Garlic's use in medicine predates modern civilization. According to the University of Maryland Medical Center, records have traced the use of garlic to the ancient Egyptians, who used it as food and medicine during the time of the pharaohs. Although most scientific studies have investigated the effects of garlic bulb, the leaves offer a similar profile of benefits and risks. Allicin, the primary active constituent of garlic bulb, appears in lower amounts in the leaves or chives of the plants. Consult your health care provider before using any medicinal herb.
According to the National Institutes of Health, garlic can lower both total cholesterol and LDL, or "bad", cholesterol, over the course of 4 to 12 weeks. Although the organization grants a "B" rating to this use-- meaning that there is good scientific evidence-- the NIH notes that this use remains controversial an ultimately unproven. More studies are needed to evaluate the efficacy of garlic as a treatment for high cholesterol, and to determine whether leaves provide the same scope of benefits compared to the plant's fleshy bulb.
Heart Disease Prevention
Garlic leaves may help to defend against several serious forms of cardiovascular disease. According to the UMMC, allicin in garlic may help to prevent hypertension, blood clots, hardening of the arteries and heart attack. Additionally, garlic leaf's antioxidant capacity can prevent free radical damage to cholesterol, a risk factor for several serious illnesses.
The regular use of garlic leaves may help to prevent some forms of cancer. The UMMC reports a 30 percent reduction in colorectal cancer risk among people who ingest garlic regularly. Garlic in the diet can also defend against breast, prostate, stomach and throat cancer. More studies are needed to evaluate garlic leaf's role in cancer prevention. If you are undergoing treatment for cancer or have a history of the condition, talk to your health care provider about the benefits of garlic as a complementary treatment.
The NIH regards body odor as the primary side effect associated with garlic. Allicin, a pungent-smelling sulfur compoudn found in garlic leaves, tends to emanate from sweat glands and breath. Many garlic leaf users experience halitosis and persistent body odor after taking the supplements. Although garlic leaves contain a lower concentration of malodorous compounds than garlic bulb, body odor remains a common complaint.
According to the NIH, some people develop a runny nose while using garlic supplements. Garlic, along with onion and other related plants, contains compounds that may be irritating to the eyes and sinuses. Heat neutralizes some of these compounds and may help to may help to mitigate some of the irritating effects associated with raw garlic leaves.
Changes in Body Temperature
According to the NIH, some people using garlic supplements experience fluctuations in body temperature. Garlic leaf can cause fevers, chills or hot flashes. Rarely, this may be accompanied by other uncomfortable symptoms such as dizziness, vertigo or headache. Consult a qualified health care provider if these symptoms persist.