Suggestions of a statin link are not new, but the results of a recent study linking low LDL cholesterol to Parkinson's provide the strongest evidence to date that it could be real, because statins work by reducing LDL cholesterol. The study by researchers at University of North Carolina showed that patients with low levels of LDL cholesterol are more than three and a half times more likely to develop Parkinson's disease than those with higher LDL levels.

When asked whether she was concerned by the new results, study leader Xuemei Huang said: 'Yes I am very concerned, which is why I am planning a 16000-patient prospective study to examine the possible role of statins.' Huang was quick to point out, however, that a causal link with statins had not yet been proven. And Yoav Ben-Shlomo, a professor of clinical epidemiology at University of Bristol said that it is also a possibility that LDL cholesterol is a consequence rather than a cause of Parkinson's.

But according to Huang, the well-established link between Parkinson's and apoE2, a gene associated with lower LDL cholesterol, supports her theory that low LDL is the culprit in many cases of Parkinson's.

Huang says that if there is a link with statins, we could see big surges in the number of Parkinson's diagnoses in the next five years, because at that stage, statins will have been in common usage for more than a decade.

Huang's new study will examine the statin link. A total of 16000 patients for whom 20 years of baseline fasting cholesterol measurements are available will be involved. Another large-scale trial investigating a cholesterol link with Parkinson's risk is underway at Harvard. This study differs in that there are no baseline data available for the study group.

Pfizer's statin Lipitor is the world's biggest selling drug with $12.2bn in sales in 2005. Parkinson's has previously been linked with pesticides. Pfizer were unavailable for comment.

Source: Society of Chemical Industry