Allium vegetable intake associated with the risk of incident gastric cancer: a continuous follow-up study of a randomized intervention trial.

BACKGROUND: Allium vegetable components have antibacterial, antioxidative, and immune modulation properties, thus potentially exhibiting antitumor effects. Despite evidence from case-control studies, prospective studies linking allium vegetables with gastric cancer (GC) have been sparse. OBJECTIVE: In a prospective study, we examined whether allium vegetable intake would change the risk of GC occurrence and whether the associations would be modified by vitamin supplementation, garlic supplementation, and Helicobacter pylori (H. pylori) treatment. METHODS: The study was conducted on the basis of the Shandong Intervention Trial, a randomized, placebo-controlled, factorial-designed trial (1995-2003) in a well-recognized high-risk area for GC in China. Participants were continuously followed up to December 2017 for 22.3 y (1995-2017). A total of 3229 subjects were included, with information on the intake of allium vegetables (garlic vegetables and scallions), collected by structured questionnaires in 1994. The associations of total and individual allium vegetable intake with the risk of GC were examined, respectively. RESULTS: During the follow-up, 144 incident cases of GC were identified. Garlic vegetable intake was associated with a decreased risk of incident GC (P-trend = 0.02; OR: 0.83; 95% CI: 0.70, 0.98, per 1 kg/y increment), whereas scallion intake showed no association (P-trend = 0.80). An inverse association of the risk of GC with total allium vegetable and garlic vegetable intake was particularly stronger among those receiving the placebo for vitamin supplementation or garlic supplementation, indicating potential effect modifications by nutritional supplementation on allium vegetable intake and the risk of developing GC. Similar findings were found for analyses of the combined prevalence of dysplasia or GC. CONCLUSIONS: We found a significant reduction in the risk of developing GC with increasing dietary intake of allium vegetables, particularly garlic vegetables. The findings add to the literature on the potential inverse association of garlic vegetable intake with the risk of GC, therefore holding public health implications for dietary recommendations. This trial was registered at clinicaltrials.gov as NCT00339768.

Suppression of Helicobacter pylori infection by daily cranberry intake: A double-blind, randomized, placebo-controlled trial.

BACKGROUND AND AIM: Dietary strategies that contribute to reducing incidence of Helicobacter pylori infection without negative side effects are highly desirable owing to worldwide bacterial prevalence and carcinogenesis potential. The aim of this study was to determine dosage effect of daily cranberry consumption on H. pylori suppression over time in infected adults to assess the potential of this complementary management strategy in a region with high gastric cancer risk and high prevalence of H. pylori infection. METHODS: This double-blind, randomized, placebo-controlled trial on 522 H. pylori-positive adults evaluated dose-response effects of proanthocyanidin-standardized cranberry juice, cranberry powder, or their placebos on suppression of H. pylori at 2 and 8 weeks by 13 C-urea breath testing and eradication at 45 days post-intervention. RESULTS: H. pylori-negative rates in placebo, low-proanthocyanidin, medium-proanthocyanidin, and high-proanthocyanidin cranberry juice groups at week 2 were 13.24%, 7.58%, 1.49%, and 13.85% and at week 8 were 7.35%, 7.58%, 4.48%, and 20.00%, respectively. Consumption of high-proanthocyanidin juice twice daily (44 mg proanthocyanidin/240-mL serving) for 8 weeks resulted in decreased H. pylori infection rate by 20% as compared with other dosages and placebo (P < 0.05). Percentage of H. pylori-negative participants increased from 2 to 8 weeks in subjects who consumed 44 mg proanthocyanidin/day juice once or twice daily, showing a statistically significant positive trend over time. Encapsulated cranberry powder doses were not significantly effective at either time point. Overall trial compliance was 94.25%. Cranberry juice and powder were well-tolerated. CONCLUSIONS: Twice-daily consumption of proanthocyanidin-standardized cranberry juice may help potentiate suppression of H. pylori infection. TRIAL REGISTRATION: ChiCTR1800017522, per WHO ICTRP.

Association Between Lifestyle Factors, Vitamin and Garlic Supplementation, and Gastric Cancer Outcomes: A Secondary Analysis of a Randomized Clinical Trial.

