Is Gum Disease Linked to Stomach and Esophageal Cancer?
People with history of gum disease appear to have higher risk of developing oesophageal and gastric cancer, suggest researchers
A large Harvard study found that adults who reported a history of gum disease were more likely to develop adenocarcinoma of the esophagus or stomach over the next two decades. The increase was roughly 40% to 50% in relative terms, but these cancers are uncommon, so the added risk for any one person is small. The study shows an association, not proof that gum disease causes these cancers.
What did the study look at?
Researchers at the Harvard T.H. Chan School of Public Health used two long-running studies of US health professionals: 98,459 women in the Nurses' Health Study and 49,685 men in the Health Professionals Follow-up Study. Participants reported on questionnaires whether they had gum disease and how many teeth they had lost. Researchers then followed them for 22 to 28 years and confirmed cancer diagnoses from medical records. [1]
During that time, 199 people developed esophageal adenocarcinoma and 238 developed stomach adenocarcinoma.
What did it find?
History of gum disease: about 43% higher risk of esophageal adenocarcinoma and about 52% higher risk of stomach adenocarcinoma, compared with people without gum disease. [1]
Tooth loss: people who had lost two or more teeth also showed higher risk, but these results were weaker and less certain, especially for stomach cancer. [1]
The researchers adjusted for smoking and for other lifestyle and dietary factors that could affect both the mouth and the digestive tract.
What are the limits?
Self-reported gum disease. No one examined participants' gums.
Small numbers of cancers. Fewer than 450 cases across nearly 150,000 people make the estimates less precise.
A research letter, not a full paper. The findings were published as a short letter in the journal Gut. The authors noted that earlier studies on this question had mixed results. [1]
Observational design. The study can't rule out other shared causes.
Researchers suspect oral bacteria or long-term inflammation could play a role, but that remains a hypothesis.
What does this mean for you?
These cancers are uncommon, and the steps that lower risk are mostly the same steps that protect your mouth: don't smoke, limit alcohol, and treat gum disease when it is found. If you have ongoing heartburn, trouble swallowing or unexplained weight loss, see your physician. Those symptoms matter more than your gum history.
Related research and where to get care
Gum disease has also been linked with breast cancer and with overall cancer risk in older women. A comprehensive dental exam at our Jacksonville office includes a full gum evaluation. Contact us or call 904-398-1549 to schedule.
Sources
Lo CH, Kwon S, Wang L, et al. Periodontal disease, tooth loss, and risk of oesophageal and gastric adenocarcinoma: a prospective study. Gut. 2021;70(3):620-621. doi:10.1136/gutjnl-2020-321949 (retrieved via PubMed; full text via PubMed Central)
About the author. CJ Henley, DMD, is a general dentist in Jacksonville whose practice focuses on cosmetic and restorative dentistry, dental implants and dental care around head and neck cancer. Meet Dr. Henley.
CJ Henley, DMD, PA · 3675 Hendricks Avenue, Jacksonville, FL 32207 · 904-398-1549
Updated October 2026.
What a Tiny Jaw From Greenland Shows About the Origin of Molars
Scientists have described the earliest known example of dentary bone with two rows of cusps on molars and double-rooted teeth. The new findings offer insight into mammal tooth evolution, particularly the development of double-rooted teeth.
A fossil jaw about 2 centimeters long, found in eastern Greenland and about 215 million years old, has the oldest known molar-like teeth with two roots and two rows of cusps. It belongs to a small, shrew-like animal named Kalaallitkigun jenkinsi, a close relative of the first mammals. Engineering tests in the same 2020 study suggest that two roots help a tooth withstand the stress of biting, which may be one reason complex chewing teeth and divided roots evolved together.
What question were the researchers asking?
Mammals chew in a way most other animals do not. Our upper and lower back teeth meet precisely, and their broad crowns grind food. Close relatives of early mammals were already experimenting with tooth shape in the Late Triassic period. One group, the haramiyidans, had molar-like teeth with two rows of cusps suited to a more plant-based diet. Where that pattern came from was unclear.
What did they find?
The team, led by Tomasz Sulej of the Polish Academy of Sciences and Grzegorz Niedźwiedzki of Uppsala University, described the lower jaw of Kalaallitkigun jenkinsi, an animal about the size of a large mouse.
Its molar-like teeth have two rows of cusps on the crown.
Each of those teeth has two roots.
The crown shape sits between two known groups: the insect-eating morganucodontans and the haramiyidans. This suggests the haramiyidan pattern grew out of the simpler morganucodontan tooth.
The researchers also built computer models of single-rooted and double-rooted teeth and tested them with a method engineers use to study stress in structures (finite element analysis). Teeth with two roots handled stronger forces, like those of upper and lower teeth meeting, better than teeth with one root.
What are the limits?
The study rests on a single small jaw, so the picture may change as more fossils are found. The engineering models show what two roots can do mechanically. They cannot prove why divided roots first appeared.
What does this have to do with your teeth?
Your own molars carry the same basic design. Lower molars usually have two roots and upper molars usually have three, with broad crowns built for grinding. That root anatomy matters in everyday dentistry. It affects how a tooth handles chewing forces, how a root canal is planned and how a molar is removed or replaced. Fossils like this one show how long that design has been in use.
For another look at how teeth evolved, see our post on shark teeth and human dental biology. If you have a question about a molar of your own, start with a dental examination.
Sources
Sulej T, Krzesiński G, Tałanda M, et al. The earliest-known mammaliaform fossil from Greenland sheds light on origin of mammals. Proc Natl Acad Sci U S A. 2020;117(43):26861-26867. doi:10.1073/pnas.2012437117. Retrieved via PubMed.
Uppsala University. Press release on the Greenland mammaliaform jaw (October 2020).
About the author. CJ Henley, DMD, is a general dentist in Jacksonville whose practice focuses on cosmetic and restorative dentistry, dental implants and dental care around head and neck cancer. Meet Dr. Henley.
CJ Henley, DMD, PA · 3675 Hendricks Avenue, Jacksonville, FL 32207 · 904-398-1549
Updated October 2026.