Starch Digestion-Related Amylase Genetic Variants, Diet, and Changes in Adiposity: Analyses in Prospective Cohort Studies and a Randomized Dietary Intervention.

Salivary amylase, encoded by the AMY1 gene, is responsible for the digestion of carbohydrates. We investigated associations of the AMY1 genetic variations with general and central adiposity changes considering dietary carbohydrate intake among 32054 adults from 4 prospective cohort studies. A genetic risk score (GRS) was calculated based on nine AMY1 single-nucleotide polymorphisms, with higher AMY1-GRS indicating higher activity of salivary amylase. We meta-analyzed interactions between AMY1-GRS and dietary intake for changes in general and central adiposity over 5.5–10 years. We found that carbohydrate food intake significantly altered associations of AMY1-GRS with changes in body mass index (Pinteraction=0.001) and waist circumference (Pinteraction