The aim of this study was, systematically, to evaluate the effect of die-tary changes in the prevention of dental caries. A search and analysis strategy was followed, as suggested by the Swedish Council on Tech-nology Assessment in Health Care (SBU). The search strategy for arti-cles published in 1966-2003 was performed using electronic databases and reference lists of articles and selected textbooks. Out of 714 arti-cles originally identified, 18 met the inclusion criteria for a random-ized or controlled clinical trial--at least 2 years’ follow-up and caries increment as a primary endpoint. This included the total or partial substitution of sucrose with sugar substitutes or the addition of pro-tective foods to chewing gum. No study was found evaluating the ef-fect of information designed to reduce sugar intake/frequency as a sin-gle preventive measure. It is suggested that the evidence for the use of sorbitol or xylitol in chewing gum, or for the use of invert sugar, is in-conclusive. No caries-preventive effect was found from adding calcium phosphate or dicalcium phosphate dihydrate to chewing gums. The review clearly demonstrates the need for well-designed randomized clinical studies with adequate control groups and high compliance.