Soluble fiber, found in foods such as oats, vegetables and fruits, can help lower cholesterol. Cholesterol is a fatty substance that the liver creates. Cholesterol also comes from eating animal products, such as dairy and meat. The body needs a certain amount of cholesterol to function properly. However, excess cholesterol can cause health problems.
There are two types of cholesterol:
Low-density lipoprotein (LDL) cholesterol: People call LDL cholesterol the “bad” cholesterol because high levels of LDL cholesterol can build up in the arteries and increase the risk of cardiovascular disease.
High-density lipoprotein (HDL) cholesterol: HDL is the “good” cholesterol because it transports LDL cholesterol out of the arteries and back to the liver, where the body can eliminate it. Higher HDL cholesterol may help protect against cardiovascular disease.
This article looks at the effects of fiber on LDL and HDL cholesterol levels, the most appropriate type of fiber, and foods that may help improve cholesterol levels.
Does eating fiber lower cholesterol levels?
Certain types of fiber can help lower cholesterol levels. There are two types of fiber: soluble and insoluble. Soluble fiber includes certain fruits, vegetables, oats and legumes. Insoluble fiber includes whole grain foods, nuts and seeds. According to a 2019 study, soluble fiber helps lower blood cholesterol. Soluble fiber helps absorb cholesterol, which reduces the amount of cholesterol absorbed by the liver and increases the amount of cholesterol excreted from the body.
Bacteria in the large intestine ferment soluble fiber into short chain fatty acids (SCFAs). Adding SCFAs to the gut also helps lower cholesterol. If people take statins to lower cholesterol, adding soluble fiber to their diet may also make statins twice as effective.
Although insoluble fiber does not have the same cholesterol-lowering effects as soluble fiber, it does have many health benefits, including:
they promote good digestion
bind to toxins to remove them from the body
they reduce the feeling of hunger after a meal
they can reduce the risk of certain diseases, such as type 2 diabetes, certain cancers and cardiovascular disease.
Cholesterol Lowering Foods
There are a number of fiber-rich foods that a person can try to eat to help control their cholesterol levels as part of a balanced diet, including:
Oats are high in a type of soluble fiber called beta-glucan. Beta-glucan may have beneficial effects in lowering total cholesterol and LDL cholesterol and reducing the risk of coronary heart disease. Consuming 70 grams (g) of oats each day, which contain 3 g of soluble fiber, resulted in a reduction in total cholesterol and LDL cholesterol.
Foods High in Soluble Fiber
Other foods high in soluble fiber may help lower blood cholesterol levels, including:
legumes, such as beans and lentils
Whole or ground flaxseeds and flaxseed lignans may help Safe Source lower total cholesterol and LDL cholesterol, especially in people with high cholesterol and in women (especially postmenopausal women). However, flaxseed oil does not appear to have any cholesterol lowering effect.
A 2021 review found strong evidence that tomatoes can help lower LDL cholesterol. Tomatoes are a rich source of lycopene. Research suggests that 25 milligrams (mg) of lycopene can help lower total cholesterol by about 8 milligrams per deciliter (mg/dL).
Almonds and other nuts
Almonds have been shown to lower LDL cholesterol levels. Walnuts and hazelnuts may also have mild to moderate cholesterol-lowering effects.
Avocados may have a moderate to strong effect on lowering LDL cholesterol. Avocados are rich in monounsaturated fatty acids which may help raise HDL cholesterol levels, which may benefit cardiovascular health.
Olive oil is a key part of the Mediterranean diet and may have beneficial effects on cholesterol levels. According to a study published in the journal Circulation of the American Heart Association (AHA), a traditional Mediterranean diet containing virgin olive oil may have beneficial effects on HDL cholesterol and protection against plaque formation in the arteries.
Foods containing phytosterols
Foods containing plant sterols or stanols, or phytosterols, may cause a moderate reduction in LDL cholesterol.
Phytosterols are found in foods of plant origin, including:
vegetable oils and margarine
Some foods fortified with phytosterols may include:
spreadable fats and margarine
dairy products, such as yogurt, milk, and yogurt drinks
Consuming a minimum of 2g of phytosterols daily in addition to a healthy diet can help people manage high cholesterol. It is more effective to consume phytosterols twice a day with a main meal.
Soy products may have a slight effect on cholesterol levels. Some research suggests that consuming soy protein may help lower total cholesterol and risk factors linked to high LDL levels.
Can fiber supplements help lower cholesterol?
According to a 2017 study, fiber supplements aren’t as beneficial to your health as eating a high-fiber diet. Only specific fiber supplements can help improve cholesterol. Those containing gelling fiber, such as psyllium or beta-glucan, may be effective in reducing high cholesterol. Gelling fiber may also help control blood sugar in people with type 2 diabetes.
Fiber supplements containing insoluble fiber or non-gelling fiber do not have the same benefits. This includes :
Other Ways to Lower Cholesterol
Other measures can help lower cholesterol levels:
limiting the intake of saturated and trans fats, and replacing them with unsaturated fats, such as olive oil
increasing physical activity, especially aerobic and resistance exercise, which raise HDL cholesterol
maintain a healthy weight, to lower LDL cholesterol and raise HDL cholesterol
limiting alcohol intake, which can increase triglyceride levels and risk of heart disease
avoiding smoking, as it can lower HDL levels and increase plaque buildup in the arteries
take medications if needed to lower cholesterol, such as statins.
unfiltered coffee can raise cholesterol levels, choose filtered or decaffeinated coffee instead.
High LDL cholesterol and low HDL cholesterol can increase the risk of cardiovascular disease. Soluble fiber can help the body absorb and eliminate “bad” cholesterol and can lower LDL and total cholesterol levels. Foods high in soluble fiber include oats, barley, legumes, and many fruits and vegetables. A high-fiber diet may be more beneficial to your health than fiber supplements, although supplements containing psyllium or beta-glucan may be helpful.