Flossing your teeth isn't just important for keeping your dentist happy — it may also protect against cognitive decline.
"Given the staggering number of people diagnosed with Alzheimer's disease and dementia each year, and the opportunity to improve oral health across the life span, it's important to gain a deeper understanding of the connection between poor oral health and cognitive decline," said Bei Wu, a professor in global health at NYU Rory Meyers College of Nursing and the senior study author, in a statement.
Researchers analyzed 14 studies on tooth loss and cognitive impairment conducted over an extended period of time, which involved a total of 34,074 adults and 4,689 cases of people with diminished cognitive function.
The results showed that adults with more tooth loss had a 1.48 times higher risk of cognitive impairment and 1.28 times higher risk of dementia, even when other factors were controlled.
And with each additional missing tooth, the risk of cognitive impairment grows, according to the analysis published in JAMDA: The Journal of Post-Acute and Long-Term Care Medicine.
Adults who experienced tooth loss were more likely to have cognitive decline if they did not have dentures, the new research also revealed.
"We need to think about increasing awareness of the importance of oral health, and we also need to think about preventive treatment and dentures," Wu told CNN.
Dentures are important because they allow patients to maintain a healthy diet, as well as provide "the confidence to smile naturally," according to Dr. James Wilson, president of the American Academy of Periodontology, who was not affiliated with the study.
"Being able to eat a normal diet is extremely important to a person's physical health," Wilson said via email. "The positive self-image that dentures provide a patient works to improve their mental health as well."
Healthy mouth, healthier brain
The analysis offered several explanations for those links between poor mouth health and poor brain health, including the problem of missing teeth, which can impact chewing, which limits the options for healthy food and can even lead to the loss of key nutrients for brain health. The analysis also highlighted evidence that oral inflammation is connected to brain inflammation and cognitive impairment.
"Untreated gum disease can lead to tooth loss and may also increase the risk of developing other health complications," Wilson added.
"Inflammation as a result of gum disease has been linked to other disease states, including cardiovascular disease, pancreatic cancer, diabetes, rheumatoid arthritis and Alzheimer's disease."
Previous studies have also found links between P. gingivalis — the bacteria associated with gum disease — and Alzheimer's, Wilson told CNN.
Socioeconomics play a role
The NYU-led analysis also noted that tooth loss could reflect "lifelong socioeconomic disadvantages, such as limited access to and quality of medical and dental care, fewer years of education, and poor nutrition."
"Income and education are very much related to oral health, probably even more so than many other chronic conditions, particularly because of the lack of dental insurance for many people," Wu said.
Wu added that these oral health disparities are especially prominent in the United States, where the health care system is complicated to navigate, and many people do not have access to dental care as part of their health insurance or are required to pay dental expenses out-of-pocket.
She said the analysis should serve as a reminder — to both governments and everyday people — of the importance of maintaining good oral health from an early age all the way through to adulthood.
"Gum disease is preventable with daily tooth brushing and flossing and routine visits to a dental health professional," Wilson added. "Patients should also expect to receive a comprehensive periodontal evaluation on an annual basis."