Garlic is a popular addition to a wide variety of dishes, but this member of the onion genus, allium, is best for health when eaten raw. Garlic is a great source of nutrients – selenium, manganese, vitamin B6 and calcium, among them – but it's garlic's allium content that scientists are crediting with the bulb's more famous (and provable) healing properties. For example, in the article 'Allicin and Other Functional Active Components In Garlic: Health Benefits and Bioavailability,' published in the International Journal of Food Properties (April 26, 2007), “Recent studies identify the active functional components providing the medicinal benefits, as well as their mechanisms of action including the best possible ways to consume garlic. Allicin (diallyl-thiosulfinate) is one of the major organosulfur compounds in garlic considered to be biologically active.” And, like most nutrients, allium is negatively affected by heat.
Anecdotal and historical evidence would suggest that garlic is excellent for relieving and preventing a wide array of ailments, but garlic has only been scientifically studied for its effect on a handful of ailments. Below are a few of the most researched benefits of consuming garlic:
- Protects heart and arterial health
- Protects cell integrity
- Improves immune system response
- Acts as an antibacterial agent
- Reduces the formation of blood clots
- Helps normalize blood glucose levels
- Helps the body excrete heavy metals
The results of the study 'A meta-analysis of the effect of garlic on blood pressure', published in the Journal of Hypertension (April 1994), demonstrated that Garlic can lower blood pressure. “Eight trials were identified (all using the same dried garlic powder preparation (Kwai) with data from 415 subjects included in the analyses. Only three of the trials were specifically conducted in hypertensive subjects, and many had other methodological shortcomings. Of the seven trials that compared the effect of garlic with that of placebo, three showed a significant reduction in systolic blood pressure (SBP) and four in diastolic blood pressure (DBP). The overall pooled mean difference in the absolute change (from baseline to final measurement) of SBP was greater in the subjects who were treated with garlic then in those treated with placebo. For DBP the corresponding reduction in the garlic-treated subjects was slightly smaller”.
Later studies not only corroborated the 1994 study's blood pressure results, but showed that garlic has the ability to neutralize other heart damaging conditions, protect cell integrity, improve immune system response and more. According to 'Garlic: Nature's Protection Against Physiological Threats', published in Critical Reviews in Food Science and Nutrition (May 28, 2009), “Extensive research work has been carried out on the health promoting properties of garlic, often referred to its sulfur containing metabolites i.e. allicin and its derivatives. [...] Its components/formulations can scavenge free radicals and protect membranes from damage and maintains cell integrity. It also provides cardiovascular protection mediated by lowering of cholesterol, blood pressure, anti-platelet activities, and thromboxane formation thus providing protection against atherosclerosis and associated disorders. [...] Garlic could be useful in preventing the suppression of immune response associated with increased risk of malignancy as it stimulates the proliferation of lymphocytes, macrophage phagocytosis, stimulates the release of interleukin-2, tumor necrosis factor-alpha and interferon-gamma, and enhances natural killer cells.” FYI, natural killer cells are an important part of the immune system, because they are the body's first line of defense against mutated and viral-infected cells, that may go undetected by less sensitive immune system cells.
'Garlic: Health benefits and actions', published in the journal BioMedicine (March 2012), supports the findings of previous garlic studies, in addition to suggesting that anecdotal accounts of garlic being able to arrest the growth of bacteria, reducing the formation blood clots, and helping to normalize blood glucose levels are also accurate. “Recent years have seen an increasing emphasis on foods and food components in disease prevention. Garlic (Allium sativum L.), one of the best-researched herbal remedies, holds a unique position in history, traditionally employed to treat infection, colds, diabetes, heart disease, and a host of other disorders. Clinically, it has been evaluated for lowering blood pressure, cholesterol, and glucose concentration, as well as for the prevention of arteriosclerosis and cancer. Epidemiologically, garlic consumption inversely correlates with the risk of oral, stomach, esophageal, colon, and prostate cancers. In addition, the biological activities of garlic, including antibacterial, antithrombotic, antioxidant, immunomodulatory, and antidiabetic actions and modulation of drug metabolism, have been extensively investigated.”
Garlic's ability to assist the body in excreting heavy metal toxins from the system was verified in a rat study, published in the December 1987 edition of the Journal of Korean Medical Science. “When garlic (Allium sativum) was administered to rat per os simultaneously with cadmium, methylmercury and phenylmercury to detect the protective effect against the heavy metal poisoning, accumulation of heavy metals in liver, kidneys, bone and testes were decreased, and histopathological damages and the inhibition of serum alkaline phosphatase activities by heavy metals were reduced. Such effect of garlic was not shown in the 1.7% garlic treated group and most remarkable in the 6.7% garlic treated group. The protective effect of garlic was superior to those of 2,3 dimercapto-1-propanol (BAL) and D-penicillamine (PEN), and nearly similar to those of 2,3-dimercaptosuccinic acid (DMSA) and N-acetyl-DL-penicillamine (APEN), the current remedies, while garlic was not effective as a curative agent for heavy metal poisoning. The excretion of cadmium was enhanced, more through feces than urine by garlic but the effect to the urinary excretion of cadmium was not significant comparing with DMSA or APEN when cadmium was ip injected in the first 3 days during the 12 days of oral administration of DMSA, APEN or garlic.” To clarify, N-acetyl-DL-penicillamine is a common remedy for mercury poisoning, Dimercapto-1-propanol is a chelator of heavy metals and is used as an antidote to a variety of heavy metals (including arsenic and gold), D-penicillamine is an anti-rheumatoid drug used to inhibit excessive copper accumulation in the body, and 2,3-dimercaptosuccinic acid is used to counteract lead poisoning. While garlic was not considered effective as a “curative agent” for heavy metal poisoning, its “protective effect” was considered superior to that of the four leading heavy metal intoxication remedies used by physicians today.
The History of Garlic
Garlic is one of the earliest documented examples of herbs used as medicine, to both treat and prevent illness. Hippocrates, who penned more than seventy volumes describing, in a detailed and scientific manner, the many diseases that he encountered and his methods of treatment, wrote much about garlic, and prescribed it for a variety of ills. The “father of modern medicine” was not alone in his admiration for the bulb; other ancient physicians – Galen, Dioscorides, Pliny the Elder and, more recently, Louis Pasteur and Albert Schweitzer – also found garlic useful for a variety of complaints.
There's evidence that garlic was used medicinally as early as 3000BC. According to the article 'Historical perspective on the use of garlic', published in the Journal of Nutrition (March 2001). “There are Biblical references to garlic. Ancient medical texts from Egypt, Greece, Rome, China and India each prescribed medical applications for garlic. In many cultures, garlic was administered to provide strength and increase work capacity for laborers. Hippocrates, the revered physician, prescribed garlic for a variety of conditions. Garlic was given to the original Olympic athletes in Greece, as perhaps one of the earliest "performance enhancing" agents. It is of interest that cultures that developed without contact with one another came to similar conclusions about the efficacy of garlic.”
While modern scientists have yet to study garlic's medicinal effect on even a quarter of the various afflictions that the plant was long used to treat, it's good to know that those they have studied, have been scientifically validated. Hopefully, such validation will encourage further study and a desire to better understand the plant's medicinal properties. In the meantime, to gain all of the health benefits garlic has to offer, eat it raw, peeling and cutting each clove shortly before eating, to preserve as much of its biologically active nutrients as possible.
A guest blog post by holistic writer Andrea Lewis. Consult with your doctor before making any medical or health changes.