Gallstones are a common disorder.

About 20 million Americans - roughly 15 percent of the population - are estimated to have them at any given time. Most have no symptoms.

But each year, about three percent of these people develop the familiar, awful signs: strong, sharp pain at the top of the stomach after eating, especially after eating fat (Cleveland Clinic).

You are more likely to develop gallstones if you are female, over 40, overweight, have a family history of developing them, and/or are of Native American or Mexican ancestry (U.S. Department of Health and Human Services).

The good news is that the problem has become so common that surgical treatment has become both routine and remarkably safe. Over 700,000 such surgeries are performed each year.

But a larger question looms – why is the disease common? Theoretically, if we understood this, we might make lifestyle changes to lower our risk of getting gallstones, or of getting more of them.

A new look at research seems to suggest that low-fat, high-carbohydrate diets – the kind recommended by mainstream nutrition authorities since the late 1960s – are a potential culprit in gallstone formation.

That’s the opposite of the usual medical take. Let’s look further…

What does the gallbladder do?

3D illustration of human body with gallbladder highlighted
The gallbladder is about the size of your thumb, and holds about two ounces of bile. Note its position on the top-right of the stomach. That’s where pain from gallbladder dysfunction tends to be felt.

The liver makes a yellow-green substance called bile, which is necessary to digest the fat we eat. The gallbladder, a thumb-sized organ nestled next to the liver, stores that bile.

The gallbladder then, ideally, delivers just the right amount of bile via ducts to the stomach to help a person digest dietary fat.

But if a gallstone – typically made of cholesterol – develops in the gallbladder, that flow of bile to the stomach can be blocked. The backed-up bile behind the stone leads to inflammation and pain, which can become so severe the sufferer can eat almost nothing.

The solution is often surgical removal of the gallbladder. It’s a fairly simple small-incision surgery done by laparoscope, usually allowing the patient to leave the hospital within 24 hours. The recipient of gallbladder-removal surgery usually recovers well, but experiences some lost ability to digest fat.

Why do stones form?

The conventional answer – which aligns with the anti-fat campaign mainstream authorities such as the American Heart Association have waged since the late 1960s – is the stones are a result of eating too much fat.

But is that true?

Three separate studies of people eating low-fat diets showed that in all cases, contrary to the conventional wisdom, low-fat diet led to the formation of new gallstones (Liddle, R. A., 1989) (Broomfield, P. H., 1988). Notably, in one of the studies, this group was compared to a group eating a diet somewhat higher in fat.

No one in that group developed new stones (Festi, D., 1998).

These studies suggest a diet low in fat and high in carbohydrate contributes to formation of additional stones. The opposite – a diet relatively high in fat, and low in carbohydrate – appears to prevent new stone formation.

Use it or lose it

How about avoiding any stones forming or remaining in the gallbladder in the first place?

Poached haddock fillets in butter herb sauce
Healthful fats from butter and fish – as in this haddock poached in a butter/herb sauce - may help to keep the gallbladder stone-free.

As it turns out, here again, regularly eating fat-containing food appears to help. Swedish physician and nutrition researcher Andreas Eenfeldt, M. D., has made a careful study of gallbladder research. He writes that the studies on fat content and stone formation suggest that if dietary fat is not restricted, “The bile ducts and gallbladder will be flushed regularly. Theoretically, stones will not have time to form.”

Further, he says, “pre-existing stones might (if you are lucky) be flushed out into the small intestine. (Eenfeldt, 2021).

In other words, when it comes to the gallbladder, the operating principal may be the same as with any other metabolic system: Use it or lose it.

Bottom line

The relatively small number of studies above is far from definitive, but the premise makes logical sense. Carefully avoiding dietary fat, as many Americans have done for the last six decades, would lead the liver to create less bile. This means the flow through the gallbladder becomes so slow that the bile essentially pools there, leading the cholesterol in the bile to accrete into stones.

So if this is true, what does it suggest about how to eat?

The answer is not to indiscriminately eat fat. If you pay attention to these pages, you know some dietary fats are far better for health than others. Worst, by far, are “seed oil” fats.

Instead, the answer appears to be avoid engineered low-fat foods, such as skim milk, and “bad-fat” ones such as vegetable oil (which is nearly always a euphemism for soybean oil), and eat a variety of foods that retain their full-fat component.

This would include whole-milk dairy products, fatty fish such as salmon and cod, and grass-fed dairy or beef. When you cook, incline toward healthful fats such as butter or olive oil, or fats from naturally raised cattle or pigs.

But remember, as with all health conditions, gallstones aren’t simple. If you have a genetic propensity to get them, no lifestyle measure may help.

If you do feel the characteristic top-of-stomach pain after eating a fat-containing meal, have a chat with your physician.

Together, you can determine a course of diet, drug intervention and or surgery that will yield the best long-term result.

 

Citations:

Broomfield, P. H., Chopra, R., Sheinbaum, R. C., Bonorris, G. G., Silverman, A., Schoenfield, L. J., & Marks, J. W. (1988). Effects of ursodeoxycholic acid and aspirin on the formation of lithogenic bile and gallstones during loss of weight. New England Journal of Medicine, 319(24), 1567–1572. https://doi.org/10.1056/nejm198812153192403

Eenfeldt, Andreas, M. D. (2021, February 10). Gallstones and low carb. Diet Doctor. https://www.dietdoctor.com/gallstones-and-low-carb. 

Festi, D., Colecchia, A., Orsini, M., Sangermano, A., Sottili, S., Simoni, P., Mazzella, G., Villanova, N., Bazzoli, F., Lapenna, D., Petroni, M. L., Pavesi, S., Neri, M., & Roda, E. (1998). Gallbladder motility and gallstone formation in obese patients following very low calorie diets. use it (fat) to lose it (well). International Journal of Obesity22(6), 592–600. https://doi.org/10.1038/sj.ijo.0800634 

Gallbladder and biliary tract disease. Cleveland Clinic. (n.d.). https://my.clevelandclinic.org/departments/digestive/medical-professionals/hepatology/gallbladder-biliary-tract-disease. 

Liddle, R. A. (1989). Gallstone formation during weight-reduction dieting. Archives of Internal Medicine, 149(8), 1750. https://doi.org/10.1001/archinte.1989.00390080036009

U.S. Department of Health and Human Services. (n.d.). Definition & facts for gallstones. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/digestive-diseases/gallstones/definition-facts.