Adherence to the Mediterranean Diet and its association with gastric cancer: health benefits from a Planeterranean perspective.

The Mediterranean Diet (MD) has garnered increasing attention for its potential protective effects against gastric cancer (GC). The MD's rich content of antioxidants, polyphenols, and other bioactive compounds contributes to its ability to modulate gene expression, inhibit tumor growth, and regulate apoptosis. Studies have shown significant reductions in inflammatory markers such as C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) among individuals adhering to the MD, suggesting its pivotal role in mitigating chronic inflammation-associated with cancer development. Furthermore, the MD's anti-angiogenic properties, particularly in components like olive oil, red wine, fish, and tomatoes, offer promising avenues for reducing GC risk by inhibiting tumor angiogenesis. Additionally, the MD's influence on intestinal microbiota composition underscores its potential in maintaining immune homeostasis and reducing systemic inflammation, factors crucial in GC prevention. Despite challenges such as variability in dietary adherence scoring systems and the need for further gender and geographical-specific studies, evidence supports the MD as a cost-effective and holistic approach to GC prevention. Emphasizing the role of nutrition in public health is a promising strategy with broad implications for global health and cancer prevention initiatives. Therefore, this review explores the multifaceted impacts of the MD on GC prevention, delving into its anti-inflammatory, anti-angiogenic, and molecular mechanisms.

Type 2 Diabetes Mellitus and Helicobacter pylori Eradication in a Clinical Population.

OBJECTIVES: Eradication of Helicobacter pylori reduces the risk of gastric cancer (GC). Individuals with type 2 diabetes mellitus (T2DM) are known to be at increased risk for GC. In a cohort of H. pylori-positive individuals, we assessed whether those with T2DM were at risk of persistent infection following H. pylori treatment compared with individuals without T2DM. METHODS: A random subset of all individuals diagnosed as having H. pylori without intestinal metaplasia at endoscopy from 2015 to 2019 were stratified evenly by race (Black and White). After excluding those with T1DM and those without eradication testing after H. pylori treatment, logistic regression analysis was used to determine the association of T2DM with the risk of persistent H. pylori infection following treatment. RESULTS: In 138 patients, H. pylori eradication rates did not differ between the 27% of individuals with T2DM compared to those without (81.1% vs 81.2%). After adjusting for age, race, and insurance status, we found no significant increased risk of persistent H. pylori infection for individuals with T2DM (odds ratio 1.40; 95% confidence interval 0.49-3.99). CONCLUSIONS: H. pylori eradication rates do not differ by T2DM status, providing support for clinical trials of H. pylori eradication to reduce GC incidence among high-risk populations in the United States, such as individuals with T2DM.

Dietary intake of vitamin C and gastric cancer: a pooled analysis within the Stomach cancer Pooling (StoP) Project.

BACKGROUND: Previous studies suggest that dietary vitamin C is inversely associated with gastric cancer (GC), but most of them did not consider intake of fruit and vegetables. Thus, we aimed to evaluate this association within the Stomach cancer Pooling (StoP) Project, a consortium of epidemiological studies on GC. METHODS: Fourteen case-control studies were included in the analysis (5362 cases, 11,497 controls). We estimated odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for the association between dietary intake of vitamin C and GC, adjusted for relevant confounders and for intake of fruit and vegetables. The dose-response relationship was evaluated using mixed-effects logistic models with second-order fractional polynomials. RESULTS: Individuals in the highest quartile of dietary vitamin C intake had reduced odds of GC compared with those in the lowest quartile (OR: 0.64; 95% CI: 0.58, 0.72). Additional adjustment for fruit and vegetables intake led to an OR of 0.85 (95% CI: 0.73, 0.98). A significant inverse association was observed for noncardia GC, as well as for both intestinal and diffuse types of the disease. The results of the dose-response analysis showed decreasing ORs of GC up to 150-200 mg/day of vitamin C (OR: 0.54; 95% CI: 0.41, 0.71), whereas ORs for higher intakes were close to 1.0. CONCLUSIONS: The findings of our pooled study suggest that vitamin C is inversely associated with GC, with a potentially beneficial effect also for intakes above the currently recommended daily intake (90 mg for men and 75 mg for women).

Chinese national clinical practice guidelines on the prevention, diagnosis, and treatment of early gastric cancer.

