Garlic and allicin (cancer prevention)
Garlic, a widely used culinary ingredient, contains a compound called allicin that has garnered interest for its potential cancer prevention properties. Historically, garlic has been valued for its medicinal benefits, particularly in addressing digestive and circulatory issues. Research into garlic and its allyl sulfur components began in the mid-twentieth century, leading to the identification of allicin as a significant chemical with possible cancer-fighting abilities. Studies have explored garlic's effects on various types of cancer, including gastric, colon, breast, prostate, and throat cancers, with some laboratory results in animal models showing promising outcomes.
Despite these encouraging findings, the efficacy of garlic and allicin in preventing or treating cancer in humans remains inconclusive, as most studies have not yet undergone rigorous clinical trials. While people with cancer often incorporate garlic into their diets for its perceived immune-boosting and health benefits, there are also potential side effects and interactions with medications that individuals should consider. Overall, while garlic and allicin may contribute to a healthy diet, their definitive role in cancer prevention has not been scientifically established, encouraging further research in this area.
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Garlic and allicin (cancer prevention)
Also known as:Allium sativum
Definition: Garlic (Allium sativum) is a nontoxic plant bulb in the Allium genus, which includes onions, leeks, and shallots. Allicin, a chemical created by enzymes when garlic is processed, produces garlic’s odor and taste.
Cancers treated or prevented:Gastric (stomach) cancer, colon cancer, breast cancer, prostate cancer, throat cancer
Delivery routes: Oral ingestion by pill or in food
How this compound works: Historically, humans have consumed garlic for medicinal purposes to soothe digestive and circulatory problems. Aware of nutritional strategies to prevent and control diseases, scientists initiated cancer research exploring garlic and its allyl sulfur components in the mid-twentieth century. Researchers identified allicin as garlic’s most significant chemical that could fight cancer. Allicin is created as the enzyme alliinase reacts with alliin when garlic bulbs are sliced or crushed. Scientists hypothesized that biochemical processes in garlic which boost distribution of antioxidants might prevent cancerous cells from forming and increasing.
Studies regarding use of garlic and allicin for cancer prevention and treatment have given rise to both skepticism and optimism. In 1990, the National Cancer Institute (NCI) studied the potential use of allium vegetables, including garlic, for stomach cancer. That year, researchers attended the First World Congress on the Health Significance of Garlic in Washington, DC. Despite some scientists’ suggestion that garlic and its allyl sulfur components could prevent or inhibit malignancies, experts emphasized that garlic’s anticancer effectiveness had not been scientifically proven.
By the early twenty-first century, international researchers had published several thousand scientific journal articles discussing allium plants. Studies focused on garlic’s effect on gastric, colon, breast, prostate, and throat cancers. Investigators achieved promising laboratory results regarding allicin use in mice. At the Weizmann Institute of Science at Rehovot, Israel, scientists delivered alliinase and alliin to malignant tumors, where they produced allicin that entered and destroyed those cells. When researchers combined allicin with rituximab, an anticancer drug, they found that this mixture killed 95 percent of cancerous cells in mice.
In October, 2006, the University of California, Berkeley Wellness Letter noted that the cancer-fighting properties of garlic and allicin remained uncertain because tests had been limited to animal subjects and cell cultures and were inconclusive. That newsletter discounted previous studies as presenting minimal evidence, stressing that clinical scientific trials using humans were necessary to declare definitively anticancer properties expressed by garlic and allicin.
Although garlic and allicin have not been scientifically shown to cure cancer in humans, they contribute to healthy diets. People with cancer often consume garlic to strengthen their immune systems and receive other health benefits relevant to cholesterol and heart concerns. Garlic can be consumed raw, cooked, or in synthetic formats, providing people varying amounts and versions of allyl sulfur compounds.
Side effects and interactions: Garlic, when ingested regularly as part of diet, may cause halitosis and body odors. These effects are mitigated by taking it in pill form. Some people develop gas, bloating, diarrhea, or heartburn when taking garlic, which can be mitigated by taking enteric-coated supplements. Because garlic and allicin can increase prothrombin time (PT), a measure of how long it takes for blood to form clots, people taking blood thinners such as warfarin (Coumadin) and anyone about to undergo surgery should consult their physicians before taking these substances. Taking garlic while also taking gingko, policosanol, fish oil, high-dose vitamin E, or other herbs and supplements that might slow blood clotting may cause a risk of bleeding problems. Garlic may not combine well with some medications used to treat HIV/AIDS, such as nevirapine (Viramune), delavirdine (Rescriptor), and efavirenz (Sustiva), and may reduce their effectiveness. In 2014 MedlinePlus, a service of the US National Library of Medicine (2014), also stated that, in addition to HIV/AIDS medications, people should not ingest garlic in combination with isoniazid (INH, Nydrazid) and saquinavir (Fortovase, Invirase), and should exercise caution when combining garlic with certain oral contraceptives, cyclosporine (Neoral, Sandimmune), and a wide variety of medications that are processed by the liver.
Bibliography
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MedlinePlus. "Garlic." MedlinePlus. US NLM/NIH, 21 Aug. 2014. Web. 22 Oct. 2014.
Robotin, Monica C., and Ian N. Olver. Perspectives on Complementary and Alternative Medicines. London: Imperial College P., 2012. Digital file.
Trio, P. Z., et al. "Chemopreventive Functions and Molecular Mechanisms of Garlic Organosulfur Compounds." Food and Function 5.5 (2014): 833–844. CAB Abstracts. Web. 22 Oct. 2014.
US Natl. Insts. of Health, Natl. Center for Complementary and Alternative Medicine. "Garlic." NCCAM.NIH.gov. NIH/NCCAMApr. 2012. Web. 22 Oct. 2014.