Consumption Of Allium Vegetables Research Articles

Diallyl Trisulfide Induces ROS-Mediated Mitotic Arrest and Apoptosis and Inhibits HNSCC Tumor Growth and Cancer Stemness.

Despite advances in therapeutic approaches, the five-year survival rate for head and neck squamous cell carcinoma (HNSCC) patients is still less than fifty percent. Research has indicated that the consumption of Allium vegetables or processed garlic containing diallyl trisulfide (DATS) can lower the risk of multiple types of cancer. Nevertheless, the effectiveness and underlying mechanisms of DATS against HNSCC have not been thoroughly explored until the current study. In this research, it was found that DATS notably curtailed the growth and viability of HNSCC cells. Additionally, DATS triggered a significant G2/M cell cycle arrest in these cells, accumulating cyclin B1, Cip1/p21, and Ser-10 phospho-histone H3-this was indicative of mitotic arrest attenuated by NAC pretreatment, suggesting the role of reactive oxygen species (ROS) induction. The production of ROS induced by DATS led to DNA damage and apoptosis, a process associated with elevated levels of cleaved caspase-3 and cleaved PARP, along with reduced XIAP. When HNSCC cells were exposed to pharmacological concentrations of DATS, it resulted in the suppression of cancer stem cell (CSC) populations, as indicated by a decrease in the CD133high/CD44high cell fraction, reduced aldehyde dehydrogenase 1 (ALDH1) activity, inhibited spheroid formation and downregulated SOX2 and Oct4 expression. Furthermore, the administration of DATS to tumor xenografts demonstrated its in vivo capacity to hinder CSCs. Further, DATS treatment inhibited the growth of UMSCC-22B head and neck cancer tumor xenograft in immunocompromised mice. Overall, DATS inhibited cell proliferation; induced cell cycle mitotic arrest and apoptosis involving DNA damage through ROS generation; reduced the CSC fraction and spheroid formation; and downregulated SOX2 and Oct4 expression. More importantly, DATS inhibited HNSCC tumor growth and CSC fraction in vivo. Thus, DATS could be a potential anticancer agent that can be used against head and neck cancer.

Maternal diet in pregnancy and acute leukemia in infants: a case-control study in Mexico City.

Epidemiological studies around the world on acute leukemia (AL) and risk factors in infants are scarce. Infant AL has been proposed to originate in utero, which facilitates its study by establishing a short exposure time in pregnant women to environmental and dietary factors that could contribute to the risk of or protection against leukemia. We hypothesized that maternal diet during pregnancy may be an important factor involved in AL in offspring. We conducted a hospital-based case-control study from 2010 to 2019 on maternal diet during pregnancy in nine high-specialty public hospitals of different health institutions that diagnose and offer treatment to children with AL in Mexico City. Cases (n=109) were children ≤24 months of age with de novo diagnosis of AL, and controls (n=252) were children obtained in hospitals from second-level medical care matched for age, sex, and health institution. Maternal diet during pregnancy was obtained by a semiquantitative food frequency questionnaire. Unconditional logistic regression models were used to assess the association between food groups and infant AL. Potential confounders were assessed by constructing directed acyclic graphs (DAGs) with Dagitty software in which adjusted options were identified for the construction of unconditional logistic regression models. Cases were slightly predominantly female (52.3%). The years of education of the mother in cases and controls was 0-9 on average, and those who reported smoking cigarettes and consuming alcohol during pregnancy did so at a low frequency. Regarding the mother's diet, the main findings were that the consumption of allium vegetables during pregnancy was inversely associated with AL for medium and high consumption (OR=0.26, 95% CI 0.14-0.46; P-trend< 0.001). In contrast, the high consumption of high-fat dairy products had a positive association with AL (OR=2.37, 95% CI 1.30-4.34; P-trend<0.001). No association was found between consumption of topoisomerase II inhibitor foods during pregnancy and AL. The results suggest that maternal intake during pregnancy of allium vegetables, specifically garlic, is inversely associated with the development of AL in children ≤24 months old. On the other hand, consumption of high-fat dairy products is positively associated with AL in children ≤24 months old.