BACKGROUND: Gastric cancer is one of the most common malignant tumors in the digestive system in China. Few comprehensive practice guidelines for early gastric cancer in China are currently available. Therefore, we created the Chinese national clinical practice guideline for the prevention, diagnosis, and treatment of early gastric cancer. METHODS: This clinical practice guideline (CPG) was developed in accordance with the World Health Organization's recommended process and with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) in assessing evidence quality. We used the Evidence to Decision framework to formulate clinical recommendations to minimize bias and increase transparency in the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guidelines to ensure completeness and transparency of the CPG. RESULTS: This CPG contains 40 recommendations regarding the prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer based on available clinical studies and guidelines. We provide recommendations for the timing of Helicobacter pylori eradication, screening populations for early gastric cancer, indications for endoscopic resection and surgical gastrectomy, follow-up interval after treatment, and other recommendations. CONCLUSIONS: This CPG can lead to optimum care for patients and populations by providing up-to-date medical information. We intend this CPG for widespread adoption to increase the standard of prevention, screening, diagnosis, treatment, and follow-up of early gastric cancer; thereby, contributing to improving national health care and patient quality of life.

Points to consider regarding prophylactic total gastrectomy in germline CDH1 variant carriers.

Pathogenic germline CDH1 mutation confers high risk for developing diffuse gastric and lobular breast cancers in asymptomatic carriers. In these individuals, the estimated gastric cancer risk at 80 years of age is up to 70% for males and 56% for females. Due to this high-risk predisposition, prophylactic total gastrectomy is considered a unique life-saving approach in germline CDH1 carriers, as endoscopy often fails to detect early stage diffuse gastric carcinoma. However, surgical indication is controversial in some clinical contexts, with possible contraindications. This review discusses points against and in favor of a more aggressive surgical approach for consideration during the decision-making process.

[1983-2023 - Four decades Helicobacter pylori - what's next?] / 1983­2023 ­ Vierzig Jahre Helicobacter pylori ­ und nun?

Four decades ago the discovery of Helicobacter pylori was first reported in the international medical literature. Since then, there have been significant developments in basic and clinical science that have been translated into daily clinical practice. Changes in the management of H. pylori infection have occurred in diagnostic algorithms, indications for therapy and therapy itself. A special focus is directed to strategies of gastric cancer prevention.This manuscript briefly reviews the milestone in 40 years of H. pylori management.

Establishment of a novel tumor neoantigen prediction tool for personalized vaccine design.

The personalized neoantigen nanovaccine (PNVAC) platform for patients with gastric cancer we established previously exhibited promising anti-tumor immunoreaction. However, limited by the ability of traditional neoantigen prediction tools, a portion of epitopes failed to induce specific immune response. In order to filter out more neoantigens to optimize our PNVAC platform, we develop a novel neoantigen prediction model, NUCC. This prediction tool trained through a deep learning approach exhibits better neoantigen prediction performance than other prediction tools, not only in two independent epitope datasets, but also in a totally new epitope dataset we construct from scratch, including 25 patients with advance gastric cancer and 150 candidate mutant peptides, 13 of which prove to be neoantigen by immunogenicity test in vitro. Our work lay the foundation for the improvement of our PNVAC platform for gastric cancer in the future.

Not all carotenoids can reduce the risk of gastric cancer: a systematic review with meta-analysis.

