Taking statins may help to prevent Alzheimer’s disease, a study has directly suggested for the first time.

Researchers in the US claim to have uncovered clear evidence that the cholesterol-lowering drugs – taken daily by about three million people in Britain – could ward off the illness. The large-scale study, conducted at Boston University from 2002, found that the drugs may cut the risk of getting Alzheimer’s by as much as 79 per cent, even in people thought to be genetically susceptible to the disease. The lead author, Gail Li, said the study was the first to compare the brains of people who had received statins with those who had not.

Previous research has indicated that Alzheimer’s may be caused by poor blood flow and vascular changes in the brain, which statins may help to prevent. Dr Li, from the University of Washington School of Medicine in Seattle, and her colleagues examined the brains of 110 Americans who had died aged between 65 and 79, and had donated their organs for research.

The two changes in the brain considered the hallmarks of Alzheimer’s are known as brain “plaques” and “tangles”. These are protein deposits that appear to spread in the brain, although the cause of Alzheimer’s is not yet fully understood.

The researchers found significantly fewer tangles in the brains of people who had taken statins than those who had not, even allowing for variables such as age, gender and past health.

Eric Larson, a co-author of the study, said: “These results are exciting, novel and have important implications for prevention strategies.” He said further studies were needed to confirm the findings but praised the researchers’ reliance on automated records and postmortem examinations of people with and without dementia.

Dr Li said: “Statins are probably more likely to help prevent the disease in certain kinds of people than others. Some day we may be able to know more precisely which individuals will benefit from which types of statins.”

In June, the National Institute for Health and Clinical Excellence (NICE) published draft guidance suggesting millions of people should be assessed to find out how many more would benefit from statins, which are estimated to prevent up to 7,000 deaths a year from heart attacks and strokes.

Information collected routinely by GPs should be used to identify those most at risk of developing cardio-vascular disease, it said.

Adults who have a 20 per cent or greater risk of developing heart disease over the next decade should be offered statins, it added.

Such a move would double the number of people prescribed the drug to about six million. Final guidance from NICE is expected in January.

Other studies suggest a downside to statins. They are known to interact with other drugs and can have side-effects, including abdominal pain, diarrhoea and nausea.

In July researchers in Massachusetts found that people who took statins had a slightly increased risk of cancer. Statins reduce levels of low-density lipoprotein, an enzyme involved in the transportation of “bad” cholesterol.

There are currently 700,000 people with dementia in Britain, of whom about two thirds have Alzheimer’s.

Statin stats

— Statins reduce blood levels of cholesterol, the fatty substance that builds up in arteries, and save an estimated 7,000 lives a year

— The drugs are often given to patients after a heart attack or bypass surgery

— Statins can trigger muscle weakness, which can progress to rhabdomyolysis, a complete breakdown of muscle cells that can lead to kidney failure and death

Source: Times database

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