Grains, Cereals, and Legumes: Implications in Glycemic Index and Perspectives.

BACKGROUND/OBJECTIVES: The glycemic index (GI) is a critical factor in managing blood sugar levels and related diseases. Grains, as staple foods consumed worldwide, are primary sources of carbohydrates, starch, and dietary fiber (DF). The carbohydrate composition of grains can significantly influence postprandial blood glucose levels. Therefore, understanding how different carbohydrate components affect blood glucose is essential. METHODS: This study retrospectively examined the relationship between carbohydrate composition and GI in various grains, cereals, and legumes. Data on grain and cereal components were obtained from reputable public databases, including PubMed, the U.S. Department of Agriculture (USDA), FooDB, and published studies. RESULTS: Analysis of the GI and glycemic load (GL) across grain components revealed several key findings. In addition to total carbohydrate (TC), both dietary starch (DS) and dietary fiber (DF) had substantial effects on GI. Interestingly, total sugar (TS), often considered a primary concern, showed no significant association with GI. Multiple regression and linear regression analyses demonstrated strong correlations between GI and both TC and DS. Among ratio metrics, the TC-to-DF ratio displayed significant correlation with GI (R = 0.48, p = 0.0003), followed by the DS-to-DF ratio (R = 0.33, p = 0.0159). The TS-to-DF ratio, however, showed no significant correlation (R = 0.04, p = 0.7544). CONCLUSIONS: These findings suggest that carbohydrate-to-fiber ratios, especially TC-to-DF, may play an important role in determining GI. Other dietary components, such as dietary fiber and dietary starch, might also affect these results. Additional studies are needed to examine how factors beyond carbohydrates influence GI. These observations may help guide future work aimed at better understanding dietary effects on health. Further, our results offer valuable insights for making healthier nutritional choices and improving the management of chronic diseases.