TIDBITS : A Gritty Discovery

Doctors have long cautioned their patients against using smokeless tobacco, citing an increased risk of oral cancer.

But researchers at the Baylor College of Dentistry in Dallas report that tobacco also contains tiny particles of silica that may abrade teeth.

William H. Bowles, an associate professor at Baylor, and his colleagues analyzed eight brands of snuff, four brands of chewing tobacco and 16 cigars--since smokers typically chew the end of the cigar.

Insoluble mineral particulate--primarily silica or silicon dioxide--made up an average concentration of .5% of the tobacco’s dry weight, they reported in the Journal of the American Dental Assn.

Most of the silica could not be washed away, according to the study, because it came from the soil and was carried into the leaves as the plant grew.

“When tobacco products containing abrasive silica are mixed with saliva and chewed, an abrasive paste is formed that over time can wear down teeth very efficiently,” the authors wrote.