Cholesterol is made in your liver and has many important functions. For example, it helps keep the walls of your cells flexible and is needed to make several hormones.
Like anything in the body, too much cholesterol or cholesterol in the wrong places creates problems.
Like fat, cholesterol does not dissolve in water. Instead, its transport in the body depends on molecules called lipoproteins, which carry cholesterol, fat and fat-soluble vitamins in the blood.
Different kinds of lipoproteins have different effects on health. For example, high levels of low-density lipoprotein (LDL) result in cholesterol deposits in blood vessel walls, which can lead to clogged arteries, strokes, heart attacks and kidney failure (1).
In contrast, high-density lipoprotein (HDL) helps carry cholesterol away from vessel walls and helps prevent these diseases ( 2).
The Link Between Dietary and Blood Cholesterol
The liver produces as much cholesterol as the body needs. It packages cholesterol with fat in very low-density lipoproteins (VLDL).
As VLDL delivers fat to cells throughout the body, it changes into the more dense LDL, or low-density lipoprotein, which carries cholesterol wherever it is needed.
The liver also releases high-density lipoprotein (HDL), which carries unused cholesterol back to the liver. This process is called reverse cholesterol transport, and protects against clogged arteries and other types of heart disease.
Some lipoproteins, especially LDL and VLDL, are prone to damage by free radicals in a process called oxidation. Oxidized LDL and VLDL are even more harmful to heart health (3).
Although food companies often advertise products as low in cholesterol, dietary cholesterol actually only has a small influence on the amount of cholesterol in the body.
This is because the liver changes the amount of cholesterol it makes depending on how much you eat. When your body absorbs more cholesterol from your diet, it makes less in the liver.
For example, a study randomly assigned 45 adults to eat more cholesterol in the form of two eggs daily. In the end, those eating more cholesterol did not have higher total cholesterol levels or changes in lipoproteins, compared to those eating less cholesterol (4).
While dietary cholesterol has little influence on cholesterol levels, other foods in your diet can worsen them, as can family history, smoking and a sedentary lifestyle.
Likewise, several other lifestyle choices can help increase the beneficial HDL and decrease the harmful LDL. Below are 10 natural ways to improve your cholesterol levels.
1. Focus on Monounsaturated Fats
As opposed to saturated fats, unsaturated fats have at least one double chemical bond that changes the way they are used in the body. Monounsaturated fats have only one double bond.
Although some recommend a low-fat diet for weight loss, a study of 10 men found a 6-week, low-fat diet reduced levels of harmful LDL, but also reduced beneficial HDL (5).
In contrast, a diet high in monounsaturated fats reduced harmful LDL, but also protected higher levels of healthy HDL.
A study of 24 adults with high blood cholesterol came to the same conclusion, where eating a diet high in monounsaturated fat increased beneficial HDL by 12%, compared to a diet low in saturated fat ( 6).
Monounsaturated fats may also reduce the oxidation of lipoproteins, which contributes to clogged arteries. A study of 26 people found that replacing polyunsaturated fats with monounsaturated fats in the diet reduced the oxidation of fats and cholesterol (7, 8).
Overall, monounsaturated fats are healthy because they decrease harmful LDL cholesterol, increase good HDL cholesterol and reduce harmful oxidation (9).
Here are a few great sources of monounsaturated fats. Some are also good sources of polyunsaturated fat:
Olives and olive oil
Tree nuts, such as almonds, walnuts, pecans, hazelnuts and cashews
Summary Monounsaturated fats like those in olive oil, canola oil, tree nuts and avocados reduce the “bad” LDL, increase the “good” HDL and reduce the oxidation that contributes to clogged arteries.
2. Use Polyunsaturated Fats, Especially Omega-3s
Polyunsaturated fats have multiple double bonds that make them behave differently in the body than saturated fats. Research shows that polyunsaturated fats reduce “bad” LDL cholesterol and decrease the risk of heart disease.
