As most people know, there are significant health benefits to be gained from losing excess pounds. For example many people can reduce high blood pressure and cholesterol levels through weight loss. Overweight people are at greater risk of developing gallstones than people of average weight. However, people who are considering a diet program requiring very low intake of calories each day should be aware that during rapid or substantial weight loss, a person's risk of developing gallstones is increased.
What Are Gallstones?
Gallstones are clumps of solid material that form in the gallbladder. They may occur as a single, large stone or many small ones. Gallstones are a mixture of compounds, but typically they are mostly cholesterol.One in ten Americans has gallstones. However, most people with gallstones don't know they have them and experience no symptoms. Painless gallstones are called silent gallstones. For an unfortunate minority, however, gallstones can cause painful attacks. Painful gallstones are called symptomatic gallstones, because they cause symptoms. In rare cases gallstones can cause life-threatening complications. Symptomatic gallstones result in 600,000 hospitalizations and more than 500,000 operations each year in the United States.
What Causes Gallstones?
Gallstones develop in the gallbladder, a pear-shaped organ beneath the liver on the right side of the abdomen. It's about 3 inches long and an inch wide at its thickest part. The gallbladder stores and releases bile into the intestine to aid digestion.Bile is a fluid made by the liver that helps in digestion. Bile contains substances called bile salts that act like natural detergents to break down fats in the food we eat. As food passes from the stomach into the small intestine, the gallbladder releases bile into the bile ducts. These ducts, or tubes, run from the liver to the intestine. Bile also helps eliminate excess cholesterol from the body. The liver secretes cholesterol into the bile, which is then eliminated from the body via the digestive system.
Most researchers believe three conditions are necessary to form Most researchers believe three conditions are necessary to form gallstones. First, the bile becomes supersaturated with cholesterol, which means the bile contains more cholesterol than the bile salts can dissolve. Second, an imbalance of proteins or other substances in the bile causes the cholesterol to start to crystallize. Third, the gallbladder does not contract enough to empty its bile regularly.
Are Obese People More Likely To Develop Gallstones?
Yes. Obesity is a strong risk factor for gallstones.Scientists often use a mathematical formula called body mass index (BMI) to define obesity. (BMI = weight in kilograms divided by height in meters squared. The accompanying table shows BMI in pounds and inches.) For example, an obese woman who is 5 ft. 4 in. tall (64 in.) and weighs 174 pounds has a BMI of 30. The more obese a person is, the greater his or her risk is of developing gallstones. Several studies have shown that women with a BMI of 30 or higher have at least double the risk of developing gallstones than women with a BMI of less than 25. (See Table 1, Body Weights in Pounds According to Height and Body Mass Index)
Why obesity is a risk factor for gallstones is unclear. But researchers believe that in obese people, the liver produces too much cholesterol. The excess cholesterol leads to supersaturation in the gallbladder.
