Onion and garlic use and human cancer

BACKGROUND: Interest in the potential benefits of allium vegetables, in particular, onion (Allium cepa) and garlic (Allium sativum), has its origin in antiquity, but the details of these benefits are still open to discussion. OBJECTIVE: We investigated the role of allium vegetables in the etiology of various neoplasms. Previous data are scanty and are based mainly on Chinese studies. DESIGN: Using data from an integrated network of Italian and Swiss case-control studies, we analyzed the relation between frequency of onion and garlic use and cancer at several sites. We calculated odds ratios (ORs) by using multivariate logistic regression models that were adjusted for energy intake and other major covariates. RESULTS: Consumption of onions varied between 0-14 and 0-22 portions/wk among cases and controls, respectively. The multivariate ORs for the highest category of onion and garlic intake were, respectively, 0.16 and 0.61 for cancer of the oral cavity and pharynx, 0.12 and 0.43 for esophageal cancer, 0.44 and 0.74 for colorectal cancer, 0.17 and 0.56 for laryngeal cancer, 0.75 and 0.90 for breast cancer, 0.27 and 0.78 for ovarian cancer, 0.29 and 0.81 for prostate cancer, and 0.62 and 0.69 for renal cell cancer. CONCLUSIONS: This uniquely large data set from southern European populations shows an inverse association between the frequency of use of allium vegetables and the risk of several common cancers. Allium vegetables are a favorable correlate of cancer risk in Europe.     

Dietary garlic and onion reduce the incidence of atherogenic diet-induced cholesterol gallstones in experimental mice

Mice fed with diet containing 0.5 % cholesterol for 10 weeks resulted in cholesterol supersaturation in gallbladder bile which promoted the formation of cholesterol gallstones (CGS). In this study, dietary hypocholesterolaemic spices, garlic and onion (both raw or heat-processed) were examined for their antilithogenic potential by including at 0.6 and 2.0 % level, respectively, along with lithogenic (LG) diet for 10 weeks. Dietary garlic and onion reduced the CGS incidence by 15-39 %, the effect being maximum in the heat-processed onion group. Dietary garlic and onion markedly reduced biliary cholesterol. The cholesterol:phospholipid ratio which was 1.58 in the LG diet group was reduced to 0.73-0.96 in the garlic and onion groups. The biliary cholesterol saturation index was 0.92, 1.25, 1.09 and 0.86, respectively, in the heat-processed onion, raw garlic, heat-processed garlic and raw onion groups, while it was 1.9 in the LG group. The hydrophobicity index of bile was - 0.08, - 0.079, - 0.032 and - 0.073, respectively, in the heat-processed onion, raw garlic, heat-processed garlic and raw onion groups, while it was +0.054 in the LG group. Hepatic hydroxymethyl glutaryl-CoA reductase activity was lowered in the LG diet-fed group, while dietary garlic or onion countered this alteration and also increased the activities of hepatic cholesterol 7 alpha-hydroxylase and sterol 27-hydroxylase. Serum and liver cholesterol were decreased by feeding garlic or onion compared to the LG diet. Thus, dietary Allium spices exerted antilithogenic influence by decreasing the cholesterol hyper-secretion into bile and increasing the bile acid output thus decreasing the formation of lithogenic bile in experimental mice.     

Gastric Cancer and Allium Vegetable Intake: A Critical Review of the Experimental and Epidemiologic Evidence

There are suggestions of an anticancerogenic effect of allium vegetables and their associated organosulfur components against several cancer types, including gastric cancer, but the issue remains open to discussion and quantification. The present critical review discussed the history, the health properties, the chemistry, the anticancerogenic evidences from experimental studies, and the anticancer mechanisms of allium vegetables. We also summarized findings from epidemiological studies concerning the association between different types of allium vegetables and gastric cancer risk, published up to date. Available data, derived mainly from case-control studies, suggested a favorable role of high intakes of allium vegetables, mainly garlic and onion, in the etiology of gastric cancer. In particular, of 10 studies, 7 suggested a favorable role of high intake of total allium vegetables and gastric cancer. All 14 studies on garlic and most studies on onion (more than 80%) reported a beneficial role of these allium types against gastric cancer. However several limitations, including possible publication bias and the difficulty to establish a dose-risk relationship, suggest caution in the interpretation. Evidences on other types of allium vegetables, as well as on the influence of different gastric cancer anatomical and histological types, are less consistent.     

