Midlife Cholesterol Linked To Dementia

LINDA WERTHEIMER, host:

This is MORNING EDITION from NPR News. I'm Linda Wertheimer.

STEVE INSKEEP, host:

And I'm Steve Inskeep. Good morning. Today in Your Health, helping older folks deal with delirium. But first, we have an advisory of sorts for people in their 40s. Two recent studies suggest that high cholesterol and belly fat in middle age may increase the risk of Alzheimer's disease and dementia. NPR's Allison Aubrey explains how researchers are trying to nail down these links between lifestyle, weight and disease.

ALLISON AUBREY: The standard advice to older folks for preventing Alzheimer's disease goes something like this: Keep your brain active, exercise and maintain social relationships. So if you do all these and toss in a daily crossword or Sudoku, surely you'll keep dementia at bay, right? Well, not exactly.

Dr. REISA SPERLING (Director of Alzheimer's Research, Brigham and Women's Hospital): There'll be some individuals who do everything right, who exercise, who are very bright, who are very active and still get Alzheimer's disease.

AUBREY: Reisa Sperling directs Alzheimer's research and treatment at Brigham and Women's Hospital in Boston. She says there is some evidence that a healthy lifestyle is protective. But she explains genes seem to play a very significant role, too. Those who have a parent with Alzheimer's or inherit a certain gene called ApoE4 are more susceptible to the disease. And once people begin to experience the first symptoms, it's difficult to slow the progression, even with medicines. This is why Sperling and lots of other researchers are interested in studying people in their 40s, just hitting middle age.

Dr. SPERLING: I believe that factors that affect changes in the brain decades before people actually get Alzheimer's disease are the ones we need to be looking at.

AUBREY: One factor that may affect changes in the brain is cholesterol. A new study of about 10,000 men and women found that people who had elevated levels of cholesterol when they were in their early 40s were significantly more likely to be diagnosed with Alzheimer's and vascular dementia in their 70s and 80s. Researcher Rachel Whitmer of Kaiser Permanente in Oakland, California, led the study. She says it's well documented that high cholesterol raises the risk of cardiovascular disease. But this study, she says, adds to a growing body of evidence suggesting high cholesterol's also a risk factor for brain disease.

Dr. RACHEL WHITMER (Kaiser Permanente): One of the bottom lines here is what's good for the heart is also good for the mind, so one should be even thinking about these risk factors in midlife.

AUBREY: All the Alzheimer's experts I interviewed agreed with this notion. There's a clear overlap between brain and heart disease risks. But what hasn't been worked out yet is exactly how to control or reduce the risks of dementia. In theory, if you take the findings of this recent study linking high cholesterol to Alzheimer's, you might think that simply lowering cholesterol would reduce the risk of dementia. But it may not be that easy. Sam Gandy heads Alzheimer's research at the Mt. Sinai School of Medicine in New York. He says there've been several experiments with people taking statin medications. These are the drugs most widely used to lower cholesterol. [POST-BROADCAST CORRECTION: Dr. Gandy is associate director of the Alzheimer's Disease Research Center at Mount Sinai School of Medicine.]

Dr. SAM GANDY (Associate Director, Alzheimer's Disease Research Center, Mount Sinai School of Medicine): Unfortunately, so far they've been disappointing. Despite the fact that in these trials cholesterol has been controlled, we haven't seen the expected impact on later dementia that we would have hoped.

AUBREY: It's possible that people didn't start taking statins early enough in life. Or it's possible that there's some other process in the body that leads to dementia, even when cholesterol and other risk factors are controlled. Researchers are looking at genetics. It could be that genes contribute to a buildup of a protein in the brain called amyloid beta. Brain imaging studies suggest that people with Alzheimer's tend to have abnormal accumulations of amyloid in their brains. Reisa Sperling says figuring out a way to prevent the buildup would be significant.

Dr. SPERLING: I envision a time where we will treat Alzheimer's disease just the way we treat cholesterol, or we will find agents that lower amyloid and we will give them to people in a preventative fashion.

AUBREY: There are some anti-amyloid therapies already being tested, but this could be a long way off. If the strategy pans out, Sterling says it may be the best hope for prevention.

Allison Aubrey, NPR News. Transcript provided by NPR, Copyright National Public Radio.