Isn’t it amazing that an animal sterol, cholesterol is reduced by sterols and stanols—the chemicals present in plant cell membranes? While describing the health benefits of phytosterols, this NutriNeat article also describes the best sources and the recommended daily intake of these naturally occurring chemicals.
According to most nutritional studies, an average American consumes about 250 milligrams of sterols every day. Vegetarians get a bit more, averaging around 700 milligrams. But those who prefer fast food, get an insignificant amount of phytosterols through their diet.
Plant sterols and stanols, also known as phytosterols, are the compounds that are naturally present in plants. Although they are found in small quantities, they help prevent certain life-threatening conditions and keep you fit. Saturated sterols are known as stanols. Structurally, sterols resemble human cholesterol, but when ingested, they help lower blood cholesterol levels. Both plant sterols and stanols are equally effective in lowering bad (LDL) cholesterol. The person who is consuming sterol supplements would be able to see the effect within the first 2-3 weeks. A continued consumption of these wonder-chemicals can help him/her enjoy the health benefits over an extended period of time. During some studies, this cholesterol lowering effect has been seen up to 85 weeks.
Sterols and stanols are found in whole grains, vegetables, fruits, legumes, nuts, seeds, and vegetable oils. As of today, more than 200 sterols have been identified by the researchers. Beta-sitosterol, campesterol, and stigmasterol are the three most abundant plant sterols. Cooking may destroy these important elements. Moreover, our body cannot digest them. So, it is difficult to get sufficient quantity of these plant chemicals through diet. Therefore, it is necessary to increase the intake of vegetables, nuts, seeds, and fruits in regular diet.
These days, dietary supplements that provide plant sterols and stanols are available in the market. Manufacturers of various food products have started fortifying their products like margarine, milk, and bread, with phytosterols. They are using sterols and stanols as food additives. But it is necessary to consult your doctor before incorporating such supplements in your diet.
Various studies show that about 2g of phytosterols should be present in your daily diet to gain its health benefits. Studies also show that the effects of phytosterols seem to taper off when more than 2g of these compounds are consumed every day. The amount may vary slightly from person to person. Regular consumption of 2 g per day of plant sterols and stanols can help lower LDL cholesterol concentrations by an average of 10% – 15%.
High cholesterol levels eventually lead to cardiovascular disease (CVD). Usually, statins (‘HMG-CoA reductase inhibitors) are used to treat CVD in the early stages of the disease. They curb the release and action of the enzyme ‘HMG-CoA reductase’ that plays an important role in the production of cholesterol in the liver. But statins come with several side effects like muscle pain, increased risk for diabetes, and even muscle damage. Studies show that along with statins, sterols can be used to gain maximal effect.
Phytosterols interfere with the cholesterol in the intestine and prevent it from being absorbed into your bloodstream. They help lower LDL (bad) cholesterol and do not affect the levels of HDL (good) cholesterol. This improves the cholesterol ratio. To see the expected effect, a good amount of phytosterols should be present in your diet.
Since phytosterols have powerful cholesterol-lowering properties, including them in your diet can help reduce the chances of coronary heart disease (CHD) and stroke. Although studies don’t show that sterols can lower the chances of heart attack and stroke, it is always good to have less cholesterol circulating in your blood. Sterols lead to excretion of cholesterol with the waste. Thus, chances of having clogged arteries are significantly lowered. This ensures proper functioning of the heart and an uninterrupted blood flow to all organs including brain.
Researchers believe that regular consumption of phytosterols can inhibit lung, breast, ovarian, colorectal, and stomach cancers. Sterols seem to have antioxidant properties which help reduce the chances of having cancer and atheroma. More studies are required to prove this benefit.
Those who have been diagnosed with high triglyceride levels should consume more vegetables and fruits. Phytosterols bring about a reduction in triglyceride-rich VLDL particles produced by the liver, which eventually helps lower triglyceride levels. In a study, when the subjects were given 1.6 g of plant sterols every day, for six weeks, it was noticed that triglycerides were reduced by 14% .
