Cashew oil may conquer cavities.

Cashew oil may conquer cavities

Don't be surprised if a nut-flavored toothpaste makes its way to the drugstore shelf sometime in the next decade. Increased consumer demand for all-natural products has revived interest in tapping foods--edible plants in particular -- for useful chemicals. In this quest, two organic chemists have discovered that the cashew may fight tooth decay and other bacterial infections, according to a report in the February JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY.

In their research, Masaki Himejima and Isao Kubo tested various tropical fruits and vegetables for antimicrobial activity. The oil from the cashew nut shell, normally a waste product of the food industry, seemed to hold some potential, so the researchers extracted and tested 16 compounds from it. The oil and some of the extracts worked well against gram-positive bacteria, in particular Propionibacterium acnes, which causes acne, and Streptococcus mutans, which causes tooth decay.

When killing bacteria in the mouth, these compounds also appear to interfere with production of the microbes' enamel-eroding acids. "It has anti-plaque activity, too," says Kudo.

The shell oil is not edible, but Kubo notes that its bacteria-fighting components also exist in the nut and in the juice of the surrounding fruit. This fruit, called cashew apple, is eaten in tropical countries with no ill effects. Kubo thinks the cashew compounds may prove safe when mixed into toothpaste or mouthwash. And he sees another benefit of their commercialization: The cashew represents a renewable resource and potentially important product from tropical forests.