins over a course of about five-to-seven years, it reduces the risk of dementia by half, and that’s a really big change,” says Haan, who notes the study did not look at statins as a treatment for existing dementia, only as a preventative. Statins are drugs that specifically lower LDL or bad cholesterol.
The longitudinal study originally was funded in 1997 to look at metabolic and vascular conditions like hypertension and diabetes and their effect on the risk of dementia and Alzheimer’s disease. Earlier landmark findings by Haan’s group of the same study cohort established that certain metabolic and vascular disorders predicted Alzheimer’s and dementia. For instance, people with Type 2 diabetes are up to three times more likely to develop Alzheimer’s disease, they found.
In this current study Haan’s group set out to measure whether taking statins over time lowered the development of dementia in that same high-risk population. The resulting paper, “Use of Statins and Incidence of Cognitively Impaired Not Demented and Dementia in a Cohort Study,” appears in the July 29 issue of Neurology.
“In older people you have so many different chronic conditions, especially in this group, that the chance of any intervention having an effect is fairly limited,” Haan says. “Say you’re 75 or 80 and you’ve got six diseases. How much is a treatment really going to help? This showed if you started using statins before the dementia developed you could prevent it in about half of the cases.”
It’s likely that many people taking statins have already benefited unknowingly from the dementia fighting properties, she says. Haan hopes the study will help fuel randomized trials to test statins and their ability to prevent dementia.
Statins lowered the risk of dementia in all participants, but the statins had more of an impact on the group at high risk due to metabolic syndrome. The next step, Haan says, is to determine exactly how the statins work on the biochemical pathways involved in dementia.
Co-authors include Caryn Cramer and Sandro Galea of the Department of Epidemiology, SPH; Kenneth Langa of the Division of General and Internal Medicine and Institute for Social Research; and John Kalbfleisch of the Department of Biostatistics, SPH.