Carbohydrate quality vs quantity on cancer Risk: Perspective of microbiome mechanisms

Extensive research has established the benefits of incorporating low carbohydrate diets (LCDs) for managing obesity, diabetes, and metabolic syndrome (Mets). Recent findings indicate that LCDs could additionally impact cancer development and progression by creating an unfavorable metabolic micro-environment that promotes reprogrammed metabolism in cancer cells. This has led to LCDs being considered as a possible complementary treatment for cancer. Our review specifically examines the association between cancer risk, consumption of dietary carbohydrate, glycemic index (GI), and glycemic load (GL), with a focus on prostate, breast, and colorectal cancer. We also explore relevant mechanism underlying the potential anti-tumor effects of LCD diets, especially in gut microbiota modulation. However, findings in this area remain controversial, and further research is needed to evaluate their application in clinical practice. On the other hand, resistant starch (RS) has gained attention as a healthy and high-quality component of carbohydrate diets. It not only serves as a dietary fiber but also acts as a valuable source of prebiotics due to its ability to influence gut microbial composition, leading to improved metabolic control. This has positioned RS as a potential means for preventing and treating cancer. In this review, we also summarized the RS-gut microbiota-cancer risk axis to enhance our understanding of the health effects of RS consumption. From a clinical perspective, RS supplementation shows promise as a strategy for preventing diseases and managing cancer. It is evident that simply assessing the quantity of dietary carbohydrate intake may not be enough to determine cancer risk; the quality of carbohydrates should also be considered to draw definitive conclusions which will help clinician and nutritionist make a reasonable choice in management cancer.