A lot of things that are bad for your heart can also hurt your brain. High cholesterol, for example, contributes to heart disease. And it ups your risk of Alzheimer's and dementia. Another heart and brain hazard is called C-reactive protein, or CRP. It’s a marker for inflammation in your body. High levels are associated with heart disease and cognitive decline.

Unless, that is, you're over 75. Because in a study of nearly 300 elderly men, researchers found that the guys with the highest levels of CRP were just half as likely to have siblings or parents with dementia—which bodes well for them. Those results are in the journal Neurology. [Jeremy M. Silverman et al., C-reactive protein and familial risk for dementia]

Another study found the same counterintuitive link between high cholesterol and better memory function in folks in their 80s. [R West et al, Better memory functioning associated with higher total and low-density lipoprotein cholesterol levels in very elderly subjects without the apolipoprotein e4 allele, American Journal of Geriatric Psychiatry, 2008]

It's not that these things suddenly become good for your brain later in life. Instead, these older individuals and their families probably have genes protecting them against these risk factors, allowing them to stay healthy in spite of high cholesterol and CRP. The next step, the researchers say, is to zero in on those dementia-proof genes. So maybe more of us can access that protection.

—Christopher Intagliata

[The above text is a transcript of this podcast.]