Prevention:

Diet may play a role in gallstones. Following are some observations on specific dietary factors.

Fats. Although fats (particularly saturated fats found in meats, butter, and other animal products) have been associated with gallstone attacks, some studies have found a lower risk for gallstones in people who consume foods containing monounsaturated fats (found in olive and canola oils) or omega-3 fatty acids (found in canola, flaxseed, and fish oil). Fish oil may be particularly beneficial in patients with high triglyceride levels, because it improves the emptying actions of the gallbladder.

Fiber. High intake of fiber has been associated with a lower risk for gallstones.

Nuts. Studies suggest that people may be able to reduce their risk of gallstones by eating more nuts (peanuts and tree nuts, such as walnuts and almonds).

Fruits and Vegetables. Researchers who followed more than 77,000 healthy women for 16 years in the Nurses' Health Study found that those who ate the most fruits and vegetables had the lowest risk of developing symptomatic gallstones that required removal of the gallbladder. The effect was consistent regardless of which fruits or vegetables they ate.

Lecithin. Lecithin is a key component of bile. It contains choline and inositol, two compounds that are important for the breakdown of fat and cholesterol. Low levels of lecithin may precipitate the formation of cholesterol gallstones. Dietary lecithin is available in health food stores and is found in eggs, soybeans, liver, wheat germ, and peanuts. There is no evidence, however, that lecithin supplements or foods containing it can prevent gallstones in humans.

Sugar. High-intake of sugar has been associated with an increased risk for gallstones. Diets that are high in carbohydrates such as pasta and bread can also increase risk, since carbohydrates are converted to sugar in the body.

Alcohol. A few studies have reported a lower risk for gallstones with alcohol consumption. Even small amounts (1 ounce per day) have been found to reduce the risk of gallstones in women by 20%. Moderate intake (defined as 1 - 2 drinks a day) also appears to have heart protection benefits. It should be noted, however, that even moderate intake increases the risk for breast cancer in women. Pregnant women, people who can't drink moderately, and people with liver disease should not drink at all.

Preventing Gallstones during Weight Loss

Maintaining a normal weight and avoiding rapid weight loss are the keys to reducing the risk of gallstones. Taking the medication ursodiol (also called ursodeoxycholic acid, or Actigall) during weight loss may reduce the risk for people who are very overweight and need to lose weight quickly. This medication is ordinarily used to dissolve existing gallstones. A promising 2001 study suggested that orlistat (Xenical), a drug for treating obesity, may protect against gallstone formation during weight loss. The drug appeared to reduce bile acids and other components involved in gallstone production.

The Effects of Cholesterol-Lowering Drugs

Although it would be reasonable to believe that agents used to lower cholesterol would protect against gallstones, they either have little effect or, in the case of fibrates, actually increase the risk. One study reported a weak association between statins and a lower risk for gallstones. These are the most effective drugs for treating high cholesterol and include lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), fluvastatin (Lescol), atorvastatin (Lipitor), and rosuvastatin (Crestor). Most evidence, however, has found no protection even from these agents. Reducing cholesterol itself, then, does not have any effect on cholesterol gallstones.