Relationship Between Dietary Acid Load and Risk of Metastatic Colorectal Cancer: A Case-Control Study.

PURPOSE

Colorectal cancer (CRC) is a type of cancer affecting the colon and rectum, primarily originating from intestinal polyps. Recently, increasing attention has been given to the role of dietary acid-base balance in cancer development. This study aimed to investigate the relationship between dietary acid load and the risk of metastatic colorectal cancer (mCRC).

DESIGN/METHODOLOGY/APPROACH: This hospital-based case-control study was conducted on 120 adults with mCRC and 240 non-neoplastic adults in the control group, matched for age and gender. Dietary intake was assessed using a food frequency questionnaire. Net endogenous acid production (NEAP) and potential renal acid load (PRAL) were calculated using predetermined formulas. Odds ratios (ORs) were used to estimate the risk of mCRC across PRAL and NEAP tertiles.

FINDINGS

There were no significant differences between the two groups in terms of demographic characteristics, anthropometric measures, smoking, and alcohol consumption. However, energy intake and energy-adjusted carbohydrate, fiber, potassium, magnesium, and calcium intake were significantly higher in the control group compared to the case group ( < 0.05). The mean PRAL in the case group (10.5 ± 1 mEq/day) was significantly higher than in the control group (5.2 ± 0.5 mEq/day) ( < 0.001). However, no significant difference was observed between the groups regarding NEAP (35 ± 7 mEq/day in the control group vs. 36 ± 5.5 mEq/day in the case group,  = 0.12). The second and third tertiles of PRAL were associated with an increased risk of mCRC compared to the first tertile (OR = 3.4, 95% CI: 1.6-7; OR = 4.1, 95% CI: 2-8.5, respectively) ( < 0.001).

ORIGINALITY/VALUE: High PRAL levels were associated with an increased risk of mCRC, whereas NEAP scores were not linked to mCRC risk.