Dietary patterns and stomach cancer: a meta-analysis

Association between priori and posteriori dietary patterns and gastric cancer risk: an updated systematic review and meta-analysis of observational studies

An increasing number of epidemiological studies have explored the relationship between the risk of gastric cancer and specific dietary patterns, but the findings remain inconclusive. We, therefore, performed this comprehensive systematic review and meta-analysis to analyze the available evidence regarding the associations between a priori and a posteriori dietary patterns and the risk of gastric cancer. A systematic search of six electronic databases, including PubMed, Web of Science, EBSCO, Scopus, China National Knowledge Infrastructure (CNKI), and Wanfang Data, was carried out to retrieve the relevant articles published up to March 2024. Thirty-six studies (10 cohort and 26 case-control studies) with a total of 2 181 762 participants were included in the final analyses. Combining 15 effect sizes extracted from 12 articles, we observed a reduced risk of gastric cancer in the highest versus the lowest categories of the Mediterranean diet [relative risk (RR), 0.72; 95% confidence interval (CI), 0.61-0.85; P < 0.001]. Combining 11 effect sizes from 10 articles (involving 694 240 participants), we found that the highest Dietary Inflammatory Index scores were significantly associated with an increased risk of gastric cancer (RR, 1.32; 95% CI, 1.11-1.57; P < 0.001). A reduced risk of gastric cancer was shown for the highest compared with the lowest categories of healthy dietary pattern (RR, 0.78; 95% CI, 0.67-0.91; P = 0.002). Conversely, the highest adherence to the Western dietary pattern was associated with an increased risk of gastric cancer (RR, 1.33; 95% CI, 1.19-1.49; P < 0.001). Our study demonstrated that the Mediterranean diet and a healthy dietary pattern were associated with a decreased risk of gastric cancer. Conversely, the Dietary Inflammatory Index and Western dietary pattern were associated with an increased risk of gastric cancer.

Review of dietary patterns and gastric cancer risk: epidemiology and biological evidence

Due to rapid research expansion on dietary factors and development of cancer prevention guidelines, the field of dietary pattern and its relationship to cancer risk has gained more focus. Numerous epidemiology studies have reported associations between Gastric Cancer (GC) and both data-driven posteriori dietary pattern and priori dietary pattern defined by predetermined dietary indexes. As dietary patterns have evolved, a series of patterns based on biological markers has advanced, offering deeper insights into the relationship between diet and the risk of cancer. Although researches on dietary patterns and cancer risk are booming, there is limited body of literature focusing specifically on GC. In this study, we compare the similarities and differences among the specific components of dietary patterns and indices, summarize current state of knowledge regarding dietary patterns related to GC and illustrate their potential mechanisms for GC prevention. In conclusion, we offer suggestions for future research based on the emerging themes within this rapidly evolving field.

Adherence to the Mediterranean diet and risk of gastric cancer: a systematic review and dose-response meta-analysis

Background

Despite growing evidence for the association of adherence to the Mediterranean diet with gastric cancer risk, the results remain inconclusive. The purpose of this systematic review and meta-analysis was to summarize the evidence from previous observational studies and assess the potential association between adherence to the Mediterranean diet and risk of gastric cancer using a dose-response meta-analysis.

Methods

A comprehensive literature search for all observational studies published up to June 30, 2023 was conducted using the databases of PubMed, ISI Web of Science, EBSCO, China National Knowledge Infrastructure (CNKI) and Wanfang Data. The pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated for the highest versus the lowest categories of Mediterranean diet score in relation to gastric cancer risk, using random-effects models. The Cochran's Q test and I-squared (I2) statistic were used to detect the sources of heterogeneity among the included studies.

Results

Overall, 11 studies (five cohort and six case-control studies) with a total number of 1,366,318 participants were included in the final analysis. Combining 14 effect sizes from 11 studies revealed that compared with the lowest category, the highest adherence to the Mediterranean diet was associated with a 29% reduction in the risk of gastric cancer (RR:0.71; 95%CI:0.59-0.84, p < 0.001). In addition, linear dose-response analysis showed that each 1-score increment in Mediterranean diet score was associated with a 5% lower risk of gastric cancer (RR:0.95; 95%CI: 0.94-0.96, p < 0.001). Stratified analysis showed a significant association between adherence to the Mediterranean diet and risk of gastric cancer in case-control studies (RR = 0.44;95%CI:0.32-0.61, p < 0.001), and a marginally significant association in prospective cohort studies (RR = 0.88; 95%CI: 0.79-0.98, p = 0.024), respectively. At the same time, a more significant association between Mediterranean diet and reduced risk of gastric cancer was observed in other countries (RR = 0.28; 95%CI:0.16-0.49, p < 0.001) than in Western countries (RR = 0.75; 95%CI:0.64-0.88, p = 0.001).

