New research co-authored by UC Davis faculty member Dr. Bethany P. Cummings, an affiliated faculty member with the UC Davis Innovation Institute for Food and Health (IIFH), highlights how a common genetic difference may help explain why people respond differently to starch-rich foods. The review examines decades of research on variation in the AMY1 (salivary amylase) gene, which influences how efficiently individuals begin digesting starch. By synthesizing evidence across studies, the authors found that higher AMY1 gene copy number is consistently associated with stronger post-meal glucose responses and may help protect against insulin resistance, while relationships with obesity appear to depend on factors such as habitual starch intake, genetics, and lifestyle.
For IIFH, this work underscores the promise of precision nutrition—moving beyond one-size-fits-all dietary recommendations toward nutrition strategies informed by an individual’s biology. Dr. Cummings’ research contributes to a growing body of evidence that genetics, diet, and the gut microbiome interact in complex ways to influence metabolic health. While additional research is needed before AMY1 can be used routinely in clinical practice, these findings help lay the scientific foundation for more personalized approaches to preventing obesity and type 2 diabetes, advancing IIFH’s mission to translate cutting-edge research into practical solutions that improve food, health, and long-term wellbeing.
Because this is a preprint, these findings should be considered preliminary until validated through peer review.