Importance: The associations of lifestyle factors with gastric cancer (GC) are still underexplored in populations in China. Long-term nutritional supplementation may prevent GC in high-risk populations, but the possible effect modification by lifestyle factors remains unknown. Objective: To evaluate how lifestyle factors, including smoking, alcohol intake, and diet, may change the risk of GC incidence and mortality and whether the effects of vitamin and garlic supplementation on GC are associated with major lifestyle factors. Design, Setting, and Participants: This is a secondary analysis of the Shandong Intervention Trial, a masked, randomized, placebo-controlled trial that aimed to assess the effect of vitamin and garlic supplementations and Helicobacter pylori treatment on GC in a factorial design with 22.3 years of follow-up. The study took place in Linqu County, Shandong province, China, a high-risk area for GC. Data were collected from Jully 1995 to December 2017. Overall, 3365 participants aged 35 to 64 years identified in 13 randomly selected villages who agreed to undergo gastroscopy were invited to participate in the trial and were included in the analysis. Data analysis was conducted from March to May 2019. Interventions: Participants received vitamin and garlic supplementation for 7.3 years, H pylori treatment for 2 weeks (among participants with H pylori ), or placebo. Main Outcomes and Measures: The primary outcomes were GC incidence and GC mortality (1995-2017). We also examined the progression of gastric lesions (1995-2003) as a secondary outcome. Results: Of the 3365 participants (mean [SD] age, 47.1 [9.2] years; 1639 [48.7%] women), 1677 (49.8%) were randomized to receive active vitamin supplementation, with 1688 (50.2%) receiving placebo, and 1678 (49.9%) receiving active garlic supplementation, with 1687 (50.1%) receiving placebo. Overall, 151 GC cases (4.5%) and 94 GC deaths (2.8%) were identified. Smoking was associated with increased risk of GC incidence (odds ratio, 1.72; 95% CI, 1.003-2.93) and mortality (hazard ratio [HR], 2.01; 95% CI, 1.01-3.98). Smoking was not associated with changes to the effects of vitamin or garlic supplementation. The protective effect on GC mortality associated with garlic supplementation was observed only among those not drinking alcohol (never drank alcohol: HR, 0.33; 95% CI, 0.15-0.75; ever drank alcohol: HR, 0.92; 95% CI, 0.55-1.54; P for interaction = .03), and significant interactions were only seen among participants with H pylori (never drank alcohol: HR, 0.31; 95% CI, 0.12-0.78; ever drank alcohol: HR, 0.91; 95% CI, 0.52-1.60; P for interaction = .04). No significant interactions between vitamin supplementation and lifestyle factors were found. Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, smoking was associated with an increased risk of GC incidence and mortality. Not drinking alcohol was associated with a stronger beneficial effect of garlic supplementation on GC prevention. Our findings provide new insights into lifestyle intervention for GC prevention, suggesting that mass GC prevention strategies may need to be tailored to specific population subgroups to maximize the potential beneficial effect. Trial Registration: ClinicalTrials.gov Identifier: NCT00339768.

Effects of Helicobacter pylori treatment and vitamin and garlic supplementation on gastric cancer incidence and mortality: follow-up of a randomized intervention trial.

OBJECTIVE: To assess the effects of Helicobacter pylori treatment, vitamin supplementation, and garlic supplementation in the prevention of gastric cancer. DESIGN: Blinded randomized placebo controlled trial. SETTING: Linqu County, Shandong province, China. PARTICIPANTS: 3365 residents of a high risk region for gastric cancer. 2258 participants seropositive for antibodies to H pylori were randomly assigned to H pylori treatment, vitamin supplementation, garlic supplementation, or their placebos in a 2×2×2 factorial design, and 1107 H pylori seronegative participants were randomly assigned to vitamin supplementation, garlic supplementation, or their placebos in a 2×2 factorial design. INTERVENTIONS: H pylori treatment with amoxicillin and omeprazole for two weeks; vitamin (C, E, and selenium) and garlic (extract and oil) supplementation for 7.3 years (1995-2003). MAIN OUTCOME MEASURES: Primary outcomes were cumulative incidence of gastric cancer identified through scheduled gastroscopies and active clinical follow-up through 2017, and deaths due to gastric cancer ascertained from death certificates and hospital records. Secondary outcomes were associations with other cause specific deaths, including cancers or cardiovascular disease. RESULTS: 151 incident cases of gastric cancer and 94 deaths from gastric cancer were identified during 1995-2017. A protective effect of H pylori treatment on gastric cancer incidence persisted 22 years post-intervention (odds ratio 0.48, 95% confidence interval 0.32 to 0.71). Incidence decreased significantly with vitamin supplementation but not with garlic supplementation (0.64, 0.46 to 0.91 and 0.81, 0.57 to 1.13, respectively). All three interventions showed significant reductions in gastric cancer mortality: fully adjusted hazard ratio for H pylori treatment was 0.62 (95% confidence interval 0.39 to 0.99), for vitamin supplementation was 0.48 (0.31 to 0.75), and for garlic supplementation was 0.66 (0.43 to 1.00). Effects of H pylori treatment on both gastric cancer incidence and mortality and of vitamin supplementation on gastric cancer mortality appeared early, but the effects of vitamin supplementation on gastric cancer incidence and of garlic supplementation only appeared later. No statistically significant associations were found between interventions and other cancers or cardiovascular disease. CONCLUSIONS: H pylori treatment for two weeks and vitamin or garlic supplementation for seven years were associated with a statistically significant reduced risk of death due to gastric cancer for more than 22 years. H pylori treatment and vitamin supplementation were also associated with a statistically significantly reduced incidence of gastric cancer. TRIAL REGISTRATION: ClinicalTrials.gov NCT00339768.