Anti-oxidant, anti-glycant, and inhibitory activity against α-amylase and α-glucosidase of selected spices and culinary herbs

Aqueous and methanol extracts of dry sage, rosemary, basil, parsley, chili, garlic and onion were analyzed to investigate their anti-oxidant and anti-glycant activities and in vitro inhibitory potential against enzymes involved in glycemic regulation. The aqueous extracts of rosemary and sage were the richest in phenolic compounds and showed the highest ability in binding iron and inhibiting DPPH, superoxide radicals and advanced glycation end-product production, lipid peroxidation, and the activity of α-glucosidase and α-amylase. On the other hand, the methanol extracts of both these Labiatae were less efficient than those of garlic, onion, parsley and chili in scavenging hydroxyl radicals. As far as protein glycation is concerned, methanol extracts were more effective in inhibiting the production of Amadori compounds and the aqueous ones in preventing advanced glycation end-product formation. Therefore these spices may be preventive not only against cardiovascular diseases but also type 2 diabetes.     

富硒大蒜和洋葱中功能性硒化合物的稳定性研究

本研究设计了几个实验 ,研究富硒大蒜和洋葱中水溶性含硒化合物的稳定性。结果发现 :冷冻干燥加工能保持富硒大蒜中含硒化合物化学性质 ,富硒大蒜室温水提液中Se 甲基 硒半胱氨酸不稳定 ,蒜氨酸酶专一抑制剂盐酸羟胺能有效抑制该含硒化合物丢失 ,提示Se 甲基 硒代半胱氨酸的分解反应可能主要受蒜氨酸酶催化。富硒洋葱中同样含有蒜氨酸酶 ,但其室温水提液中Se 甲基 硒半胱氨酸却能稳定存在。Se 甲基 硒半胱氨酸是富硒大蒜一种主要功能硒组分 ,加工储存过程中应避免它损失 ,以保障富硒大蒜医学功能的发挥。富硒大蒜和洋葱含硒化合物的稳定性差异、分解机理以及分解产物活性等均有待于进一步的研究。     

Anti-oxidant,anti-glycant,and inhibitory activity against α-amylase and α-glucosidase of selected spices and culinary herbs

Aqueous and methanol extracts of dry sage, rosemary, basil, parsley, chili, garlic and onion were analyzed to investigate their anti-oxidant and anti-glycant activities and in vitro inhibitory potential against enzymes involved in glycemic regulation. The aqueous extracts of rosemary and sage were the richest in phenolic compounds and showed the highest ability in binding iron and inhibiting DPPH, superoxide radicals and advanced glycation end-product production, lipid peroxidation, and the activity of α-glucosidase and α-amylase. On the other hand, the methanol extracts of both these Labiatae were less efficient than those of garlic, onion, parsley and chili in scavenging hydroxyl radicals. As far as protein glycation is concerned, methanol extracts were more effective in inhibiting the production of Amadori compounds and the aqueous ones in preventing advanced glycation end-product formation. Therefore these spices may be preventive not only against cardiovascular diseases but also type 2 diabetes.     

