Plant Sterols: What Are They? How Do They Work?

Plants produce plant sterols. Animals produce cholesterol. Structurally similar, both bind to sites in our intestines where the cholesterol produced in our livers and consumed in our foods are absorbed into our blood.

Yet, our bodies have evolved the ability to distinguish between these types of sterols. On average, we absorb about 55% of cholesterol and less than 1% of the plant sterols. Plant sterols work to lower cholesterol by filling the "absorption gateways," thus blocking the cholesterol from entering the blood stream. Blocked cholesterol is execreted along with most of the plant sterols.

In nature, small quantities of plant sterols can be found in a range of foods, particularly vegetable oils (sources of plant sterols). The average plant sterol intake in the U.S. is about 250 milligrams. Vegetarians consume in a range of 400 to 750 milligrams. Plant sterol intake in traditional diets has been estimated to be about 1g (1000mg). Medical studies have concluded that 2-3g (2000-3000mg) effectively lower cholesterol. Fortified foods are typically required to obtain these levels.

The effectiveness of plant sterols will vary from person-to-person. Many people absorb cholesterol more effectively than others. For these individuals, the impact of plant sterols may be more significant.

Overall, plant sterols are an important component of a nutritional system designed to promote healthier cholesterol and blood lipid levels. Achieving maximum benefits from natural cholesterol management may require other nutrients---including the soluble fibers found in oats, beans, fruit and psyllium, certain types of niacin, Omega-3s, monounsaturated fats in place of saturated fats----all in the context of balanced nutrition, calorie-mindfulness and physcial activity.