From 2002 through 2018, more than 21 million statins were bought annually in the U.S. to lower levels of bad LDL cholesterol, which is known to clog arteries and cause strokes and heart attacks.

In contrast, no one thinks much about the good HDL cholesterol, which is designed to shuttle excess LDL cholesterol out of the bloodstream and soft plaques in artery walls to the liver, where it's ushered from the body. It also stimulates production of nitric oxide, which helps counter high blood pressure and prevents blood clots.

But it isn't always such a good guy. Various particles of HDL can help transfer fat into (not out of) LDL cholesterol and cells, and power up LDL with oxygen so it's even more destructive.

The key to getting the positive benefits of HDL cholesterol is to have it, along with LDL and triglycerides, at healthy levels. You want HDL at 45 mg/dL to 60 mg/dL, triglycerides at less than 50 mg/dL, and LDL below 70 mg/dL.

(You may be told higher levels than that for LDL and triglycerides are acceptable for optimal HDL functioning, but they aren't optimal for avoiding a heart attack or stroke.)

A blood test can reveal your lipid levels, but getting your apolipoprotein B (apoB) level measured provides a clearer idea of your cardiovascular disease risks.

If your HDL is low:

• Exercise regularly doing moderate-intensity activities and/or HIIT.

• Lose 5% to 10% of your weight, if needed.

• Ditch highly processed foods. Add lean proteins such as skinless poultry, fish, tofu, beans, and lentils.

• Limit alcohol to one to two drinks daily.

• Don’t smoke anything.