Cholesterol-lowering drugs may help to delay the progression of Alzheimer’s disease, the leading cause of dementia in the elderly, French scientists said on Thursday.

In a three-year study involving 342 Alzheimer’s patients, they found that the illness did not develop as quickly in sufferers with High cholesterol levels who were given statins as in patients not taking the drugs.

Professor Florence Pasquier, of the University Hospital in Lille, France, said the drugs “may slow cognitive decline in Alzheimer’s disease and have a neuroprotective effect.”

Nearly 130 patients in the study had High cholesterol levels. About half were given statins while the remainder did not receive any treatment.

The findings, which are reported in the Journal of Neurology Neurosurgery and Psychiatry, support the results of other human and animal studies which have suggested that High cholesterol levels may play a role in the progression of Alzheimer’s.

Most of the patients in the study were women. Their average age was 73. The progression of the disease was rated at 1.5 points a year for the women taking the drugs, compared to 2.4 for those who were not treated with statins and 2.6 for patients with normal cholesterol levels.

Millions of people around the world are prescribed the drugs. Pfizer’s Lipitor, Merck & Co. Inc’s Zocor and AstraZeneca’s Crestor are among the leading statins. The drugs lower cholesterol by inhibiting an enzyme that controls how much is produced in the body.

In an editorial in the journal, Dr Frank-Erik de Leeuw, of University Medical Center in Nijmegen in the Netherlands, said more work needs to be done before any conclusions about the usefulness of statins for Alzheimer’s disease can be drawn.

“There is conflicting evidence for a causal relation between cholesterol, its treatment, and the incidence of Alzheimer’s disease,” he added.

Alzheimer’s affects an estimated 12 million people around the world. There is no cure for the progressive illness that robs people of their memory and mental ability but drug treatments may slow its early progression.