Phytosterols In Human Nutrition

Phytosterols are cholesterol-like compounds found in a variety of plants. Research into the health effects of phytosterols has produced promising results, for their role in the prevention and management of some health conditions, as well as cautionary information regarding the risks and downsides associated with these naturally-occurring compounds, particularly when used as highly concentrated extracts or supplements.

Cardiovascular Disease

One study looked into the the effect of phytosterols cells that line the walls of blood vessels and found a beneficial effect on cardiovascular health. Phytosterols from rapeseed oil were tested on cells involved in plaque formation in the linings of the abdominal aorta --- a location where blockages can occur. Phytosterol components of rapeseed oil had a cytotoxic effect on plaque cells, thereby reversing plaque formation, according to a study by B. Rubis et al., published in the 2008 "British Journal of Nutrition." Additionally, phytosterols have a similar structure to cholesterol and, thus, lower LDL cholesterol levels by competing for absorption.

Colon Cancer

Beta-sitosterol extract of a plant used in traditional Indian medicine had anti-cancer properties on colon cancer cells in a study on Asclepias curassavica, common name English bloodwort. The plant is a perennial herb used traditionally to treat a variety of intestinal ailments and has been shown to inhibit growth and induce cell death in human colon cancer cells by acting as a potent scavenger of molecules that cause oxidative damage to cells. The phytosterol extract also inhibited a gene for colon cancer, according to the study by Albert A. Baskar et al., published in the 2010 "BMC Complimentary and Alternative Medicine," and the researchers reported that no toxic effects were observed.

Inflammation

The anti-inflammatory properties of phytosterols are currently being investigated, with promising results. Pistachio oil phytosterols have shown potent anti-inflammatory properties, in a study by J. Zhang et al., published in the May 2010 "Molecular Nutrition and Food Research." The oil extract was shown to inhibit genes that promote inflammation, immune response and defense response to bacteria. Additionally, two new phytosterols were recently discovered in Red Sea sponges and found to have anti-inflammatory effects, as reported in a study by D.T. Youseff et al., published in the 2010 "Natural Product Communications."

Breast Cancer

Phytosterols were shown to be protective against breast cancer in a study. Two of the most common dietary phytosterols, beta-sitosterol and campesterol, were tested on advanced breast cancer cells, in a study by A.B. Awad, published in the 2003 "Journal of Nutritional Biochemistry." The cells that were exposed to beta-sitosterol exhibited a 70 percent reduction in cell growth, while campesterol-treated breast cancer cells had a 6 percent decline in cell growth.

Risks

While phytosterols have been shown to be helpful in the reduction of risk for certain cancers, and cardiovascular and inflammatory diseases, they may not be completely without health risk. A study by Qixuan Chen et al., published in the 2010 "Nutrition and Metabolism" found that phytosterols caused a significant increase in blood pressure. The researchers reported that both systolic --- the top number of the blood pressure ratio --- and diastolic were raised and that the phytosterols had their effect at the level of the kidneys' blood pressure control system.