The association of diet-dependent acid load with gastrointestinal cancer risk in the Cancer Screenee Cohort in Korea.

Background/objectives: Diet-induced acidosis is a determinant of gastrointestinal (GI) cancer susceptibility. However, the current evidence remains insufficient to establish a link between an acidogenic diet and cancer because the majority of previous studies were restricted to a case‒control design. We investigated whether the dietary acid load is involved in GI carcinogenicity.

Subjects/methods: We conducted a prospective cohort study of 10,741 participants who attended check-ups from October 2007 to December 2020 at the National Cancer Center, Korea. The participants were followed up until December 2020 to determine incident GI cancer cases. A Cox proportional hazards regression model was used to examine the dietary acid load, as reflected by the potential renal acid load (PRAL), the net endogenous acid production (NEAP), and net acid excretion (NAE), in relation to GI cancer risk.

Results: A total of 208 incident GI cancer cases were identified during the follow-up period. We observed a significantly increased GI cancer risk among male participants with high PRAL, NEAP, and NAE scores (hazard ratios (HRs) = 1.53 (95% confidence interval (CI): 1.05-2.22), 1.51 (1.04-2.19), and 1.73 (1.18-2.53), respectively). Importantly, acidogenic foods seem to have detrimental effects even in individuals who are not obese.

Conclusions: Our findings add substantial evidence to the argument that diet-dependent acid load plays certain roles in GI carcinogenesis, especially in males. Thus, attention should be given to the dietary acid‒base load for the prevention of GI cancer.