P23-056-23 How is Allium Vegetable Consumption Associated With Mental Disorders? A Cross-Sectional Study

P23-056-23 How is Allium Vegetable Consumption Associated With Mental Disorders? A Cross-Sectional Study

THERAPEUTIC ASPECTS OF ONION IN TREATMENT OF CANCER AND RELATED ISSUES: A REVIEW

Human has always found nature as its good mate. Human beings have always used herbal/ayurvedic remedies in the treatment of their several diseases with very less side effect. Allium species are one of the herbs whose parts like roots, leaves, stems and also juices is very useful for curing cancer, cardiovascular diseases, inflammation, reducing blood sugar, baldness, gastric ulcer, colic diseases, oxidative study (Khan, May 2017). Consumption of Allium vegetables indicated decreased cancer risk, particularly gastrointestinal tract cancers as reported by epidemiological studies; though of limited asses. Mechanistic studies give the major supporting evidence of cancer preventive effect of Allium vegetables. The studies highlight mechanism of compounds having sulfur, extracts of onion, various preparations and their lower activation of carcinogens, antioxidant, antimicrobial, antibacterial and oxidoreduction modification. Onion is also seen as reducing obesity and thus reducing the risk of cancer associated with potential obesity. Onion can be used as an obesity reducing agent by acting on the low-density cholesterol and increase high density lipoprotein cholesterol.

Association of allium vegetables intake and non-alcoholic fatty liver disease risk

PurposeNon-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease worldwide. The purpose of this study is to assess the possible association between habitual intake of allium vegetables and NAFLD risk.Design/methodology/approachIn this study, 196 cases of NAFLD and 803 age-matched controls were enrolled from the same clinic. Dietary intakes were assessed using a validated food frequency questionnaire. Consumption of allium vegetables, including raw garlic and onions, were calculated and considered as grams/day in all participants.FindingsParticipants in the highest tertile of allium vegetable intake had 64% lower risk of NAFLD compared with those in the lowest tertile of the allium vegetables intake (odds ratio [OR]: 0.35; 95% confidence interval [CI]: 0.23-0.51;p&lt; 0.001). After controlling for potential confounders, there was no significant change in this inverse association (OR: 0.36; 95% CI: 0.22-0.56;p&lt; 0.001).Originality/valueThis study for the first time showed that higher consumption of allium vegetables was associated with lower risk of NAFLD. The results did not change when the authors adjusted the analysis for the known risk factors of the disease, which indicate the independency of the association.

Allium vegetable consumption and health: An umbrella review of meta-analyses of multiple health outcomes.

Previously, our meta‐analysis and other studies have suggested that allium vegetable consumption is beneficial for health, but no umbrella review has been conducted to assess the evidence of the various health benefits of allium vegetable consumption. Therefore, we conducted this umbrella review on this topic. This umbrella review included a total of 16 meta‐analyses with 50 unique outcomes. The most beneficial cancer‐related outcome was shown for gastric cancer (risk ratio 0.78; 95% confidence interval [CI] 0.67–0.91). In addition, only 8 weeks of garlic consumption significantly decreased serum total cholesterol (weighted mean differences −17.20 mg/dl; 95% CI −23.10 to −11.30), and patients with dyslipidemia who consumed garlic experienced more benefits than the whole population. Diabetic patients with longer durations of garlic intake experienced more benefits in terms of fasting blood glucose (FBG), HbA1c, and serum fructosamine than healthy participants, and garlic intake was associated with blood pressure reduction in hypertensive patients but not in normotensive participants. Limited side effects of garlic, such as garlic odor and gastrointestinal complaints, were reported among the included meta‐analyses. Our results suggested that allium vegetables might be beneficial for cancer prevention. In particular, garlic was comparatively safe and is recommended as a long‐term dietary component for patients with dyslipidemia, diabetes, and hypertension.