BACKGROUND: Gastric cancer is characterized by high invasiveness, heterogeneity, and late diagnosis, leading to high incidence and mortality rates. It is a significant public health concern globally. Early prevention is crucial in reducing the occurrence of gastric cancer, and dietary prevention, particularly focusing on carotenoids, has been considered a convenient and effective approach. However, the association between carotenoid intake and gastric cancer incidence remains controversial. METHODS: A systematic search was conducted in PubMed, Ovid Embase, Web of Science, and Cochrane databases from inception to January 5, 2023. Two reviewers independently screened search results, extracted relevant data, and evaluated study quality. Statistical analysis was performed using the "metan" command in STATA 16 software. Random-effects or fixed-effects models were chosen based on the magnitude of heterogeneity among studies. RESULTS: This study included a total of 35 publications, consisting of 23 case-control studies and 12 cohort studies. Meta-analysis of case-control studies showed that alpha-carotene (OR = 0.71, 95% CI: 0.55-0.92), beta-carotene (OR = 0.62, 95% CI: 0.53-0.72), and lutein (OR = 0.82, 95% CI: 0.69-0.97) significantly reduced the risk of gastric cancer, while beta-cryptoxanthin (OR = 0.88, 95% CI: 0.75-1.04) and lycopene (OR = 0.86, 95% CI: 0.73-1.00) showed no significant correlation. Meta-analysis of cohort studies indicated no significant associations between any of the five carotenoids and gastric cancer incidence (alpha-carotene: RR = 0.81, 95% CI: 0.54-1.23; beta-carotene: RR = 0.86, 95% CI: 0.64-1.16; beta-cryptoxanthin: RR = 0.86, 95% CI: 0.64-1.16; lutein: RR = 0.94, 95% CI: 0.69-1.29; lycopene: RR = 0.89, 95% CI: 0.69-1.14). CONCLUSIONS: The relationship between carotenoids and gastric cancer incidence may vary depending on the type of study conducted. Considering that evidence from cohort studies is generally considered stronger than evidence from case-control studies, and high-quality randomized controlled trials show no significant association between carotenoids and gastric cancer incidence, current evidence does not support the supplementation of carotenoids for gastric cancer prevention. Further targeted research is needed to explore the association between the two.

Gastric intestinal metaplasia and gastric cancer prevention: Watchful waiting.

Gastric intestinal metaplasia (GIM), a common histologic finding, is associated with increased risk of gastric cancer, and GIM associated with Helicobacter pylori infection is classified as an environmental metaplastic atrophic gastritis. Patients may be asymptomatic or present with various dyspeptic symptoms. Autoimmune metaplastic atrophic gastritis is a less common but important cause of chronic gastritis. The Correa cascade describes the evolution of precancerous mucosal changes that lead to development of GIM, with differentiation of 2 histologic types of GIM (complete and incomplete) and the consequences of each type. The risk of progression to malignancy is higher with incomplete GIM. It is also higher for those who immigrate from regions with a high incidence of H pylori infection to areas where the incidence is low. Guidelines regarding endoscopic management of GIM vary by geographic region.

Polyphenol intake and gastric cancer: A case-control study in the Brazilian Amazon region.

BACKGROUND: Polyphenol intake has been associated with a decreased risk of some types of cancer, including gastric cancer (GC). However, few studies address this topic in the Latin American population. In the present study, we evaluated the association between polyphenol intake and the risk of GC in the Brazilian Amazon region. METHODS: A case-control study was conducted in Belém (Amazon region) from July 2017 to February 2021. A total of 193 GC cases and 194 controls of both sexes, between 18 and 75 years old, were included in the study. Dietary data were collected using a validated food-frequency questionnaire and polyphenol intake identified using the Phenol-Explorer database. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI), with adjustement for potential confounders. RESULTS: Cases and controls had similar total polyphenol intake (356.4 mg/1000 kcal/d and 331.1 mg/1000 kcal/d, respectively; p = 0.086). After adjusting for potential confounders, high consumption of flavan-3-ols (highest vs. lowest tertile: OR 0.41, 95% CI 0.18-0.94) and hydroxybenzoic acids (highest vs. lowest tertile: OR 0.24, 95% CI 0.10-0.56) was associated with a decreased risk of GC. The opposite was true regarding the intake of flavones (OR 2.46, 95% IC 1.17-5.18) and other polyphenols (OR 2.54, 95% IC 1.16-5.54). When stratifying according to anatomical topography, we observed that the intake of total flavonoids, flavan-3-ols, and flavanones reduced the risk of cardia GC while that of hydroxybenzoic acids reduced the risk of non-cardia GC. In addition, the intake of flavones and other polyphenols was associated with an increased risk of non-cardia GC. According to histologic subtypes, hydroxybenzoic acid intake was associated with a reduced risk of intestinal-type GC (OR 0.21, 95% IC 0.07-0.64), while flavone consumption was associated with an increased risk of diffuse-type GC (OR 2.59, 95% IC 1.05-6.42). CONCLUSIONS: Our findings suggest that in the Brazilian Amazon region the high intake of flavan-3-ols and hydroxybenzoic acids is associated with a reduced risk of GC, suggesting a potential beneficial role of these compounds against GC.

Natural products for gastric carcinoma prevention and treatment: Focus on their antioxidant stress actions in the Correa's cascade.

