A new study by researchers at the Washington University School of Medicine in St. Louis has found that compounds known as plant sterols can help lower levels of low-density lipoprotein (LDL) cholesterol. The study, appearing in the American Journal of Cardiology, found that the sterols were of most benefit to those patients already taking statins, such as Lipitor, to control cholesterol. The researchers said that the addition of plant sterols helped further lower total cholesterol and contributed to a nearly 10 percent reduction in LDL (bad) cholesterol.
Plant sterols are structurally similar to cholesterol. They work by reducing the absorption of cholesterol in the gut by competing with cholesterol to get absorbed and transported into the body. When consumed in the diet, sterols are known to lower cholesterol levels, but sterols are not readily absorbed in the intestine unless they have been dissolved in something that the intestine can easily absorb. Because sterols are not water-soluble, treatments in the past have involved dissolving them in fat. Most sterol-containing foods studied so far have been brands of margarine. These studies have found that a daily intake of one or two tablespoons of sterol-containing margarine could significantly lower LDL cholesterol.
"One problem is many of our patients already have lowered their intake of fats and calories and don't use products like margarine on a regular basis," said Washington University researcher Anne Carol Goldberg. "In addition, many of these people eat out regularly, and they can't easily take a particular brand of margarine to a restaurant."
Packaging the sterols in pill form involved combining the plant compounds with a substance called lecithin. When mixed with lecithin, the normally insoluble sterols are able to dissolve in water and get absorbed in the intestine.
The study found that after treatment, those who took the sterol pills averaged a 9 percent reduction in LDL cholesterol and a 6 percent decline in total cholesterol. It also seems that the higher the LDL before the treatment began, the greater the drop in the bad cholesterol. "Those who started with higher LDL got a bigger response, a bigger drop in their LDL, when they added plant sterols to their regimen," Goldberg said.
Goldberg believes that the sterols probably work best when given as an additional therapy, and she recommends they be used in combination with diet and/or cholesterol-lowering statin drugs. "This type of treatment would be in addition to dietary changes and other medication," she said. "There probably are some people who have very mild abnormalities in cholesterol who could get by with a sterol supplement alone, but people with higher cholesterol levels will need medication, too."
Over-the-counter sterol pills may become commercially available after further studies confirm their efficacy.
Source: Washington University School of Medicine in St. Louis