Gallstones

Clearing Out the Gravel Pit

The woman was about 20 pounds overweight. Nevertheless, she downed pizza, fries and a milk shake with barely a pause to breathe, then topped it off with cheesecake.

Three hours later, she was in the emergency room, a sharp pain boring into the upper right quarter of her abdomen.

The diagnosis? One nasty little gallstone about the size of a pea, stuck in a duct that connects the gallbladder to the bowel. And it was there to stay until it would somehow squeeze through to the bowel or drop back into the gallbladder or until a surgeon would go in and yank it out—along with her gallbladder.

Eat and Squirt

Whether or not a doctor has ever looked you in the eye and announced the presence of a pea-size pellet wandering through your digestive system, there’s a good chance that you have at least one. Close to 30 million Americans do. Most of them are over age 40, most of them are women, and most of them don’t even know that the gallstones are there.

The stones are formed when a grain or two of calcium arrives in the gallbladder and hangs around long enough to become coated with either cholesterol or bilirubin, a substance that is part of the hemoglobin in your blood. Eighty to 85 percent of all stones are coated with layer upon layer of waxy-looking cholesterol, although many stones are coated with both substances. A few are made exclusively of yellowish green bilirubin.

Exactly what causes this buildup of cholesterol or bilirubin on the calcium is not totally clear. Normally, the gallbladder is a storage compartment for the somewhat slimy bile that your body needs to digest fat. You eat fat, the stomach sends it through to the bowel, and your gallbladder squirts some bile onto the food to break up the fat. Your body then finishes its digestive process, and everything heads for the exit.

But occasionally, your body screws up. Something breaks down during the eat-squirt-exit process, and the gallbladder’s sludgelike contents crystallize. This provides the opportunity to layer thicker and thicker coats of cholesterol or bilirubin around a calcium speck, thus forming a gallstone.

Naturally occurring female reproductive hormones are known to encourage that process by delaying gallbladder emptying, such as during pregnancy and dieting. What’s more, birth control implants that contain progesterone may do the same, while birth control pills containing estrogen seem to increase the cholesterol content of bile—not a helpful situation, either.

Blame Your Genes and Diet

All told, hormones, pregnancy, dieting and birth control may help explain why two-thirds of all gallstones belong to women. But aside from being a woman, what else puts you at risk for gallstones? (After all, many men get them, too.)

“Diet and genetics,” replies Henry Pitt, M.D., vice-chairman of surgery at Johns Hopkins University School of Medicine in Baltimore. And it’s difficult to sort out which is responsible for what. So far, many scientific studies of populations only add to the confusion.

In Chile, for example, 60 percent of people have gallstones by the time they’re 80 years of age. Yet in Africa, gallstones affect only 1 to 2 percent of the population.

Is that diet or genetics?

It could be one or the other or both, says Dr. Pitt. Studies of ethnic groups who rarely get gallstones indicate that when they move from a geographic location in which they have consumed a low-fat, low-cholesterol diet to a location in which they consume a high-fat, high-cholesterol diet, they start getting gallstones.

Aside from lowering calories and fat, another dietary factor may have an impact on gallstone formation, and it involves a mineral: calcium.

The Calcium Controversy

A low-fat, low-cholesterol diet may help prevent gallstones, agrees Alan Hofmann, M.D., Ph.D., professor at the University of California, San Diego, but the most important aspect of the diet is that it doesn’t have too many calories, so a person stays slender. But Dr. Hofmann also feels there is reason to believe that supplementing the diet with calcium may act to prevent gallstones.

“In addition to helping your bones, calcium has a good effect on bile acid metabolism,” explains Dr. Hofmann. “What has been found is that large doses of oral calcium form calcium phosphate in the gut.” This sets off a chain of chemical events that eventually lowers the amount of cholesterol in the gallbladder, thus reducing the possibility that gallstones will form, he explains.

It also seems to explain why a study of 872 Dutchmen between the ages of 40 and 59 found that the more calcium the men consumed over a 25-year period, the fewer gallstones they were likely to have.

In fact, one study in the Netherlands revealed that men who had more than 1,442 milligrams of calcium in their diets every day had a 50 percent lower prevalence of gallstones.

“Since most individuals have stopped drinking much milk by the time they’re 45 years old, it makes good sense to take calcium supplements,” says Dr. Hofmann. Nonetheless, the view that large doses of supplemental calcium can prevent gallstones has not yet been tested experimentally. Normal doses of calcium do not increase the risk of kidney stones, however, and are likely to be good for both bones and bile. Studies are needed to prove this point as well as to prove that there are no important risks associated with long-term use of oral calcium supplements, says Dr. Hofmann.

Experts who recommend calcium to help prevent gallstones suggest aiming for the Daily Value, which is 1,000 milligrams. But before you race out to the drugstore, Dr. Pitt suggests that you take a moment to check with your physician, especially if you’re a woman.

“Calcium may have something to do with the origin of most of the gallstones in this country,” says Dr. Pitt. “It’s at the center of almost every stone we find. And in our animal studies, diets with high calcium seem to enhance the formation of pigment stones,” the stones made of bilirubin.

And keep in mind all of the hormonal factors that affect women, says Dr. Pitt. It may turn out that calcium prevents gallstones in men but actually contributes to their formation in women.

So while men can feel comfortable taking calcium supplements, women should ask their family physicians to help evaluate individual risks and benefits, particularly in light of their family medical histories, says Dr. Pitt.

“If all of the women in your family get gallstones and none of them gets osteoporosis, then I’d stay away from calcium,” he advises. But if all of the women get osteoporosis and only an occasional stone rolls down someone’s duct, then calcium should be okay, he adds.

Prescriptions for Healing Although reducing dietary fat and cholesterol and keeping your weight down are clearly the two most important strategies that you can choose to prevent gallstones, there is one mineral that may help as well, according to Alan Hofmann, M.D., Ph.D., professor at the University of California, San Diego. Nutrient Daily Amount Calcium 1,000 milligrams MEDICAL ALERT: If you have a gallstone, you should be under a doctor's care. Dr. Hofmann considers calcium supplementation to be fine for men. Calcium may contribute to the formation of some kinds of gallstones in women, however. He suggests that women discuss supplementation with their physicians.