Conclusion

Our results demonstrate that high adherence to the Mediterranean diet is associated with 29% reduced risk of gastric cancer. Further large prospective studies and randomized controlled trials are warranted to confirm our findings.

Alcohol intake and the risk of glioma: a systematic review and updated meta-analysis of observational study

The association between alcohol intake and the risk of glioma has been widely studied, but these results have yielded conflicting findings. Therefore, we conducted this systematic review and updated meta-analysis to systematically evaluate the association between alcohol intake and the risk of glioma. A systematic literature search of relevant articles published in PubMed, Web of Science, CNKI and Wan fang databases up to December 2021 was conducted. Pooled estimated of relative risk (RR) and 95 % CI were calculated using fixed-effects models. A total of eight articles with three case-control studies involving 2706 glioma cases and 2 189 927 participants were included in this meta-analysis. A reduced risk of glioma was shown for the low-moderate alcohol drinking v. non-drinking (RR = 0·87; 95 % CI (0·78, 0·97); P = 0·014). In addition, there was no evidence of an increased risk of glioma in the heavy alcohol drinking compared with non-drinking (RR = 0·89; 95 % CI (0·67, 1·18); P = 0·404). The findings suggest an inverse association between low-moderate alcohol drinking and the risk of glioma, in the absence, however, of a dose-response relationship. More prospective studies are needed to provide further insight into the association between alcohol drinking and glioma risk.

Dietary patterns with combined and site-specific cancer incidence in Alberta's Tomorrow Project cohort

BACKGROUND/OBJECTIVES

Poor diet quality has been associated with an increased risk of cancer. Here, we examine the association between dietary patterns derived with two methods, and combined and site-specific cancer incidence in Canada.

SUBJECTS/METHODS

Dietary data were obtained from participants enrolled in Alberta's Tomorrow Project, a prospective cohort study, between 2000 and 2008. Principle component analysis (PCA) and reduced rank regression (RRR) were used to derive dietary patterns, and data linkage with the Alberta Cancer Registry was used for incident cancer cases. Cox proportional hazard regressions were used to estimate multivariable-adjusted models for the association between each dietary pattern score with combined and site-specific cancer incidence.

RESULTS

PCA revealed three dietary patterns ("western", "prudent", and "sugar, fruits, and dairy") and RRR resulted in four patterns ("dietary fiber", "vitamin D", "fructose", and "discretionary fat"). Five cancer sites were included in our site-specific analysis: lung, colon, breast, prostate, and endometrial cancers. The most protective dietary patterns for combined cancer sites were the "Prudent" pattern (HR = 0.82, CI = 0.73-0.92) and the "Dietary fiber" pattern (HR = 0.82, CI = 0.69-0.97). The "Fructose" pattern was associated with increased risk of combined cancers (HR = 1.14, CI = 1.02-1.27). Three dietary patterns were protective against colon cancer ("Prudent", "Dietary fiber", and "Discretionary fats"), and other risk reductions were seen for the "sugar, fruit, and dairy" pattern (lung cancer), and the "Dietary fiber" pattern (prostate cancer).

CONCLUSIONS

These results support cancer prevention strategies for a diet high in vegetables, fruits, fish, and whole grains. Further studies should explore the possible association between discretionary fats and colon cancer.

Whole Grains, Refined Grains, and Cancer Risk: A Systematic Review of Meta-Analyses of Observational Studies

