People who lose teeth have an increased risk of esophageal, head and neck, and lung cancers, according to Japanese researchers.

The authors of the study said that they suspect that infections and inflammation from poor dental care -- which can cause tooth loss -- could also help the cancers develop.

After studying more than 5,000 cancer patients and 10,000 people without the disease, the researchers determined there was a 136 percent greater chance of developing esophageal in those who had lost teeth. The rates went up 68 percent for head and neck cancer and 54 percent for lung cancer.

The researchers also found that the more teeth someone lost, the greater the chance of cancer.

Lead researcher Akio Hiraki, noted that while widespread inflammation could explain the link between tooth loss and cancer risk, they also note that tooth loss in the cancer patients may simply reflect unhealthy behaviors that contribute to cancer risk.

Also, people who have lost teeth may not be able to eat a healthy diet, and diet is also a factor in cancer development.