Onion (Allium cepa) and garlic (Allium sativum) are among the oldest cultivated plants. They are used both as a food and for medicinal applications. Allium bulb plants are a rich source of several phytonutrients recognized as important elements of the Mediterranean diet, but are also used in the treatment and prevention of a number of diseases, including cancer, coronary heart disease, obesity, hypercholesterolemia, diabetes type 2, hypertension, cataract and disturbances of the gastrointestinal tract (e.g. colic pain, flatulent colic and dyspepsia). These activities are related to the thiosulfinates, volatile sulfur compounds, which are also responsible for the pungent of these vegetables. Besides these low-molecular weight compounds, onion and garlic are characterized by more polar compounds of phenolic and steroidal origin, often glycosilated, showing interesting pharmacological properties. These latter compounds, compared to the more studied thiosulfinates, present the advantages to be not pungent and more stable to cooking. Eating allium sativum can cause bad breath.
Eat raw garlic and onions, heating can destroy some of
the beneficial substances
J Agric Food Chemistry. 2012. Effect of processing and cooking conditions on onion (Allium cepa) induced antiplatelet activity and thiosulfinate content. Allium vegetables serve as sources of antiplatelet agents that may contribute to the prevention of cardiovascular disease. However, onion and garlic, the major Allium species, are usually cooked before consumption. Here, we examined the effect of cooking on onion in vitro antiplatelet activity (IVAA). Two different cooking systems (convection oven and microwaves) and several time-temperature variables were tested on whole bulbs, quarters of bulbs, and completely crushed bulbs, monitoring the degradation of sulfur antiplatelet compounds (e.g., thiosulfinates) by analysis of pyruvate levels. Although heating was, in general, detrimental for onion IVAA, the extent of this effect varied greatly, from unaffected antiplatelet activity (AA) (i.e., similar to raw onion) to a complete lost of activity, depending upon the manner in which onions were prepared prior to heating, the cooking method, and the intensity of the heat treatment. "Whole", "quarters", and "crushed" onions lost their IVAA after 30, 20, and 10 min of oven heating, respectively. The longer retainment of AA in intact bulbs was attributed to a later alliinase inactivation. Proaggregatory effects observed in samples subjected to the most intense oven and microwave heat treatments suggest that extensively cooked onions may stimulate rather than inhibit platelet aggregation.
Blood pressure, hypertension
Br J Nutrition. 2015. Effects of a quercetin-rich onion skin extract on 24 h ambulatory blood pressure and endothelial function in overweight-to-obese patients with (pre-)hypertension: a randomised double-blinded placebo-controlled cross-over trial. The polyphenol quercetin may prevent heart disease due to its antihypertensive and vasorelaxant properties. We investigated the effects of quercetin after regular intake on blood pressure (BP) in overweight-to-obese patients with pre-hypertension and stage I hypertension. In addition, the potential mechanisms responsible for the hypothesised effect of quercetin on BP were explored. Subjects (n 70) were randomised to receive 162 mg/d quercetin from onion skin extract powder or placebo in a double-blinded, placebo-controlled cross-over trial with 6-week treatment periods separated by a 6-week washout period. Supplementation with 162 mg/d quercetin from onion skin extract lowers ABP in patients with hypertension, suggesting a cardioprotective effect of quercetin. The mechanisms responsible for the BP-lowering effect remain unclear.
Allium sativum and cancer
Diallyl disulfide, an important component of garlic has been demonstrated to exert a potential chemopreventive activity against human cancers. Diallyl disulfide inhibits proliferation of both androgen dependent and independent prostate cancer cells in vitro.
Those who eat garlic and onion have a lesser risk for several cancers include cancer of the oral cavity, esophageal cancer, prostate cancer, colon cancer, and other cancers.
Reduce cancer risk
There appears to be an inverse correlation between allium consumption and cancer.
Onion and garlic use and human cancer
American Journal of Clinical Nutrition, 2006. From the Istituto di Ricerche Farmacologiche "Mario Negri," Milan, Italy.
Interest in the potential benefits of allium vegetables, in particular, onion Allium cepa and garlic Allium sativum, has its origin in antiquity. We investigated the role of allium vegetables in the etiology of various neoplasms. 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. Consumption of onions varied between 0–14 and 0–22 portions per week among cases and controls, respectively. 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.
Cancer Prev Res (Phila). 2015. 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. Epidemiological 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 biological 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.
Diabetes mellitus, blood sugar
Nutrition. 2014. Spice plant Allium cepa: dietary supplement for treatment of type 2 diabetes mellitus. Diabetes mellitus (DM) is associated with significant morbidity and mortality and its prevalence is increasing worldwide. Although conventional antidiabetic agents are known to ameliorate the symptoms of diabetes, they also may cause adverse effects. The purpose of this review was to organize and discuss various studies that have been previously conducted indicating the efficacy of Allium cepa in DM.
Effective against germs, microbes, bacteria, fungi, viruses and microorganisms
Microbes Infect. 1999;
Antimicrobial properties of allicin from garlic.
Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel.
Allicin, one of the active principles of freshly crushed garlic homogenates, has a variety of antimicrobial activities. Allicin in its pure form was found to exhibit i) antibacterial activity against a wide range of Gram-negative and Gram-positive bacteria, including multidrug-resistant enterotoxicogenic strains of Escherichia coli; ii) antifungal activity, particularly against Candida albicans; iii) antiparasitic activity, including some major human intestinal protozoan parasites such as Entamoeba histolytica and Giardia lamblia; and iv) antiviral activity. The main antimicrobial effect of allicin is due to its chemical reaction with thiol groups of various enzymes, e.g. alcohol dehydrogenase, thioredoxin reductase, and RNA polymerase, which can affect essential metabolism of cysteine proteinase activity involved in the virulence of E. histolytica.
