Bring 'bad' cholesterol down, regardless
Research suggesting a link between low levels of LDL cholesterol and Parkinson's is preliminary

Dr. Andrew Weil, Vancouver Sun
Published: Monday, January 14, 2008

Q: I just read that if you have low LDL cholesterol, you have a higher risk of Parkinson's disease. Does that mean you shouldn't try to lower your LDL if you have a family history of Parkinson's?

A: Parkinson's disease is a neurological condition affecting the "substantia nigra," a small area of cells in the midbrain. Degeneration of these cells results in lower levels of the neurotransmitter dopamine (a brain-signaling chemical) and upsets the balance between dopamine and another brain chemical, acetylcholine. The most familiar signs of the disease are resting tremors, a generalized slowness of movement, stiff limbs, and problems with balance or gait. Depression is also common. In advanced cases, mental function can deteriorate. Parkinson's disease is progressive and incurable.

A small study from the University of North Carolina (UNC) at Chapel Hill suggests that people with low LDL (low-density lipoprotein, the "bad" cholesterol) are more likely to develop Parkinson's than those whose LDL is high. (As far as your heart is concerned, low LDL is good -- the lower it is, the lower your risk of heart disease.) The North Carolina researchers tested the cholesterol of 124 Parkinson's patients being treated at the UNC Movement Disorder Clinic and 112 spouses of clinic patients. They found that those with LDL levels of less than 114 (mg per deciliter) had a 3.5 times higher incidence of Parkinson's than study participants whose LDL was more than 138.

However, we don't know whether the Parkinson's patients' LDL was low before the onset of the disease. The researchers did determine that study participants with Parkinson's were less likely to have taken cholesterol-lowering drugs than those in the control group.

While these findings are interesting, the investigators described them as preliminary and called for larger studies to help clarify how LDL affects the risk of Parkinson's.

In the meantime, if your LDL cholesterol is high, you should follow medical advice to bring it down. After all, it's long been known that smoking is linked to a lower risk of Parkinson's, but it's certainly not a good idea to take up cigarettes to protect yourself from the disease. Keep the relative risks in mind: the incidence of Parkinson's disease is 12 to 20 cases per 100,000 persons per year. The incidence of heart disease is 1 in 12.

Iodine therapy

Q: I just had my thyroid removed due to papillary cancer. I am told that radioactive iodine to destroy the tiny remnant of thyroid tissue remaining after surgery is recommended, that it's "well tolerated" and has "no side effects." My research (and intuition) tell me otherwise! What is your opinion?

A: As I'm sure you know by now, the type of thyroid cancer you had is very slow-growing and very rarely fatal, particularly in younger people. Radioactive iodine is used to destroy any thyroid tissue that wasn't removed by surgery in order to be sure that all traces of cancer are eliminated. It is considered to be a safe procedure.

I discussed your case with Randy Horwitz, M.D., medical director of the Program in Integrative Medicine, and Merilyn Goldschmid, M.D., an endocrinologist; both are here at the University of Arizona. Both agreed that the use of radioactive iodine in cases such as yours is appropriate and carries low risk. Dr. Goldschmid advised a single dose of radioactive iodine and recommended that you drink plenty of fluids following your treatment to flush the iodine out of the salivary gland, the only gland beside the thyroid that can retain it. She and Dr. Horwitz also cautioned that women need to use contraception for about a year after the treatment, because radioactive iodine can affect the ovaries. Women's periods can become irregular for a while but should return to normal at the end of a year.

Side effects of radioactive iodine treatment are rare, but occasionally patients do experience some neck tenderness, nausea and stomach irritation, dry mouth and tenderness of the salivary glands (sucking on lemon drops can reduce this). There is a very small risk of developing leukemia in the future. In my view, the risk of the iodine treatment is much lower than that of leaving a bit of cancer behind following thyroid surgery. Therefore, I suggest that you follow your physician's recommendations and have the treatment. I know of no alternative that would serve you as well.

The views expressed in this column are the author's. Readers are advised always to consult their doctor for specific information on personal health matters. The naming of any product or therapy in this column does not represent an endorsement by The Vancouver Sun.

Ask Dr. Weil does not provide specific medical advice and is not intended as a substitute for the advice provided by your physician or other health-care professional. You should always consult your physician to discuss specific symptoms and conditions.

Readers who wish to ask Dr. Weil a question may do so by visiting his Web site, www.drweil.com, and clicking "Ask Dr. Weil" and then "Ask Your Question." Because Dr. Weil receives so many questions, it is impossible for him to personally respond to every query.