Chapter 167 Gallstones

image General Considerations

Gallstones are another example of a “Western diet”–induced disease. In the United States, autopsy studies have shown that gallstones exist in approximately 20% of women and 8% of men older than age 40. Conservative estimates suggest that about 20 million Americans (10% of the U.S. population) and 5% to 22% of the population in the Western world have gallstones.1 Each year 1 million more develop gallstones. More than 300,000 gallbladders are removed each year in the United States owing to the presence of gallstones.25 Gallstones are also considered a significant risk factor for gallbladder cancer.6,7

The bile components include bile salts, bilirubin, cholesterol, phospholipids, fatty acids, water, electrolytes, and other organic and inorganic substances.8 Table 167-1 shows the characteristics of the major bile components. Gallstones arise when a normally solubilized component of bile becomes supersaturated and precipitates. Gallstones can be divided into four major categories:

Pure stones, either cholesterol or calcium bilirubinate, are extremely rare in the United States, where recent studies indicate that approximately 80% of the stones are of the mixed variety. The remaining 20% of the stones are composed entirely of minerals, principally calcium salts, although some stones contain oxides of silicon and aluminum.24

image Pathogenesis

The formation of gallstones has been divided into three steps:

Risk Factors for Cholesterol and Mixed Stones

The major risk factors for the development of cholesterol and mixed gallstones include the following24:

The role of a low-fiber, high-fat diet in the development of gallstones, as well as other dietary factors, is discussed later. The other factors are briefly discussed here.


Obese subjects are at risk for developing gallstones both by being overweight and when initially losing weight.10 Obesity causes an increased activity of HMG-CoA reductase with increased secretion of cholesterol in the bile as a result of increased cholesterol synthesis. Therefore, obesity is associated with a significantly increased incidence of gallstones due to biliary cholesterol saturation.

Important to note is that during active weight reduction, changes in body fat and diet can actually promote gallstone problems. During the first stages of weight loss, biliary cholesterol saturation initially increases.4 The secretion of all biliary lipids is reduced during weight loss, but the secretion of bile acids decreases more than that of cholesterol. Once the weight is stabilized, bile acid output returns to normal levels while the cholesterol output remains low. The net effect is a significant reduction in cholesterol saturation. In prescribing diet therapies for obese patients with a high risk of gallstones, it should be recognized that prolonged dietary fat reduction can also promote biliary stasis,1 thus contributing to cholesterol saturation. Studies show that at least 10 g of fat per day is necessary in order to assure proper gallbladder emptying.11


Gallstones have been reported from fetal age to extreme old age, but the average patient is 40 to 50 years old. Decline in the activity of cholesterol 7-α-hydroxylase with age1 leads to an increase in biliary cholesterol hypersecretion13 and thus cholesterol saturation, with accelerated formation of gallstones.

image Therapeutic Considerations

Gallstones are easier to prevent than to reverse. Primary treatment, therefore, involves reducing the controllable risk factors discussed earlier. Once gallstones have formed, therapeutic intervention involves avoiding aggravating foods and employing measures that increase the solubility of cholesterol in bile. If symptoms persist or worsen, cholecystectomy should be considered.

A number of dietary factors are important in the prevention and treatment of gallstones. Foremost is the elimination of foods that can produce symptoms. Also important are increasing dietary fiber, eliminating food allergies, and reducing the intake of refined carbohydrates and animal protein. There is a protective effect of vegetables and fruits against gallbladder cancer, and red meat (beef and mutton) was found to be associated with an increased risk of gallbladder carcinogenesis.14 Because gallstones are a risk factor for gallbladder cancer,6,7,14 appropriate nonlithogenic dietary practices will protect against both cancer and the development of gallstones.

Other treatment measures involve the use of nutritional lipotropic compounds, herbal choleretics, and other natural compounds in an attempt to increase the solubility of bile.

Biliary cholesterol concentration and serum cholesterol levels do not seem to correlate.15 Although some authors have reported an inverse correlation between high-density-lipoprotein cholesterol and bile saturation and a direct correlation between low-density-lipoprotein cholesterol and bile saturation,16,17 more detailed research does not appear to support these correlations.15 There does, however, seem to be an association between increased levels of serum triglycerides and bile saturation.18


Dietary Fiber

The hypothesis that the main cause of gallstones is the consumption of fiber-depleted refined foods has considerable research support.4,5 As mentioned earlier, in population studies, gallstones are associated with the Western diet. Such a diet, high in refined carbohydrates and fat and low in fiber, leads to a reduction in the synthesis of bile acids by the liver and a lower bile acid concentration in the gallbladder.

Another way in which fiber may prevent gallstone formation is by reducing the absorption of deoxycholic acid.4,5 This compound is produced from bile acids by bacteria in the intestine. Deoxycholic acid greatly lessens the solubility of cholesterol in bile.

Dietary fiber has been shown both to decrease the formation of deoxycholic acid and to bind deoxycholic acid and promote its excretion in the feces. This greatly increases the solubility of cholesterol in the bile. A diet high in fiber, especially those fibers capable of binding to deoxycholic acid (i.e., predominantly the water-soluble fibers found in vegetables and fruits, pectin, oat bran, and guar gum), is extremely important in both the prevention and reversal of most gallstones.5

Interestingly, diets rich in legumes with high concentrations of water-soluble fibers are associated with an increased risk for gallstones.9 Chileans, Pima Indians, and other North American Indians have the highest prevalence rates for cholesterol gallstones, and all consume a diet rich in legumes. Evidently, legume intake increases biliary cholesterol saturation as a result of legumes’ saponin content.9 A study conducted in The Netherlands showed just the opposite, because legume intake was shown to offer significant protection against gallstones.62 Until this issue is clarified, it might be best to restrict legume intake in individuals with existing gallstones.

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Sep 12, 2016 | Posted by in MANUAL THERAPIST | Comments Off on Gallstones

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