An estimated 25 million American adults have gallstones, and nearly 1 million new cases are diagnosed each year. Are you at risk? That depends, partly, on your diet and your genes.
The gallbladder is a small organ that sits below the rib cage on the right side, behind the liver. It stores and releases bile, made by the liver, into the intestine to aid in the absorption of fats. Cholesterol and bile salts are normal components of bile, but if there is an imbalance between them, crystals and eventually stones may form. Most gallstones in developed countries consist primarily of cholesterol. Stones may also form if the gallbladder does not contract properly to expel bile.
Heredity is partly to blame: People who have parents or siblings with gallstones are up to four times more likely to form them, and white Americans have a higher risk than blacks. Stones are also more common in women and older people, people who are obese, and those who lose weight rapidly. Some chronic inflammatory conditions (such as Crohn’s disease), diabetes, high triglycerides, low HDL (“good”) cholesterol, and a sedentary lifestyle are associated with gallstones. Estrogen therapy, birth control pills, and pregnancy increase the risk.
The diet connection?Diets rich in sweets and other refined carbohydrates are linked to gallstones, while fiber appears to reduce risk. The role of dietary cholesterol and fat is not clear, but some studies show that saturated and trans fats increase risk, while unsaturated fats decrease risk. Ironically, too little fat may be a problem. There is some evidence that fish oils are protective. An analysis of data from the Nurses' Health Study found that women who ate the most fruits and vegetables—particularly leafy greens, citrus, and others rich in vitamin C—were less likely to need gallbladder surgery. Preliminary studies suggest that caffeinated coffee, nuts, and vegetable protein may be protective, while high amounts of heme iron (found only in meat, fish, and poultry, not plant foods) may increase stones.
Symptoms, diagnosis, treatmentIn most cases gallstones produce no symptoms and need no treatment. In fact, 60 to 80 percent of people don’t know they have them. Some small stones may simply pass out of the body. But sometimes stones can inflame the gallbladder or block one of the ducts that carries bile, which can cause intense pain, typically in the upper right abdomen, radiating to the upper back or shoulder. The pain typically begins after a meal, particularly one high in fat, and may last several hours. There may be nausea and indigestion. Attacks are likely to recur, especially if they are not treated. Medical attention is urgently needed if the pain is accompanied by vomiting, fever, or jaundice, or if it persists; these symptoms may indicate an infection or perforation of the gallbladder, a dangerous blockage of the common bile duct, or acute pancreatitis. Symptoms can be vague or atypical, however, and can be confused with those of appendicitis, diverticulosis, duodenal ulcers, irritable bowel syndrome, reflux, or even a heart attack.
If your doctor suspects gallstones, he or she will do an ultrasound of the abdomen. Often, stones are found during a routine ultrasound done for other reasons. Endoscopic ultrasound (inserting an instrument down the throat to the small intestine) can detect smaller stones or stones that occur outside the gallbladder. The most common treatment for recurrent or severe symptoms is to remove the gallbladder (cholecystectomy). This can be done laparoscopically (requiring only a small incision and camera guidance), which has less risk than regular surgery, causes less pain, and requires a shorter hospital stay and recovery time. If surgery is not an option, there are other possible treatments. For example, bile acids can be taken in pill form to dissolve the stones (oral dissolution therapy), although this is not always effective, and the stones usually recur if the drugs are stopped.
A note on cholesterol drugs: Interestingly, one class of drugs used to lower blood cholesterol (fibrates) actually increases cholesterol in bile, thereby raising the risk of stones. But statins, another class of cholesterol drugs, do not have that effect. In fact, though statins are not, as a rule, prescribed for treating gallstones, they may actually decrease stone risk.
An ounce of preventionThe best "treatment" for gallstones is prevention. The following steps are also good for your heart and overall health:
- Choose fiber-rich fruits, vegetables, whole grains, and beans.
- Limit sweets and other refined carbohydrates.
- Limit saturated fats, as in meats and whole-fat dairy foods; eat moderate amounts of "good" fats, as in olive oil, nuts, and fish. Avoid trans fats in processed foods.
- Get regular exercise.
- If you are overweight, lose weight gradually (no more than a pound or two a week); avoid crash diets.
- Don't skip meals or fast.