Prospective study of total and various types of vegetables and the risk of metabolic syndrome among children and adolescents.

BACKGROUNDData available on the association between consumption of various types of vegetables and metabolic syndrome (MetS) remain inconsistent.AIMTo investigate the association between the intake of various types of vegetables and MetS among children and adolescents and MetS.METHODSThe Tehran Lipid and Glucose Study cohort included 424 children and adolescents initially free of MetS. At the 3.6 year follow-up, 47 new cases of MetS were identified. A 168-item semi-quantitative food-frequency questionnaire was used to collect information about total and various types of vegetables consumed, including allium-, green leafy-, fruity-, root-, stalk-, starchy-, potatoes, and cabbage. MetS was defined according to the Cook et al[32] criteria.RESULTSThe median (interquartile range) of total vegetable consumption was 217 (146-344) g/d. After adjustment for demographic characteristics and dietary intake, higher total- (≥ 350 g/d) and higher allium vegetable consumption (≥ 30 g/d) in the fourth quartile were significantly and inversely associated with risk of MetS compared to the first quartile. Consumption of green leafy vegetables in the third (21.4-38.3 g/d) versus the first quartile (≤ 13.5 g/d) demonstrated a significant inverse association with lower risk of MetS in children and adolescents; associations for other types of vegetables consumed were not significant.CONCLUSIONConsumption of vegetables, especially allium and green leafy vegetables, in sufficient amounts may be beneficial in reducing the risk of MetS among children and adolescents.

Allium vegetables are associated with reduced risk of colorectal cancer: A hospital-based matched case-control study in China.

The present study aimed to investigate and identify the association between the intake of allium vegetables and colorectal cancer (CRC) in population. A hospital-based matched case-control study was conducted between June 2009 and November 2011 in three hospitals. Eight hundred thirty three consecutively recruited cases of CRC were frequency matched to 833 controls by age (within 2.5 years of difference), sex, and residence area (rural/urban). Demographic and dietary information were collected via face-to-face interviews using a validated food frequency questionnaire. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated by using unconditional logistic regression. A decreased CRC risk was observed for the consumption of total (aORs of high total allium intake compared with low total allium intake=0.21, 95% CI=0.14-0.30, P trend <0.001) and several individual allium vegetables including garlic, garlic stalks, leek, onion, and spring onion (P trend <0.05). By further sex-stratified analysis, allium vegetable intake was demonstrated to be inversely associated with the risk of CRC in both men and women. However, the association of garlic intake with cancer risk was not significant among those with distal colon cancer (aOR=0.53, 95% CI=0.27-1.05, P trend=0.248). In this analysis in a Northeast Chinese population, both men and women that the consumption of allium vegetables is associated with a reduced risk of CRC, regardless of colonic tumor subsite, with the exception of garlic intake in distal colon cancer.

Higher consumption of Allium vegetables may modulate insulin homeostasis: A longitudinal follow-up study

ObjectivesThis study investigated the association between habitual consumption of allium vegetables (raw garlic and onion) and the incidence of insulin resistance (IR), β-cell dysfunction and hyperinsulinemia. MethodsAdult men and women, participants of the Tehran Lipid and Glucose Study (2006–2008 to 2009–2011), were recruited. Habitual dietary intakes were assessed using a validated semi-quantitative food frequency questionnaire. Fasting serum insulin (FSI) and fasting glucose were measured at baseline and again after 3 years. Homeostatic model assessment of insulin resistance (HOMA-IR) and HOMA of β-cell function were calculated. Logistic regression models were used to estimate the occurrence of IR, β-cell dysfunction and hyperinsulinemia across tertiles of allium vegetable intakes, with adjustment for potential confounding variables. ResultsMean age of participants was 39.0 ± 11.2 years and 45.5% were men. Baseline mean FSI and HOMA-IR was 8.9 ± 5.0 μU/mL, 1.93 ± 1.22, and 149 ± 86, respectively. Compared to the lowest tertile, the highest category of allium vegetables intake (≥142 vs. <8.0 g/week) was accompanied with a significant decreased risk of IR (OR = 0.61, 95% CI = 0.38–1.00) and hyperinsulinemia (OR = 0.59, 95% CI = 0.36-0.96). There was no significant association between allium vegetable intakes and β-cell function. ConclusionHigher consumption of allium vegetables may be considered as a nutritional strategy to improve glucose/insulin homeostasis.

