Association between dietary acid load and cancer: An updated systematic review and meta-analysis of observational studies

Background & Aims

Epidemiological studies have indicated a potential association between dietary acid load (DAL) and the risk and prognosis of cancer; however, the evidence needs more research. Hence, we performed an updated systematic review and meta-analysis to comprehensively investigate the relationship between DAL and risk for different types of cancer.

Methods

We conducted a systematic literature search in the PubMed, Embase, Web of Science, and Scopus databases from inception to November 2023. We calculated pooled odds risks (ORs) with 95% CIs using a random-effects model. We also conducted analyses on publication bias, subgroups, and sensitivity. This systematic review and meta-analysis included fifteen case-control studies.

Results

The pooled OR showed a statistically significant association between potential renal acid load (PRAL) (OR: 2.73, 95%CI: 2.62–2.83, P: <0.0001) and net endogenous acid production (NEAP) (OR: 2.70, 95%CI: 2.66–2.74, P: <0.0001) and a considerably increased risk of cancer. To identify potential sources of heterogeneity, subgroup analyses were performed depending on gender and country. Iranian females showed a higher odds ratio for developing cancer, according to statistical research on the PRAL index. However, the NEAP variable revealed a higher cancer risk among Uruguayan males.

Conclusion

The high DAL may be associated with an increased cancer risk and a poor cancer prognosis. We need more high-quality prospective studies to explore the connections between DAL and the risk and prognosis of specific cancers.