For example, one study replaced saturated fats in 115 adults’ diets with polyunsaturated fats for eight weeks. By the end, total and LDL cholesterol levels were reduced by about 10 per cent (10).
Another study included 13,614 adults. They replaced dietary saturated fat with polyunsaturated fat, providing about 15 per cent of total calories. Their risk of coronary artery disease dropped by nearly 20 per cent (11).
Polyunsaturated fats also seem to reduce the risk of metabolic syndrome and type 2 diabetes.
Another study changed the diets of 4,220 adults, replacing 5% of their calories from carbohydrates with polyunsaturated fats. Their blood glucose and fasting insulin levels decreased, indicating a decreased risk of type 2 diabetes (12).
Omega-3 fatty acids are an especially heart-healthy type of polyunsaturated fat. They’re found in seafood and fish oil supplements (13, 14).
Omega-3 fats are found in high amounts in fatty fish like salmon, mackerel, herring and deep sea tuna like bluefin or albacore, and to a lesser degree in shellfish including shrimp (15).
Other sources of omega-3s include seeds and tree nuts, but not peanuts.
Summary: All polyunsaturated fats are heart-healthy and may reduce the risk of diabetes. Omega-3 fats are a type of polyunsaturated fat with extra heart benefits.
3. Avoid Trans Fats
Trans fats are unsaturated fats that have been modified by a process called hydrogenation.
This is done to make the unsaturated fats in vegetable oils more stable as an ingredient. Many margarines and shortenings are made of partially hydrogenated oils.
The resulting trans fats are not fully saturated, but are solid at room temperatures. This is why food companies have used trans fats in products like spreads, pastries and cookies — they provide more texture than unsaturated, liquid oils.
Unfortunately, partially hydrogenated trans fats are handled differently in the body than other fats, and not in a good way. Trans fats increase total cholesterol and LDL, but decrease beneficial HDL by as much as 20% ( 16, 17).
A study of global health patterns estimated trans fats may be responsible for 8% of deaths from heart disease worldwide. Another study estimated a law restricting trans fats in New York will reduce heart disease deaths by 4.5 per cent (18, 19).
In the United States and an increasing number of other countries, food companies are required to list the amount of trans fats in their products on nutrition labels.
However, these labels can be misleading, because they are allowed to round down when the amount of trans fat per serving is less than 0.5 grams. This means some foods contain trans fats even though their labels say “0 grams of trans fat per serving.”
To avoid this trick, read the ingredients in addition to the nutrition label. If a product contains “partially hydrogenated” oil, it has trans fats and should be avoided.
Summary Foods with “partially hydrogenated” oil in the ingredients contain trans fats and are harmful, even if the label claims the product has “0 grams of trans fat per serving.”
4. Eat Soluble Fiber
Soluble fiber is a group of different compounds in plants that dissolve in water and that humans can’t digest.
However, the beneficial bacteria that live in your intestines can digest soluble fiber. In fact, they require it for their own nutrition. These good bacteria, also called probiotics, reduce both harmful kinds of lipoproteins, LDL and VLDL (20, 21).
In a study of 30 adults, taking 3 grams of soluble fiber supplements daily for 12 weeks decreased LDL by 18 per cent (22).
A different study of fortified breakfast cereal found that added soluble fiber from pectin reduced LDL by 4 per cent and fiber from psyllium reduced LDL by 6 per cent (23).
Soluble fiber can also help increase the cholesterol benefits of taking a statin medication.
One 12-week study had 68 adults add 15 grams of the psyllium product Metamucil to their daily 10-mg dose of the lipid-lowering medication simvastatin. This was found to be as effective as taking a larger 20-mg dose of the statin without fiber (24).
Soluble fiber’s benefits reduce the risk of disease. A large review of several studies found high fiber intakes of both soluble and insoluble fiber reduced the risk of death over 17 years by nearly 15 per cent (25).
