Cholesterol, Explained: It’s (Sometimes) Good for You, and Doesn’t Come From Exactly Where You Think

Cholesterol isn’t straightforward. It’s “good” and it’s “bad.” It’s in eggs and fatty food—but most of it is produced inside your body. But understanding how it relates to you and your diets starts with a simple checkup at the doctor.  

As a 33-year-old man whose genetics gave him an ectomorphic body, I don’t often think about cholesterol. For better or worse, I tend to only recall that one episode of “Parks and Recreation” when steak-loving, Lagavulin-swilling Ron Swanson wonders what cholesterol even is.

Most of us, however, are primed to think about cholesterol as a silent bogeyman come to wreak bodily havoc, mainly for the role it can play in heart disease. The truth, as always, is a bit more complicated. 

Consider that most of the cholesterol in your body is actually generated not by hamburgers and sunny-side up eggs, but by your body. What you eat contributes only about one-fifth of your total cholesterol level. Your liver and your intestines make the rest, and that’s because cholesterol plays a number of crucial functions within the body. The waxy, yellow fat is part of all animal cells; in humans, it’s mortar for our cell membranes. Cholesterol is essential for many of the body’s metabolic processes. It plays a role in producing hormones like estrogen and testosterone. It’s required to make vitamin D, which we recently told you was so important for your immune function.

“We need cholesterol,” says Angel Planells, a Seattle-based registered dietitian and spokesman for the Academy of Nutrition and Dietetics. “The question comes up about how much do we need, or am I getting too much.” So let’s break it down.

The Good, the Bad, and the Ugly

Because cholesterol is a fat, it can’t travel around the body by its lonesome. Instead, it’s packaged into lipoproteins, particles that move cholesterol and other fats around the body via the bloodstream. This is where we get the LDL and HDL that we hear about when it comes to our cholesterol levels.

The former, standing for low-density lipoprotein, is the bad cholesterol. It transports cholesterol throughout the body, which is useful, but excess amounts can build up, lining our blood vessels and making it difficult for blood and oxygen to flow. These deposits—commonly known as plaques—can break, forming clots and blockages that may lead to a heart attack or stroke. Meanwhile, HDL is high-density lipoprotein, the good cholesterol that picks up excessive amounts of the stuff in your body for transport back to the liver, where it gets chewed up.

Keep in mind, however, that your body is a calibrated system that enjoys balance. The number to keep in mind is 200 milligrams per deciliter. Ideally, this is your total cholesterol level, incorporating both LDLs and HDLs. If this is the goal level, then the LDL level should be under 100 milligrams per deciliter. Very high LDL levels—think close to 190—will warrant lifestyle measures and other treatments to keep cholesterol in check.

Cholesterol Check

If you see a primary-care doctor for annual checkups, your yearly blood work will provide your level. And for men over 35 and women over 40, it’s important to have an idea of what that is.

“This provides the opportunity to focus on ‘primary prevention,’ or preventing the development of heart disease by making sure that you are following a healthy diet and exercising regularly, as well as maintaining a healthy weight,” says Anne Thorndike, an associate professor of medicine at Harvard Medical School and director of the Metabolic Syndrome Clinic at Massachusetts General Hospital.

Several risk factors, including obesity, smoking, and a poor diet can contribute to high cholesterol.

“Our body tightly regulates the amount of cholesterol in the blood by controlling its production. If you eat foods with greater amounts of cholesterol, our body will make less, and vice versa,” Planells said. “So for many people, what you eat will not have an impact, but for others, cholesterol could increase if a person consumes high-cholesterol foods.”

Fried foods, red meat, and baked goods can increase levels of LDL cholesterol, while foods high in fiber—fruits, vegetables, oatmeal, whole grains—can help maintain a good balance of LDL and HDL cholesterol. (Remember, people: balance in all things.) Getting exercise, at least 30 minutes a day, will also help you manage your cholesterol.

“That being said, some people are genetically predisposed to high levels of cholesterol and early heart disease,” says Thorndike, who also serves as volunteer chair of the American Heart Association’s Nutrition Committee.

What About Statins?

People genetically predisposed to high cholesterol, or people with accompanying risk factors like old age, high blood pressure, and diabetes, might be good candidates for taking drugs that help lower cholesterol. These drugs are known as statins. You know what statins are if you’ve ever seen a commercial for Lipitor while watching football. These drugs work by blocking the production of cholesterol in the body. 

Going on any prescription is a decision that begins with a conversation with your doctor. In addition to discussing your risk factors and getting a measurement of your cholesterol levels, a clinician might also use a calculator that determines your risk for cardiac arrest over the next decade. The calculator also takes into account your age, blood pressure, and whether you smoke or have diabetes. Generally, Thorndike says, a risk score greater than 10% will lead a doctor to recommend a statin.

Knowing about the health of your liver is also crucial, since it’s the liver that breaks down and metabolizes drugs. (You don’t want toxic levels of statins in your blood due to a faulty liver.) But the side effects of statins are rare: Of the millions of people per year who take statins, only a few of them will develop serious complications.

In any event, you’ll want to get exercise and keep a good diet to manage cholesterol. The baked goods or ribeye steak you may cherish can stick around. But maybe think about eating broccoli or rice, too.