Diet, inflammation, and cancer

Chronic inflammation provides the substrate for the cellular machinery that leads to cancer; and diet is the most important modulator of inflammation. Here, we continue the conversation that our inflammatory and immune responses are needed to respond to perceived danger. Critical in this is the ability to discern self from nonself. Things sensed as being foreign to the body are considered nonself—and a highly functioning organism that is not in a state of chronic inflammation will mount an immune response to destroy anything seen as nonself. Regarding diet, we now must consider the synthetic and other dietary factors tied to a Western diet as “foreign” (nonself). Therefore, dietary factors are key to determining whether the organism is in a state of chronic inflammation. With the backdrop of individual, familial, and societal factors, proinflammatory dietary patterns can induce a state of chronic inflammation, with collateral damage to by-standing healthy cells; including genetic mutations, epigenetic, proliferative, and apoptotic alterations. Over the past several decades, there have been many studies implemented to understand the impact of diet on carcinogenesis. Disappointingly, the use of individual dietary ingredients (e.g., specific micronutrients) has proven mostly unsuccessful in preventing cancer. Recent attention has turned toward dietary behaviors and overall patterns as determinants of inflammatory potential, cancer risk, and survivorship. Indeed, sustained consumption of an antiinflammatory, plant-based (e.g., Mediterranean or Asian) diet reduces inflammation and cancer risk. By contrast, consuming a proinflammatory Western-style diet consisting of ultraprocessed foods rich in animal fat, sugar, and food additives results in chronic inflammation, which increases cancer risk. This chapter summarizes the available evidence supporting these conclusions and makes the case that inflammation is at the crossroads of diet and cancer.