USA – It’s one of the most universal recommendations in all of public health: Floss daily to prevent gum disease and cavities. Except there’s little proof that flossing works.
Still, the federal government, dental organisations and manufacturers of floss have pushed the practice for decades. Dentists provide samples to their patients; the American Dental Association insists on its website that flossing “is an essential part of taking care of your teeth and gums.”
The federal government has recommended flossing since 1979, first in a surgeon general’s report and later in the Dietary Guidelines for Americans issued every five years. The guidelines must be based on scientific evidence, under the law.
Last year, The Associated Press asked the departments of Health and Human Services and Agriculture for their evidence, and followed up with written requests under the Freedom of Information Act.
When the federal government issued its latest dietary guidelines this year, the flossing recommendation had been removed without notice. In a letter to the AP, the government acknowledged the effectiveness of flossing had never been researched, as required.