PubMed, Web of Science, and the Cochrane Database of Systematic Reviews were searched for meta-analyses that provided risk estimates (±95% confidence intervals) for associations between intakes of whole and refined grains and risk of total and site-specific cancer. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Only meta-analyses that included whole grains and refined grains as separate food groups, and not as part of dietary patterns, were included. A total of 17 publications were identified that met inclusion criteria. Within these, results from a total of 54 distinct meta-analyses were reported for whole grains and 5 meta-analyses for refined grains. For total cancer mortality, 7 meta-analyses of cohort studies indicated that whole grain intake was associated with 6% to 12% lower risk in comparison of highest vs. lowest intake groups, and 3% to 20% lower risk for doses ranging from 15 to 90 g/day. For site-specific cancers, meta-analyses indicated that whole grain intake was consistently associated with lower risks of colorectal, colon, gastric, pancreatic, and esophageal cancers. Limited data were available for refined grains, with only 4 publications providing risk estimates, and only 1 of the meta-analyses included more than 3 studies. High intake of refined grains was associated with increased risk of colon and gastric cancer. By contrast, in the only dose-response meta-analysis, each 90 g/day consumption of refined grains was associated with a 6% lower risk of total cancer. In addition to the limited number of published meta-analyses on refined grains, results were also weakened due to the fact that refined grains were frequently defined to include both staple grain foods and indulgent grain foods, and the majority of studies included in the meta-analyses provided no specific definition of refined grains. Overall, meta-analyses of cohort and case-control studies consistently demonstrate that whole grain intake is associated with lower risk of total and site-specific cancer, and support current dietary recommendations to increase whole grain consumption. By contrast, the relationship between refined grain intake and cancer risk is inconclusive.

Dietary patterns and gastric cancer risk in a Korean population: a case-control study

PURPOSE

Dietary pattern analysis has been considered as an approach to capture the complex interactions of overall diet, which are often lost in studies of single dietary components (e.g., foods and nutrients). The aim of this study was to identify the major dietary patterns of Koreans via principal component analysis based on the food groups and to investigate the association between dietary patterns and gastric cancer (GC) risk.

METHODS

In this study, participants were recruited from the National Cancer Center, Korea. Among them, 415 cases were diagnosed with early GC, and 830 controls were age- and sex-matched at a ratio of 1:2. To determine the subjects' dietary patterns, 34 predefined food groups based on the 106-item semiquantitative food frequency questionnaire (SQFFQ) were used. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated across the tertiles of dietary pattern scores using logistic regression models.

RESULTS

The two dietary patterns derived in this study were named westernized and prudent. Those patterns explained 24.83% of the total variation in food intake. Higher scores on the prudent pattern was inversely associated with the risk of GC (OR [95% CI] for the highest vs. lowest tertiles: 0.58 [0.41-0.84], p for trend = 0.004).

CONCLUSION

Our findings suggest that adherence to the prudent dietary pattern represented by high loadings of vegetables and fruits, was associated with lower GC risk. Further studies with a prospective design and larger sample sizes are necessary.

Mediterranean dietary pattern is associated with lower incidence of premenopausal breast cancer in the Seguimiento Universidad de Navarra (SUN) Project

OBJECTIVE

Due to the growing interest in the role of dietary patterns (DPs) on chronic diseases, we assessed the association between a posteriori identified DPs in the Seguimiento Universidad de Navarra (SUN) Project - a prospective cohort study in a Mediterranean country - and breast cancer (BC) risk.

DESIGN

DPs were ascertained through a principal component analysis based on 31 predefined food groups. BC cases were initially identified through self-report or, if deceased, from death certificates or by notification by the next kin. Women reporting BC were asked to provide a copy of their medical report and diagnoses for confirmation purposes. We fitted Cox regression models to assess the association between adherence to the identified DPs and BC risk.

SETTING

Spanish university graduates.

PARTICIPANTS

We included 10 713 young and middle-aged - mainly premenopausal - women.

RESULTS

After a median follow-up of 10·3 years, we identified 100 confirmed and 168 probable incident BC cases. We described two major DPs: 'Western dietary pattern' (WDP) and 'Mediterranean dietary pattern' (MDP). A higher adherence to a WDP was associated with an increased risk of overall BC (multivariable-adjusted HR for confirmed BC Q4 v. Q1 1·70; 95 % CI 0·93, 3·12; P for trend = 0·045). Contrarily, adherence to a MDP was inversely associated with premenopausal BC (multivariable-adjusted HR Q4 v. Q1 0·33; 95 % CI 0·12, 0·91). No significant associations were observed for postmenopausal BC.

CONCLUSIONS

Whereas a higher adherence to the WDP may increase the risk of BC, a higher adherence to the MDP may decrease the risk of premenopausal BC.