Garlic-A Golden Wonder

Garlic belongs to the family of Allium which produce organosulfur compounds like allicin and diallyl disulfide (DADS) which give its pungent as well as spicy aroma. It’s benefits have been attributed to hypotensive and vasorelaxant activities. It has also been found that chronic Helicobacter pylori is reduced with Allium vegetable intake. Garlic preparations are widely available as garlic powder (GP) or garlic oil (GO). Epidemiological studies have shown a close link between stomach cancer, H. pylori infection and the consumption of Allium vegetables. Since a long time, garlic has been used as herbal medicines for treating a variety of ailments like hypertension, high blood cholesterol and thrombosis. At the same time, it can also produce adverse effects such as cutaneous irritation, edema and allergic contact dermatitis.

Allium vegetable intakes and the incidence of cardiovascular disease, hypertension, chronic kidney disease, and type 2 diabetes in adults: a longitudinal follow-up study.

This study investigated the association between habitual consumption of allium vegetables (garlic and onion) and the incidence of cardiovascular disease (CVD) outcomes, hypertension (HTN), chronic kidney disease (CKD), and type 2 diabetes (T2D). Adult men and women, participated in the Tehran Lipid and Glucose Study (2006-2008 to 2012-2014), were recruited. Habitual dietary intakes were assessed using a validated semiquantitative food frequency questionnaire. Demographics, anthropometrics, blood pressure, and biochemical variables were evaluated at baseline and during follow-up examinations. Multivariate Cox proportional hazard regression models adjusted for potential confounders were used to estimate the development of CVD outcomes, HTN, CKD, and T2D in relation to allium vegetable intakes. Mean age of participants (44.2% men) was 40.3 ± 14.3 years, at baseline. During an average of 6 years of follow-up, the incidence rate of CVD outcomes, HTN, CKD, and T2D were 3.3, 15.5, 17.9, and 6.7%, respectively. A higher habitual intake of allium vegetables was associated with a 64% reduced risk of CVD outcomes (hazard ratio = 0.36, 95% confidence interval, CI = 0.18-0.71; P for trend = 0.011), 32% lower incidence of CKD (hazard ratio = 0.69, 95% CI = 0.46-0.98; P for trend = 0.11), and 26% decreased HTN development (hazard ratio = 0.74, 95% CI = 0.54-1.00; P for trend = 0.06). No significant association was observed between allium vegetable intakes and the risk of T2D. Allium vegetable intake was related to 6 years' changes of triglyceride levels (β = -0.81, P = 0.01) and creatinine clearance (β = 0.56, P = 0.01). Data of the current study support the available mechanistic findings regarding cardiorenal protective properties of allium vegetables.

Dietary Bioactive Diallyl Trisulfide in Cancer Prevention and Treatment.

Bioactive dietary agents have been shown to regulate multiple cancer hallmark pathways. Epidemiologic studies have linked consumption of Allium vegetables, such as garlic and onions, to decreased incidence of cancer. Diallyl trisulfide (DATS), a bioactive compound derived from Allium vegetables, has been investigated as an anti-cancer and chemopreventive agent. Preclinical studies provide ample evidence that DATS regulates multiple cancer hallmark pathways including cell cycle, apoptosis, angiogenesis, invasion, and metastasis. DATS has been shown to arrest cancer cells at multiple stages of the cell cycle with the G2/M arrest being the most widely reported. Additionally, increased pro-apoptotic capacity as a result of regulating intrinsic and extrinsic apoptotic pathway components has been widely reported following DATS treatment. Invasion, migration, and angiogenesis represent emerging targets of DATS and support its anti-cancer properties. This review summarizes DATS mechanisms of action as an anti-cancer and chemopreventive agent. These studies provide rationale for future investigation into its use as a cancer chemopreventive agent.

