Statins have been around since the late 1980s as cholesterol-lowering drugs, but in the last decade or so they've been earning 'superdrug' status.
They've been found to dramatically cut the risk of heart attack and stroke. It's also claimed that they reduce the risk of dementia, could ease some symptoms of multiple sclerosis, protect those with diabetes against cardiovascular disease and may even trigger the 'suicide' of some cancer cells.
Oxford University's Heart Protection Study, the world's largest study of cholesterol-lowering drugs, recruited 20,000 people with an increased risk of cardiovascular disease - people with diabetes, angina or high blood pressure, plus people who'd already had heart attacks, strokes and mini-strokes.
After seven years' monitoring, they reported in 2002 that taking a statin every day cut the risk of heart disease and stroke by a third. The drugs worked on people with normal cholesterol levels as well as people with very high levels. Over-75s benefited too, suggesting it's never too late to address raised cholesterol levels.
Currently the UK's national service framework advises doctors to prescribe statins for people whose risk of heart disease is greater than 30% over ten years. But with evidence that statins can be effective even with a 1% increased risk, some experts are calling for lower thresholds and wider availability.
In May 2006 a group of doctors led by Paul Durrington, professor of medicine at the Manchester Royal Infirmary, wrote in Heart Today that for effective heart disease prevention, 'statin treatment must be provided for most men from middle age onwards and for most older women'
High blood pressure
Professor Peter Sever at Imperial College, London, leader of the British arm of a huge Anglo-Scandinavian study, looked at 9,000 patients with hypertension. The study was halted two years early because the statin had such a dramatic effect on cutting the risk that the researchers decided it wasn't fair for half the group to be taking a placebo!
Professor Sever commented: "There are eight million people with high blood pressure in Britain. If our results are correct, and I know no reason why they should not be, we could be potentially preventing 20,000 to 30,000 strokes and heart attacks a year if they were all taking statins."
A trial involving nearly 6,000 people with diabetes, half of whom showed signs of cardiovascular disease, found that taking a statin everyday cut the risk of cardiovascular problems by about a third in both groups.
Lead researcher of the study, Professor Rory Collins said: "People with diabetes have a higher risk of heart attacks and strokes than the general population, and most of their deaths are due to cardiovascular disease." Dr Sue Roberts, the UK's National Clinical Director for diabetes, said the research provided clear evidence that taking statins was an effective way for people with diabetes to ward off cardiovascular problems.
Preliminary results suggest that people with such different problems as osteoporosis and multiple sclerosis, or patients recovering from transplants, might all benefit from taking statins.
In 2005 researchers in Toronto discovered that statins seem to trigger the self-destruction of some cancer cells in the laboratory, but only at higher than normal doses. Statins have also been linked positively with arthritis and erectile dysfunction
Dr David Dracman, Professor of Neurology at the University of Massachusetts Medical School, examined the medical records of 60,000 British patients over 50, divided into groups of people prescribed statins to lower their cholesterol, people who hadn't been prescribed statins, plus people with normal cholesterol levels. He found that 70 per cent fewer people on statins developed dementia compared to those who were not.
However, another study reported in the Archives of Neurology failed to concur. Researchers at the University of Washington studied 2,798 people with an average age of 75 who had no sign of cognitive problems at the start of the study. The team monitored those who developed dementia, including Alzheimer's, over a six-year period. Those participants who took statins developed dementia at the same rate as those not taking the drug.
Far from discounting statins, the team believes that the average age of the participants could explain the negative findings. Larry Sparks, an Alzheimer's researcher at the American Sun Health Research Institute, agrees.
"Maybe if you start giving these drugs when people are 50 instead of 75, you'll get a better effect," he argues. Sparks published a small study suggesting that statin drug atorvastatin helps boost memory and cognitive ability in people with mild to moderate Alzheimer's.
Statins in the UK
Around 2.5million people take statins in the UK. But with a much wider population that could potentially benefit from the drug, debate is raging about how we could pay for medicating otherwise well people, effectively for life.
Statins cost an average of £152.52 a year per patient. The NHS bill for statins in 2004 came to £769m. Meeting this cost could mean diverting money from other treatments or even increasing taxes.
Some experts argue that if we did more to tackle the root causes of high cholesterol - through healthy eating and physical exercise, for instance - there'd be no need to be giving out statins to such a huge group.
The UK was the first country to make a statin - Simvastin - available over the counter. Simvastin is available in low doses on the high street, but this has caused some controversy because statins needs to be used with caution by heavy drinkers and people with a history of liver disease.
How statins work in the body
Statins work by blocking the action of a certain enzyme in the liver which makes 'bad' cholesterol (LDL) and slightly raises levels of 'good' cholesterol HDL.
Most people who take a statin have no side-effects, or only minor ones. But one statin, cerivastatin (named Baycol), was withdrawn in 2001 after some people suffered a severe and sometimes fatal muscle reaction.
The most common symptoms include headache, pins and needles, stomach upset, muscle and joint aches, diarrhoea, and a rash. If you experience any of these, report them to you doctor when they occur - do not wait for you next visit.