Plant Sterols and Stanols for Cholesterol and Other Benefits

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Plant-based foods are high in nutrients, particularly the phytochemicals known as phytosterols. The two types of phytosterols are plant sterols and plant stanols, which are plant-derived compounds that have structures very similar to cholesterol. Therefore, it may be unsurprising that some science supports the use of plant stanols and plant sterols for cholesterol management, as well as for reducing the risk of heart disease.

In humans, cholesterol is derived either from the diet or from cholesterol synthesis mainly in the liver and intestines. Phytosterols, on the other hand, are only derived from the diet in humans since the human body cannot synthesize them. These phytosterols are naturally found in plant-based foods like vegetables, fruit, vegetable oils, seeds, and nuts.

In this article, we will take a deeper look at the potential plant stanol and plant sterol benefits, including how the phytosterols might mimic cholesterol and impair its absorption in the body.

Plant Sterols and Cholesterol: The Benefits

The cholesterol-lowering effect of stanols and sterols has been well documented for many years. Because of their similar molecular structure, plant phytosterols appear to prevent cholesterol and bile (a cholesterol byproduct) absorption in your intestines. This has the potential to reduce total cholesterol and LDL (low-density lipoprotein) cholesterol levels in the blood.

To make bile, cholesterol must be removed from the body, and this is how phytosterols are thought to reduce cholesterol. This reduction is gradual, and is based solely on large amounts of plant sterols and plant stanols being consumed.

The research certainly supports the effects of phytosterols on cholesterol. One study published in the American Journal of Clinical Nutrition in 2010 found that both moderate (0.46 grams [g] daily) and high (2.1 g daily) intakes of phytosterol-rich beverages had reduced cholesterol absorption by around 10% and 25%, respectively.

There is also a wealth of research showing that daily consumption of plant stanols and plant sterols in foods can lower both total and LDL cholesterol.

One study published in the journal Atherosclerosis in 2014 showed that two grams daily of plant sterols and plant stanols had significantly inhibited cholesterol absorption and reduced LDL cholesterol by between eight percent and 10%. The researchers also noted that the amount of phytosterols given in the study, at two grams daily, had not been linked to any adverse health effects in long-term studies.

A meta-analysis of 124 randomized controlled studies published in the British Journal of Nutrition in 2014 found that plant sterols and plant stanols showed a similar effect on LDL cholesterol levels with an average dose of 0.6 g daily to 3.3 g daily.

Between 0.6 g and 1.1 g daily of phytosterols was found to significantly reduce LDL cholesterol by at least five percent, while an average of 3.3 g daily of phytosterols lowered cholesterol by about 12.4%.

Another meta-analysis of 59 randomized controlled studies published in the journal Food & Nutrition Research in 2008 suggested that the phytosterols had reduced LDL cholesterol more effectively in those with higher LDL cholesterol levels at the beginning of the studies.

How Do Sterols Compare to Statins? Plant Sterols vs. Statins

In this section, we compare the effectiveness of plant stanols and sterols with that of traditional prescription drugs for lowering cholesterol, called statins.

A meta-analysis of 15 randomized controlled studies published in the journal Scientific Reports in 2016 found the combination of both statins and phytosterols significantly lowered total cholesterol and LDL cholesterol compared to statin therapy alone.

Statins are often deemed the gold standard, blockbuster drug for reducing high cholesterol levels, especially the amounts of LDL cholesterol made in the liver. Statins will also help the body reabsorb cholesterol buildup in the arteries.

Some common statin drugs include rosuvastatin (“Crestor”), atorvastatin (“Lipitor”), and simvastatin (“Zocor”).

Phytosterols, on the other hand, are considered one of the better natural treatments for lowering harmful high cholesterol levels. As mentioned, 2014 research showed that two grams daily of phytosterols had the ability to reduce LDL cholesterol by up to 10%. The researcher also noted that the two-gram dose of plant sterols and plant stanols daily was equivalent to doubling the dose of statins.

However, the concern here isn’t over whether statins work; it is the laundry list of side effects associated with them. Although phytosterols may not reduce the risk of stroke and heart attack in the same way statins can, side effects associated with statins may include:

• Weakness
• Nausea
• Memory loss
• Muscle damage or pain
• Diabetes
• Lung disease
• Severe irritability
• Violence
• Depression
• Bipolar disorders
• Schizophrenia
• Antisocial behavior
• Homicidal impulses
• Statins may also increase the risk of both cancer and death.

Still, the drugs may be necessary for your condition. If you are on statins, talk to your doctor about taking them with phytosterols, lowering the dose, or possibly weaning off the statin drugs altogether.

Other Benefits of Plant Sterols and Stanols

Besides their ability to reduce LDL cholesterol, what are some other plant stanol and plant sterol benefits? This section will detail additional potential health benefits associated with phytosterols.

Improved Overall Heart Health

Phytosterols may improve your heart health overall, and not just your LDL cholesterol levels. One randomized controlled study of 92 people published in the journal BMC Cardiovascular Disorders in 2013 suggested a beneficial effect on endothelial function and arterial stiffness with the consumption of three grams of plant stanol daily for six months.

High LDL cholesterol is also a risk factor for coronary heart disease. So, regular consumption of foods rich in plant sterols and plant stanols may reduce the risk of heart disease in general.

Reduced Risk of Cancer

Phytosterols may also help reduce inflammation and lower the risk of developing cancer. Very high intakes of plant sterols and stanols may inhibit the growth of both prostate and breast cancer, according to animal and in vitro studies.

A few observational human studies show the potential anti-cancer effects of phytosterols as well.

