Research director Hideki Masuda of Ogawa & Co Ltd. in Tokyo, Japan, thinks he has identified a breakthrough ingredient to help reduce tooth decay: wasabi. The green horseradish, popular with sushi, “contains isothiocyanates, which have been found to inhibit the activity of an enzyme that plays an important role in the formation of dental plaque,” Masuda says. “If it is effective in humans, we can expect to see a wide range of applications, including wasabi toothpaste.” However, “we might need to add something to mask the pungent taste.” (Reuters) ...Tuna.