by Reed Mangels, PhD, RD, FADA
Gallstones are hard pebble-like substances, that form in the gallbladder. Many people aren’t aware that they have gallstones.
When these stones move around such that they block a duct—a tube-like passage that connects the gallbladder to the intestines—symptoms occur including nausea, vomiting, or pain in the abdomen, back, or just below the right arm. Surgical treatment may be needed.
Risk factors for developing gallstones include being female, older age, a family history, obesity, rapid weight loss, and having a low fiber diet.
Some older, small studies have found a lower risk of gallstones in vegetarian women (1, 2) than in non-vegetarian women, or no significant difference in gallstone prevalence in vegetarian men and women compared to meat eaters (3).
A recent study from Taiwan found that vegetarians and non-vegetarians had a similar prevalence of gallstone disease (4). Interestingly, women, whether vegetarian or non-vegetarian, were no more likely to have the disease than were men, although older age was a risk factor (4).
After a mean follow-up time of 13.8 years and after adjusting for a number of variables including smoking and alcohol intake, the EPIC-Oxford study found no significant difference in the risk of symptomatic gallstone disease in vegetarians compared to meat eaters (5).
When a further adjustment was done for body mass index (BMI), vegetarians had a higher risk (1.22, 1.06-1.41; p=0.006) for symptomatic gallstone disease compared to non-vegetarians. Among both vegetarians and non-vegetarians, those with the highest BMI had the highest risk of developing the disease (5).
The study authors weren’t able to find a reason why vegetarians might have a higher risk of gallstone disease.
3. Walcher T, Haenle MM, Mason RA, Koenig W, Imhof A, Kratzer W; EMIL Study Group. The effect of alcohol, tobacco and caffeine consumption and vegetarian diet on gallstone prevalence. Eur J Gastroenterol Hepatol. 2010 Nov;22(11):1345-51.