Dietary factors in the aetiology of gall stones: a case control study.

Dietary intake was studied in 121 women with gall stones (identified in a prevalence survey using ultrasonography) and a similar number of age-matched controls in order to investigate nutritional factors in the aetiology of the condition. Despite the appreciably lower frequency of gall stones in vegetarians as compared with non-vegetarian women (11.5% and 24.6% respectively) nutrient intake did not differ between cases and controls. This may indicate the existence of a threshold effect where virtually all non-vegetarian women in affluent societies have a diet high in saturated fat, animal protein, and simple sugar to the extent that it is not possible to distinguish between cases and controls. In women with newly discovered gall stones, the prevalence of upper gastrointestinal symptoms was no different from that in the controls. Thus cholecystectomies carried out to relieve relatively low grade symptoms may not do so.