(CNN) A new analysis of clinical trials reverses current thinking on giving statins to most people over 75, finding that the cholesterol-lowering drugs benefit all ages with minimal risk.
"There has been a longstanding controversy over whether statins are effective and safe in the elderly," said the University of Oxford's Colin Baigent, a member of the Cholesterol Treatment Trialists' Collaboration, an international group of doctors and researchers who conducted the analysis.
"I think the debate about whether statins are associated with particular hazards has got out of control," Baigent said, "and it's blinding us to the clear evidence of benefit that we already have."
The Cholesterol Treatment Trialists' Collaboration has been studying statins since 1995. Its newest meta-analysis was published Thursday in the medical journal The Lancet.
In this analysis, the group looked at 23 randomized controlled trials and another five that investigated intensive vs. standard statin therapy. There were over 185,000 people with an average age of 63 in those trials. Almost 15,000 were over 75.
Although the analysis found a slight dip in benefit for the oldest patients, it wasn't enough to keep the researchers from recommending the use of statins for people who, "simply because of their age, are at higher risk of cardiovascular disease," said Baigent, who directs the Medical Research Council Population Health Research unit at the University of Oxford.
"If this was a policy that was adopted more widely," Baigent said, "this could prevent many thousands of deaths per year in the UK alone and many more deaths worldwide."
In an related editorial, Bernard Cheung, a professor at the University of Hong Kong, agreed.
"The present meta-analysis makes a case to reduce LDL cholesterol in people at risk of cardiovascular events regardless of age," Cheung said, "provided that the benefits outweigh the risks and the patient accepts long term treatment."
Heart disease is a global killer. According to the World Health Organization, more people die each year from cardiovascular disease than from any other cause. In the United States, 1 in 4 deaths each year is due to heart disease; in the UK, the number exceeds 150,000.
A new report from the American Heart Association shows that heart disease is on the rise again in the United States. Due partly to a change in blood pressure guidelines, which lowered risk levels, nearly half of all adults in the United States have some type of cardiovascular disease, defined as coronary heart disease, heart failure, stroke or high blood pressure.
Cardiovascular disease and stroke hit the elderly the hardest, yet some doctors have been reluctant to prescribe risk-reducing drugs called statins, Baigent said, because of inconclusive evidence of the benefits for anyone over 75.
That thinking, Baigent said, had been fueled by poor-quality studies with known flaws. When only large, randomized clinical trials were reviewed, the benefits for the elderly are clear.
"We found statin therapy reduces the risk of major vascular events by about 20 percent for every millimoles per liter reduction in LDL, or bad, cholesterol," Baigent said, "and it's effective throughout the age range, including in those over 75."
In the United States, cholesterol is measured by milligrams of cholesterol per deciliter of blood; in the UK, Canada and Europe, it's measured by millimoles per liter. Current US guidelines recommend that anyone at risk for cardiovascular disease keep that bad cholesterol under 100 mg/dL or 2.6 mmol/L. Those with signs of disease should strive for levels below 70 mg/dL or 1.8 mmol/L.
Cardiologist Dr. Kevin Campbell, who was not involved with the analysis, said it is not surprising that the elderly saw fewer positive results from use of the drugs.
"Statins protect us from cardiovascular events over time," Campbell said. "Over the long haul, those over 75 do not have the same 'longevity' as those who are younger.
"Nonetheless, those in that age group should be considered for statin therapy," Campbell said. "As always, the risks must not outweigh the benefits when choosing any treatment -- particularly in elderly populations who may be more prone to side effects."
Statins work by blocking the action of a liver enzyme that is responsible for producing cholesterol, a waxy, fat-like substance found in all the cells of the body. Though the body needs cholesterol to create vitamin D and hormones and digest food, the liver makes all that the body needs.
When it consumes foods with saturated or trans fats, such as often found in baked goods or fried and processed foods, the body can end up with more cholesterol than it can manage. The excess can back up in the arteries and create plaques that hinder blood flow, leading to strokes, heart attacks and heart disease.
Statins can lower low-density lipoprotein, or LDL, known as the "bad" type of cholesterol; another type of fat called triglycerides; and total overall cholesterol levels.
At the same time, statins can raise high-density lipoprotein, or HDL, considered the "good" type of cholesterol because it helps the liver remove excess cholesterol from the body.
The drugs are even being investigated as possible treatments for cancer, autoimmune and inflammatory diseases.
Side effects such as liver damage, bleeding, neurological effects and the possibility of increasing the risk for Type 2 diabetes have worried patients and doctors for years, but recent studies seem to show that the benefits of statins far outweigh any risk.
It may depend on the type of statin used, however. A study released last year found that risk levels were lower for the statin drugs atorvastatin and rosuvastatin than for simvastatin and pravastatin.
Muscle pain and weakness are the most commonly reported complaints about statins. However, several double-blind randomized studies show that only about 1% of patients develop muscle symptoms that are probably caused by these drugs.
One extremely rare and serious side effect, called rhabdomyolysis, can damage the cells of muscle tissue but is most likely to occur when statins are taken with other medications that carry a similar risk.
There were two categories of elderly patients in whom statins showed no benefit in the meta-analysis: people with moderate to severe heart failure and those with end-stage renal disease who were on dialysis.
Statin use is not also not recommended for pregnant women or anyone with current or chronic liver disease.