Define Plant Sterols

Sterols are defined as any of a group of natural steroid alcohols derived from plants or animals. They are essential components of plant cells, contributing to the regulation of cell structure, growth and development. Surprisingly perhaps, plant sterols have a similar structure to cholesterol.

Significance

• In the 1950s, a research paper by O.J.Pollak showed the positive effect of plant sterols on cholesterol levels in humans. Plant sterols have a similar structure to cholesterol but are poorly digested. Once in the gut they reduce the absorption of the dangerous LDL cholesterol into the bloodstream.
  Following this research plant sterols were used as part of the treatment of elevated blood cholesterol, a practice that continued until the pharmaceutical industry developed drugs that offered great efficacy and patient acceptance.

Sterols and Diet

• Because sterols are a natural component of vegetables, nuts and other foods, a western diet already contains an estimated 200 to 300 mg per day. According to the United Kingdom Advisory Committee on Novel Foods and Processes, to lower cholesterol in the blood the intake of plant sterols required is 1 to 3 g per day. This would achieve a reduction of LDL cholesterol of 5 to15 percent.

Sterols and Food Products

• In 2000, the FDA gave permission for a health claim on foods containing plant sterols that were also low in saturated fats and cholesterol. The claim related to the reduction of risk of coronary heart disease from use of these foods. In the United States, the food industry soon picked up on the profit potential of plant sterols with the launch of spreads, dairy alternatives, yogurts and juice containing sterols, and these are now readily available.

Warning

• The UK Advisory Committee on Novel Foods and Processes has stated that in their view foods with added plant sterols are only suitable for "at risk" groups of the population who have been advised by a medical practitioner to adjust their diet to lower blood cholesterol. Their reasoning is that sterols may interfere with absorption of carotenoids---essential for the body to make vitamin A---which might be a health risk for children, pregnant women and those breastfeeding.

The Market

• According to market analysts ACNeilsen, the total market value of foods containing sterols was around $50 to 55 million from 2001 to 2003 and up to $93 million in 2005. But plant sterols are not the only food additive or component for which similar health claims are made. In the United States, oats, whole grains, soy protein and a whole range of natural additives are now able to carry heart-health claims. Just-food's "Global market review of functional foods" estimates that by 2013 the global market is expected to reach a value of at least US$90.5 billion.