When we talk about cholesterol, it generally refers to cholesterol in the blood. This is waxy, fatty, and can be found in every cell in the body. The body uses cholesterol to make hormones, vitamin D, and bile acid, which help 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 (also known as plaque) in the arteries, making the heart work harder to circulate blood.
The plaques can rupture and cause blood clots that block blood to the brain (a stroke ) or the heart ( a heart attack ). For these reasons, LDL is nicknamed “bad” cholesterol. In contrast, HDL carries cholesterol from the entire body to the liver, which removes it from the body and is called “good cholesterol.”
Having high cholesterol largely refers to having too much LDL and this puts you at higher risk for heart disease. In general, there are no signs or symptoms that indicate you have high cholesterol, which is part of the reason why heart disease, the number one killer of men and women, is called a silent killer.
Myths about cholesterol
It is worth noting that the body produces all the cholesterol it needs, so there is no biological need to obtain it from food, although it is present in foods of animal origin and is called “dietary cholesterol.”
1. Eating cholesterol increases cholesterol
It seems like a pretty reasonable assumption, right? So before 2015, dietary guidelines 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 does not raise blood cholesterol to worrying levels and that it is no longer a public health reduction goal. That said, many foods that contain cholesterol, such as red meat, also contain saturated fat. Also, low-cholesterol diets, such as plant-based ones, can be very healthy.
2. Coffee raises cholesterol
Some short-term studies found that unfiltered coffee increased LDL. The good news is that filtered coffee, which is much more common, doesn’t seem to affect cholesterol much. They note that there is strong evidence that it is okay for healthy adults to enjoy a cup or two of coffee a day without worrying about increasing their risk of heart disease, cancer or premature death.
3. Fatty foods are full of cholesterol
Not all fatty foods are rich. In fact, cholesterol is only found in foods of animal origin. That means fatty plant foods like avocados, walnuts, and olive oil are naturally cholesterol-free.
These foods appear in many of the healthiest eating patterns. In particular, walnuts and olive oil are called key components of a very heart-healthy Mediterranean diet.
4. Replacing saturated fat with carbohydrates is a healthy way to lower cholesterol.
According to the 2015 guidelines, replacing saturated fat with carbohydrates lowers total and LDL cholesterol (this is a good thing). However, it also increases triglycerides and lowers HDL (which is not that great). Replacing saturated fat with carbohydrates can be especially harmful if those carbohydrates come from refined grains and added sugars (soda, cookies, or potato chips, for example).
For better health, you should lower your total and LDL cholesterol by eating polyunsaturated fats instead of saturated fats. For every one percent of calories exchanged (PUFA in, SFA out), the risk of heart disease is reduced by 2 to 3 percent. For a 2,000 calorie diet, that equates to just 20 calories (about two grams) of saturated fat to replace and start to reap the benefits. Some foods high in polyunsaturated fats include salmon, trout, sunflower oil, walnuts, and tofu.
5. A poor diet is the only reason
Most people with high cholesterol have unbalanced diets . However, one in 500 people will remove LDL from the bloodstream, leaving it accumulated in the blood and causing damage that could lead to an early heart attack, stroke, or cardiac arrest before age 65.
Up to 90 percent of people with this genetic condition do not know they have it. Although this is a different route to high cholesterol, treating it still begins 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, vegetables, nuts, and oils. Depending on your situation, your doctor may add cholesterol-lowering medications to the mix, but a healthy lifestyle is an important foundation for treatment.
6. Only Adults Need to Have Their Cholesterol Tested
National standards for health screenings recommend that even healthy children have their cholesterol levels checked once when they are between 9 and 11 years old, and again when they are between 17 and 21 years old.
By comparison, adults without risk factors should check their cholesterol once every four to six years. It’s a good idea to talk to your doctor to find out if there are risk factors that may require more regular monitoring (for example, smoking, diabetes, obesity, high blood pressure, a family history of premature heart disease).
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. In general, total cholesterol scores above and beyond 200 milligrams per deciliter of blood are red flags. Within total cholesterol scores are results for LDL, HDL, and very low-density lipoprotein (VLDL).
The lowest risk of heart disease is associated with LDL of less than 100 milligrams per deciliter, HDL of more than 60 milligrams per deciliter, and triglycerides of less than 150 milligrams per deciliter (that is, 30 milligrams per deciliter of VLDL).