Other research out of Uruguay shows that phytosterol consumption is lower in those diagnosed with lung cancer, stomach cancer, and breast cancer compared to cancer-free individuals.

Women diagnosed with endometrial (uterine) or breast cancer had lower dietary intakes of phytosterols than women who had not been diagnosed with cancer.

Men diagnosed with prostate cancer also had a higher dietary intake of a certain phytosterol called campesterol than men without cancer; however, total phytosterol consumption was not linked with a reduced prostate cancer risk.

Although higher intakes of phytosterol-rich foods may be linked with a reduced risk of cancer, it is still not clear whether this anti-cancer effect is due to phytosterols or other phytochemicals, minerals, or vitamins in the plant-based foods.

Treatment of Benign Prostatic Hyperplasia (BPH)

Benign prostatic hyperplasia (BPH) is also known as an enlarged prostate. Common symptoms include frequent urination, difficulty in postponing urination, straining while urinating, dripping and leaking after urination, and taking longer to start urinating despite the immediate need to urinate.

Phytosterols in the form of beta-sitosterol are often used to relieve the urinary symptoms related to BPH.

One six-month study found that 60 milligrams (mg) daily of beta-sitosterol had increased urine flow and reduced post-urination residual urine volume compared to the placebo in 200 men with BPH.

A follow-up to this study saw that these improvements were maintained for up to 18 months in 38 people who continued with the beta-sitosterol treatment.

A systematic review of these and three other studies found that beta-sitosterol extracts had increased peak urinary flow by an average of 3.9 milliliters (ml) per second while also reducing post-void residual volume by an average of 29 ml.

List of Foods with Plant Sterols and Stanols

Some believe it is not possible to get enough plant sterols and stanols from whole, plant-based foods. For this reason, certain sources of plant sterols and plant stanols have been fortified with the phytosterols. Some of these processed foods include fortified milk and yogurt and spreads like mayonnaise and vegetable oil.

Although it is true that the amounts are small, whole and plant-based foods remain the best sources of phytosterols since they are free of added chemicals and preservatives. Also, despite their phytosterol content, some foods such as corn oil, soybean oil, and canola oil are highly genetically modified and consumption is therefore not recommended.

What foods are high in plant sterols? The following is a table with a list of foods containing plant sterols and stanols. The data reflects milligrams per 100 grams.

—- Not reported

Dangers and Side Effects of Plant Sterols and Stanols

Are there plant stanol or plant sterol side effects? It is thought that there are no side effects in regular doses for up to one year; however, in high amounts, there may be plant stanol or plant sterol dangers or concerns.

The U.S. Food and Drug Administration (FDA) has classified plant stanols and plant sterols as generally recognized as safe. It is recommended that intakes of plant stanols and plant sterols not exceed three grams per day.

Potential side effects of plant sterols and stanols in high doses include indigestion, nausea, constipation, and diarrhea. Phytosterols may also interfere with the absorption of fat-soluble vitamins and fat-soluble phytochemicals known as carotenoids.

The following is further detail about plant stanol and plant sterol side effects, as well as information about the way phytosterols interact with drugs and other nutrients.

Sitosterolemia

Sitosterolemia is also called phytosterolemia. It is a rare genetic disease that results from inheriting mutations of ABCG5 and ABCG8 genes. People with sitosterolemia have dramatically high phytosterol levels due to increased intestinal absorption and reduced biliary excretion of phytosterols.

Sitosterolemia patients are also at risk of premature atherosclerosis. As a result, people with sitosterolemia should avoid supplements or foods with plant sterols and plant stanols.

Pregnancy and Lactation

Phytosterol-rich foods and supplements are not recommended for breastfeeding or pregnant women since their safety has not been studied. That being said, there is currently no evidence that a high intake of phytosterols through a vegan or vegetarian diet can lead to problems in pregnant or breastfeeding women.

Drug Interactions

Some evidence also suggests that statins initially lower plant sterol concentration in the blood; however, this may be due to a reduction in circulating LDL cholesterol from the enhanced hepatic uptake of LDL.

Yet, enough research exists that supports statin therapy for increasing the absorption of plant sterols and plant stanols. “Ezetimibe” is also a cholesterol-lowering drug that may interfere with the absorption of phytosterols in the intestines.

Nutrient Interactions

Fat-soluble vitamins such as vitamins A, D, E, and K may interfere with the absorption of plant sterols and stanols. But, research has found no adverse effects of phytosterol-enriched food consumption on fat-soluble vitamin status in people who are well nourished.

Studies also show that phytosterols may inhibit the absorption of carotenoids such as beta-carotene, alpha-carotene, and lycopene.

Final Thoughts on Plant Sterols and Stanols

Since phytosterols such as plant sterols and plant stanols have structures similar to cholesterol, it may be beneficial to use plant stanols and plant sterols for cholesterol problems, especially high LDL cholesterol levels.

When it comes to plant stanols and plant sterols vs. statins, the phytosterols might be preferable for some. This is because phytosterols appear to reduce cholesterol without the potential side effects associated with statins and other cholesterol-lowering drugs.

Other potential plant stanol and plant sterol benefits include improving overall heart health, reducing cancer risks, and treating an enlarged prostate. Be sure to consume healthy amounts of plant stanol and plant sterol foods, such as whole foods like cauliflower, broccoli, lettuce, avocado, and apples.

Although phytosterol-rich foods have many benefits, there are also plant stanol and plant sterol side effects or interactions to consider. That is why it is a good idea to consult with both your doctor and a natural practitioner. These professionals will be able to tell you how to take phytosterols for lowering your high cholesterol.

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