Low Cholesterol on Shaky Ground

March 2, 2006:-  The mantra in many medical circles concerning LDL cholesterol continues to be "the lower the better," which is understandable because LDL cholesterol, under certain circumstances, is the one that can clog arteries, leading to heart attacks and strokes. But our bodies need LDL because, among other things, it is critical for cellular membrane walls, it forms a protective sheath around the peripheral nerves and it is a precursor for a number of the body's hormones.

Some medical professionals have serious concerns about the drive to lower LDL through statin medications, as I have written about before. They point out that possible repercussions of very low LDL (that found in a total cholesterol level of less than 160 mg/dl) include impaired mental functioning, such as depression and anxiety. Now another worrisome link between low LDLs and possible neurological impairment has emerged via a study from the University of North Carolina, Chapel Hill.

THE LDL-PARKINSON'S CONNECTION

The study found that men with LDL levels between 91 and 135 were six times more likely to have Parkinson's disease (PD) than men with LDL levels higher than 135... men with LDL levels below 91 were four times more likely. This is particularly startling because many doctors consider LDLs of 130 as the point at which statin treatment should begin. I spoke with Xuemei Huang, MD, PhD, lead author of the study, about the possible causes for this increased risk.

Dr. Huang theorizes about several possible explanations, including that the body uses cholesterol to help rid itself of environmental toxins that may be contributory to PD. Furthermore, she says, as a precursor of hormones and chemical modulators, cholesterol may contribute to a variety of central nervous system functions.

The study results did not find a correlation between lowered LDLs and PD in women, but Dr. Huang points out interesting gender considerations about PD in general. The onset of PD is usually after people turn 60, and two-thirds of those affected people are male. Men's LDL cholesterol begins to drop naturally around age 65 while women's natural decrease doesn't start until age 75. Perhaps, she says, the naturally lower LDL levels in men at a younger age relates to why more men develop PD.

Future studies will have to examine that issue, but in the meantime Dr. Huang has advice based on her study. Specifically, she says that people who do not have a family risk of cardiovascular disease but who do have PD in the family, especially if it is a sibling, should think carefully before taking statins or beginning treatment strategies to lower cholesterol. She does not suggest that people who already have PD and are on statin therapy stop it, however, because the study suggests that lower LDLs came before onset of PD. As for general advice, she reminds people that the cultural belief in her native China supports the idea of balance in all things and it might be time to reconsider the belief that promoting low, lower and lowest LDL levels isn't optimal, at least for some groups, after all.

Be well, Carole Jackson, Bottom Line's Daily Health News