Cholesterol, a fat-like substance, travels around in your bloodstream in high-density lipoproteins (HDL) and low-density lipoproteins (LDL).
HDL is known as good cholesterol because it gobbles up cholesterol and takes it back to the liver for disposal.
LDL carries cholesterol around to the parts of your body that need it. It’s sometimes referred to as bad cholesterol. This is because if you have too much of it in your bloodstream, it can cling to the walls of your arteries, eventually clogging them up.
Narrowed or blocked arteries can prevent blood from reaching your heart, brain, or other organs. This can lead to stroke, heart attack, or even heart failure.
Your liver produces all the cholesterol you need. You can also get a lot of cholesterol from food.
In general, high levels of HDL and low levels of LDL help reduce the risk of heart disease.
What the research says
For decades, research has indicated that diet and cholesterol play a role in heart health. More recent research suggests that the connection may be more complex.
The association between cholesterol and heart disease
The 2015-2020 Dietary Guidelines for Americans recommend eating as little dietary cholesterol as possible. It points to studies and trials that have produced strong evidence that eating patterns can reduce the risk of heart disease in adults. However, the 2010 recommendation to limit dietary cholesterol to 300 milligrams per day wasn’t included in the recent guidelines.
An eight-week study published in 2016 stated that elevated LDL is an established risk factor for heart disease. According to this study, dietary fatty acids play a significant role in the development of heart disease. The researchers wrote that minor dietary changes, such as choosing foods with better fat quality, could potentially reduce cholesterol and your future risk of heart disease.
Researchers raise questions
Newer research questions the role cholesterol plays in the development of heart disease.
A paper published in 2012 notes that while 50 years of research indicated a strong positive correlation between dietary cholesterol and heart disease, newer research doesn’t support that.
The authors found that most people don’t have an increase in blood cholesterol due to diet. Of those who do, both HDL and LDL rise. They concluded there’s a need to rethink guidelines for dietary cholesterol, especially for healthy people.
A systematic review published in 2016 found that people over 60 years old who have high LDL cholesterol live as long or longer than people with low LDL. The researchers suggest re-evaluating the guidelines for heart disease prevention in older adults.
It’s worth noting that this review has some limitations. The team chose studies from only one database, and only those published in English. The review did not look at HDL cholesterol levels, other health or lifestyle factors, or use of cholesterol-lowering medications.
Sources of cholesterol in your diet
More research on cholesterol, particularly dietary cholesterol, needs to be done. Even so, it’s clear that diet plays an important role in heart health and overall health.
Trans fats and saturated fats
Trans fats raise your LDL cholesterol and lower your HDL cholesterol. Both of these changes are associated with increased risk of heart disease, according to the American Heart Association. Trans fats also offer no nutritional value.
Partially hydrogenated oils (PHOs) are the main source of trans fat in our diets. They’re found in many types of processed foods.
In 2016, the U.S. Food & Drug Administration determined that PHOs aren’t safe for human consumption. They’re now being phased out of our food supply. In the meantime, try to avoid food that lists PHOs or trans fats on the label.
Saturated fats are another source of LDL cholesterol and should be consumed sparingly. Foods containing saturated fats include:
- sweet treats and pastries such as donuts, cakes, and cookies
- sugary beverages
- red meat, fatty meat, and highly-processed meat
- palm and coconut oils
- cocoa butter, butter, shortening, lard, and stick margarine
- fried foods
- whole-fat dairy products such as milk, butter, cheese, and cream
These high-cholesterol foods, along with processed and fast foods, can contribute to weight gain and obesity. Being overweight or obese raises your risk of heart disease, as well as other health conditions.
These foods may help lower LDL and raise HDL, and help manage your weight:
- oats and oat bran
- barley and other whole grains
- beans and lentils including navy, kidney, garbanzo, and black-eyed peas
- nuts, including walnuts, peanuts, and almonds
- citrus fruits, apples, strawberries, and grapes
- okra and eggplant
- fatty fish such as sardines, mackerel, and salmon
- olive oil
Healthy cooking tips
- use canola, sunflower, or safflower oil in place of butter, shortening, or lard
- grill, broil, or bake instead of frying
- trim the fat off meats and remove skin from poultry
- use a rack to drain fat off meat and poultry cooked in the oven
- avoid basting with fat drippings
What are the risk factors for heart disease?
Having high blood cholesterol is one risk factor for heart disease. Other risk factors include:
- high blood pressure
- diabetes and prediabetes
- family history of heart disease
- having had preeclampsia during a pregnancy
- being overweight or obese
- physical inactivity
- unhealthy diet
Your risk for heart disease increases with age. For women, the risk rises after menopause.
Your chance of developing heart disease rises with each additional risk factor. Some factors, like age and family history, are out of your control. Others, like diet and exercise, are within your control.
What’s the outlook?
Untreated, heart disease can lead to a variety of complications including:
You’ll need to work closely with your doctor to monitor your condition. If you need medications to control high blood pressure, cholesterol, diabetes, or other problems, take them exactly as directed. Tell your doctor about any new symptoms.
Along with healthy lifestyle changes, this can help improve your overall outlook.
Tips for preventing heart disease
Here are a few things you can do to lower your risk of developing heart disease:
- Watch your weight. Being overweight tends to make your LDL rise. It also puts added strain on your heart.
- Get active. Exercise can help control your weight and improve your blood cholesterol numbers.
- Eat right. Choose a diet high in vegetables, fruits, and whole grains. Nuts, seeds, and legumes are also heart-healthy foods. Opt for lean meats, skinless poultry, and fatty fish over red or processed meat. Dairy products should be low fat. Avoid trans fats altogether. Choose olive, canola, or safflower oils over margarine, lard, or solid shortening.
- Don’t smoke. If you currently smoke, talk to your doctor about smoking cessation programs.
- Get an annual checkup, especially if you have a family history of heart disease. The sooner you discover you may be at risk, the sooner you can take action to help prevent heart disease.