A meta-analysis published in the Journal of Clinical Endocrinology & Metabolism suggests that antacids can improve blood sugar control in people with diabetes; however, they had no effect on reducing the risk of diabetes in the general population.

Researchers noted that giving antacids as an add-on to standard therapy was found superior to standard therapy alone in reducing hemoglobin A1c (HbA1c) levels and fasting blood sugar in diabetes patients. However, for individuals without diabetes, taking antacids had no significant impact on their risk of developing it. The meta-analysis included seven studies for glycemic control and 5 studies for the risk of incident diabetes. It was found that antacids could decrease HbA1c levels by 0.36% in those with diabetes and reduced fasting blood sugar level by 10 mg/dl… (Medscape)