Grain consumption and risk of gastric cancer: a meta-analysis

Association of whole grain food consumption with lung cancer risk: a prospective cohort study

BACKGROUND

Whether the intake of whole grain foods can protect against lung cancer is a long-standing question of considerable public health import, but the epidemiologic evidence has been limited. Therefore we aim to investigate the relationship between whole grain food consumption and lung cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) cohort.

METHODS

Diet was assessed with a self-administered Diet History Questionnaire (DHQ) at baseline. All incident lung cancer cases were pathologically verified. Hazard ratios and 95% confidence intervals for lung cancer risk associated with whole grain food consumption were estimated by Cox proportional hazards regression.

RESULTS

During a median follow-up of 12.2 years, a total of 1,706 incident lung cancer events occurred, including 1,473 (86.3%) cases of non-small cell lung cancer (NSCLC) and 233 (13.7%) of small cell lung cancer (SCLC). After multivariate adjustment, comparing the highest quarter of consumption of whole grain foods to the lowest quarter, a 16% lower rate (HR 0.84, 95% CI 0.73-0.98) of lung cancer risks and a 17% lower rate (HR 0.83, 95% CI 0.69-0.98) for NSCLC were found, but no significant difference was shown for SCLC (HR 0.95, 95% CI 0.63-1.44). These results were consistently observed after a large range of subgroup and sensitivity analyses. A linear dose-response pattern was shown for lung cancer, NSCLC, and SCLC (P for non-linearity > 0.05).

CONCLUSIONS

In this large prospective cohort study, whole grain food consumption was associated with reduced lung cancer and NSCLC. Our findings suggest a potential protective role of whole grain foods against lung cancer.

Association of unsweetened and sweetened cereal consumption with all-cause and cause-specific mortality: a large prospective population-based cohort study

Background & aims: Although previous observational studies have suggested an association between whole grain consumption (including breakfast cereals) and a reduced risk of death, no study has explored in detail the association between consumption of cereal with or without added sweeteners and death. We therefore aimed to evaluate the association between unsweetened, sugar-sweetened, and artificially sweetened cereals and all-cause and cause-specific mortality. Methods: We conducted a prospective cohort study of 186 419 UK Biobank participants who met the inclusion criteria for this study. Participants with baseline demographic, lifestyle, dietary, and clinical data were recruited from 2006 to 2010 and followed up until 2023. The intake of unsweetened, sugar-sweetened, or artificially sweetened cereals was estimated through repeated 24 hour dietary recalls. The non-linear relationships between daily dosage of cereal and all-cause, cancer-specific, and cardiovascular disease (CVD)-specific mortality were calculated using a restricted cubic spline curve. Hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality were calculated using Cox regression models. Results: During a median follow-up of 13.6 years, 11 351 all-cause deaths were recorded, including 6176 cancer deaths and 2126 CVD deaths. Cox regression models with restricted cubic splines showed a non-linear association between unsweetened cereals and all-cause and cancer-specific mortality. Compared with non-consumers, consumers of different amounts of unsweetened cereals (0 to 0.5, 0.5 to 1.5, and >1.5 bowls per day) had lower risks of all-cause mortality in the multivariate Cox models, with respective HRs of 0.89 (95%CI: 0.84-0.95), 0.90 (95%CI: 0.86-0.94), and 0.89 (95%CI: 0.82-0.97). However, no association was observed between consumption of sugar or artificially sweetened cereals and the risk of mortality. When cereals were divided into those with or without dried fruit, the findings were consistent with our primary results. Conclusions: Moderate consumption of unsweetened cereals was associated with a reduced risk of all-cause mortality, suggesting caution in consuming cereals with added sugar or artificial sweeteners.

Humanistic Health Management and Cancer: Associations of Psychology, Nutrition, and Exercise with Cancer Progression and Pathogenesis

The incidence rate of cancer is increasing year by year due to the aging of the population, unhealthy living, and eating habits. At present, surgery and medication are still the main treatments for cancer, without paying attention to the impact of individual differences in health management on cancer. However, increasing evidence suggests that individual psychological status, dietary habits, and exercise frequency are closely related to the risk and prognosis of cancer. The reminder to humanity is that the medical concept of the unified treatment plan is insufficient in cancer treatment, and a personalized treatment plan may become a breakthrough point. On this basis, the concept of "Humanistic Health Management" (HHM) is proposed. This concept is a healthcare plan that focuses on self-health management, providing an accurate and comprehensive evaluation of individual lifestyle habits, psychology, and health status, and developing personalized and targeted comprehensive cancer prevention and treatment plans. This review will provide a detailed explanation of the relationship between psychological status, dietary, and exercise habits, and the regulatory mechanisms of cancer. Intended to emphasize the importance of HHM concept in cancer prevention and better prognostic efficacy, providing new ideas for the new generation of cancer treatment.