Another study of over 350,000 adults found those eating the most fiber from grains and cereals lived longer, and they were 15–20 per cent less likely to die during the 14-year study (26).
Some of the best sources of soluble fiber include beans, peas and lentils, fruit, oats and whole grains. Fiber supplements like psyllium are also safe and inexpensive sources.
Summary Soluble fiber nourishes healthy probiotic gut bacteria and removes cholesterol from the body, reducing LDL and VLDL. Good sources include beans, peas, lentils, fruit, psyllium and whole grains including oats.
Exercise is a win-win for heart health. Not only does it improve physical fitness and help combat obesity, but it also reduces harmful LDL and increases beneficial HDL (27, 28).
In one study, twelve weeks of combined aerobic and resistance exercise reduced the especially harmful oxidized LDL in 20 overweight women (29).
These women exercised three days per week with 15 minutes each of aerobic activity including walking and jumping jacks, resistance-band training and low-intensity Korean dance.
While even low-intensity exercise like walking increases HDL, making your exercise longer and more intense increases the benefit (30, 31).
Based on a review of 13 studies, 30 minutes of activity five days a week is enough to improve cholesterol and reduce the risk of heart disease.
Ideally, aerobic activity should raise the heart rate to about 75 per cent of its maximum. Resistance training should be 50 per cent of maximum effort.
Activity that elevates the heart rate to 85 per cent of its maximum increases HDL and also decreases LDL. The longer the duration, the greater the effects (32).
Resistance exercise can decrease LDL even at modest intensity. At maximum effort it also increases HDL. Increasing the number of sets or repetitions increases the benefit (32).
Summary Any type of exercise improves cholesterol and promotes heart health. The longer and more intense the exercise, the greater the benefit.
6. Lose Weight
Dieting influences the way your body absorbs and produces cholesterol. A two-year study of 90 adults on one of three randomly assigned weight loss diets found weight loss on any of the diets increased the absorption of cholesterol from the diet and decreased the creation of new cholesterol in the body (33).
Over these two years, “good” HDL increased while “bad” LDL did not change, thus reducing the risk of heart disease.
In another similar study of 14 older men, “bad” LDL decreased as well, providing even more heart protection (34).
A study of 35 young women showed decreased creation of new cholesterol in the body during weight loss over six months (35).
Overall, weight loss has a double benefit on cholesterol by increasing beneficial HDL and decreasing harmful LDL.
Summary Weight loss reduces total cholesterol, in part by decreasing the creation of new cholesterol in the liver. Weight loss has had different, though generally beneficial, effects on HDL and LDL in different studies.
7. Don’t Smoke
Smoking increases the risk of heart disease in several ways. One of these is by changing how the body handles cholesterol.
The immune cells in smokers are unable to return cholesterol from vessel walls to the blood for transport to the liver. This damage is related to tobacco tar, rather than nicotine (36).
These dysfunctional immune cells may contribute to the faster development of clogged arteries in smokers.
In a large study of several thousand adults in Pacific Asia, smoking was associated with decreased HDL levels and increased total cholesterol (37).
Fortunately, giving up smoking can reverse these harmful effects (36, 38).
Summary Smoking appears to increase bad lipoproteins, decrease “good” HDL and hinder the body’s ability to send cholesterol back to the liver to be stored or broken down. Quitting smoking can reverse these effects.
8. Use Alcohol in Moderation
When used in moderation, the ethanol in alcoholic drinks increases HDL and reduces the risk of heart disease.
A study of 18 adult women found that drinking 24 grams of alcohol from white wine daily improved HDL by five per cent, compared to drinking equal amounts of white grape juice (39).
Alcohol also improves “reverse cholesterol transport,” meaning cholesterol is removed from blood and vessel walls and taken back to the liver. This reduces the risk of clogged arteries and heart disease (40).
