Carbohydrates and cancer: A metabolic and epidemiological overview

Cancer causes dysregulation of apoptosis, a genetically controlled mechanism necessary for growth and homeostasis, which permits unchecked cell division and resistance to cell death. The Warburg effect, metabolic flexibility, and glucose reliance of malignant cells are highlighted in this chapter's analysis of the molecular interactions among insulin/IGF-1 signaling, carbohydrate metabolism, and tumor biology. We examine the data relating increased tumor survival, proliferation, and metastasis to hyperglycemia, hyperinsulinemia, and inflammatory cytokines. In the context of primary, secondary, and tertiary cancer prevention across a variety of tumor types, including colorectal, prostate, breast, and head and neck cancers, the epidemiological and experimental literature on dietary carbohydrates-from simple sugars to complex fibers-is assessed. There is discussion of mechanistic processes involving altered metabolism, hormonal regulation, and acidity of the microenvironment. While recognizing discrepancies and data gaps that need more study, the chapter emphasizes dietary modification-specifically, limiting carbohydrates and increasing fiber intake-as a promising adjunct in cancer prevention and survivorship.