Plant Sterols – Super Nutrients from Nature

How these simple molecules can help you fight inflammation, stress and cancer

Plant sterols have been in the news lately, after studies showed that they lower blood cholesterol levels in humans. Nearly half of Canadians over the age of 40 have above-normal cholesterol levels. Sterols can block the absorption of dietary cholesterol by up to 50%. With less cholesterol available, the body pulls cholesterol from the blood to do important jobs such as making hormones.

Plant sterols, also known as phytosterols, have also been found to mitigate allergic reactions, fight cancer, and reduce symptoms of autoimmune disorders. There are at least 250 different plant sterols in the foods we eat. Sterols are a group of plant molecules that closely resemble cholesterol, an essential fat used by your body to manufacture hormones and cell membranes. Cholesterol has been portrayed as a villain in the past, whereas phytosterols are viewed as superheroes in the world of nutrition.

How Plant Sterols Balance Your Immune System

In our immune system, we have cells called B lymphocytes which produce antibodies that inactivate incoming invaders such as bacteria. If the invader is able to get inside our cells, as a virus does, then T-cells take over the fight. Sterols modulate the functions of T-cells by enhancing their cellular division and secretion of lymphokines. By ingesting a minimum of 300 mg of enteric coated phytosterols in a capsule, or eating 3000 mg of plant sterols in fruits, veggies and seeds, your immune system will be prepared to respond to many invaders before they get the upper hand.

The immune modulating effect  of sterols can be important for alleviating certain autoimmune diseases such as rheumatoid arthritis, where the immune system produces antibodies that attack and destroy synovial tissue in the joints. This reaction takes the form of inflammation (synovitis) leading to redness, swelling and joint pain. Sterols can assist the immune system in correcting this problem.

Immune modulation plays a significant role in combating allergies, too. Skip the itching and sneezing with sterols! Sterols decrease the specific immune factor (Interleukin 4) that stimulates the allergic response. This works as a powerful antihistamine without the side effects of drugs.

Sterols even combat stress hormones! Imagine the stress you would be under if you were to run a marathon. You would experience a spike in cortisol (the stress hormone) production, and your body would increase the release of pro-inflammatory factors. In this case, sterols would be your best friend as they decrease both the level of cortisol in the blood and the factors that induce inflammation such as tissue damage, muscular aches, and stiffness. This would also help prevent post-marathon infections.

Sterols Reduce Inflammation Markers

Research from the University of Manitoba shows that sterols’ role in human health extends beyond improvement of a major risk factor for heart disease. In July 2011, Othman and colleagues conducted a review of all the human and animal studies involving plant sterols. They found that many studies demonstrated a reduction in inflammatory markers such as C-reactive protein after dietary intake of sterols. Although more studies are required to understand how and to what extent phytosterols can impact inflammation, the authors consider sterols to play an important role in prevention of inflammatory and immune diseases.

Sterols Reduce Bowel Diseases

Crohn’s and colitis are characterized by chronic inflammation of the gastro-intestinal mucosa, an immune response perpetuated by T-cell accumulation. In a 2008 study, Mencarelli and colleagues looked at these two types of intestinal inflammation in mice and the effect of the plant sterol guggulsterone. Also called guggul lipid, this steroidal compound is found in the resin of the Commiphora mukul tree. Guggulsterone was shown to protect the mice against colon inflammation and lessen the severity of wasting disease. Intake of guggulsterone also reduced generation of interleukin-2 and -4 and interferon-gamma as well as T-cell proliferation. The authors concluded that guggulsterone is an anti-inflammatory compound with the capacity to prevent and improve T-cell-induced colitis and can be used in the treatment of chronic inflammatory diseases.

Beta Sitosterol and Cancer

Mounting evidence suggests that sterols fight cancer. Unlike normal cells, cancerous cells lose their ability to respond to death signals that initiate apoptosis (programmed cell death). Sitosterol enhances the function of T-cells that attack cancer cells. In three separate studies, sterols have been shown to induce apoptosis when added to cultured human prostate, breast, and colon cancer cells.
A more recent 2008 study by cancer researchers at the University of Buffalo also found that beta-sitosterol could affect the growth of cancer cells. Specifically, these researchers looked at the effect of combining tamoxifen, an anti-estrogenic drug, with dietary sources of beta-sitosterol on cell lines with estrogen receptor positive or negative breast cancer. They found that both the drug and the dietary sterols increased cancer cell death by different mechanisms, indicating that the addition of dietary beta-sitosterols would be beneficial to breast cancer patients on tamoxifen.
Similarly, another study completed in 2010 found that beta-sitosterol had a cytotoxic effect on estrogen-dependent and independent cancer cells, and, moreover, may have the ability to target types of cancer that have resisted many drugs. Clearly, phytosterols can act as potent anticancer agents though much remains to be understood regarding effective dosage and mechanism of action.

The Richest Sources of Plant Sterols

Thousands of years ago, sterols were found in everything we ate. Nuts, seeds, veggies and fruit all supplied sterols. So it is no surprise that when those foods started to disappear from the human diet, immune system function started to decline. The suggested amount of sterols per day is between 2000 mg and 3000 mg. The Standard American Diet (SAD) provides less than 200 mg of sterols a day. Let’s face it: We don’t eat a head of broccoli, a cup of sesame seeds, a few cups of figs, edamame, and an avocado for good measure each day.

Plant sterols are small but essential components of certain plant membranes. They are found naturally in some vegetable oils, nuts, grains, legumes, fruits and vegetables. In their natural state, sterols are bound to the fibres of plants, and for this reason they are difficult to separate and properly absorb. While seeds are the richest source of plant sterols, refining processes used by the food industry damage and deplete the sterols – which are either removed to make the product completely clear, or destroyed with high-heat processing. The key is to buy unrefined, cold-pressed virgin oils to ensure the healthy sterols are present.

If one chooses to take plant sterol supplements, it is important to take them in an enteric-coated capsule because stomach acids can break sterols down into esters, reducing their effectiveness. It is also important to avoid taking sterols with dairy or animal fat, because the sterols will function to reduce absorption of cholesterol instead of focusing on immune modulation.

Adding plant sterol supplements to your vitamin regime is recommended for most people. Thousands of studies on sterols conducted over 50 years show that they are safe. Multiple Sclerosis patients or pregnant or nursing mothers should be monitored by a Naturopathic Doctor before considering supplemental use. People with a rare hereditary disease called Sitosterolemia (phytosterolemia) must avoid sterols.

I regularly take an enteric-coated sterol supplement and find that I escape most cold and ‘flu rampages. Being a foodie, I am also happy to enjoy sterol-rich gourmet food that heals both the body and satisfies the taste buds! Try some of these delicious recipes and balance your immune system at the same time!

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