(P22-07-26) Adding Roasted Peanut Powder to Traditional Indian Staples Lowers Glycemic Index and Postprandial Glycemia

Objectives: India has a high type 2 diabetes burden and diets dominated by high glycemic index (GI) refined cereals. Peanuts are low GI, nutrient dense, and widely consumed in India, but their impact on the GI of starchy staples is unknown. We evaluated whether adding 30g roasted peanut powder to common starchy Indian foods lowers GI and acute glycemic responses.

Methods: In 7 phases, we conducted a randomized within‑participant crossover GI study at the Madras Diabetes Research Foundation, India, following ISO protocol. Healthy adults who were overweight (n=15 per phase; 18-45 y; BMI ≥23 kg/m²) were recruited from a volunteer registry. Nineteen starchy foods were each tested in two forms (with and without 30 g roasted peanut powder), with portions standardized to 25g or 50g available carbohydrates. Capillary blood glucose was measured at 0–120 min after ingestion of test foods and a reference glucose drink. GI (primary outcome) was calculated as the incremental area under the curve (iAUC) for each test food expressed as a percentage of the participant’s mean iAUC for the reference. Secondary outcomes include peak glucose (C_max), incremental peak glucose (max[ΔGlucose(t)]), and time to peak (T_max). Mean differences between foods with and without peanuts were assessed using paired t-tests and multivariable linear models adjusting for age, sex, and BMI.

Results: In the control condition, GI values ranged from 40 to 92, with many cereal staples classified as high GI (≥70). Adding roasted peanut powder reduced GI by ~5–30 units for most foods; several staples, including steamed rice cakes (idli), Indian flatbread (chapathi), rice and lentil porridge (pongal), semolina porridge (upma), vegetable noodles, white bread, and plain rice, shifted into favorable GI categories. With addition of peanuts, for several refined‑grain dishes, C_max, incremental peak glucose, and iAUC were generally lower, and T_max was longer.

Conclusions: Among overweight but normoglycemic Indian adults, adding 30 g roasted peanut powder to many traditional staples substantially lowered GI and attenuated postprandial glycemia, particularly for refined‑grain dishes. Strategic incorporation of peanuts into the food matrix of starchy staples may offer a culturally acceptable, low‑cost strategy to reduce meal‑level GI in populations at high risk of type 2 diabetes.

Funding Sources: USDA and The Peanut Institute