Stomach cancer remains a significant global health concern, contributing substantially to worldwide mortality rates despite efforts to combat Helicobacter pylori infection and improve food preservation practices, which have led to reductions in both the incidence and fatality rates of stomach cancer.
Exploring the Relationship between Dietary Patterns and Stomach Cancer Risk:
Various epidemiological studies have uncovered associations between dietary habits and the risk of developing stomach cancer. While individual dietary components have shown inconsistent results in terms of stomach cancer risk, assessing overall dietary patterns appears to offer more reliable estimations and outcomes, thus underscoring the importance of comprehensive cancer prevention recommendations.
Insights from the Review:
In a recent review, researchers delved into existing data to evaluate the impact of diet on gastric cancer risk. They identified two main types of diet patterns: posteriori patterns, derived from cohort population data, and a priori patterns, created using information on food, nutrients, and diseases. Posteriori patterns are determined through statistical methods like principal component analysis, factor analysis, and cluster analysis, whereas a priori patterns can originate from country-specific standards, preventive diets for chronic diseases, or cultural dietary practices.
Association between Diet Patterns and Stomach Cancer Risk:
Studies have found that adopting healthy eating patterns in case-control settings can reduce the risk of stomach cancer, while “unhealthy” dietary patterns tend to increase the risk. A comprehensive meta-analysis showed that adherence to a “prudent” diet pattern was associated with a lower incidence of stomach cancer (odds ratio of 0.8). In contrast, increased adherence to Western diets was linked to a higher risk of total stomach cancer (odds ratio of 1.5). Notably, the association between poor dietary habits and stomach cancer risk was more pronounced for cardia stomach cancers (odds ratio of 2.1) compared to distal stomach cancers (odds ratio of 1.4).
Further meta-analyses suggested that individuals consuming healthy foods had significantly reduced risks of stomach cancer (odds ratio of 0.7), while following unhealthy diets increased the risk (odds ratio of 1.6). Moreover, a 2017 meta-analysis emphasized that “Western” diets were correlated with an increased risk of gastric cancer.
Considering A Priori Dietary Patterns and Gastric Cancer:
The relationship between dietary habits and stomach cancer risk is intricate, with limited research assessing the impact of high scores on health eating indices like HEI or AHEI on stomach cancer risk. Recent case-control studies from Iran demonstrated that adhering to the Dietary Approaches to Stop Hypertension (DASH) diet was associated with a 54% lower incidence of stomach cancer. Components of the DASH diet, such as salt intake, red meat consumption, and fruit intake, have been linked to stomach cancer risk reduction.
Exploring Biological Markers and Dietary Patterns:
Inflammation plays a crucial role in gastric cancer risk, particularly among men, with pro-inflammatory foods increasing the incidence of specific cancer subtypes. The review highlighted the association between the ketogenic diet (KD) and advanced gastric cancer treatment. The KD alters glucose metabolism, inhibits insulin signaling and insulin-like growth factor 1 (IGF-1), and reduces nicotinamide adenine dinucleotide phosphate (NADPH) generation to induce oxidative stress in tumor cells.
Conclusion:
Overall, the findings from the review suggest that dietary patterns can indeed impact stomach cancer risk by influencing various factors such as metabolites, gut microbiota, inflammation, and immune function. However, inconsistencies in study results may arise from factors like meal types, recall biases, overall energy intake, and other confounding variables. Large-scale prospective cohort studies could provide further clarity on the validity of these findings.