Summary: Cholesterol is the Anna Nicole Smith of the Alzheimer’s world – it’s always in the news, and its relationships are hard to understand. High cholesterol in mid-life may be a risk factor for developing dementia. Studies on whether cholesterol-lowering drugs called statins can reduce that risk have had mixed results, with more recent research finding no effect. As with the men claiming to be the father of Ms. Smith’s baby, further tests will determine the role cholesterol-lowering drugs will play.
Going through my father’s medical records, I found a 2004 notation from his first neurologist: The recent total cholesterol (on Mevacor) was only 139 (LDL 81). Therefore, the Mevacor will be decreased to 10 mg. daily beginning today.
Mevacor is a statin, prescribed to lower cholesterol levels. But as far as I know, Dad’s cholesterol was always low – why was he taking Mevacor?
In the last few years, headlines on the use of statins to prevent dementia have swung from wild optimism to flat-out skepticism, and it seems Dad was dragged along for the ride.
In early 2000, when Dad started calling himself “stupid,” Loyola University researchers announced their analysis of hospital records showed patients taking statin drugs had a lower prevalence of probable Alzheimer’s. A paper by Boston University scientists that same year showed that British patients taking statins seemed to have a reduced risk of developing dementia. Dad probably saw the headlines: “Cholesterol drug may prevent Alzheimer’s” and “Statins Take On the Brain: Cholesterol-lowering drugs may also treat or prevent Alzheimer's disease.”
By 2001, he was combing through newsletters from Mayo Clinic and Harvard Medical School looking for ways to improve his memory. That year, Finnish researchers at the University of Kuopio published an article in BMJ that seemed to confirm the Alzheimer’s/cholesterol link. In their study of 1449 Finns followed over 21 years, high cholesterol levels at midlife were a risk factor for Alzheimer’s disease later in life. Shortly after that, studies in several labs showed a relationship between cholesterol and beta amyloid plaques and suggested that, at least in a test tube, high cholesterol leads to increased beta amyloid production. Surely the newsletters Dad subscribed to carried stories about these studies.
In 2003 or 2004, his family doctor must have prescribed Mevacor, but none of us know why. Maybe both Dad and his doctor had read about these studies, and agreed to give a statin a try.
By early 2005, Dad wasn’t reading much at all. But when I called to say hi one day, he was exasperated by a headline he’d seen in the local paper. “Did you see that?” he asked. “Now they say those drugs don’t help your brain.” The story was about a study by Johns Hopkins University researchers. After following approximately 5000 people over a period of five years, they found “no association between statin use and subsequent onset of dementia or AD”. Later that year, University of Washington scientists said that their analysis of statin use and dementia prevalence among 2798 participants in the Cardiovascular Health Study showed the use of statins was not associated with decreased risk of dementia. They wrote that the results of their investigation and similar studies depended on how they looked at the data, and that more research is needed.
After these negative results were published, the excitement about using statins to prevent Alzheimer’s had died down. Dad had stopped taking Mevacor anyway, and had definitely developed dementia.
Although statins may not prevent Alzheimer’s, studies are underway to see if they can be used to treat the disease after onset. I’ll write more about that in my next post.