Benefits Of Garlic Questioned

By Margarita Nahapetyan

Garlic has always had a long history of use as a good medicine. From many studies we have known that it has several health benefits such as chemical properties which help to prevent many diseases related to our cells. Scientists have told us that garlic can reduce the cancer in one way as it fights the oxidative stress (caused by "free radical" molecules) that increases the cancer risks and gives birth to other health-related concerns. Previous researches showed that garlic was an effective remedy in fighting atherosclerosis, bacteria, viruses, and cancer, in lowering high cholesterol levels and high blood pressure, and it was a general belief that those people who ate garlic on a regular basis had better health in general than those who did not. But a new study, published in the January issue of the American Journal of Clinical Nutrition, suggests that garlic consumption has very little or limited effect on fighting different types of cancer.

Researchers at Ewha Women's University in Seoul, South Korea evaluated studies on garlic and cancer published between 1955 and 2007. The searches were conducted using the Medline and EMBASE databases with search terms Allium sativum, vegetables, diet and nutrition in combination with cancer, neoplasm and individual cancers. The search was limited to human studies published in English and Korean. 19 studies in humans have been examined. The criteria was used from the U.S. Food and Drug Administration's evidence-based review system for scientific evaluation of health claims. The standards included use of a control group, statistical analysis, and other factors to reduce bias and make sure the findings are accurate.

What the researches found was that eating garlic dos not reduce the risk of developing stomach (gastric), breast, lung and endometrial cancers. And only very limited evidence supported the claim of its effects in tackling colon, prostate, esophageal, laryngeal, oral, ovary and renal cell cancers. Dr. Oran Kwon, a researcher at Ewha Women's University and a lead author of the study, said, "The public wants to believe that garlic may be effective in reducing the risk of cancer, but so far scientific evidence is limited to conclude that it works for all types of cancers."

On the basis of the review, researchers suggest that the following wording should be used for food labels indicating health benefits of the plant in regard to cancer prevention:

1. garlic is "highly unlikely" to reduce the risk of colon cancer

2. garlic is "highly uncertain" to reduce prostate cancer risk.

3. garlic is "highly unlikely" to reduce the risk of esophageal, larynx, oral, ovary and renal cell (kidney) cancers.

There was an editorial that accompanied the study which said that it is too early to draw any conclusions based on such a small analysis and facts. Richard S. Rivlin, a researcher at Weill Cornell Medical College in New York, said that without any doubt more research is needed to reconcile the findings of the new study with those of previous scientific research that garlic is good for health. Richard Rivlin has received grant money for garlic studies from Wakunaga of America, Ltd., which makes a garlic extract supplement.

Researchers say it is hard to evaluate the potential benefits of garlic against cancer for several reasons. They say that first of all it is very difficult to make an analysis on how much garlic a person intakes because garlic is intended for use as a seasoning, in small quantities. Besides, it is very important to know in which method garlic is being used, whether it is cooked, raw, whole or extracted as there are many variables that affect the chemical composition of the plant. "For some of these reasons, although this systemic review found many studies on garlic intake and cancer, most of the results indicate that additional studies are needed," says Dr. Kwon.

"The bottom line is, there is certainly not enough evidence for garlic for a health claim for any cancer prevention," said Colleen Doyle, director of nutrition and physical activity for the American Cancer Society in Atlanta. "There is weak evidence it may have an impact on some cancer sites." Her advice for those who really like and enjoy eating garlic is to continue doing so, "Roast it, chop it up, it's not going to be harmful to you," she said. "If, down the line, stronger evidence emerges that garlic has an impact on cancer, great. If you like it, eat it." She, being a lover of a garlic herself, also emphasized the fact that people who are concerned about their health should concentrate mostly on a well-balanced diet, which includes eating plenty of fruits and vegetables, "We do know that people who eat a diet with a mixture of fruits and vegetables, who eat mostly a plant-based diet, do tend to have lower rates of cancer."

SOURCES: The American Journal of Clinical Nutrition; Colleen Doyle, M.S., R.D., director, nutrition and physical activity, American Cancer Society, Atlanta.; Oran Kwon, Ph.D., department of nutritional science and food management, Ewha Women's University, Seoul, South Korea.