Heart Disease and The Cholesterol Connection
Medically reviewed by Dr. C.H. Weaver M.D 2/2020
Every day we are bombarded with messages about our food. With so many foods labeled “cholesterol free,” it can be easy to assume that cholesterol is a bad thing. But the truth is that although there is no dietary requirement for cholesterol, this complex fatty substance is vital to our health.
What Is Cholesterol?
Cholesterol is a soft, waxy substance found in the bloodstream and in each cell of your body. It is an important structural component of human and animal cells and serves as a building block for many hormones.2
There are two general sources of cholesterol: your body and your food. The liver and other cells in the body produce about 75 percent of the cholesterol that circulates in the bloodstream. The remaining 25 percent is a result of the food you eat.
Cholesterol is essential to life, but, as with anything, too much of a good thing can be bad. Hypercholesterolemia is a medical term that refers to high levels of cholesterol in the blood. The condition is associated with a higher risk of cardiovascular disease and stroke. According to the Centers for Disease Control and Prevention, one in six Americans has high blood cholesterol.
Sometimes people refer to “good” cholesterol and “bad” cholesterol. Low-density lipoproteins, or LDLs, are the “bad” cholesterol that can build up and form plaque that blocks arteries and potentially leads to heart attack or stroke. High-density lipoproteins (HDLs), on the other hand, appear to protect against heart attacks by carrying cholesterol away from the arteries and back to the liver.
What Causes High Cholesterol?
Cholesterol levels are maintained by a number of regulated steps and to a large extent are genetically predetermined. Several lifestyle factors can affect cholesterol levels, however, including diet, obesity, and smoking.
Being overweight or obese can raise blood cholesterol levels, so losing as little as 10 percent of total weight, or 10 to 20 pounds, is often enough to lower the levels into a range that is associated with a reduced risk of heart disease. Tobacco and high blood pressure also raise blood cholesterol levels, so quitting smoking will make a big difference (for a number of health concerns). Type 2 diabetes is an additional risk factor.
When you put all of these risk factors together, the risk of heart disease is elevated six times.
Diet and Cholesterol
Foods that are naturally rich in cholesterol include egg yolks and organ meats. In the United States, most of the cholesterol in our diet comes from meat—especially processed meats, which include organ meats. For many people simply reducing the amount of meat, whole eggs, and dairy products in their diet is enough to bring cholesterol levels into a healthy range.
The National Cholesterol Education Program recommends consuming a diet that contains less than 200 milligrams of cholesterol per day. To put that number in perspective, a large egg yolk has 212 milligrams, so eating an egg each day would exceed this limit. We don’t need to assess day by day, however, but can take an average amount within our usual eating pattern. For example, using this method, eating a couple of eggs twice a week would be within the recommended limit. Of course, if you are eating other food sources of cholesterol, such as meat, you would need to be more careful of your intake of egg yolks. Egg whites have no cholesterol and are an excellent choice for extending eggs in omelets and other breakfast dishes.
Saturated fats, especially those that come from dairy and meat sources, also raise blood cholesterol levels. Saturated fats are described as “solid fat” in newer government guidelines because they are solid at room temperature. The recommended amount depend on a person’s activity level. A very active teenage boy might consume 3,200 calories, with 20 percent coming from extra discretionary calories, but a sedentary woman who burns 1,600 calories a day would have a smaller allowance of 8 percent of “extras.”
Making Healthy Choices
There are three major diet regulators of healthy blood cholesterol levels.
1. Avoid saturated fat. Eating a diet that is low in meat and saturated animal fats (processed meats like sausage and full-fat dairy products, for example) appears to regulate liver production of cholesterol and is more important in some people than in others. Interestingly, the liver is capable of making as much as 80 percent of your cholesterol requirements, so we don’t actually need to consume it in the diet. This is why vegans who don’t consume any cholesterol usually don’t suffer from cholesterol deficiency.