Fruit and vegetables and cancer risk: a review of southern European studies.

High intakes of fruit and vegetables may reduce the risk of cancer at several sites. Evidence has been derived mainly from case-control studies. We reviewed the relationship between consumption of vegetables and fruit and the risk of several common cancers in a network of Italian and Swiss case-control studies including over 10,000 cases of fourteen different cancers and about 17,000 controls. Data were suggestive of a protective role of vegetable intake on the risk of several common epithelial cancers. OR for the highest compared with the lowest levels of consumption ranged from 0.2 (larynx, oral cavity and pharynx) to 0.9 (prostate). Inverse associations were found for both raw and cooked vegetables, although for upper digestive tract cancers the former were somewhat stronger. Similar inverse associations were found for cruciferous vegetables. Frequent consumption of allium vegetables was also associated with reduced risk of several cancers. Fruit was a favourable correlate of the risk of several cancers, particularly of the upper digestive tract, with associations generally weaker than those reported for vegetables. A reduced risk of cancers of the digestive tract and larynx was found for high consumption of citrus fruit. Suggestive protections against several forms of cancer, mainly digestive tract cancers, were found for high consumption of apples and tomatoes. High intakes of fibres, flavonoids and proanthocyanidins were inversely related to various forms of cancer. In conclusion, data from our series of case-control studies suggested a favourable role of high intakes of fruit and vegetables in the risk of many common cancers, particularly of the digestive tract. This adds evidence to the indication that aspects of the Mediterranean diet may have a favourable impact not only on CVD, but also on several common (epithelial) cancers, particularly of the digestive tract.

Garlic and onions: their cancer prevention properties.

The Allium genus includes garlic, onions, shallots, leeks, and chives. These vegetables are popular in cuisines worldwide and are valued for their potential medicinal properties. Epidemiologic studies, while limited in their abilities to assess Allium consumption, indicate some associations of Allium vegetable consumption with decreased risk of cancer, particularly cancers of the gastrointestinal tract. Limited intervention studies have been conducted to support these associations. The majority of supportive evidence on Allium vegetables cancer-preventive effects comes from mechanistic studies. These studies highlight potential mechanisms of individual sulfur-containing compounds and of various preparations and extracts of these vegetables, including decreased bioactivation of carcinogens, antimicrobial activities, and redox modification. Allium vegetables and their components have effects at each stage of carcinogenesis and affect many biologic processes that modify cancer risk. This review discusses the cancer-preventive effects of Allium vegetables, particularly garlic and onions, and their bioactive sulfur compounds and highlights research gaps.

Allium vegetable intake and gastric cancer: a case-control study and meta-analysis.

To provide new epidemiological data and summarize evidence on the association between allium vegetable intake and gastric cancer risk. Data were from an Italian case-control study including 230 cases and 547 controls. Odds ratios were derived using multiple logistic regression. We combined results from all published studies using random-effect models. In our case-control study, the odds ratios were 0.59 (95% confidence interval, CI, 0.25-1.41) for ≥2 portions of onion per week, 0.69 (95% CI, 0.41-1.15) for high garlic intake, and 0.70 (95% CI, 0.39-1.28) for frequent use of both onion and garlic. Besides our study, 22 case-control and four cohort studies were included in the meta-analyses (>10000 cases). The pooled relative risks for the highest versus lowest intake category were 0.78 (95% CI, 0.67-0.91) for allium vegetables (ten case-control and four cohort studies), 0.60 (95% CI, 0.47-0.76) for garlic (12 case-control studies), and 0.55 (95% CI, 0.41-0.73) for onion (13 case-control studies). The pooled relative risk for high allium vegetable intake from the four cohorts was 1.02 (95% CI, 0.88-1.18). High allium vegetable consumption is likely to reduce gastric cancer risk. This evidence is derived mainly from case-control studies. Further data from large cohorts are desirable for conclusive confirmation.

