This simple study shows that frozen red raspberries in quantities of 125-250 mg (1-2 cups), when taken with a typical high-carb breakfast, improve insulin resistance in adults with prediabetes. Although these results would need to be validated, having red raspberries for breakfast sounds just right.
This study investigated the effect of red raspberry intake on meal‐induced postprandial metabolic responses in individuals who have overweight or obesity with prediabetes and insulin resistance, and in metabolically healthy individuals.
32 adults (PreDM‐IR, n = 21; Reference, n = 11) were randomized to a controlled, three‐arm, single‐blinded, crossover trial. Participants were provided:
0 g of frozen red raspberries (Control),
125 g of frozen red raspberries (RR‐125) (~1 cup), or
250 g of frozen red raspberries (RR‐250) (~2 cups), with a challenge breakfast meal (high carbohydrate/moderate fat) on three separate days.
Multiple blood samples were collected up to 8 hours post breakfast with a final blood sample at 24 hours. A snack was provided at 6 hours.
Breakfast containing RR‐125 and RR‐250 significantly reduced 2‐hour insulin area under the curve, and RR‐250 reduced peak insulin, peak glucose, and 2‐hour glucose AUC compared with Control in the PreDM‐IR group (P < 0.05).
Postprandial triglycerides were lower after RR‐125 versus RR‐250 (P = 0.01) but not different from Control (P > 0.05).
No significant meal‐related differences were observed for oxidative stress or inflammatory biomarkers.
Our findings suggest that red raspberries aid in post-meal glycemic control in individuals with PreDM‐IR, reducing glycemic burden with less insulin, which may be related to improved tissue insulin sensitivity.