BACKGROUND: Correa's cascade is a pathological process beginning from gastritis to gastric precancerous lesions, and finally to gastric carcinoma (GC). While the pathogenesis of GC remains unclear, oxidative stress plays a prominent role throughout the entire Correa's cascade process. Studies have shown that some natural products (NPs) could halt and even reverse the development of the Correa's cascade by targeting oxidative stress. METHODS: To review the effects and mechanism by which NPs inhibit the Correa's cascade through targeting oxidative stress, data were collected from PubMed, Embase, Web of Science, ScienceDirect, and China National Knowledge Infrastructure databases from initial establishment to April 2023. NPs were classified and summarized by their mechanisms of action. RESULTS: NPs, such as terpenoid, polyphenols and alkaloids, exert multistep antioxidant stress effects on the Correa's cascade. These effects include preventing gastric mucosal inflammation (stage 1), reversing gastric precancerous lesions (stage 2), and inhibiting gastric carcinoma (stage 3). NPs can directly impact the conversion of gastritis to GC by targeting oxidative stress and modulating signaling pathways involving IL-8, Nrf2, TNF-α, NF-κB, and ROS/MAPK. Among which polyphenols have been studied more and are of high research value. CONCLUSIONS: NPs display a beneficial multi-step action on the Correa's cascade, and have potential value for clinical application in the prevention and treatment of gastric cancer by regulating the level of oxidative stress.

Evolving Concepts in Helicobacter pylori Management.

Helicobacter pylori is the most common chronic bacterial infection worldwide and the most significant risk factor for gastric cancer, which remains a leading cause of cancer-related death globally. H pylori and gastric cancer continue to disproportionately impact racial and ethnic minority and immigrant groups in the United States. The approach to H pylori case-finding thus far has relied on opportunistic testing based on symptoms or high-risk indicators, such as racial or ethnic background and family history. However, this approach misses a substantial proportion of individuals infected with H pylori who remain at risk for gastric cancer because most infections remain clinically silent. Moreover, individuals with chronic H pylori infection are at risk for gastric preneoplastic lesions, which are also asymptomatic and only reliably diagnosed using endoscopy and biopsy. Thus, to make a significant impact in gastric cancer prevention, a systematic approach is needed to better identify individuals at highest risk of both H pylori infection and its complications, including gastric preneoplasia and cancer. The approach to H pylori eradication must also be optimized given sharply decreasing rates of successful eradication with commonly used therapies and increasing antimicrobial resistance. With growing acceptance that H pylori should be managed as an infectious disease and the increasing availability of susceptibility testing, we now have the momentum to abandon empirical therapies demonstrated to have inadequate eradication rates. Molecular-based susceptibility profiling facilitates selection of a personalized eradication regimen without necessitating an invasive procedure. An improved approach to H pylori eradication coupled with population-level programs for screening and treatment could be an effective and efficient strategy to prevent gastric cancer, especially in minority and potentially marginalized populations that bear the heaviest burden of H pylori infection and its complications.

Protective effect of dietary micronutrients on gastric cancer risk among Jordanians.

Introduction: Objective: several dietary and non-dietary factors and genetic predisposition may play an important role in gastric carcinogenesis. The findings about associations between micronutrients and gastric cancer (GC) is still inconsistent. This study aimed to investigate the effect of dietary micronutrients on gastric cancer risk. Methods: a case-control study comprised of 173 GC (107 males: 66 females) patients and 313 (190 males: 123 females) population-based controls matched for age, occupation, and marital status. Demographics, medical history, physical activity, and nutrient intake information were collected using reliable interview-based questionnaires. Information on dietary micronutrient intake was collected from the participants using a validated food frequency questionnaire (FFQ). Multinomial logistic regression was used to calculate Odds ratios (ORs) and their corresponding 95 % confidence intervals (CIs) and evaluate associations between dietary micronutrients and GC risk. Results: GC was inversely associated with the consumption of vitamin A, beta-carotene, vitamins D, E, K, B2, B3, B6, B12, and C, folate, chromium, iodine, and selenium. Additionally, a protective effect was observed for consumption of calcium, copper, iron, magnesium, phosphate, sodium, and zinc. In almost all the micronutrients, the second tertile showed a more pronounced reduction in GC risk as compared to the first tertile. Conclusions: our data support favorable effects of dietary consumption of some vitamins and minerals against GC risk.