Allium Vegetables and Garlic Supplements Do Not Reduce Risk of Colorectal Cancer, Based on Meta-analysis of Prospective Studies

Laboratory studies have provided evidence that allium vegetables and garlic supplements might protect against colorectal cancer (CRC), but epidemiologic studies have produced inconsistent findings. We conducted a meta-analysis of prospective studies evaluating the associations between allium vegetables, garlic supplements, and CRC risk. We pooled effect measures using fixed- or random-effect models, assessing the highest vs the lowest intakes. We used a dose-response regression model to evaluate the relationship between allium vegetable intake and CRC risk. Our analysis included 8 studies with 20 reports of the effects of allium vegetables (5458 patients with CRC including 7,125,067 person-years) and 5 studies with 11 reports of the effects of garlic supplements (2685 patients with CRC including 2,304,439 person-years). We found no association between higher intake of allium vegetables and CRC risk (relative risk [RR], 1.06; 95% confidence interval [CI], 0.96-1.17; P = .26). Intake of allium vegetables did not correspond to CRC risk (P for nonlinear = .24, P for linear = .20). In subgroup analysis, a higher consumption of allium vegetables was associated marginally with increased risk of colon cancer among women (RR, 1.23; 95% CI, 1.01-1.50; P = .05). Use of garlic supplements was associated significantly with an increased risk of CRC (RR, 1.18; 95% CI, 1.02-1.36; P = .03). In a meta-analysis, we found no evidence that higher intake of allium vegetables reduced the risk for CRC. We observed that garlic supplements increased the risk for CRC, but this finding requires external validation.

Garlic‐derived organosulfur compound diallyl trisulfide induces apoptosis in pancreatic cancer cells

Epidemiological observations have shown an inverse association between consumption of Allium vegetables (e.g., onions and garlic) and pancreatic cancer risk. The cancer preventive effect of Allium vegetables has been attributed to organosulfur compounds. The objective of this study was to determine the efficacy of diallyl trisulfide (DATS), a garlic‐derived organosulfur compound, against pancreatic cancer cells. Treatment with DATS inhibited the growth of MIAPaca2 and PL45 pancreatic cancer cells in a dose‐dependent manner. DATS induced apoptosis in pancreatic cancer cells as determined by cytoplasmic‐associated DNA fragmentation assay after exposure to DMSO (control) or DATS (20, 40, and 60 μmol/L) for 24 h. Exposure of pancreatic cancer cells to DATS increased levels of cleaved caspase 3 and induced proteolytic cleavage of poly‐(ADP‐ribose) polymerase (PARP). In addition, DATS treatment upregulated the expression of pro‐apoptotic Bim‐s and Bim‐L isoforms in MIAPaca 2 and PL45 cells. In conclusion, this study shows that DATS induces apoptotic cell death in pancreatic cancer cells and supports further investigation of DATS as a chemopreventive agent for pancreatic cancer.

Consumption of Large Amounts of Allium Vegetables Reduces Risk for Gastric Cancer in a Meta-analysis