Beta-sitosterol when provided to human prostate cancer cell line helped slow down the cell growth rate by 24%. It increased cell death ‘apoptosis’ by 400 %. More studies are required to understand and confirm the role of sterols in treating prostate cancer.
Research shows that phytosterols help control your immune response. While enhancing the activity of beneficial immune cells, they curb the activity of those cells that cause inflammation and chronic diseases. During one study program, a beneficial T-helper-cell-1 response was seen in HIV positive people who were given a sterol supplement. It is believed that the supplements can help lower inflammation in arthritis.
The fruits of the saw palmetto (Serenoa repens) are loaded with fatty acids and phytosterols. Studies show that the fruit extract helps alleviate the symptoms of benign prostatic hyperplasia (BPH). In Europe and America, it is widely used to lower the BPH symptoms like frequent urination, urgency and incomplete voiding. In such cases, use of this extract helps reduce the need for surgery. It is believed that this extract is useful for the men who have prostate cancer. However, according to American Cancer Society, studies do not support the claims that S. Repens extract can treat prostate cancer.
Phytosterols have been in use since 1950. The first pharmaceutical preparation of phytosterols in the U.S. was introduced in 1954, and it was in use till 1982. No serious side effects have been reported.
The patients with ‘phytosterolaemia’, a rare genetic disorder, should not consume excessive amount of plant sterols. The sterols are absorbed quite readily in their intestines (unlike other healthy people) and can lead to heart disease at a young age. Excessive absorption of sterols may lead to rapid development of coronary atherosclerosis. The findings of a study conducted in Netherlands show that regular consumption of plant sterol additives can increase the chances of having atherosclerosis.
Studies show that plant sterols can reduce the absorption of some fat soluble vitamins. It was observed that consumption of phytosterols lowered blood concentrations of beta carotene, alpha carotene, and vitamin E by 25, 10, and 8%, respectively. These vitamins help prevent oxidation of LDL cholesterol. Consumption of more fruits and vegetables can compensate the depleted levels of these vitamins.
The American Heart Association (AHA) has suggested that supplemental plant sterols be taken only by those who have higher than normal blood cholesterol, and that they should not be taken by pregnant women or nursing mothers. The AHA also suggests that those who are already taking cholesterol lowering medication need to consult their doctor before consuming plant sterol products.
The British heart foundation also agrees with the AHA. It further states that various factors are responsible for the increased risk of coronary heart disease, for example, sedentary lifestyle, bad eating habits, smoking, etc. Incorporating phytosterols supplements in diet cannot help reduce the risk of CHD unless and until people eat a lot of fruits and vegetables, increase their activity, and stop smoking. The fact remains that despite reducing the amount of saturated fat in diet (and replacing it with good fat), one can still have heart disease.
It is true that supplements that are fortified with sterols do not offer as many benefits as naturally occurring phytosterols, and the long-term side effects of these supplements are not known.
✦ Sterol-fortified spreads (butter, margarine, etc.), orange juice, cookies, energy bars, etc.
✦ Phytosterols supplements.
✦ Cooking oils, salad dressings, snack bars, mayonnaise, and juices can contain both natural as well as added sterols and stanols.
✦ Milk, yogurt, cheeses, etc.
✦ Berries and fruits like apples, avocados, tomatoes, and blueberries.
✦ Whole grains like brown rice, whole wheat, oat bran, and whole grain products like bread.
✦ Legumes and cereals like dried peas, beans, and lentils.
✦ Nuts and seeds like peanuts, almonds, walnuts, sesame seeds, sunflower seeds, pumpkin seeds, etc.
✦ Vegetables like broccoli, Brussels sprouts, dill, cauliflower, and mushrooms.
It can be concluded that although sterols and stanols help lower LDL cholesterol in blood, balanced diet, stress-free lifestyle, regular exercise, and good eating and sleeping habits are equally essential for healthy heart and body.
Disclaimer: This article is for informative purposes only and does not in any way attempt to replace the advice offered by an expert on the subject.