Garlic for food and medicine - a brief history
Garlic has been used all over the world for thousands of years. Records indicate that garlic was in use when the Giza pyramids were built, about five thousand years ago.
Rid S. Rivlin wrote in the Journal of Nutrition1 that the ancient Greek physician Hippocrates (circa. 460-370 BC), known today as "the father of Western medicine", prescribed garlic for a wide range of conditions and illnesses. Hippocrates promoted the use of garlic for treating respiratory problems, parasites, poor digestion and fatigue.
According to the National Library of Medicine3, part of the NIH (National Institutes of Health), USA, garlic is widely used for several conditions linked to the blood tem and heart, including atherosclerosis (hardening of the arteries), high cholesterol, heart attack, coronary heart disease and hypertension.
benefits of garlic
Lung cancer risk
People who ate raw garlic at least twice a week had a 44 lower risk of developing lung cancer, according to a study carried out at the Jiangsu Provincial Center for Disease Control and Prevention in China.
The researchers, who published their study in the journal Cancer Prevention Research, had carried out face-to-face interviews with 1,424 lung cancer patients as well as 4,543 healthy individuals. They were asked about their diet and lifestyle habits, which included questions on their smoking habits and how often they ate garlic.
The study authors wrote "Protective association between intake of raw garlic and lung cancer has been observed with a dose-response pattern, suggesting that garlic may potentially serve as a chemo-preventive agent for lung cancer."
Organo-sulfur compounds found in garlic have been identified as effective in destroying the cells in glioblastomas, a type of deadly brain tumor.
Scientists at the Medical University of South Carolina reported in the journal Cancer that three pure organo-sulfur compounds from garlic - DAS, DADS and DATS - "demonstrated efficacy in eradicating brain cancer cells, but DATS proved to be the most effective".
Co-author, Ray Swapan, Ph.D., said "This research highlights the great promise of plant-originated compounds as natural medicine for controlling the malignant growth of human brain tumor cells," Ray said. "More studies are needed in animal models of brain tumors before application of this therapeutic strategy to brain tumor patients."
Women whose diets were rich in allium veges had lower levels of osteoarthritis, a team at King&39s College London and the University of East Anglia, both in England, reported in the journal BMC Musculoskeletal Disorders. Examples of allium veges include garlic, leeks, shallots, onions and rakkyo.
The study authors said their findings not only highlighted the possible impact of diet on osteoarthritis outcomes, but also demonstrated the potential for using compounds that exist in garlic to develop treatments for the condition.
The long-term study, involving more than 1,000 healthy female twins, found that those whose dietary habits included plenty of fruit and veges, "particularly alliums such as garlic", had fewer signs of early osteoarthritis in the hip joint.
Potentially a powerful antibiotic:
Diallyl sulfide, a compound in garlic, was 100 times more effective than two popular antibiotics in fighting the Campylobacter bacterium, according to a study published in the Journal of Antimicrobial Chemotherapy.
The Campylobacter bacterium is one of the most common causes of intestinal infections.
Senior author, Dr. Xiaonan Lu, from Washington State University, said "This work is very exciting to me because it shows that this compound has the potential to reduce disease-causing bacteria in the environment and in our food supply."
Diallyl trisulfide, a component of garlic oil, helps protect the heart during cardiac surgery and after a heart attack, researchers at Emory University School of Medicine found. They also believe diallyl trisulfide could be used as a treatment for heart failure.
Hydrogen sulfide gas has been shown to protect the heart from damage. However, it is a volatile compound and difficult to deliver as therapy. Hence, the scientists decided to focus on diallyl trisulfide, a garlic oil component, as a safer way to deliver the benefits of hydrogen sulfide to the heart.
In animal experiments using laboratory mice, the team found that after a heart attack the mice that had received diallyl sulfide had 61 less heart damage in an area of risk, compared to the untreated mice.
The team presented their findings at the American Heart Association (AHA) Scientific Sessions conference in Orlando, Florida in November, 2011.