Targeting PI3K/AKT/mTOR and MAPK Signaling Pathways in Gastric Cancer

Gastric cancer (GC) is the fourth leading cause of death worldwide, with more than 1 million cases diagnosed every year. Helicobacter pylori represents the main risk factor, being responsible for 78% of the cases. Increased amounts of salt, pickled food, red meat, alcohol, smoked food, and refined sugars negatively affect the stomach wall, contributing to GC development. Several gene mutations, including PIK3CA, TP53, ARID1A, CDH1, Ras, Raf, and ERBB3 are encountered in GC pathogenesis, leading to phosphatidylinositol 3-kinase (PI3K) protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-PI3K/AKT/mTOR-and mitogen-activated protein kinase (MAPK) signaling pathway activation and promoting tumoral activity. Helicobacter pylori, growth factors, cytokines, hormones, and oxidative stress also activate both pathways, enhancing GC development. In clinical trials, promising results have come from monoclonal antibodies such as trastuzumab and ramucirumab. Dual inhibitors targeting the PI3K/AKT/mTOR and MAPK signaling pathways were used in vitro studies, also with promising results. The main aim of this review is to present GC incidence and risk factors and the dysregulations of the two protein kinase complexes together with their specific inhibitors.

Eating habits and stomach cancer risk

Stomach cancer (GC) ranks fifth in the structure of cancer incidence and remains the third leading cause of cancer mortality worldwide. The formation of gastric cancer occurs under the influence of genetic and epigenetic factors. Among the latter, eating habits play a significant role. Primary prevention of cancer through lifestyle and dietary changes is an important and high priority strategy in modern health care. This article presents an overview and systematization of the available data on the influence of nutritional factors on the risk of gastric cancer formation.

Risk factors for gastric cancer: A comprehensive analysis of observational studies

Background

Multifarious factors have a causal relationship with gastric cancer (GC) development. We conducted a comprehensive analysis to evaluate the strength of the evidence examining non-genetic risk factors for gastric cancer.

Methods

PubMed, Web of Science, and the Cochrane Library were searched from inception to November 10, 2021 to identify meta-analyses of observational studies examining the association between environmental factors and GC risk. For each meta-analysis, the random effect size, 95% confidence interval, heterogeneity among studies, and evidence of publication bias were assessed; moreover, the evidence was graded using predefined criteria, and the methodological quality was evaluated using AMSTAR 2.

Results

A total of 137 associations were examined in 76 articles. Among these meta-analyses, 93 associations yielded significant estimates (p < 0.05). Only 10 associations had strong epidemiologic evidence, including 2 risk factors (waist circumference and bacon), and 8 protective factors (dietary total antioxidant capacity, vegetable fat, cruciferous vegetable, cabbage, total vitamin, vitamin A, vitamin C, and years of fertility); 26 associations had moderate quality of evidence; and the remaining 57 associations were rated as weak. Ninety-four (68.61%) associations showed significant heterogeneity. Twenty-five (18.25%) associations demonstrated publication bias.

Conclusions

In this comprehensive analysis, multiple associations were found between environmental factors and GC with varying levels of evidence. Healthy dietary habits and lifestyle patterns could reduce the risk for GC. However, further high-quality prospective studies are still necessary to draw more definitive conclusions.

Gastric Cancer Risk Was Associated with Dietary Factors Irritating the Stomach Wall: A Case-Control Study in Korea

The incidence of gastric cancer is high in Korea, and dietary factors are important risk factors for gastric cancer. This study examined whether gastric cancer risk was related to dietary factors that directly irritate the stomach wall. This case−control study consisted of 308 matched pairs of gastric cancer cases and controls recruited from 2002 to 2006 at two hospitals in Korea. Dietary assessments were completed using a food frequency questionnaire and a dietary habit questionnaire. Gastric cancer risk was increased for high meal frequency of >3 vs. low meal frequency of ≤3 times per day, overeating vs. not overeating, and preferred vs. not preferred spicy or salty foods. Furthermore, participants with dietary factors of high meal frequency, overeating, and preference for spicy or salty foods elevated the risk of gastric cancer compared to those with low meal frequency, not overeating, and not preferring spicy or salty foods, simultaneously. In conclusion, gastric cancer risk was significantly increased in people with dietary factors that irritate the stomach wall, such as high meal frequency, overeating, and preference for spicy or salty foods.

