Beta-sitosterols are fat-soluble compounds commonly found in many plants throughout the world, mainly as a constituent of plant oils. Beta-sitosterols, one of a family of similar compounds known as phytosterols, can have a variety of health effects in humans including lowering cholesterol, according to a study published in the 2006 "Journal of the American College of Nutrition."
Amaranth
Amaranth contains all three of the major phytosterols: beta-sitosterol, campesterol and stigmas-terol, according to a 2003 study published in "Plant Foods for Human Nutrition." Total phytosterol content for four amaranth varieties tested was several times greater than that for other plants, making amaranth an excellent source for this nutrient. Considerable variation was seen in the phytosterol content among varieties of amaranth tested, with the variety most commonly cultivated in the United States scoring the highest for beta-sitosterol content.
Avocados
Avocado oil is high in beta-sitosterol, containing as much as 1 percent. A study published in the 2009 "Journal of Agricultural and Food Chemistry" indicated that avocados retained their beta-sitosterol content well through a period of refrigeration. The avocados were cut into slices and stored at 8 degrees C for 13 days. While fatty acid content was largely lost during the refrigeration, no significant changes were observed for phytosterols.
Nuts
Brazil, pecan, pine, pistachio and cashew nuts were evaluated for their levels of a variety of health-promoting compounds, including beta-sitosterol content, in a study published in the 2006 "International Journal of Food Science and Nutrition." Beta-sitosterol was the most prevalent phytosterol in the nuts tested, which ranged from approximately 1300 mg/g of oil to 4700 mg/g of oil. The website fao.org lists pistachio as the richest nut source of beta-sitosterol, with 199 mg/100 g of whole nuts, followed by almonds with 111 mg/100 g, hazelnuts with 89 mg/100 g and walnuts at 64 mg/100 g.
Cocoa
Cocoa was listed as high among the top 100 best food sources of polyphenols, in a 2010 study published in the "European Journal of Clinical Nutrition." To evaluate the health benefits of cocoa polyphenols a study in the 2010 "European Journal of Cancer Prevention" tested cocoa polyphenol extract, including beta-sitosterol, on prostate cancer cells and found an inhibitory effect on the cells.
Corn Oil
Corn oil is notably high in beta-sitosterol with 23 mg/g of oil; however, a study of the effect of dietary corn oil on cancer published in the 2004 "Experimental Biology and Medicine" found that corn oil promoted colon cancer by inhibiting a tumor suppressing gene.
References
- PubMed: Amaranth as a rich dietary source of beta-sitosterol and other phytosterols.
- PubMed: Fatty acids, sterols, and antioxidant activity in minimally processed avocados during refrigerated storage.
- PubMed: Fatty acid profile, tocopherol, squalene and phytosterol content of brazil, pecan, pine, pistachio and cashew nuts.
- PubMed: Effect of pistachio oil on gene expression of IFN-induced protein with tetratricopeptide repeats 2: a biomarker of inflammatory response.
- Dweck Data: Avocado
- fao: Tree Nuts in the Mediterranean Diet Context
