Nutrition scientists have long investigated the connection between the AMY1 gene—which produces salivary amylase, an enzyme that breaks down starch—and type 2 diabetes. Now, a new study published on July 2 in PLOS One offers important clarity, suggesting that a higher number of AMY1 gene copies may protect against the disease.
More AMY1 Copies, Lower Diabetes Risk?
The study, led by Angela Poole, assistant professor of molecular nutrition at Cornell University, found that individuals with more copies of the AMY1 gene exhibited higher salivary amylase activity. These higher enzyme levels could trigger earlier insulin release during starch digestion, potentially protecting against spikes in blood sugar—a hallmark of type 2 diabetes.
“This is significant because diabetes is widespread and growing rapidly,” Poole emphasized. “Knowing your genetic risk early could shape your lifestyle and help prevent the disease from developing.”
Study Design and Technical Insights
As reported by medicalxpress, the research team genotyped over 100 participants, dividing them into two groups: those with self-reported type 2 diabetes or prediabetes, and those without either condition. They measured AMY1 gene copies using both quantitative PCR (qPCR) and digital PCR.
Contrary to previous skepticism, Poole’s team found that well-executed qPCR protocols yielded results comparable to digital PCR. “You shouldn’t dismiss qPCR results outright,” Poole noted.
Time of Day Matters in Enzyme Testing
The team also measured amylase activity in fasting morning samples and evening samples. Results showed a significant diurnal variation—activity was consistently higher in the evening, regardless of gene copy number.
“This confirms that researchers must standardize the time of sample collection,” Poole said.
Unexpected Findings Among Diabetic Individuals
Interestingly, individuals with type 2 diabetes or prediabetes showed higher amylase activity per AMY1 copy compared to those without the disease. Poole believes that although the copy number is fixed, how the gene is expressed might vary based on disease status, diet, or gut microbiome.
“If two people each have 10 copies of AMY1, the one with diabetes tends to have higher enzyme activity,” she explained. “This suggests the body might respond differently based on metabolic condition.”
Looking Ahead: Diet, Genes, and Long-Term Risk
While the findings point to a potentially protective role of AMY1 against type 2 diabetes, Poole cautions that more extensive, long-term studies are needed. Future research must include dietary control, larger participant numbers, and extended follow-ups to fully understand how AMY1 gene copy number and starch intake interact.
“People with fewer gene copies may be at higher risk, especially if they eat a starch-heavy diet,” Poole said.