People who brush their teeth regularly and keep their teeth and gums healthy have a lower risk of developing dementia later in life, according to the results of a U.S. study. Researchers at the University of California followed 5,500 seniors for 18 years and found that those who brushed their teeth less frequently than once a day had a 65 percent higher risk of developing dementia compared to those who brushed every day. The findings were published in the Journal of the American Geriatrics Society, and its principal investigator, Annlia Paganini-Hill, said, “It’s not just your mental state that predicts your oral health habits, but oral hygiene habits may affect whether you develop dementia.” Infections caused by gum disease-associated bacteria have been linked to a range of other diseases, including heart disease, stroke and diabetes, Paganini-Hill said, adding that some studies have also found that patients with Alzheimer’s disease (AD), the most common form of dementia, have more gum disease-associated bacteria in their brains compared to those without AD. more. Bacteria associated with gum disease may enter the brain and lead to inflammation and brain damage. Paganini-Hill and her team followed 5,468 California residents in the retirement community between 1992 and 2010. Most of them were white, well-educated and relatively affluent. At the beginning of the study, the participants’ ages ranged from 52 to 105 years old, with an average of 81 years old. None of the participants had dementia at the beginning of the study, and they were able to answer questions about their own dental hygiene habits, the condition of their teeth and whether they wore dentures. When the researchers followed the study for 18 years, they used interviews, case histories and death certificates to determine whether the 1,145 older adults initially enrolled had dementia. 21 of the 78 women who brushed their teeth less than once a day in 1992 had dementia, or about 1 in 3.7 older women. In comparison, those who brushed their teeth at least once a day had about 1 case of dementia for every 4.5 women. When converted, the incidence of dementia was 65% higher among those who brushed their teeth less than once a day. Among men, the effect was less pronounced, with about six people who did not brush regularly developing dementia, a 22 percent increase over those who brushed every day. Paganini-Hill can only speculate on the reasons for the different results for men and women. Perhaps women wear dentures more often and visit the dentist more frequently than men. The study also has limitations. Paganini-Hill and his team equated brushing habits and tooth count with gum disease and oral hygiene, and did not perform any dental exams. Ignoring the fact that teeth may be a sign of early susceptibility to dementia, a number of other factors may also have an impact. Amber Watts, a dementia researcher at the University of Kansas who was not part of the study, said head trauma and poor nutrition are also important causes of tooth loss in adults, and these may increase the risk of dementia. I would hate to conclude that brushing your teeth definitely prevents you from getting Alzheimer’s disease, she said.