Association of dietary patterns and endoscopic gastric mucosal atrophy in an adult Chinese population

Atrophy gastritis harbor a high risk for the development of dysplasia and gastric cancer. The study investigated the relationships of specific dietary patterns and endoscopic gastric mucosal atrophy. In this cross-sectional study, we enrolled 574 consecutive outpatients who were diagnosed as chronic gastritis according to endoscopic examination. Dietary intakes of study individuals was assessed using the semi-quantitative food group frequency questionnaire. Logistic regression analyses were used to evaluate the relationship between dietary patterns and endoscopic gastric mucosal atrophy adjusted for potential confounders. A total of 574 participants were included, 286 with endoscopic gastric mucosal atrophy. Three dietary patterns were identified by factor analysis. “Alcohol and fish” (tertile 1 vs. tertile 3: adjusted odds ratio = 1.85, 95% confidence interval: 1.06–3.22) and “coarse cereals” (tertile 1 vs. tertile 3: adjusted odds ratio = 2.05, 95% confidence interval: 1.24–3.39) were associated with an increased risk for endoscopic gastric mucosal atrophy but a “traditional” pattern was not. Dietary pattern was not associated with gastric mucosal atrophy in women or in participants with H. pylori infection. A high adherence to both “Alcohol and Fish” and “Coarse cereals” dietary patterns seem to be associated with higher odds of endoscopic gastric mucosal atrophy in men and in patients without H. pylori infection. Further prospective cohort studies needed to confirm these findings.

Empirically derived dietary patterns and ovarian cancer risk: a meta-analysis

Dietary patterns, which reflect overall diet and possible nutrient and food interactions, have been reported to be related to ovarian cancer (OC) risk. However, studies on the relationship between dietary patterns and OC risk have been inconsistent. Thus, we carried out a systematic meta-analysis to assess the relationship between dietary patterns and the risk of OC. Relevant studies are identified by searching the Medline and Embase electronic databases up to December 2016. The Cochrane Q statistic and the I statistical were used to evaluate heterogeneity. A total of 22 studies fulfilled the inclusion criteria and were included in this meta-analysis. There was evidence of a decreased risk for OC in the highest versus the lowest categories of healthy dietary pattern [odds ratio (OR)=0.86; 95% confidence interval (CI): 0.74-0.99; P=0.04]. An increased risk of OC was shown for the highest versus the lowest category of a western-style dietary pattern (OR=1.19; 95% CI: 1.01-1.41; P=0.04). No significant association with OC risk was observed in the highest versus the lowest category of a heavy drinking pattern (OR=0.89; 95% CI: 0.67-1.19; P=0.42). The results of this meta-analysis suggest that a healthy dietary pattern is associated with reduced risk for OC and a western-style dietary pattern is associated with an increased risk of OC. Further studies are needed to confirm our results.

The role and diagnostic potential of gastrokine 1 in gastric cancer

Introduction

Gene for gastrokine 1 (GKN1) was identified as one of the most significant in gastric cancer and indicated as a potential therapeutic target.

Aim

The aim was a review of literature reports concerning the role and diagnostic potential of GKN1 in gastric cancer.

Materials and methods

PubMED database was searched for sources using the following keywords: gastrokine 1/GKN1/AMP-18 and gastric cancer, Helicobacter pylori, aspirin, nonsteroidal anti-inflammatory drugs. Preference was given to the sources which were published within the past 10 years.

Conclusion

GKN1 is a stomach-specific protein, and its role consists of maintaining mucosal integrity as well as the replenishment of the surface lumen epithelial cells layer. The evaluation of GKN1 expression seems to be a useful indicator of the presence of neoplastic or inflammatory lesions in the gastric mucosa. GKN1 expression is decreased in gastric tumor tissues and derived cell lines and its upregulation in cell lines of gastric cancer induces cells apoptosis. The mechanism by which GKN1 is inactivated in gastric cancer cells is still not fully understood. The future diagnostic capabilities of gastric cancer concern the assessment of serum GKN1 concentration by means of ELISA method. Serum GKN1 concentration is not related to patients’ sex. Moreover, the measurement of GKN1 concentration is possible only after the incubation of samples at 70°C for 10 minutes. Nevertheless, the aspect of quantitative serum GKN1 evaluation is new in the context of available literature and requires further studies.

