|
|
| |
|
Garlic |
Health Benefits and Uses of Garlic
Garlic health benefits and medicinal properties have long been known . Garlic has long been considered a herbal "wonder drug", with a reputation for preventing everything from the common cold and flu to the Plague! It has been used extensively in herbal medicine (phytotherapy, sometimes spelt phitotherapy). Raw garlic is used by some to treat the symptoms of acne and there is some evidence that it can assist in managing high cholesterol levels. It can even be effective as a natural mosquito repellent.
In general, a stronger tasting clove of garlic has more sulphur content and hence more medicinal value. Some people have suggested that organically grown garlic tends towards a higher sulphur level and hence greater benefit to health. In my experience it certainly tastes better and I buy organic whenever possible.
Some people prefer to take garlic supplements. These pills and capsules have the advantage of avoiding garlic breath.
Healthy Antioxidant:
Studies have shown that garlic - especially aged garlic - can have a powerful antioxidant effect. Antioxidants help to protect the body against damaging "free radicals".
Health Effects of Garlic
Garlic has long been used medicinally, most recently for its cardiovascular, antineoplastic, and antimicrobial properties. Sulfur compounds, including allicin, appear to be the active components in the root bulb of the garlic plant. Studies show significant but modest lipid-lowering effects and antiplatelet activity. Significant blood pressure reduction is not consistently noted. There is some evidence for antineoplastic activity and insufficient evidence for clinical antimicrobial activity. Side effects generally are mild and uncommon. Garlic appears to have no effect on drug metabolism, but patients taking anticoagulants should be cautious. It seems prudent to stop taking high dosages of garlic seven to 10 days before surgery because garlic can prolong bleeding time.
Uses and Efficacy:
Garlic has been studied extensively in vitro, in animal and human clinical trials, and in epidemiologic evaluations for its multiple medicinal properties. The quality of human trials has been variable, making comparisons among the trials difficult. Some trials are not well blinded; some are only of short duration; some have only small numbers of patients; and many are not well controlled. In addition, many different garlic preparations have been used, with unpredictable release of active ingredients.
ANTIHYPERTENSIVE EFFECTS:
The antihypertensive effects of garlic have been studied but remain controversial. In a 1994 meta-analysis15 assessing the effect of garlic on hypertension, three trials showed significant reductions in systolic blood pressure (7.7 mm Hg greater reduction), and four trials showed reductions in diastolic blood pressure (5 mm Hg greater reduction) with garlic treatment compared with placebo. In a more recent meta-analysis, 23 placebo-controlled trials were analyzed. Only three trials showed a statistically significant reduction in diastolic blood pressure (2 to 7 percent), and one showed a statistically significant reduction in systolic blood pressure (approximately 3 percent) in patients treated with garlic compared with placebo.
OTHER CARDIOVASCULAR-RELATED EFFECTS:
A recent review10 of 10 trials assessing the effect of garlic on thrombotic risk showed modest but significant decreases in platelet aggregation with garlic compared with placebo, but mixed results on fibrinolytic activity and plasma viscosity were reported. The same review analyzed 12 trials of garlic supplementation in diabetic and nondiabetic adults; only one trial showed a significant decrease in glucose levels in nondiabetic patients who took garlic when compared with placebo. Atherosclerotic plaque volume reduction in humans also has been noted in two trials comparing garlic treatment with placebo. One observational study19 showed that regular garlic powder intake weakened age- and pressure-related increases in aortic stiffness.
ANTINEOPLASTIC EFFECTS:
Epidemiologic evidence, primarily from case-control and some cohort studies, has shown a decreased risk of stomach and colon cancer with the high consumption of garlic and other alliums vegetables (e.g., onions, leeks, shallots, chives), but many of these studies were not well controlled. In one cohort study, garlic supplementation did not confer the same protective benefit, but there are no studies assessing the use of particular garlic supplements and cancer incidence.
ANTINEOPLASTIC EFFECTS:
Epidemiologic evidence, primarily from case-control and some cohort studies, has shown a decreased risk of stomach and colon cancer with the high consumption of garlic and other allium vegetables (e.g., onions, leeks, shallots, chives), but many of these studies were not well controlled. In one cohort study, garlic supplementation did not confer the same protective benefit, but there are no studies assessing the use of particular garlic supplements and cancer incidence.
Contraindications, Adverse Effects, Interactions:
The ingestion of one to two cloves of raw garlic per day is considered safe in adults. The most common side effect of ingested garlic is breath and body odor. Consumption of excessive amounts of raw garlic, especially on an empty stomach, can cause gastrointestinal upset, flatulence, and changes in the intestinal flora. There have been reports of allergic dermatitis, burns, and blisters from topical application of raw garlic.
Garlic appears to have no effect on drug metabolism,22 although recent studies23,24 in healthy volunteers show conflicting results related to garlic's effect on protease inhibitor pharmacokinetics. It has been suggested that patients taking anticoagulants use caution when taking garlic because of its antithrombotic properties.10,22 It seems prudent to stop taking high dosages of garlic seven to 10 days before surgery because garlic can prolong bleeding time and has been associated (in one case report) with spontaneous spinal epidural hematoma.
Contraindications, Adverse Effects, Interactions:
The ingestion of one to two cloves of raw garlic per day is considered safe in adults. The most common side effect of ingested garlic is breath and body odor. Consumption of excessive amounts of raw garlic, especially on an empty stomach, can cause gastrointestinal upset, flatulence, and changes in the intestinal flora. There have been reports of allergic dermatitis, burns, and blisters from topical application of raw garlic.
Garlic appears to have no effect on drug metabolism,22 although recent studies23,24 in healthy volunteers show conflicting results related to garlic's effect on protease inhibitor pharmacokinetics. It has been suggested that patients taking anticoagulants use caution when taking garlic because of its antithrombotic properties.10,22 It seems prudent to stop taking high dosages of garlic seven to 10 days before surgery because garlic can prolong bleeding time and has been associated (in one case report) with spontaneous spinal epidural hematoma.
|
|
|
|
|
