Researchers looked at data from thousands of Americans to understand if having healthy, working teeth might protect against gallstones—hard deposits that form in the gallbladder. They found that people who couldn’t chew well due to missing or damaged teeth were nearly twice as likely to have gallstones compared to those with good chewing ability. The study suggests that taking care of your teeth isn’t just about your smile—it might also help protect your digestive system. However, scientists say more research is needed to understand exactly why this connection exists.

The Quick Take

  • What they studied: Whether having the ability to chew food properly (based on how many healthy teeth someone has) is connected to developing gallstones
  • Who participated: Over 5,000 Americans who participated in a national health survey between 2017 and 2020, representing different ages, races, and backgrounds
  • Key finding: People with poor chewing ability were 81% more likely to have gallstones. For every pair of working teeth someone lost, their gallstone risk increased slightly. The biggest jump in risk happened when people had 6 or fewer working tooth pairs.
  • What it means for you: Keeping your natural teeth healthy and replacing missing teeth might help reduce your gallstone risk. However, this study shows a connection, not proof that poor teeth cause gallstones. Talk to your doctor if you’re concerned about gallstone risk, especially if you have tooth problems.

The Research Details

Scientists used information from a large, ongoing U.S. health survey called NHANES that tracks the health of thousands of Americans. They looked at data collected between 2017 and 2020 and examined the relationship between two things: how well people could chew (measured by counting pairs of opposing natural or artificial teeth that actually work together) and whether they had gallstones (detected by ultrasound imaging of the belly).

Instead of just counting total teeth, researchers used a special measurement called “functional tooth units” (FTUs). This is more accurate because it only counts teeth that actually work together for chewing—a tooth is only useful if it has a matching tooth across from it to bite against. This approach is more realistic than traditional tooth counts because a single tooth by itself doesn’t help you chew.

The researchers then used statistical methods to see if people with fewer working tooth pairs were more likely to have gallstones, while accounting for other factors that might affect gallstone risk, like age, weight, and whether someone had diabetes.

This approach matters because it’s more precise than just counting teeth. Many previous studies only counted how many teeth people had, which doesn’t tell you if those teeth actually work for chewing. By measuring functional tooth units, this study gives a clearer picture of whether actual chewing ability—not just tooth presence—affects gallstone risk. This helps scientists understand if the problem is about teeth themselves or about the ability to properly chew food.

This study used data from a well-respected national health survey that carefully tracks Americans’ health, which is a strength. The researchers used ultrasound to confirm gallstones rather than relying on what people reported, which is more reliable. However, because this is a cross-sectional study (a snapshot in time), it can only show that chewing problems and gallstones are connected—it cannot prove that poor chewing causes gallstones. The study included diverse groups of people, which makes the findings more generalizable. The researchers also checked their results in different subgroups to see if the pattern held true across different ages and backgrounds.

What the Results Show

The study found a clear connection between chewing ability and gallstone risk. For every additional pair of working teeth someone had, their gallstone risk decreased by about 10%. More importantly, people with poor chewing ability (defined as having very few working tooth pairs) were 81% more likely to have gallstones compared to people with good chewing ability.

When researchers looked at the specific numbers, they found that the biggest jump in gallstone risk happened when people had 6 or fewer working tooth pairs. Below this threshold, the risk increased noticeably as chewing ability got worse. This suggests there might be a critical point where chewing ability becomes significantly protective.

The pattern held true across most groups of people—different ages, races, and education levels all showed similar results. This consistency suggests the finding is fairly robust and not just a coincidence in one particular group.

When researchers looked at specific subgroups, they found that the chewing-gallstone connection was particularly strong in younger people and women. Interestingly, the pattern was less clear in people over 65, men, and people with certain health conditions like diabetes or obesity. This suggests that age and sex might influence how chewing ability affects gallstone risk, though the reasons aren’t clear from this study.

Previous research has shown that tooth loss is associated with various health problems, including digestive issues. This study builds on that by being more specific—it’s the first to look at actual chewing capacity (using functional tooth units) rather than just tooth count. Earlier studies suggested tooth loss might affect gallstone risk, but this research provides stronger evidence by using a more accurate measurement of chewing ability.

This study has several important limitations. First, it’s a snapshot in time, so researchers can’t prove that poor chewing causes gallstones—only that they’re connected. People with gallstones might have started chewing poorly because of other health problems, not the other way around. Second, the study relied on people’s current tooth status, but didn’t know when they lost teeth or why, which could affect the results. Third, the researchers didn’t have detailed information about people’s diets or eating habits, which could influence both chewing ability and gallstone risk. Finally, the study couldn’t determine the exact biological reasons why chewing ability might affect gallstone formation.

The Bottom Line

Based on this research, maintaining healthy teeth and good chewing ability appears to be associated with lower gallstone risk. If you have missing teeth, discussing replacement options (like dentures or implants) with your dentist might be worthwhile. However, this study shows association, not causation, so tooth care should be one part of overall health maintenance, not a guaranteed gallstone prevention strategy. Confidence level: Moderate—the finding is consistent and based on a large sample, but more research is needed to confirm causation.

This research is most relevant for people who have lost teeth or have poor dental health and are concerned about gallstone risk. It’s also important for dentists and doctors to understand the broader health impacts of tooth loss. People with a family history of gallstones or other risk factors should pay special attention. However, this doesn’t mean people with healthy teeth won’t get gallstones—many other factors contribute to gallstone formation.

If you improve your chewing ability by replacing missing teeth or improving dental health, you wouldn’t expect immediate changes in gallstone risk. The protective effect likely builds over time as your overall digestive health improves. Any benefits would probably take months to years to develop, similar to other preventive health measures.

Want to Apply This Research?

  • Track your dental health status monthly by noting: number of natural teeth, any missing teeth, denture/implant status, and any chewing difficulties. Rate your chewing ability on a scale of 1-10 for different food types (hard, chewy, soft).
  • Set a reminder to schedule regular dental checkups every 6 months. If you have missing teeth, use the app to track progress toward getting them replaced. Log any changes in your ability to chew different foods, which can help you and your doctor monitor your digestive health.
  • Create a quarterly review where you assess your overall dental health status and any changes in digestion or gallbladder-related symptoms. Use the app to correlate any improvements in chewing ability with changes in digestive comfort. Share this data with both your dentist and doctor to help them understand your complete health picture.

This study shows an association between chewing ability and gallstone risk but does not prove that poor chewing causes gallstones. This research is for informational purposes only and should not replace professional medical advice. If you have concerns about gallstones, tooth loss, or digestive health, consult with your doctor or dentist. Do not make decisions about dental treatment or gallstone prevention based solely on this study. Individual risk factors vary greatly, and what applies to the general population may not apply to you specifically.