Food Preservatives May Help Prevent Dental Caries Glenn Rutherford Box 672 University of Rochester Medical Center Rochester, NY 14642-8672 716/275-1675 Paper K-24, Session 53-K Weak acids and parabens (esters of para-hydroxybenzoic acid) are common food additives. If you look at a list of ingredients in common food products, you are likely to see the chemical names ascorbate, benzoate, salicylate and sorbate. These weakly acidic chemicals act to preserve food and extend its shelf-life by inhibiting growth of molds, yeast and bacteria that would otherwise spoil the food. In other words, they are preservatives. Many other products that you use everyday also contain preservatives, such as the parabens, which are chemicals closely related to weak acid preservatives. In a recent study, it was found that over 75% of cosmetics contain parabens as preservatives to inhibit microbial growth. In addition, many oral health products, including some toothpaste, have parabens on the list of ingredients. Therefore, everyday we ingest weak acids from foods or are exposed to parabens in a variety of products. Another weak acid we ingest daily is fluoride, which may be added to drinking water, food or oral health products to prevent tooth decay or dental caries. We shall be describing our most recent work on the actions of weak acids and parabens on dental plaque bacteria in our presentation entitled "Inhibition of the arginine deiminase system of oral streptococci by weak acids and parabens" at the Annual Meeting, of the American Society for Microbiology in Atlanta, GA, paper K-024 in session 053/K on Monday morning, May 18th at 9:00 a.m. The work was carried out at the University of Rochester, NY, by Glenn C. Rutherford, Yousheng Ma and Robert E. Marquis and was funded in part by the U. S. National Institute of Dental Research. On the basis of the results obtained over the past few years, we now believe that weak-acid food preservatives and parabens may help in prevention of caries because they act, like fluoride, to prevent production of acid by microorganisms in dental plaque, which is the white adherent material that forms on teeth and is made up mainly of bacteria and sticky polysaccharides. In the paper being presented this year, we describe how weak acids and parabens can also inhibit desirable activities of dental plaque bacteria, specifically production of alkali from proteins, peptides and amino acids from the host diet or from saliva. Alkali production is desirable because it results in neutralization of acids produced by plaque bacteria from sugar. Thus, there are good and bad aspects of the actions of preservatives on oral bacteria. We feel that the good effects, inhibition of acid production, outweigh the bad effects, inhibition of alkali production. The weak acids are most effective against bacteria in acid environments and it is only very acid plaque that causes caries. When a person eats food containing sugar, the bacteria in plaque degrade the sugar to produce acids, and the acids cause tooth enamel to dissolve. If the person does not eat sugary foods for awhile, the plaque will no longer be acid, in part because of washing away of acids by saliva and!
in part because of alkali production by bacteria. Because weak-acid preservatives work best to inhibit metabolism in acid environments, they would be most effective during the acid attack after eating sugars and less effective when the plaque is not so highly acidified. Therefore, in the mouth, they would act more to inhibit acid production than to inhibit alkali production. In effect, we may be gaining an unexpected benefits from preservatives and enjoying better oral health.
RSS