by EBSCO Medical Review Board

The liver's job is to filter blood. Cancer causes illness and makes it harder for the liver to work as it should. Daily habits can affect the risk of liver cancer. Regular infections can also increase the risk of cancer. These infections are often picked up from the blood. For example, an infection in the mouth can travel to the stomach and intestines. There it passes through the blood and is sent to the liver to be processed. The infection may cause damage in the liver that can increase the risk of cancer.

Researchers wanted to investigate the link between oral health conditions and the risk of gastrointestinal cancers, such as liver, colon, rectum, and pancreatic cancer. The study, published in SAGE, found that poor oral health is associated with a 75% increased risk of hepatocellular carcinoma, the most common form of liver cancer.

About the Study

The large cohort study included 475,766 adults in the United Kingdom. Researchers asked participants to report signs of oral health problems, such as painful gums, bleeding gums, and loose teeth. The participants were then followed for an average of 6 years to track the development of any type of cancer in the belly such as stomach, intestinal, or liver cancer.

The study found that 4,069 gastrointestinal cancer cases were detected, of which 13% of participants self-reported poor oral health. Those who noted poor oral health issues had a 75% increased risk of hepatocellular carcinoma, which is a type of liver cancer.

How Does This Affect You?

Cohort studies are observational studies. These studies simply watch events as they happen. They do not interfere or control factors that can change the result. This means the study cannot prove that poor oral health can cause liver cancer. It can only suggest a link. This study also used self-reports of oral health from participants which may not be reliable. People may be embarrassed or unaware of some habits and symptoms. Observational studies also do not control a number of other factors that can affect cancer risk. More studies will need to be done to determine why poor oral health may be more strongly associated with liver cancer.

Poor oral health has been linked to a number of health problems. Fortunately there is an easy fix. Practice good oral health by brushing your teeth twice a day. Clean between your teeth once a day. Have a routine dental cleaning every six months. See your dentist if you have painful gums, bleeding gums, or loose teeth.


American Cancer Society 

Mouth Healthy—American Dental Association 


Jordão H, McKenna G, et al. The association between self-reported poor oral health and gastrointestinal cancer risk in the UK Biobank: A large prospective cohort study. SAGE Journals website. Available at: Published June 8, 2019. Accessed June 24, 2019.

Revision Information

  • Reviewer: EBSCO Medical Review Board
  • Review Date: 06/2019