Dietary patterns and Helicobacter pylori infection in a group of Chinese adults ages between 45 and 59 years old: An observational study

Limited studies have reported the association between dietary patterns and the risk of Helicobacter pylori (H pylori) infection. The purpose of this study was to evaluate the relationship between dietary patterns and H pylori infection in a Chinese population ages from 45 to 59 years. We performed a cross-sectional examination of the associations between dietary patterns and H pylori infection in 3014 Chinese adults ages between 45 and 59 years from Hangzhou city, Zhejiang province, China. Dietary intake was assessed through a semi-quantitative food frequency questionnaire (FFQ). H pylori infection was diagnosed using the C-urea breath test. Multivariable logistic regression analyses were used to determine the associations between dietary patterns and the risk of H pylori infection. The prevalence of H pylori infection was 27.5%. Four major dietary patterns were identified by means of factor analysis: health-conscious, Western, grains-vegetables and high-salt patterns. After adjustment for the potential confounders, participants in the highest quartile of the "grains-vegetables" pattern scores had a lower odds ratio (OR) for H pylori infection (OR = 0.82; 95% confidence interval [CI]: 0.732-0.973; P = .04) than did those in the lowest quartile. Compared with those in the lowest quartile, participants in the highest quartile of the "high-salt" pattern scores had a greater OR for H pylori infection (OR = 1.13; 95%CI: 1.004-1.139; P = .048). Besides, no significant associations were found between the "health-conscious" and "Western" dietary patterns and the risk of H pylori infection.Our findings demonstrate that the "grains-vegetables" pattern is associated with a decreased risk, while "high-salt" pattern is associated with an increased risk of H pylori infection.

Helicobacter pylori: History and facts in Peru

Helicobacter pylori (H. pylori) is a cosmopolite bacteria and the main responsible for the high burden of gastric cancer in developing countries, such as Peru. In this review, we describe some historical facts in the H. Pylori discovery, the first researches of this bacterium in Peru, as well as its epidemiology, clinical characteristics, diagnosis, treatments, and outcomes. Our literature and review of real-life data suggest that several efforts should be conducted in our country to deal with antibiotic-resistance and lack of adherence to treatment in order to reduce our incidence of gastric cancer.

High adherence to the Western, Prudent, and Mediterranean dietary patterns and risk of gastric adenocarcinoma: MCC-Spain study

BACKGROUND

The influence of dietary habits on the development of gastric adenocarcinoma is not clear. The objective of the present study was to explore the association of three previously identified dietary patterns with gastric adenocarcinoma by sex, age, cancer site, and morphology.

METHODS

MCC-Spain is a multicase-control study that included 295 incident cases of gastric adenocarcinoma and 3040 controls. The association of the Western, Prudent, and Mediterranean dietary patterns-derived in another Spanish case-control study-with gastric adenocarcinoma was assessed using multivariable logistic regression models with random province-specific intercepts and considering a possible interaction with sex and age. Risk according to tumor site (cardia, non-cardia) and morphology (intestinal/diffuse) was evaluated using multinomial regression models.

RESULTS

A high adherence to the Western pattern increased gastric adenocarcinoma risk [odds ratio_{fourth_vs._first_quartile} (95% confidence interval), 2.09 (1.31; 3.33)] even at low levels [odds ratio_{second_vs._first_quartile} (95% confidence interval), 1.63 (1.05; 2.52)]. High adherence to the Mediterranean dietary pattern could prevent gastric adenocarcinoma [odds ratio_{fourth_vs._first_quartile} (95% confidence interval), 0.53 (0.34; 0.82)]. Although no significant heterogeneity of effects was observed, the harmful effect of the Western pattern was stronger among older participants and for non-cardia adenocarcinomas, whereas the protective effect of the Mediterranean pattern was only observed among younger participants and for non-cardia tumors.

CONCLUSION

Decreasing the consumption of fatty and sugary products and of red and processed meat in favor of an increase in the intake of fruits, vegetables, legumes, olive oil, nuts, and fish might prevent gastric adenocarcinoma.

Can a gastric cancer risk survey identify high-risk patients for endoscopic screening? A pilot study

BACKGROUND

A questionnaire that distinguishes how variability in gastric cancer prevalence is associated with ethnicity/birth country/immigration/cultural diet along with known risk factors may improve targeting populations for gastric cancer screening in the United States.

METHODS

Existing literature was used to identify the item pool. Cluster analysis, focus groups, and cognitive interviewing were used to reduce collinear items and refine the questionnaire. Logistic regression analysis was used to determine which items distinguished gastric cancer cases from the primary care and community controls.