Medieval recipe for infection
The recipe calls for two species of Allium (garlic and onion or leek), wine and oxgall (bile from a cow's stomach) to be brewed in a brass vessel for nine days. The result showed a potion to be a very powerful antibiotic.
Prostate enlargement, BPH
Phytother Res. 2016. Anti-Proliferation Effects of Garlic (Allium sativum) on the Progression of Benign Prostatic Hyperplasia.
The onion species are divided into three groups: the Cepa Group includes the typical bulbing onions which have a single enlarged bulb, and are propagated from seeds; the Aggregatum Group includes shallots, multiplier onions, and potato onions, which do not produce seeds; the Proliferum Group includes top-setting onions, walking onions, Egyptian onions and tree onions.
Onion oil may exert chemopreventive action by inducing cell cycle arrest and apoptosis in tumor cells. Protective effects of Allium vegetables against cancers have been shown extensively in experimental animals and epidemiologic studies. Researchers investigated cell proliferation and the induction of apoptosis by onion oil extracted from Allium cepa, a widely consumed Allium vegetable, in human lung cancer A549 cells. Analysis suggested that propyl sulfides but not allyl sulfides are major sulfur-containing constituents of onion oil. Onion oil significantly induced apoptosis. It also caused cell cycle arrest.
Crit Rev Food Sci Nutr. 2015. Onion: nature protection against physiological threats. Onion (Allium cepa L.) is found in various regions of Europe, North America, Asia, and Africa. It is one of the classic examples of Allium species used not only for culinary preparations but also for medicinal purposes. Onion with a variety of purposes is often used as a raw material in many dishes and accepts almost all of the traditions and culture. Owing to its storage characteristics and durability of shipping, onions have been traded more widely than most vegetables. The pungent fractions of garlic are mostly sulfur-containing moieties while its two chemical groups have marked effect on human health. These are flavonoids and ALK (EN)-based cysteine sulfoxides (ACSOs). Compounds in onions have been reported with a range of health benefits, including anticancer properties, antiplatelet activity, antithrombotic activity, antiasthmatic activity, and antibiotic effects.
Cholesterol and heart health
Consumption of onions increases HDL cholesterol according to studies in rodents.
I would like to know if there is any allergy in eating raw white onions and what could be the symptoms? I ate 1 per day for 2 days. This morning i felt mild tickly feeling from chin radiating to parathyroid area.
Some people do have an allergy to eating onions. Symptoms could include skin hives, Itching, bloating, gas, headaches or others allergic symptoms.
Aphrodisiac and sexual enhancement
Exp Biol Med. Dec 3 2013. Fresh onion juice enhanced copulatory behavior in male rats with and without paroxetine-induced sexual dysfunction. Onion (Allium cepa) is one of the most commonly cultivated species of the family Liliaceae, and has long been used in dietary and therapeutic applications. Treatment with fresh onion juice has been reported to promote testosterone production in male rats. Testosterone is the male sex hormone responsible for enhancing sexual libido and potency. This study aimed to investigate the effects of onion juice on copulatory behavior of sexually potent male rats and in male rats with paroxetine-induced sexual dysfunction. Sexually experienced male rats were divided into seven groups: a control group, three onion juice-treated groups, a paroxetine-treated group, and two groups treated with paroxetine plus different doses of onion juice. At the end of the treatments, sexual behavior parameters and testosterone levels were measured and compared among the groups. Administration of onion juice significantly reduced mount frequency and latency and increased the copulatory efficacy of potent male rats. In addition, administration of onion juice attenuated the prolonged ejaculatory latency period induced by paroxetine and increased the percentage of ejaculating rats. Serum testosterone levels increased significantly by onion juice administration. However, a significant reduction in testosterone because of paroxetine therapy was observed. This reduction was restored to normal levels by administration of onion juice. This study conclusively demonstrates that fresh onion juice improves copulatory behavior in sexually potent male rats and in those with paroxetine-induced sexual dysfunction by increasing serum testosterone levels.
Allium Cepa and quercetin
Quercetin content in field-cured onions effects of cultivar, lifting time, and nitrogen fertilizer level.
J Agric Food Chem. 2006. Swedish University of Agricultural Sciences, Alnarp, Sweden.
Variation in quercetin content was investigated in field-cured onions that had been supplied with different nitrogen fertilizer levels and lifted at different developmental stages. Quercetin content varied significantly between years and was well correlated to global radiation in August. Field curing generally resulted in significant increases in quercetin content compared to levels at lifting. Nitrogen fertilizer level did not affect quercetin content of allium cepa, suggesting that nitrogen leakage from soil may be minimized without effects on flavonol content.
Common name is Giant Allium
Allium flower - globemaster
The ornamental flowering alliums, although relatives of plain old garlic, are much more impressive bloomers. Nor are you restricted to white blooms. Globemaster allium, for instance, bears striking purple blossoms and
is quite attractive.
Allium vegetables • onion • Allium cepa • garlic • Allium sativum • tomato • diet • risk factors • oral cancer • pharyngeal cancer • esophageal cancer • colorectal cancer • laryngeal cancer • breast cancer • ovarian cancer • prostate cancer • renal cell cancer
I have halitosis even when I don't eat allium products. What else causes this condition?
See halitosis for a full discussion.