Maintaining a healthy diet, exercising, and — for some — taking medication to control cholesterol are all good for your heart. And following cholesterol-lowering recommendations from your doctor can help prevent heart disease, including heart attack.

So why is lowering cholesterol still such a challenge?

A number of common barriers get in the way. Here are 10 ways that you may sabotage your own efforts to reduce cholesterol, along with smart steps for getting back on track:

Mistake 1: You Ignore Dietary Sugar and Alcohol

When you get a high-cholesterol diagnosis, it seems natural to focus on limiting the bad fats — saturated and trans fats — in your diet. But you may be overlooking sugary foods and alcohol, which also contribute to high cholesterol, says Erin D. Michos, MD, associate professor of medicine and associate director of cardiology at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease in Baltimore.

In your body, excess calories from sugar and alcohol are turned into cholesterol and triglycerides that can contribute to unhealthy cholesterol levels in your blood. "People don't realize that this is why their numbers are not getting any better, even though they're reducing fat and exercising," says Dr. Michos.

To get back on track, cut down on all sources of sugar, including sweetened drinks, alcohol, and refined carbohydrates like white bread and pasta, and opt for whole grains rich in cholesterol-lowering fiber.

Mistake 2: You Focus Only on LDL Cholesterol Levels

You might be focused on your low-density lipoprotein (LDL) cholesterol number alone — the so-called "bad" component of blood cholesterol — which should optimally be below 100 milligrams per deciliter (mg/dL).

Pay attention to your whole lipid profile, which includes total cholesterol, LDL, HDL, and triglycerides, too, to get to your healthiest levels.

Mistake 3: You Interrupt Your Medication Schedule

Drugs to treat high cholesterol, including statins, have a proven impact on cholesterol levels and may prevent heart attack in people with coronary heart disease. Although one in four U.S. adults takes a statin, according to a 2014 Centers for Disease Control and Prevention (CDC) health survey published in December 2014, not everyone takes them as recommended. About half of people prescribed statins stop taking them within the first year, and the numbers go down from there, notes a review published in January 2013 in the journal Current Atherosclerosis Reports, often because of drug side effects. But when you don't take medication on schedule, you won't get the heart-health benefits.

Take your medication as prescribed, and talk with your doctor about any concerns you're facing, whether it's a matter of timing, cost, or side effects.

Mistake 4: You Eat Whatever You Want

Taking statins doesn't mean you can ignore advice about a cholesterol-lowering diet, stresses Michos. Many people wrongly believe their medication will undo any cholesterol overload, regardless of what they eat.

Even while you're on medication, watch your calorie intake in addition to the fats and carbohydrates that could be contributing to unhealthy cholesterol levels. Indulge instead in cholesterol-lowering foods, like beans, fiber-rich apples, and whole grains.

Mistake 5: You Cut Out All Dietary Fat

Not all fats have to be avoided. It's true that you should cut out trans fats and saturated fats, says Michos, who adds, "The biggest source of trans fats is baked goods, like crackers and cookies."

But you do need heart-healthy monounsaturated and polyunsaturated fats — found in olive oil, olives, nuts like walnuts and almonds, and the omega-3 fatty acids in fish — in moderation, Michos explains. Watch the calorie count, which can add up fast even with healthy fats, but do include small amounts in your diet.

Mistake 6: You Don't Find Out What Your Cholesterol Numbers Are

High cholesterol has no symptoms, so if you don't get tested, you don't know you have it.

The American Heart Association (AHA) advises having your cholesterol checked every four to six years starting at age 20 — or more frequently if you're at risk.

Mistake 7: You Ban the Wrong Foods

It's true that if you have high cholesterol you should watch the amount of fat in your diet, and trans fat and saturated fat in particular. This means you need to make thoughtful choices about what you eat, and be sure to get enough protein in your diet. "Eggs are rich in protein and nutrients," says Michos. So you can have one egg, if you want it — just don't eat it with a fatty slab of steak and a glass of whole milk.

A healthy substitution, such as non-fat or low-fat instead of full-fat dairy, can allow you to keep eating favorite foods while still aiming to reduce cholesterol levels.

Mistake 8: You Stop Exercising

"Diet alone is often not enough — it should be combined with exercise," says Michos. Research published in June 2011 in the journal Heart reviewed health data from 4,469 British civil servants between ages 39 and 62 and showed that, over an 11-year period, increasing physical activity and eating more healthfully helped to lower LDL cholesterol.

Keep up with exercise, because successfully lowering high cholesterol takes a multi-pronged approach. Talk to your doctor about the role of diet and exercise in getting to your healthiest cholesterol levels.

RELATED: Can High Cholesterol Ever Be Healthy?

Mistake 9: You Yo-Yo Diet

How do you know which cholesterol-reducing weight-loss diet to choose, from those on the market? Michos says the diets that seem to work best for improving heart health and reducing cholesterol are not necessarily new.

She recommends a Mediterranean diet, which emphasizes fruits, vegetables, whole grains, healthy fats, and fish. Stick with this diet, watch portions and count calories, and you can achieve weight loss, counter high cholesterol, and get off the roller coaster of sampling the latest trendy diet.

Mistake 10: You Take Statins With Grapefruit Juice

Maybe you want to get a healthy start to your day and take your statins with breakfast. But if your breakfast includes grapefruit juice, that can interfere with your cholesterol control medication. Ask your doctor if your cholesterol-lowering medication is likely to be affected by grapefruit juice.

Michos notes that it's a good idea to separate your medication and grapefruit juice by many hours. So go ahead and drink grapefruit juice in the morning, but plan on taking your statin in the evening. This schedule is often recommended because your liver, where the statin is active, makes more cholesterol at night.

Cholesterol-reducing treatments of diet, exercise, and medication really do work. If your cholesterol numbers still aren't coming down enough to reach your personal goal, talk to your doctors about what might be keeping you from the level of success you need.