Guidelines based on “scientific evidence”

http://bigstory.ap.org/article/f7e66079d9ba4b4985d7af350619a9e3/medical-benefits-dental-floss-unproven

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…

It’s obvious that the CDC doesn’t have to base their recommendations for the treatment of chronic pain on “scientific evidence.” (Because drug war.) Of course, the scientific community’s understanding and use of the word “evidence” is always questionable.

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.

The AP looked at the most rigorous research conducted over the past decade, focusing on 25 studies that generally compared the use of a toothbrush with the combination of toothbrushes and floss. The findings? The evidence for flossing is “weak, very unreliable,” of “very low” quality, and carries “a moderate to large potential for bias.” …

Even companies with a big market share of the flossing business — by next year, the global market is predicted to reach almost $2 billion, with half in the United States, according to publisher MarketSizeInfo.com — struggled to provide convincing evidence of their claims that floss reduces plaque or gingivitis. Yet the industry has paid for most studies and sometimes designed and conducted the research…