Last week, the American College of Cardiology and the American Heart Association unveiled new recommendations that could greatly increase the number of Americans taking cholesterol-lowering statin drugs, which they believe will reduce the incidence of heart attacks and strokes in the United States. But, the new recommendations have already stirred controversy among some of the country's leading cardiologists.

Before we get to the "why" of the new guidelines, let's look at the "what" statins are, and what they get prescribed for. Statins are a class of drugs, prescribed by doctors to help lower cholesterol levels in the blood.

Cholesterol is a substance created and used by our bodies for digestion, hormonal balance and cell function, but at high concentrations can gum up arteries. Cholesterol comes from two sources: your body and food. Your liver and other cells in your body make about 75 percent of blood cholesterol. The other 25 percent comes from the foods you eat. Cholesterol is only found in animal products.

You've probably heard that there is "good" cholesterol and "bad," and it's important to understand the difference, and what levels of "good" and "bad" cholesterol are in your blood. Too much of one, or not enough of another could put you at risk for coronary heart disease, heart attack and stroke. Statins reduce cholesterol by blocking the liver's production of the waxy substance. Studies show statins can reduce the risk of heart attacks and stroke in certain patients by 25 to 35 percent. Studies also show that statins can reduce the chances of recurrent strokes and heart attacks by nearly 40 percent. So, let's look at the new guidelines and why has it prompted a debate.

Under the new guidelines, physicians are urged to prescribe statins to:

• Anyone with a history of cardiovascular disease, or high odds of suffering a heart attack or stroke in the short-term such as those who've already had such an event • People with Type 2 diabetes, and those with exceptionally high levels of LDL cholesterol (the bad type) linked to familial risk • People with Type 1 or Type 2 diabetes who are 40 to 75 years old • People 40 to 75 years old, who do not have cardiovascular disease, but have a 7.5 percent or higher risk of suffering a stroke or heart attack over the next decade • People 21 and older who have a very high level of LDL cholesterol (190 mg/dL or higher).

Until now, treatment guidelines recommended cholesterol-lowering drugs generally for patients judged to have a 20 percent probability of heart attack – around 36 million Americans. The new, expanded treatment guidelines would almost double that figure.

Why the controversy?

A couple of professors at Harvard Medical School have voiced concerns that an estimated 13 million to 16 million, of the 33 million middle-aged adults targeted by the new guidelines for statin therapy, do not have sufficiently high odds of having a heart attack or stroke over the next decade to warrant statin use.

In 2010, Americans spent more than $21 billion on cholesterol-lowering medications including statins marketed under such brand names as Crestor, Lipitor and Zocor. Truth is, in the past two to three years, most physicians have been using patient data - other than just cholesterol levels - to determine those who would benefit from taking statins. A young patient with a total cholesterol level in the 150s might not be as much at risk as an older patient whose cholesterol is around 120. There are many, many variables. including:

• History of cardiovascular disease or peripheral artery disease (PAD) • Diabetes • High blood pressure • Age (over 45 for men, 55 for women) • Ethnicity • Smoker.

Sizing up your risk for heart disease and stroke is a very individualized matter and should be made by your doctor, armed with the most accurate information you can provide your health care team.

Bryan C. Hughes, M.D., is in family practice at Oak Grove Medical Clinic and can be reached at 816-690-6566.