Monday, March 03, 2008

HDL cholesterol supports the brain too

HDL cholesterol may slow the aging process, and not just with respect to the heart. The worthy little HDL protein plays a pivotal role in reverse cholesterol transport, toting the fatty goo out of the tissues--including blood vessel walls--and back to the liver for elimination from the body. Low levels are a common abnormality in patients destined to develop coronary artery disease, even when total cholesterol values are in the normal range. Researchers have now found a correlation between robust HDL levels and mental clarity in the oldest of the old.

Scientists at the Institute for Aging Research in New York City conducted a study of healthy, really old people (average age 99). They found that these remarkable centenarians maintained much higher HDL levels than expected for their age. HDL levels decline with the passage of time by approximately 5 points for every 8 years. According to this formula, the expected HDL level in this gasp of geezers should've been 20 but averaged 55.

Across the study group, HDL levels were directly related to scores on the Mini-Mental State Examination. The higher the HDL's, the more agile the aging brain. Investigators note that cholesterol plays a key role in maintaining connections between brain cells and processing beta amyloid protein, the tenacious gunk that gums up the neural works in Alzheimer's disease.


Laura in L.A. said...

Does this mean that maybe Alzheimer's patients shouldn't take cholesterol lowering drugs? I know my 73-year-old daddy with AD takes a pill for cholesterol. Of course, he's an odd AD patient because he's still a long distance runner (finished the L.A. Marathon on Sunday! :))with a heartrate in the 40's. I'll have to find out what his HDL is. I'm always looking for ways to help his cognitive functioning!

As always, I love your blog. :)

Femail doc said...

Odd AD patient indeed. LA Marathon? Wow, that's amazing. I think on average he's better off with lower cholesterol. Generally these meds do not affect the HDL level much one way or the other.

Laura in L.A. said...

Thanks for the answer, I feel better.

Yep, my daddy finished the L.A. Marathon in 6:58:16, which makes him 55th out of 80 runners in the men's age 70-74 division! (My momma at age 70 was 8th out of 17 runners in the women's age 70-74 division. :)) The folks have run most of the big city marathons over about 12 years. I am convinced that the extreme exercise has helped slow the progression of my dad's AD. He has no major health problems other than AD; that helps too.

janemariemd said...

Hi Laura--

I saw some data that show that exercise increases blood flow to the brain, and some people think it might ward off dementia. It just seems reasonable to suppose your folks are reaping huge benefits from their exercise, so I suspect you are right!