Diet and Risk of Gastric Cancer: An Umbrella Review

Several dietary exposures have been associated with gastric cancer (GC), but the associations are often heterogenous and may be afflicted by inherent biases. In the context of an Umbrella Review (UR), we provide an overview and a critical evaluation of the strength and quality, and evidence classification of the associations of diet-related exposures in relation to the risk of GC. We searched PubMed and Scopus for eligible meta-analyses of observational studies published in English from inception to 12 December 2021, and for any identified association, we applied robust epidemiological validity evaluation criteria and individual study quality assessment using AMSTAR. We screened 3846 titles/abstracts and assessed 501 full articles for eligibility, of which 49 were included in the analysis, investigating 147 unique exposures in relation to GC, cardia (GCC) or non-cardia (GNCC) cancer. Supported by suggestive evidence, positive associations were found comparing the highest vs. lowest categories for: heavy (>42 g/day) alcohol consumption (Relative Risk (RR) = 1.42, 95% Confidence Interval (CI): 1.20−1.67), salted fish consumption (RR = 1.56, 95% CI:1.30−1.87) and waist circumference (RR = 1.48, 95% CI:1.24−1.78) and an inverse association for the healthy lifestyle index (RR = 0.60, 95% CI:0.48−0.74) in relation to GC. Additionally, a positive association was found comparing obese individuals (Body Mass Index (BMI) ≥ 30) to normal-weight individuals (BMI: 18.5−25) (RR = 1.82, 95% CI:1.32−2.49) in relation to GCC. Most of the meta-analyses were of medium-to-high quality (median items: 7.0, interquartile range: 6−9). Maintaining a normal body weight and adopting healthy dietary choices, in particular, limiting the consumption of salt-preserved foods and alcohol, can reduce the risk of gastric cancer.

The Impact of Whole Grain Intake on Gastrointestinal Tumors: A Focus on Colorectal, Gastric, and Esophageal Cancers

Cereals are one of staple foods in human diet, mainly consumed as refined grains. Nonetheless, epidemiological data indicate that whole grain (WG) intake is inversely related to risk of type 2 diabetes, cardiovascular disease, and several cancer types, as well as to all-cause mortality. Particularly responsive to WG positive action is the gastrointestinal tract, daily exposed to bioactive food components. Herein, we shall provide an up-to-date overview on relationship between WG intake and prevention of gastrointestinal tumors, with a particular focus on colorectal, stomach, and esophagus cancers. Unlike refined counterparts, WG consumption is inversely associated with risk of these gastrointestinal cancers, most consistently with the risk of colorectal tumor. Some WG effects may be mediated by beneficial constituents (such as fiber and polyphenols) that are reduced/lost during milling process. Beside health-promoting action, WGs are still under-consumed in most countries; therefore, World Health Organization and other public/private stakeholders should cooperate to implement WG consumption in the whole population, in order to reach nutritionally effective intakes.

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.

Association of whole grains intake and the risk of digestive tract cancer: a systematic review and meta-analysis

BACKGROUND

Several epidemiological studies have investigated the association between whole grains intake and digestive tract cancer risk; however, the results are still controversial. The purpose of this meta-analysis was to assess the association.

METHODS

Studies published before March 2020 were searched in database and other sources. The risk ratio (RR) with the 95% confidence interval (CI) were pooled using fix or random-effects models.

RESULTS

This meta-analysis included 34 articles reporting 35 studies, 18 studies of colorectal cancer, 11 studies of gastric cancer and 6 studies of esophagus cancer, involving 2,663,278 participants and 28,921 cases. Comparing the highest-intake participants with the lowest-intake participants for whole grains, we found that the intake of whole grains were inversely related to colorectal cancer (RR = 0.89, 95% CI: 0.84-0.93, P < 0.001), gastric cancer (RR = 0.64, 95% CI: 0.53-0.79, P < 0.001), esophagus cancer (RR = 0.54, 95% CI: 0.44-0.67, P < 0.001), respectively. However, subgroup analysis of colorectal cancer found no significant association in the case-control studies and studies of sample size < 500, and subgroup analysis of gastric cancer found no significant association in the cohort studies and studies of American population. No study significantly affected the findings in the sensitivity analysis. No publication bias was found in the studies for colorectal cancer and esophagus cancer except in the studies for gastric cancer.

CONCLUSION

This meta-analysis provides further evidence that whole grains intake was associated with a reduced risk of digestive tract cancer. Our result supports the dietary guidelines that increase whole grains intake to reduce the risk of digestive tract cancer.