Fifteen-year effects of Helicobacter pylori, garlic, and vitamin treatments on gastric cancer incidence and mortality.

In the Shandong Intervention Trial, 2 weeks of antibiotic treatment for Helicobacter pylori reduced the prevalence of precancerous gastric lesions, whereas 7.3 years of oral supplementation with garlic extract and oil (garlic treatment) or vitamin C, vitamin E, and selenium (vitamin treatment) did not. Here we report 14.7-year follow-up for gastric cancer incidence and cause-specific mortality among 3365 randomly assigned subjects in this masked factorial placebo-controlled trial. Conditional logistic regression was used to estimate the odds of gastric cancer incidence, and the Cox proportional hazards model was used to estimate the relative hazard of cause-specific mortality. All statistical tests were two-sided. Gastric cancer was diagnosed in 3.0% of subjects who received H pylori treatment and in 4.6% of those who received placebo (odds ratio = 0.61, 95% confidence interval = 0.38 to 0.96, P = .032). Gastric cancer deaths occurred among 1.5% of subjects assigned H pylori treatment and among 2.1% of those assigned placebo (hazard ratio [HR] of death = 0.67, 95% CI = 0.36 to 1.28). Garlic and vitamin treatments were associated with non-statistically significant reductions in gastric cancer incidence and mortality. Vitamin treatment was associated with statistically significantly fewer deaths from gastric or esophageal cancer, a secondary endpoint (HR = 0.51, 95% CI = 0.30 to 0.87; P = .014).

Manganese superoxide dismutase polymorphism and risk of gastric lesions, and its effects on chemoprevention in a Chinese population.

BACKGROUND: Manganese superoxide dismutase is the primary antioxidant enzyme in the mitochondria and is involved in carcinogenesis. To investigate the association between MnSOD Val(16)Ala polymorphism and risk of advanced gastric lesions, and its effects on chemoprevention, a population-based study was conducted in Linqu, a high-risk area of gastric cancer in China. METHODS: Genotypes were determined by PCR-RFLP analysis in 3,355 subjects with the baseline histopathologic diagnosis in 1994, and 2,758 of these subjects received subsequent three interventions including vitamin supplementation for 7.3 years. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression model. RESULTS: We found an increased risk of dysplasia in subjects with the Val/Ala+Ala/Ala genotype (OR, 1.31; 95% CI, 1.02-1.68) compared with the Val/Val genotype. Stratified analysis indicated that a significantly elevated risk of intestinal metaplasia (OR, 3.40; 95% CI, 2.64-4.38) or dysplasia (OR, 4.01; 95% CI, 2.79-5.74) was found in subjects carrying the Val/Ala+Ala/Ala genotype and Helicobacter pylori infection, and an interaction between this genotype and a high serum H. pylori IgG titer (>2.94) on the risk of dysplasia was observed (P(interaction) = 0.01). Furthermore, an elevated chance for regression of gastric lesions was observed in subjects with the Val/Ala+Ala/Ala genotype and high IgG titer in an intervention trial with vitamin supplementation (OR, 2.45; 95% CI, 1.37-4.38). CONCLUSIONS: These findings suggest that Val(16)Ala polymorphism may play an important role in development of advanced gastric lesions and modify the effect of vitamin supplementation on the evolution of gastric lesions. IMPACT: Val(16)Ala polymorphism is related to gastric cancer development.

