Garlic (Allium sativum) is a popular vegetable with a variety of medicinal properties.
Raw or aged garlic reliably reduces total cholesterol and Low-density Lipoprotein (LDL-C), while increasing High-density Lipoprotein (HDL-C). Garlic also provides a variety of anti-cancer properties. Eating garlic daily (10g or more) is associated with a significantly reduced risk of prostate, colon, and stomach cancer. It can also induce fat loss and adrenaline secretion, though in a minor way. Garlic supplements appear to reduce blood pressure (especially in people with hypertension). Garlic seems to mildly and unreliably reduce triglyceride levels.
Garlic’s main mechanism involves a molecule called alliin. When garlic is physically disturbed through chewing, slicing, or crushing, it releases an alliin metabolite: allicin. Allicin turns into a variety of fat and water soluble sulfur-containing compounds. In fact, these compounds are so volatile, they give off hydrogen sulfide, which is part of garlic’s unmistakable smell and taste. By tapping into the hydrogen sulfide signaling system, garlic relaxes the blood vessels and provides a variety of health benefits. Garlic also uses the hydrogen sulfide signaling system to exert its anti-cancer effects.
Garlic can be taken in several forms: fresh/raw garlic, aged garlic, garlic oil and boiled garlic. Boiled garlic prevents alliin from creating its sulfur-containing metabolites, and garlic oil, while effective as a supplement, has a potentially high level of toxicity. All of the beneficial components of garlic can be found in fresh garlic, which makes aged garlic supplements and fresh garlic the two best ways to supplement garlic. Garlic should be crushed, sliced, or chewed (prior to cooking) in order to ensure maximum allicin production, since allicin is responsible for many of garlic’s beneficial effects.
Most studies on garlic use a dosage range of 600-1,200mg a day, usually divided into multiple doses. The minimum effective dose for raw garlic is a single segment of a garlic bulb (called a clove), eaten with meals two or three times a day.
Aged garlic is a popular form of garlic to use for supplementation, since it does not have a fresh garlic scent. Garlic supplementation can also be done through food alone, though side-effects will include strong garlic-scented breath.
Microwaving garlic will partially destroy the beneficial components of the vegetable, but grilling and roasting will not damage the bioactives, provided the garlic is sliced or crushed beforehand. Garlic can be toxic if consumed in very high doses, so supplementation should never go beyond the following maximum dosages:
- 17.0 grams for a 150lb person
- 22.7 grams for a 200lb person
- 28.4 grams for a 250lb person