Inhibition of DMBA-induced mouse skin tumorigenesis by garlic oil and inhibition of two tumor-promotion stages by garlic and onion oils

A single 2-mg dose of garlic oil applied 30 minutes before a single carcinogenic dose of 7,12-dimethylbenz[a]-anthracene (DMBA) inhibited papilloma production in Sencar mice. The three groups were controls (Group 1), garlic oil applied 30 minutes before DMBA (Group 2), and garlic oil applied 30 minutes after DMBA (Group 3). The percents of mice with papillomas at 20 weeks were 94, 72, and 79, respectively. The decreases in Groups 2 and 3 were significant. The number of papillomas per mouse was 4.2 +/- 0.5 (Group 1), 2.3 +/- 0.8 (Group 2), and 3.4 +/- 0.6 (Group 3). The decrease in Group 2 was significant. A single 5-mg dose of garlic oil maximally inhibited DMBA-induced epidermal DNA synthesis by 86% when applied two hours before the carcinogen. Two-stage promotion in DMBA-initiated Sencar mice was achieved by twice-weekly applications of 8.5 nmol of 12-O-tetradecanoylphorbol-13-acetate (TPA) for 2 weeks followed by twice-weekly applications of 8.5 nmol of mezerein for 18 weeks. The oils were applied 30 minutes after each promotion by TPA or mezerein. Single doses of 1 mg onion or garlic oil inhibited the first and second stages of promotion. The groups used were control (Group 1), garlic oil applied after stage 1 (Group 2), onion oil applied after stage 1 (Group 3), propenyl sulfide applied after stage 1 (Group 4), garlic oil applied after stage 2 (Group 5), onion oil applied after stage 2 (Group 6), and propenyl sulfide applied after stage 2 (Group 7). The percent of mice with papillomas was significantly decreased by all agents in Groups 2-7. The data are 81, 83, 91, 68, 96, and 86, respectively. The number of papillomas per mouse was significantly reduced by onion and garlic oils but not by propenyl sulfide. The data are 9.4 +/- 0.8, 6.3 +/- 0.7, 7.4 +/- 0.5, 9.2 +/- 1.2, 3.7 +/- 0.9, 6.2 +/- 0.6, and 9.1 +/- 1.4 for Groups 1-7, respectively. Onion and garlic oils inhibited the TPA-stimulated DNA synthesis when given as single doses of 5 mg one hour before TPA. The inhibition by garlic oil was most effective when given one hour before TPA but was evident when given from two hours before to two hours after TPA. These results, and those of others (AS Sadhana, Cancer Lett, 40, 193-197, 1988), who obtained inhibition of initiation, indicate that onion and garlic oils inhibit all stages of mouse skin tumorigenesis.(ABSTRACT TRUNCATED AT 400 WORDS)     

Antioxidant and Anticoagulant Status Were Improved by Personalized Dietary Intervention Based on Biochemical and Clinical Parameters in Cancer Patients

We investigated whether personalized dietary intervention could improve clinical measurements such as immune cell-mediated cytotoxicity, serum albumin, derivatives of reactive oxygen metabolites (D-ROMS), D-dimer, and fibrinogen. Cancer patients received either a treatment support diet (TD, for those with chemotherapy), or a remission support diet (RD; for those in remission) for at least 3 wk (21–61 days). Both diets were low glycemic, low fat, and high plant protein diets; the diet for the TD group contained an additional 0.5 servings of protein. Based on clinical values, additional amounts of garlic, onion, tomato, shiitake, rice bran, kale, blueberry, pineapples, and/or turmeric powder were provided in regular meals. Estimated daily intake of protein, plant fat, garlic, onion, allicin, and quercetin was greater in the TD compared to the RD. An increased intake of vitamin A, vitamin C, vitamin E and selenium and a reduction in D-dimer were noted compared to baseline diets in both groups. A decrease in D-ROMS in the RD and an increase in albumin and an increased tendency in cytotoxicity in the TD were observed. In conclusion, personalized diets with supplemented functional ingredients improved antioxidant status and/or anticoagulant activity in cancer patients undergoing chemotherapy and in remission.     