A randomized factorial study of the effects of long-term garlic and micronutrient supplementation and of 2-wk antibiotic treatment for Helicobacter pylori infection on serum cholesterol and lipoproteins.

BACKGROUND: Little is known about the long-term effects of garlic or micronutrient supplementation on total, HDL, and LDL cholesterol in disease-free persons. OBJECTIVE: We aimed to assess the effects of long-term supplementation with garlic and micronutrients and of short-term amoxicillin and omeprazole treatment on serum total, HDL, and LDL cholesterol in a rural Chinese population. DESIGN: We conducted a randomized, double-blind, placebo-controlled, 2 x 2 x 2 and 2 x 2 factorial study of precancerous gastric lesions in 3411 subjects in Linqu County, Shandong Province, China. Thirty-four subjects were randomly selected from each of 12 treatment strata. Sera were analyzed at 3.3 and 7.3 y to measure effects on total, HDL, and LDL cholesterol after 2-wk twice-daily treatment with 1 g amoxicillin and 20 mg omeprazole and supplementation throughout the study with 1) 2 capsules twice daily, each containing 200 mg aged garlic extract and 1 mg steam-distilled garlic oil, or 2) twice-daily micronutrient capsules containing 250 mg vitamin C, 100 IU vitamin E, and 37.5 mg selenium. RESULTS: Regressions adjusted for covariates indicated increases of 0.22 mmol total cholesterol/L (P = 0.01) and 0.19 mmol LDL/L (P = 0.02) after 7.3 y of micronutrient supplementation, but no effect of garlic supplementation or short-term amoxicillin and omeprazole treatment. CONCLUSIONS: In this rural Chinese population with low meat intake and moderate cholesterol concentrations, long-term garlic supplementation had no effect on lipid profiles, whereas micronutrient supplementation was associated with small but significant increases in total and LDL-cholesterol concentrations at 7.3 y.

Randomized double-blind factorial trial of three treatments to reduce the prevalence of precancerous gastric lesions.

BACKGROUND: Randomized trials have yielded mixed results on the effects of treatment for Helicobacter pylori and little information on the effects of vitamins or garlic supplements on precancerous gastric lesions. We conducted a randomized trial to test the effects of one-time H. pylori treatment and long-term vitamin or garlic supplements in reducing the prevalence of advanced precancerous gastric lesions. METHODS: Most of the adults aged 35-64 years in 13 randomly selected villages in Linqu County, Shandong Province, China, were identified and given baseline endoscopies in 1994. In 1995, 3365 eligible subjects were randomly assigned in a factorial design to three interventions or placebos: amoxicillin and omeprazole for 2 weeks in 1995 (H. pylori treatment); vitamin C, vitamin E, and selenium for 7.3 years (vitamin supplement); and aged garlic extract and steam-distilled garlic oil for 7.3 years (garlic supplement). Subjects underwent endoscopies with biopsies in 1999 and 2003, and the prevalence of precancerous gastric lesions was determined by histopathologic examination of seven standard biopsy sites. The 3365 eligible randomized subjects represented 93.5% of those with baseline endoscopy and included all baseline histologic categories except gastric cancer. Only 0.18% had normal gastric mucosa. Logistic regression was used to estimate the intervention effects on the odds of advanced precancerous gastric lesions, and t-tests were used to assess effects on histologic severity. All statistical tests were two-sided. RESULTS: H. pylori treatment resulted in statistically significant decreases in the combined prevalence of severe chronic atrophic gastritis, intestinal metaplasia, dysplasia, or gastric cancer in 1999 (odds ratio [OR] = 0.77; 95% confidence interval [CI] = 0.62 to 0.95) and in 2003 (OR = 0.60; 95% CI = 0.47 to 0.75), and had favorable effects on the average histopathologic severity and on progression and regression of precancerous gastric lesions in 2003. H. pylori treatment did not reduce the combined prevalence of dysplasia or gastric cancer. However, fewer subjects receiving H. pylori treatment (19/1130; 1.7%) than receiving placebo (27/1128; 2.4%) developed gastric cancer (adjusted P = .14). No statistically significant favorable effects were seen for garlic or vitamin supplements. CONCLUSION: H. pylori treatment reduces the prevalence of precancerous gastric lesions and may reduce gastric cancer incidence, but further data are needed to prove the latter point. Long-term vitamin or garlic supplementation had no beneficial effects on the prevalence of precancerous gastric lesions or on gastric cancer incidence.