This study aimed to investigate the link between starch consumption (quantity and source) and progression of dental caries in adults across an 11-year period. Information was collected from 1,679 adults aged 30 years or older who participated in a series of three nationwide surveys in Finland. During the baseline survey, all participants completed a 128-item, semi-structured food frequency questionnaire that had been previously validated. from which daily starch intake (grams and % of total energy) and intake of seven starch-rich food categories (including potatoes, potato derivatives, roots/tubers, refined cereals, pasta, whole grains, and legumes) were estimated. Dental caries status was assessed in clinical examinations and expressed using the DMFT index, analyzed as a repeated measure. Associations between baseline starch intake and 11-year DMFT change were evaluated with linear mixed-effects modeling, adjusted for sociodemographics, lifestyle, sugar consumption, and general health. The average DMFT index was 21.9 (95% CI: 21.6–22.2) in 2000, increasing by 0.47 (95% CI: 0.38–0.56) in 2004/05, and a further 0.33 (95% CI: 0.20–0.45) in 2011. No association was detected between overall starch intake and DMFT progression, regardless of whether intake was expressed in grams/day or as % of energy intake. Among the seven food categories, only pasta intake showed an inverse association with DMFT at baseline, but it was unrelated to changes over the follow-up period. Over an 11-year timeframe, starch intake—neither in total quantity nor by food type—showed no significant relationship with dental caries development in Finnish adults.
