Cholesterol: Beyond good and bad, there's big

Are you confused about cholesterol and all of the different terms you hear to describe it?  Well, let me see if I can explain.  Lipoprotein particles are the packages that carry cholesterol through the bloodstream. Low-density lipoprotein particles (LDLs) are considered “bad” because they let cholesterol sit and fester in arteries, allowing atherosclerotic plaque to pile up, which can lead to heart attack and stroke.

But LDLs come in various sizes, and the smallest seem to have the worst health effects. Their size lets them burrow into arterial walls, triggering the atherosclerotic process.

“Good” high-density lipoprotein particles (HDLs) also come in different sizes, and the bigger ones seem to be better at carting cholesterol back to the liver for disposal than the smaller ones. HDLs may have other healthful effects that size boosts.

So bigger seems to be better for both HDL and LDL, although routine testing for size isn’t recommended just yet. File it under “more research needed.” But there are indications that lipoprotein size might very well be worth monitoring in the future.

For one thing, large lipoproteins may be one of the keys to longevity. At a symposium on the science of aging at Harvard Medical School in 2007, Dr. Nir Barzilai presented data showing that the centenarians he is following in his aging study are 10 times more likely to have large lipoprotein particles than controls. He has also found that the children of centenarians have large LDL and HDL particles, which suggests that it’s a heritable trait.

Identifying the genetic pathway that produces larger lipoproteins could help scientists find ways of mimicking the lipoprotein-enlarging process.

Dr. Barzilai, who is director of Aging Research at Albert Einstein College of Medicine in New York, has homed in on the cholesteryl ester transfer protein (CETP) gene as the likely source of large lipoproteins. His research shows that centenarians are roughly three times more likely to have a beneficial CETP mutation than controls.

Moreover, the right sort of CETP gene may help keep our brains healthy as we age. Dr. Barzilai reported in a study published in 2006 that centenarians with good cognitive function are twice as likely to have a certain CETP mutation as less able-minded counterparts.

But we don’t need a scientific breakthrough to start working on bulking up the size of our lipoproteins:

·         Studies have already shown that exercise, that all-purpose elixir, will do the trick quite nicely.

·         One reason moderate consumption of alcohol may be good for us is that it increases lipoprotein size.

·         We can avoid trans fat, the kind of fat found in partially hydrogenated vegetable oils. Studies have shown that trans fat seems to promote small LDL particles.

Have you made changes to your diet that you think worked well?  What are they?

High Cholesterol
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