In another study, published in the Journal of Agricultural and Food Chemistry, scientists found that garlic oil may help protect diabetes patients from cardiomyopathy.
Cardiomyopathy is the leading cause of death among diabetes patients. It is a chronic disease of the myocardium (heart muscle), which is abnormally thickened, enlarged and/or stiffened.
The team fed diabetic laboratory rats either garlic oil or corn oil. Those fed the garlic oil experienced significantly more changes associated with protection against heart damage, compared to the corn oil fed animals.
The study authors wrote "In conclusion, garlic oil possesses significant potential for protecting hearts from diabetes-induced cardiomyopathy."
Human studies will need to be performed to determine whether they confirm the results of this study.
High cholesterol and high blood pressure:
Researchers at Ankara university set out to determine what the effects of garlic extract supplementation might be on the blood lipid (fat) profile of patients with high blood cholesterol. Their study was published in the Journal of Nutritional Biochemistry5.
The study involved 23 volunteers, all with high cholesterol 13 of them also had high blood pressure. They were divided into two groups-
The high-cholesterol normotensive group (normal blood pressure)
The high-cholesterol hypertensive group (high blood pressure)
They took garlic extract supplements for four months and were regularly checked for blood lipid parameters, as well as kidney and liver function.
At the end of the four months the researchers concluded "...garlic extract supplementation improves blood lipid profile, strengthens blood antioxidant potential, and causes significant reductions in tolic and diastolic blood pressures. It also leads to a decrease in the level of oxidation product (MDA) in the blood samples, which demonstrates reduced oxidation reactions in the body."
In other words, the garlic extract supplements reduced high cholesterol levels, and also blood pressure in the patients with hypertension. The scientists added that theirs was a small study - a larger one needs to be carried out.
Doctors at the Department of Urology, China-Japan Friendship Hospital, Beijing, China, carried out a study evaluating the relationship between Allium vege consumption and prostate cancer risk.
They gathered and analyzed published studies up to May 2013 and reported their findings in the Asian Pacific Journal of Cancer Prevention6.
The study authors wrote "Allium veges, especially garlic intake, are related to a decreased risk of prostate cancer".
The team also commented that as there were not that many studies, they recommend further well-designed prospective studies be carried out to confirm their findings.
Alcohol-induced liver injury:
Alcohol-induced liver injury (ethanol-induced liver injury) is caused by the long-term over-consumption of alcoholic beverages.
Scientists at the Institute of Toxicology, School of Public Health, Shandong University, China, wanted to determine whether diallyl disulfide (DADS), a garlic-derived organosulfur compound, might have protective effects against ethanol-induced oxidative stress.
Their study was published in Biochimica et Biophysica Acta (BBA)7.
The researchers concluded that DADS may help protect against ethanol-induced liver injury.
Preterm (premature) delivery
Microbial infections during pregnancy raise a woman&39s risk of preterm delivery, several studies have demonstrated. Scientists at the Division of Epidemiology, Norwegian Institute of Public Health, wanted to find out what impact foods might have on antimicrobial infections and preterm delivery risk.
The study and its findings were published in the Journal of Nutrition8.
Ronny Myhre and colleagues concentrated on the effects of Alliums and dried fruits, because a literature search had identified these two foods as showing the greatest promise for reducing preterm delivery risk.
The study authors concluded "Intake of food with antimicrobial and prebiotic compounds may be of importance to reduce the risk of spontaneous PTD. In particular, garlic was associated with overall lower risk of spontaneous PTD."
The common cold
Julia Fashner, MD Kevin Ericson, MD and Sarah Werner, DO, at St. Joseph Family Medicine Residency, Mishawaka, Indiana, carried out a study titled "Treatment of the Common Cold in Children and Adults", published in American Family Physician9.
They reported that "Prophylactic use of garlic may decrease the frequency of colds in adults, but has no effect on duration of symptoms." Prophylactic use means using it with the intention of preventing disease.