Garlic belongs to the Allium family of vegetables which also includes onions, chives, shallots and leeks. Current research has shown that a number of readily available foods such as garlic and onions that make up a healthy diet, actually have a major impact on cancer prevention. These cancer fighting foods seem to have the ability to interfere with the development of cancerous tumors. Cancer fighting foods all contain large amounts of certain phytochemicals. Phytochemicals were developed by nature to protect plants against damage caused by insects, disease and environmental stress. These phytochemical molecules are the ones that give fruits and vegetables their brilliant colors, provide the smell to garlic and the astringent taste to tea. It is very likely that these phytochemicals, not the vitamins and minerals, that are the source of the cancer prevention capabilities of these healthy foods.
Current research on the anti-cancer potential of the Allium family – particularly garlic – seems to show that these vegetables seem to reduce the incidence of cancers of the digestive system. Studies have also shown that garlic may also help prevent prostrate cancer. Garlic and onions contain allicin which is unstable and breaks down into a number of phytochemical compounds including diallyl sulfide and diallyl disulfide which appear to increase the ability of immune cells to fight cancer and also break down cancer causing toxic substances. These sulfur-based phytochemicals fight tumor development and are capable of neutralizing the effect of potential nitrite carcinogens which are used as preservatives in some foods. Studies have linked garlic, onions, leeks and chives to lower risk of cancers of the digestive system. The protective effect of garlic seems to be greater than that of onions, even though onion consumption has been shown to reduce the risk of stomach cancer. Most of the available research comes from epidemiologic observational studies comparing populations who do or do not consume garlic and onions. Other studies are based on animal trials and cell culture studies. The October 2000 issue of the American Journal of Nutrition had a summary of a number epidemiologic studies which showed that people who consumed cooked or raw garlic on a regular basis compared to those that ate little or none had about half the risk of stomach cancer and one-third less risk of colorectal cancer. These studies did not show that garlic supplements had the same benefits. It should be noted that these studies are not yet verified by clinical trials in human populations.
Our garlic consumption in North America is much less than many other areas of the world even though population areas where large quantities of garlic are consumed seem to have significantly fewer cancers of the digestive system. In the US, only 20% of the population eats more than 2 grams of garlic per week. Excessive garlic consumption can have adverse effects including bad breath, allergic reactions, stomach disorders and diarrhea. Freshly crushed garlic should be our choice as a source for the anti-cancer compounds we require.
Eating a healthy balanced diet can provide our bodies with many thousands of different phytochemicals. However not all fruits, vegetables and other plant products provide the best anti-cancer phytochemicals. The ten best groups of anti-cancer foods are discussed in our website www.benefits-of-antioxidants.com . They include: berries and citrus fruits, cruciferous vegetables, garlic and onions, green tea, omega-3 essential fatty acids, olive oil, tomatoes, soy products, red wine and dark chocolate.