RESULTS

The results of analysis of data from 40 cases and 100 controls (primary care = 47; community = 53) were used to reduce the 227 item pool to 12 items. After ranking these variables using model bootstrapping, a logistic regression model using the highest ranked eight variables was chosen as the final model. Older age, foreign nativity, daily consumption of cultural food at ages 15-18, less than high-school education, and greater acculturation were significantly associated with being a gastric cancer case compared with the controls.

CONCLUSIONS

An eight-item survey that addresses gastric cancer risk factors, ethnicity, cultural habits, and immigration patterns has potential to identify high-risk persons from multicultural areas within the US, who might benefit from endoscopic screening for gastric cancer.

Changing Trends in Stomach Cancer Throughout the World

PURPOSE OF REVIEW

The paper aims to discuss the global trends in gastric cancer incidence in relation to important factors involved in the pathogenesis of gastric cancer.

RECENT FINDINGS

Despite a significant worldwide decline, gastric cancer remains a common cause of cancer death. The decline has been multifactorial and preceded the fall in Helicobacter pylori prevalence. The initial decline was associated with changes in food preservation and availability, especially of fresh fruits and vegetables, followed by a decline in the primary etiologic factor, H. pylori. Gastric cancer incidence remains high in East Asia, intermediate in Latin America, and low in developed countries. Significant racial/ethnic variability exists. The rapid decline in incidence in East Asia will continue as primary and secondary prevention strategies are implemented. The incidence in Latin America is unlikely to decline significantly over the next few decades given high H. pylori prevalence in the young. Ultimately, global H. pylori eradication will be needed to largely eliminate gastric cancer.

A Healthy Dietary Pattern Reduces Lung Cancer Risk: A Systematic Review and Meta-Analysis

Background: Diet and nutrients play an important role in cancer development and progress; a healthy dietary pattern has been found to be associated with several types of cancer. However, the association between a healthy eating pattern and lung cancer risk is still unclear. Objective: Therefore, we conducted a systematic review with meta-analysis to evaluate whether a healthy eating pattern might reduce lung cancer risk. Methods: We identified relevant studies from the PubMed and Embase databases up to October 2015, and the relative risks were extracted and combined by the fixed-effects model when no substantial heterogeneity was observed; otherwise, the random-effects model was employed. Subgroup and publication bias analyses were also performed. Results: Finally, eight observational studies were included in the meta-analysis. The pooled relative risk of lung cancer for the highest vs. lowest category of healthy dietary pattern was 0.81 (95% confidence interval, CI: 0.75–0.86), and no significant heterogeneity was detected. The relative risks (RRs) for non-smokers, former smokers and current smokers were 0.89 (95% CI: 0.63–1.27), 0.74 (95% CI: 0.62–0.89) and 0.86 (95% CI: 0.79–0.93), respectively. The results remained stable in subgroup analyses by other confounders and sensitivity analysis. Conclusions: The results of our meta-analysis suggest that a healthy dietary pattern is associated with a lower lung cancer risk, and they provide more beneficial evidence for changing the diet pattern in the general population.

Dietary patterns and CVD: a systematic review and meta-analysis of observational studies

Epidemiological studies show that diet is linked to the risk of developing CVD. The objective of this meta-analysis was to estimate the association between empirically derived dietary patterns and CVD. PubMed was searched for observational studies of data-driven dietary patterns that reported outcomes of cardiovascular events. The association between dietary patterns and CVD was estimated using a random-effects meta-analysis with 95 % CI. Totally, twenty-two observational studies met the inclusion criteria. The pooled relative risk (RR) for CVD, CHD and stroke in a comparison of the highest to the lowest category of prudent/healthy dietary patterns in cohort studies was 0·69 (95% CI 0·60, 0·78; I 2=0%), 0·83 (95% CI 0·75, 0·92; I 2=44·6%) and 0·86 (95% CI 0·74, 1·01; I 2=59·5%), respectively. The pooled RR of CHD in a case-control comparison of the highest to the lowest category of prudent/healthy dietary patterns was 0·71 (95% CI 0·63, 0·80; I 2=0%). The pooled RR for CVD, CHD and stroke in a comparison of the highest to the lowest category of western dietary patterns in cohort studies was 1·14 (95% CI 0·92, 1·42; I 2=56·9%), 1·03 (95% CI 0·90, 1·17; I 2=59·4%) and 1·05 (95% CI 0·91, 1·22; I 2=27·6%), respectively; in case-control studies, there was evidence of increased CHD risk. Our results support the evidence of the prudent/healthy pattern as a protective factor for CVD.