Peanuts Contain a Phytosterol Thought to Inhibit Cancer

Apr 19, 1999

A phytosterol, beta-sitosterol (SIT), which has previously been shown to inhibit cancer growth has been identified in peanuts and peanut products. SIT may offer protection from colon, prostate and breast cancer, all of which tend to occur at higher rates in Americans than in other populations. This exciting research was presented at the annual Experimental Biology Conference in Washington, D.C.

Researchers at the State University of New York at Buffalo examined the SIT content of peanuts, peanut butter, peanut flour and peanut oil and found that the content varied from 44 mg SIT/100 gm (peanut flour) to 191 mg SIT/100 gm (unrefined peanut oil). Snack peanuts contain 160 mg SIT/100 gm and peanut butter contains approximately 120 mg SIT/100 gm. The amount of protective SIT in unrefined peanut oil is comparable to that of soybean oil (183 mg SIT/100 gm).

There is overwhelming evidence that indicates that consumption of plant sterols, such as SIT, can lower plasma cholesterol by interfering with cholesterol absorption from the gut. Accordingly, food companies have started adding different plant sterols to foods, such as margarine, to provide this health benefit. These findings are significant because they identify a whole food that already contain these plant sterols that are so important to health.

Dr. Atif Awad, co-investigator of the study and professor of nutrition at the State University of New York at Buffalo notes, “Americans consume six pounds of peanuts per capita each year. Identifying peanuts and its products such as oil, butter and flour as good sources of SIT could provide major health benefits for many Americans.”

In addition to phytochemicals, peanuts contain significant amounts of heart healthy monounsaturated fat, plant protein, fiber, magnesium and vitamin E, all of which may contribute to their healthfulness. Many hard-to-get nutrients such as copper, phosphorus, potassium and zinc are also found in peanuts and peanut butter.

The Peanut Institute is a non-profit organization that supports nutrition research and develops educational programs to encourage healthful lifestyles.