When we talk about cholesterol, it's usually in reference to blood cholesterol. It's waxy, fatty and can be found in all of the body's cells. The body uses cholesterol to make hormones, vitamin D and bile acid, which helps break down fats. Cholesterol travels in the bloodstream in low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Too much LDL can cause cholesterol buildup (aka plaque) in the arteries, which makes your heart work harder to circulate blood. Plaques can break open and cause blood clots that block blood to the brain (a stroke) or to the heart (a heart attack). For these reasons, LDL is nicknamed "bad" cholesterol. In contrast, HDL carries cholesterol from around the body back to the liver, which removes it from the body, earning it the "good cholesterol" moniker.
Having high cholesterol largely refers to having too much LDL and puts you at greater risk for heart disease. There aren't typically signs or symptoms to let you know you have high cholesterol, which is part of why heart disease — the No. 1 killer of men and women — is called the silent killer. It's worth noting that the body makes all the cholesterol it needs, so there's no biological need to get it from food, though it is present in animal foods and is referred to as "dietary cholesterol."
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Myth 1: Eating cholesterol raises cholesterol
It seems like a reasonable enough assumption, right? Which is why prior to 2015, the Dietary Guidelines for Americans (DGAC) recommended a daily limit of 300 milligrams of cholesterol, with the idea that eating cholesterol raised blood cholesterol, a risk factor for heart disease.
However, the most recent review of the evidence found that eating cholesterol doesn't raise blood cholesterol to worrying levels and that it's no longer a public-health target for reduction (egg lovers, rejoice). That said, many cholesterol-containing foods, such as red meat, also contain saturated fat, which raises cholesterol more than eating cholesterol does. Plus, low-cholesterol diets, such as plant-based ones, can be very healthy.
Myth 2: Coffee raises cholesterol
According to the 2015 DGAC, some short-term studies found that unfiltered coffee raised LDL. The good news is that filtered coffee, which is much more common, doesn't seem to affect cholesterol much at all. They note that there is strong evidence that it's OK for healthy adults to enjoy three to five cups of coffee a day (or up to 400 milligrams per day of caffeine) without worrying about raising their risk of heart disease, cancer or premature death. There's even evidence that moderate coffee intake actually reduces the risk of Type 2 diabetes, heart disease and liver and endometrium cancers. That's something to drink (coffee) to.
Myth 3: Fatty foods are full of cholesterol
Not all fatty foods are cholesterol-rich. In fact, cholesterol is only found in animal foods. That means fatty plant foods like avocados, nuts and olive oil are naturally cholesterol-free. These foods are featured in many of the healthiest eating patterns. In particular, nuts and olive oil are called out as key components of the very heart-healthy Mediterranean-style diet.
Myth 4: Replacing saturated fat with carbs is a healthy way to lower cholesterol
According to 2015 guidelines, replacing saturated fat with carbohydrates brings total and LDL cholesterol down (this is a good thing). However, it also increases triglycerides and lowers HDL (not such a good thing). Replacing saturated fat with carbs can be especially harmful if those carbs are coming from refined grains and added sugars (soda, cookies, crackers and chips).
For a better health bargain, lower total and LDL cholesterol by eating polyunsaturated fats (PUFA) instead of saturated fats. For every one percent of calories that are swapped out (PUFA in, SFA out), the risk of heart disease goes down by 2 to 3 percent. For a 2,000-calorie diet, that's a mere 20 calories' (about two grams) worth of saturated fat to replace to start reaping benefits. Some PUFA-rich foods include salmon, trout, sunflower oil, walnuts, tofu and soybeans.
Myth 5: A poor diet is the only reason cholesterol gets too high
Most people with high cholesterol have unbalanced diets to thank. However, one in 500 people are missing the gene that takes LDL out of the bloodstream, leaving it to build up in the blood and cause damage that could lead to an early heart attack, stroke or cardiac arrest before age 65.
According to Harvard Medical School, up to 90 percent of people with this genetic condition are unaware that they have it. Even though this is a different route to high cholesterol, treating it still starts with eating better and moving more. In particular, that means exercising regularly, eating less red meat and full-fat dairy, and eating more fish, whole grains, veggies, nuts and oils. Depending on your situation, your doctor may add cholesterol-reducing drugs into the mix, but a healthy lifestyle is an important foundation for treatment.
Myth 6: Only adults need to have their cholesterol tested
National standards for health screenings recommend that even healthy children get cholesterol levels checked once when they are 9 to 11 years old, and again when they are 17 to 21 years old. By comparison, adults without risk factors should get their cholesterol checked once every four to six years. It's a good idea to talk to your doctor if there are risk factors that may require more regular monitoring (e.g., smoking, diabetes, obesity, high blood pressure, family history of premature heart disease).
Myth 7: The only number I need to know is my total cholesterol
The total cholesterol score is a starting point, but not the whole cholesterol picture. Generally speaking, total cholesterol scores above and beyond 200 milligrams per deciliter of blood are red flags. Within the total cholesterol scores are results for LDL, HDL and very low-density lipoproteins (VLDL).
The lowest risk for heart disease is associated with LDL under 100 milligrams per deciliter, HDL above 60 milligrams per deciliter and triglycerides under 150 milligrams per deciliter (i.e., 30 milligrams per deciliter VLDL).
Any scores on the wrong side of these levels means you should start a discussion with your health care provider.