Introducción: Objetivo: varios factores dietéticos y no dietéticos y predisposiciones genéticas pueden jugar un papel importante en la carcinogénesis gástrica. Los hallazgos sobre las asociaciones entre los micronutrientes y el cáncer gástrico (CG) aún son inconsistentes. Métodos: este estudio tuvo como objetivo investigar el efecto de los micronutrientes sobre el riesgo de cáncer gástrico. Métodos: Un estudio de casos y controles comprendió 173 pacientes con GC (107 hombres: 66 mujeres) y 313 (190 hombres: 123 mujeres) controles basados en la población emparejados por edad, ocupación y estado civil. La información demográfica, el historial médico, la actividad física y la ingesta de nutrientes se recopilaron mediante cuestionarios confiables basados en entrevistas. La información sobre la ingesta de micronutrientes en la dieta se recopiló de los participantes mediante un cuestionario de frecuencia de alimentos (FFQ) validado. Se utilizó la regresión logística multinomial para calcular las razones de probabilidad (OR) y sus correspondientes intervalos de confianza (IC) del 95 % y evaluar las asociaciones entre los micronutrientes de la dieta y el riesgo de GC. Resultados: la GC se asoció inversamente con el consumo de vitamina A, betacaroteno, vitaminas D, E, K, B2, B3, B6, B12 y C, folatos, cromo, yodo y selenio. Adicionalmente, se observó un efecto protector para el consumo de calcio, cobre, hierro, magnesio, fosfato, sodio y zinc. En casi todos los micronutrientes, el tercer tercil mostró una reducción más pronunciada del riesgo de CG en comparación con el primer tercil en hombres. Por el contrario, el segundo tercil exhibió un nivel de protección significativamente marcado en comparación con el primer tercil en mujeres. Conclusiones: nuestros datos respaldan los efectos favorables del consumo dietético de algunas vitaminas y minerales para el riesgo de desarrollar cáncer gástrico.

Targeting Stem Cells and Dysplastic Features With Dual MEK/ERK and STAT3 Suppression in Gastric Carcinogenesis.

BACKGROUNDS & AIMS: Precancerous metaplasia progression to dysplasia can increase the risk of gastric cancers. However, effective strategies to specifically target these precancerous lesions are currently lacking. To address this, we aimed to identify key signaling pathways that are upregulated during metaplasia progression and critical for stem cell survival and function in dysplasia. METHODS: To assess the response to chemotherapeutic drugs, we used metaplastic and dysplastic organoids derived from Mist1-Kras mice and 20 human precancerous organoid lines established from patients with gastric cancer. Phospho-antibody array analysis and single-cell RNA-sequencing were performed to identify target cell populations and signaling pathways affected by pyrvinium, a putative anticancer drug. Pyrvinium was administered to Mist1-Kras mice to evaluate drug effectiveness in vivo. RESULTS: Although pyrvinium treatment resulted in growth arrest in metaplastic organoids, it induced cell death in dysplastic organoids. Pyrvinium treatment significantly downregulated phosphorylation of ERK and signal transducer and activator of transcription 3 (STAT3) as well as STAT3-target genes. Single-cell RNA-sequencing data analyses revealed that pyrvinium specifically targeted CD133+/CD166+ stem cell populations, as well as proliferating cells in dysplastic organoids. Pyrvinium inhibited metaplasia progression and facilitated the restoration of normal oxyntic glands in Mist1-Kras mice. Furthermore, pyrvinium exhibited suppressive effects on the growth and survival of human organoids with dysplastic features, through simultaneous blocking of the MEK/ERK and STAT3 signaling pathways. CONCLUSIONS: Through its dual blockade of MEK/ERK and STAT3 signaling pathways, pyrvinium can effectively induce growth arrest in metaplasia and cell death in dysplasia. Therefore, our findings suggest that pyrvinium is a promising chemotherapeutic agent for reprogramming the precancerous milieu to prevent gastric cancer development.

Paradigm Shift in Gastric Cancer Prevention: Harnessing the Potential of Aristolochia olivieri Extract.