While moderate alcohol intake reduces heart disease risk, too much alcohol harms the liver and increases the risk of dependence. The recommended limit is two drinks daily for men and one for women (41).
Summary 1–2 drinks per day may improve HDL cholesterol and reduce the risk of clogged arteries. However, heavier alcohol use increases heart disease risk and harms the liver.
9. Consider Plant Sterols and Stanols
Multiple types of supplements show promise for managing cholesterol.
Plant stanols and sterols are plant versions of cholesterol. Because they resemble cholesterol, they are absorbed from the diet like cholesterol.
However, because parts of their chemistry are different from human cholesterol, they do not contribute to clogged arteries.
Instead, they reduce cholesterol levels by competing with human cholesterol. When plant sterols are absorbed from the diet, this replaces the absorption of cholesterol.
Small amounts of plant stanols and sterols are naturally found in vegetable oils, and are also added to certain oils and butter substitutes.
One study of 60 men and women found consuming yogurt with one gram of plant stanols reduced LDL by about 15 peer cent compared to a placebo. Another study showed they decreased LDL by 20 per cent (42,43).
In spite of these benefits to cholesterol, available studies have not proven that stanols or sterols decrease the risk of heart disease. The higher doses in supplements are not as well tested as the small doses in vegetable oils (44).
Summary Plant stanols and sterols in vegetable oil or margarines compete with cholesterol absorption and reduce LDL by up to 20 per cent. They are not proven to reduce heart disease.
10. Try Supplements
There is strong evidence that fish oil and soluble fiber improve cholesterol and promote heart health. Another supplement, coenzyme Q10, is showing promise in improving cholesterol, although its long-term benefits are not yet known.
Fish oil is rich in the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
One study of 42 adults found that taking 4 grams of fish oil daily reduced the total amount of fat being carried in blood. In another study, taking 6 grams of fish oil daily increased HDL ( 45, 46).
A study of over 15,000 adults also found that omega-3 fatty acids, including from fish oil supplements, reduced the risk of heart disease and prolonged life expectancy ( 47).
Psyllium is a form of soluble fiber available as a supplement.
A four-week study of 33 adults found that cookies enriched with 8 grams of psyllium reduced total cholesterol and LDL cholesterol by nearly 10% ( 48).
Another study found similar results using a 5-gram psyllium supplement twice daily. LDL and total cholesterol decreased by about 5% over a longer, 26-week period ( 49).
Coenzyme Q10 is a food chemical that helps cells produce energy. It is similar to a vitamin, except that the body can produce its own Q10, preventing deficiency.
Even if there is no deficiency, extra Q10 in the form of supplements may have benefits in some situations.
Several studies with a total of 409 participants found coenzyme Q10 supplements reduced total cholesterol. In these studies, LDL and HDL did not change ( 50).
Coenzyme Q10 supplements may also be beneficial in treating heart failure, though it’s unclear whether they reduce the risk of developing heart failure or heart attacks ( 51).
Summary: Fish oil supplements and soluble fiber supplements like psyllium improve cholesterol and reduce the risk of heart disease. Coenzyme Q10 supplements reduce total cholesterol levels, but it’s unclear whether this prevents heart disease.
The Bottom Line
Cholesterol has important functions in the body, but can cause clogged arteries and heart disease when it gets out of control.
Low-density lipoprotein (LDL) is prone to free radical damage and contributes most to heart disease. In contrast, high-density lipoprotein (HDL) protects against heart disease by carrying cholesterol away from vessel walls and back to the liver.
If your cholesterol is out of balance, lifestyle interventions are the first line of treatment.
Unsaturated fats, soluble fiber and plant sterols and stanols can increase good HDL and decrease bad LDL. Exercise and weight loss can also help.
Eating trans fats and smoking is harmful and should be avoided.
If you’re concerned about your cholesterol levels, have them checked by your doctor. A simple blood draw, taken after an overnight fast, is all that’s required.