The chemopreventive effects of Allium vegetables (onions, garlic, shallots, leeks, chives, and so forth) have been studied extensively, although their effect on gastric cancer risk is controversial. We performed a meta-analysis of cohort and case-control studies to analyze this association. We searched MEDLINE for studies of Allium vegetable consumption and gastric cancer that were published in any language, from January 1, 1966, to September 1, 2010. We analyzed 19 case-control and 2 cohort studies, of 543,220 subjects. We pooled the relative risks from individual studies using a random-effects model and performed dose-response, heterogeneity, and publication bias analyses. In a pooled analysis of all studies, consumption of large amounts of Allium vegetables (in a comparison of the highest and lowest consumption groups) reduced the risk for gastric cancer (odds ratio, 0.54; 95% confidence interval, 0.43-0.65). Specific analyses for onion, garlic, leek, Chinese chive, scallion, garlic stalk, and Welsh onion yielded similar results, except for onion leaf. The estimated summary odds ratio for an increment of 20 g/day of Allium vegetables consumed (approximately the average weight of 1 garlic bulb) was 0.91 (95% confidence interval, 0.88-0.94), based on case-control studies from the dose-response meta-analysis. In a meta-analysis, consumption of high levels of Allium vegetables reduced the risk for gastric cancer risk. Because of potential confounding factors and exposure misclassification, further studies are required to establish this association.

Onion and Garlic Intake and the Odds of Benign Prostatic Hyperplasia

To analyze the relationship between onion and garlic intake and benign prostatic hyperplasia (BPH), using data from a multicenter case-control study conducted in Italy. A multicenter case-control study of 1369 patients with BPH and 1451 controls, admitted to the same hospitals for a wide spectrum of acute, non-neoplastic conditions, was conducted in Italy between 1991 and 2002. Information was collected by trained interviewers using a validated and reproducible food frequency questionnaire. Multivariate odds ratios (ORs) and 95% confidence intervals (CIs) were obtained after allowance for recognized confounding factors and energy intake. Compared with nonusers, the multivariate ORs for the highest category of onion and garlic intake were 0.41 (95% CI 0.24 to 0.72) and 0.72 (95% CI 0.57 to 0.91), respectively. The combined OR for frequent users versus nonusers of both onion and garlic was 0.65 (95% CI 0.49 to 0.86). The inverse relationships were consistent across age strata. This uniquely large data set from European populations showed an inverse association between allium vegetable consumption and BPH.

Habitual consumption of fruits and vegetables: associations with human rectal glutathione S-transferase.

The glutathione (GSH)/glutathione S-transferase (GST) system is an important detoxification system in the gastrointestinal tract. A high activity of this system may benefit cancer prevention. The aim of the study was to assess whether habitual consumption of fruits and vegetables, especially citrus fruits and brassica and allium vegetables, is positively associated with parameters reflecting the activity of the GSH/GST enzyme system in human rectal mucosa. GST enzyme activity, GST isoenzyme levels of GST-alpha (A1-1, A1-2 and A2-2), -mu (M1-1) and -pi (P1-1), and GSH levels were measured in rectal biopsies from 94 subjects. Diet, lifestyle, GSTM1 and GSTT1 null polymorphisms were assessed. Mean GST enzyme activity was 237 nmol/min/mg protein (SD = 79). Consumption of citrus fruits was positively associated with GST enzyme activity [difference between high and low consumption: 28.9 (95% confidence interval (CI) = 9.3-48.6) nmol/min/mg protein], but was not associated with the other parameters. A positive association with brassica vegetables was found among carriers of the GSTM1-plus genotype [difference between high and low consumption: 22.6 (95% CI = 0.2-45.0) nmol/min/mg protein], but not among GSTM1-null individuals (-25.8 nmol/min/mg protein, 95% CI = -63.3-11.8). This is in line with a positive association between consumption of brassica vegetables and GSTM isoenzyme level [difference between high and low consumption: 67.5%, 95% CI = (6.8-162.7)]. Consumption of allium vegetables was not associated with GST enzyme activity, but negatively with GSTP1-1 levels [difference between high and low consumption: -23.3%, 95% CI = (-35.5; -8.6)]. Associations were similar among those with the GSTT1-plus and GSTT1-null genotype. In conclusion, variations in habitual consumption of fruits, particularly citrus fruits, and of vegetables, in particular brassica vegetables, among those with the GSTM1-plus genotype, may contribute to variations in human rectal GST enzyme activity.