Promoting influence of combinations of amchur, β-carotene-rich vegetables and Allium spices on the bioaccessibility of zinc and iron from food grains

Deficiencies of iron and zinc among the population dependent on plant foods necessitate strategies to maximize their bioavailability. In this context, specific combinations of promoters of iron and zinc bioaccessibility—namely, amchur (0.75 g/10 g), β-carotene-rich vegetables (2.5 g/10 g) and Allium spices (1.5 g/10 g)—were evaluated for a possible additive/synergistic effect on the bioaccessibility of iron and zinc from food grains. The positive influence on the bioaccessibility of iron was additive in the case of combinations of amchur–carrot, amchur–garlic, onion–carrot, and onion–amaranth in a few specific grains. Positive influence on the bioaccessibility of iron was even synergistic for combinations of amchur–onion and amchur–garlic in a few grains. The influence of amchur–garlic and amchur–onion was additive while the combination of amchur–amaranth and amchur–garlic produced a synergistic-promoting influence on zinc bioaccessibility in a few instances. This observation would be useful in evolving dietary strategies to maximize the bioavailability of minerals from grains.     

Inhibition of DMBA‐induced mouse skin tumorigenesis by garlic oil and inhibition of two tumor‐promotion stages by garlic and onion oils

A single 2‐mg dose of garlic oil applied 30 minutes Before a single carcinogenic dose of 7, 12‐dimethylbenz[a]‐anthracene (DMBA) inhibited papilloma production in Sencar mice. The three groups were controls (Group 1), garlic oil applied 30 minutes before DMBA (Group 2), and garlic oil applied 30 minutes after DMBA (Group 3). The percents of mice with papillomas at 20 weeks were 94, 72, and 79, respectively. The decreases in Groups 2 and 3 were significant. The number of papillomas per mouse was 4.2 ± 0.5 (Group 1), 2.3 ± 0.8 (Group 2), and 3.4 ± 0.6 (Group 3). The decrease in Group 2 was significant. A single 5‐mg dose of garlic oil maximally inhibited DMBA‐induced epidermal DNA synthesis by 86% when applied two hours before the carcinogen. Two‐stage promotion in DMBA‐initiated Sencar mice was achieved by twice‐weekly applications of 8.5 nmol of 12‐O‐tetradecanoytphorbol‐13‐acetate (TPA) for 2 weeks followed by twice‐weekly applications of 8.5 nmol of mezereinfor 18 weeks. The oils were applied 30 minutes after each promotion by TPA or mezerein. Single doses of 1 mg onion or garlic oil inhibited the first and second stages of promotion.

The groups used were control (Group 1), garlic oil applied after stage 1 (Group 2), onion oil applied after stage 1 (Group 3), propenyl sulfide applied after stage 1 (Group 4), garlic oil applied after stage 2 (Group 5), onion oil applied after stage 2 (Group 6), and propenyl sulfide applied after stage 2 (Group 7). The percent of mice with papillomas was significantly decreased by all agents in Groups 2–7. The data are 81, 83, 91, 68, 96, and 86, respectively. The number of papillomas per mouse was significantly reduced by onion and garlic oils but not by propenyl sulfide. The data are 9.4 ± 0.8, 6.3 ± 0.7, 7.4 ± 0.5, 9.2 ± 1.2, 3.7 ± 0.9, 6.2 ± 0.6, and 9.1 ± 1.4 for Groups 1–7, respectively. Onion and garlic oils inhibited the TPA‐stimulated DNA synthesis when given as single doses of 5 mg one hour before TPA. The inhibition by garlic oil was most effective when given one hour before TPA but was evident when given from two hours before to two hours after TPA. These results, and those of others (AS Sadhana, Cancer Lett, 40, 193–197, 1988), who obtained inhibition of initiation, indicate that onion and garlic oils inhibit all stages of mouse skin tumorigenesis. Inhibition of DNA synthesis may be part of the mechanisms involved.