2. Consume dietary fiber. Foods such as vegetables, beans, and fruit contain indigestible carbohydrates called dietary fiber. Fiber helps modify the intestinal environment, providing support for beneficial microorganisms (probiotics), and it appears to benefit overall health. Nuts like almonds or pistachios, which are high in fiber, may be helpful in lowering cholesterol levels by providing dietary fiber as well as healthy oils.
3. Consume plant sterols. Plant sterols, or phytosterols, are the plant version of cholesterol. These compounds, which are found in beans, vegetables, and many other plant foods, appear to compete for cholesterol in the small intestine and thus reduce the overall blood levels.
4. Physical Activity. You can help manage your cholesterol levels by staying active. Exercise can help you maintain a healthy weight, which will help to control your cholesterol levels. According to the Surgeon General, you should aim for at least 30 minutes of moderate-intensity activity most days of the week.
5. Don’t Smoke Smoking, in addition to raising your risk of lung cancer and several other cancers, raises your risk of heart disease and stroke by damaging the blood vessels and hardening the arteries. If you do smoke, your doctor can help you find a program to help you quit. Also, be aware of secondhand smoke, another risk of heart attack and stroke.
Taking Care of Your Cholesterol Levels
Cholesterol is a complicated and active area of nutrition research. Diet appears to affect some people more than others. For most of us, eating a diet that is made up of predominantly plant rather than animal fats is healthy for our hearts and could reduce the risk of other chronic conditions, including many forms of cancer.
Questions to Ask Your Doctor
- What is my risk of heart disease?
- What is my blood pressure? What does it mean for me, and what do I need to do about it?
- What are my cholesterol numbers? [These include total cholesterol, LDL, HDL, and triglycerides—a type of fat found in the blood and in food.] What do they mean for me, and what do I need to do about them?
- What are my body mass index and waist measurement? Do they mean that I need to lose weight for my health?
- What is my blood sugar level, and does it mean that I’m at risk for diabetes? If so, what do I need to do about it?
- What other screening tests do I need to help protect my heart?
- What can you do to help me quit smoking?
- How much physical activity do I need to help protect my heart?
- What’s a heart-healthy eating plan for me? How can I tell if I’m having a heart attack? If I think I’m having one, what should I do?
Medications to Treat High Cholesterol
These drugs are aimed primarily at controlling LDL cholesterol levels, and your doctor will take into account your current LDL level to select the appropriate treatment. Your risk of heart disease and stroke (based on high blood pressure, smoking status, age, HDL level, and early heart disease and whether you have diabetes or existing cardiovascular disease) will also guide treatment decisions.
- Statin drugs. These work by lowering LDL cholesterol and slowing down the liver’s production of cholesterol. As well, statins can boost the liver’s ability to remove LDL cholesterol from the blood.
- Bile acid sequestrants. These drugs eliminate bile acids to help remove cholesterol from the blood. The body, which needs bile acids, will then make more and does so by breaking down LDL cholesterol. As a result, LDL levels are reduced.
- Niacin, or nicotinic acid. Niacin, a B vitamin, can help the body achieve healthy levels of all cholesterols. Nicotinic acid lowers total cholesterol, while also lowering LDL and triglyceride levels and raising HDL levels. These medicines, however, are associated with possible side effects and medical supervision is required.
- Fibrates. Fibrates are mainly intended to lower triglyceride levels but can also raise HDL levels.
Links and Further Reading
Centers for Disease Control and Prevention
National Heart, Lung, and Blood Institute
The NHLBI provides information and publications about heart disease and heart health.
U.S. Department of Agriculture
The USDA Web site provides quick access to total calories, main food group (grains, vegetables, fruits, milk, or meat and beans), and “extras” (solid fats, alcohol, and added sugars, or SoFAAS). This site also provides comparisons between foods.
This is the USDA Web site linked to the dietary guidelines for Americans; it provides tools to personalize recommendations for you and your family.
American Heart Association