Gastric cancer, particularly adenocarcinoma, is a significant global health concern. Environmental risk factors, such as Helicobacter pylori infection and diet, play a role in its development. This study aimed to characterize the chemical composition and evaluate the in vitro antibacterial and antitumor activities of an Aristolochia olivieri Colleg. ex Boiss. Leaves' methanolic extract (AOME). Additionally, morphological changes in gastric cancer cell lines were analyzed. AOME was analyzed using HPLC-MS/MS, and its antibacterial activity against H. pylori was assessed using the broth microdilution method. MIC and MBC values were determined, and positive and negative controls were included in the evaluation. Anticancer effects were assessed through in vitro experiments using AGS, KATO-III, and SNU-1 cancer cell lines. The morphological changes were examined through SEM and TEM analyses. AOME contained several compounds, including caffeic acid, rutin, and hyperoside. The extract displayed significant antimicrobial effects against H. pylori, with consistent MIC and MBC values of 3.70 ± 0.09 mg/mL. AOME reduced cell viability in all gastric cancer cells in a dose- and time-dependent manner. Morphological analyses revealed significant ultrastructural changes in all tumor cell lines, suggesting the occurrence of cellular apoptosis. This study demonstrated that AOME possesses antimicrobial activity against H. pylori and potent antineoplastic properties in gastric cancer cell lines. AOME holds promise as a natural resource for innovative nutraceutical approaches in gastric cancer management. Further research and in vivo studies are warranted to validate its potential clinical applications.

Cost-effectiveness analysis of different screening strategies for helicobacter pylori infection in Iran: A model-based evaluation.

BACKGROUND: The World Health Organization recommends assessing screening for helicobacter pylori infection to lower gastric cancer (GC) rates. Therefore, we carried out a study to evaluate the cost-effectiveness of different H. pylori screening approaches in Iran. MATERIALS AND METHODS: We used a Markov model with a 50-year time horizon and health system perspective to compare four H. pylori screening strategies (endoscopy, serology, urea breath test [UBT], stool antigen test [SAT]) to no screening in the population aged 20 years and older in Iran. Model parameters were extracted from primary data and published studies. Cost data also came from medical records of 120 patients at different stages of GC. We calculated costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) for each strategy. Probabilistic sensitivity analysis (PSA) using Monte Carlo simulation tested the model's robustness. All analyses were done in TreeAge Pro 2020. RESULTS: All screening strategies provided more QALYs compared to no screening. Base-case analysis found the UBT strategy was the most cost-effective, with an ICER of 101,106,261.5 Iranian rial (IRR) per QALY gained, despite being more costly. No screening and endoscopy were dominated strategies, meaning they had higher costs but provided fewer effectiveness compared to other options. PSA showed at a willingness-to-pay (WTP) threshold of 316,112,349 IRR (Iran's GDP per capita) per QALY, UBT was the optimal strategy in 57.1% of iterations. CONCLUSION: This cost-effectiveness analysis found that screening for H. pylori may be cost-effective in Iran. Among the 4 screening strategies examined, UBT was the most cost-effective approach. Further studies should do cost-effectiveness analyses for specific age groups to optimize the benefits achieved with limited resources.

Adherence to the Mediterranean Diet and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis.

Available results on the association between the Mediterranean diet (MD) and gastric cancer (GC) incidence are controversial. The present study aimed to determine the correlation between different subtypes of GC and MD adherence. This meta-analysis was registered on PROSPERO (CRD42021284432). We searched Embase, PubMed, Cochrane Library, and Web of Science from inception through 22 April 2023 to retrieve relevant studies. A random-effects model was used to pool odds ratios (ORs) with 95% confidence intervals (CIs). Eleven studies were included in the meta-analysis. Pooled analyses revealed that adherence to the MD was inversely associated with GC risk (ORcc, 0.43; 95% CI, 0.29 to 0.63; ORcoh, 0.84; 95% CI, 0.77 to 0.92). Higher MD adherence was significantly associated with a reduced GC risk in male (ORcc, 0.78; 95% CI, 0.65 to 0.93; ORcoh, 0.81; 95% CI, 0.65 to 1.01), but not in female (ORcc, 0.83; 95% CI, 0.68 to 1.01; ORcoh, 1.04; 95% CI, 0.82 to 1.31). Furthermore, adherence to the MD possibly decreased the risk of gastric cardia adenocarcinoma (GCA) (ORcc, 0.64; 95% CI, 0.49 to 0.83; ORcoh, 0.88; 95% CI, 0.76 to 1.02) and gastric non-cardia adenocarcinoma (GNCA) (ORcc, 0.68; 95% CI, 0.59 to 0.79; ORcoh, 0.85; 95% CI, 0.78 to 0.94). Our results indicate that adherence to the MD reduces the risk of GC and its subtypes.