Floss for Your Teeth, Not Your Heart

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Practicing good oral hygiene will lower your risk of gum disease, but it probably won't help your heart, according to a report published today in the Journal of the American Medical Association (JAMA). Contrary to previous research that linked periodontitis and chronic coronary heart disease, University of Washington scientists say their findings failed to reveal any meaningful connection between the two.

None of the earlier studies noting a correlation between the conditions could prove cause and effect, which in fairness is not an easy thing to do. Complicating the matter is the fact that the two diseases share the same risk factors--smoking, obesity and increasing age, to name a few. "Trying to figure out if periodontal disease actually causes heart disease, with the presence of all these shared risk factors, is very difficult," team member Timothy A. DeRouen said.

This time, the researchers turned to a federal database that contained medical profiles of more than 8,000 people--none of whom had any apparent heart disease at the onset of the study--whose health was then followed for 20 years. The data included detailed diagnoses of the subjects' gums and teeth, as well as other information on smoking habits and physical activity. After accounting for all of these variables, only a slight association between periodontal disease and subsequent heart disease remained. "There is no evidence that any dental treatment will have a positive impact on chronic coronary heart disease," asserts Philippe Hujoel, an author on the JAMA paper. "Our analysis suggests that the association is either nonexistent or of such small size that it will be very difficult to come up with convincing evidence."

Kate Wong is an award-winning science writer and senior editor for features at Scientific American, where she has focused on evolution, ecology, anthropology, archaeology, paleontology and animal behavior. She is fascinated by human origins, which she has covered for nearly 30 years. Recently she has become obsessed with birds. Her reporting has taken her to caves in France and Croatia that Neandertals once called home to the shores of Kenya’s Lake Turkana in search of the oldest stone tools in the world, as well as to Madagascar on an expedition to unearth ancient mammals and dinosaurs, the icy waters of Antarctica, where humpback whales feast on krill, and a “Big Day” race around the state of Connecticut to find as many bird species as possible in 24 hours. Wong is co-author, with Donald Johanson, of Lucy’s Legacy: The Quest for Human Origins. She holds a bachelor of science degree in biological anthropology and zoology from the University of Michigan. Follow her on Bluesky @katewong.bsky.social

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