Published March 25, 2016
Garlic gets a bad rap for leaving people with stinky breath. But its benefits may outweigh the potential turn-offs. That is according to researchers at the University at Buffalo, who reported finding that compared to no intake, raw garlic intake was associated with a lower risk of lung cancer in a small Chinese population. Moreover, this decrease in risk was found to be greater with increased frequency of consumption of raw garlic. The results of their study were published online in the journal Cancer Epidemiology, Biomarkers & Prevention.
“Eating raw garlic regularly may help in preventing lung cancer,” said Mr. Ajay Myneni, the study’s lead author and an epidemiology doctoral candidate in UB’s School of Public Health and Health Professions. “With garlic, it’s the amount you eat, and how you eat it. Garlic has several anti-cancer properties including inhibition of onset and growth of cancer, as well as prevention of tissue damage due to oxidation and inflammation among others. These properties are best utilized when it’s consumed in raw form,” adds Mr. Myneni. Previous experimental studies showed that heating garlic may reduce its anticancer properties significantly compared to raw garlic, Mr. Myneni noted.
Lung cancer is a major public health problem in China, which has relatively high levels of indoor air pollution, smoking, and exposure to secondhand smoke. Over the past 30 years, lung cancer deaths in China have increased by 465 percent, the researchers note. The study included 399 lung cancer patients and 466 healthy controls, and was conducted in Taiyuan city, the capital of Shanxi Province in northern China. Personnel from Taiyuan city Center for Disease Control and Prevention and Shanxi Tumor Hospital also collaborated on the study.
In the study, 23 percent of lung cancer patients consumed raw garlic — at least one clove — two or more times a week. Among healthy control subjects, 33 percent ate raw garlic at that frequency.
The study also revealed surprising new findings among smokers. “Smokers who ate raw garlic had 40 percent lower lung cancer risk compared to smokers who did not eat raw garlic,” said Mr. Myneni, noting that two previous studies of Chinese populations did not find this association. Myneni said the study’s results should not be used to suggest that smokers should substitute adding more garlic into their diet in place of quitting. But “it won’t hurt for a smoker to start eating raw garlic to cut down his risk while principally trying to quit,” he said.
Scientists have long known about garlic’s beneficial properties. Several ancient civilizations, including Egypt, Rome and Greece, all used garlic to treat ailments ranging from headache and depression to insomnia and poisoning. UB researchers note that in traditional Chinese medicine, garlic is used to treat cancer. China is the world’s largest producer and exporter of garlic, and the Chinese consume more garlic than anyone else in the world.
Garlic is rich in organo-sulfur compounds, which are responsible for most of its antibacterial, anti-inflammatory and anticancer properties. In addition, studies have shown that garlic helps stop cancer cell growth. Though more research needs to be done to draw a definitive connection between raw garlic consumption and lung cancer prevention, the study builds on previous research that has shown such a link.
Dr. Lina Mu, associate professor epidemiology and environmental health at UB, led the research team in collaboration with Dr. Zuo-Feng Zhang, professor of epidemiology at UCLA. Dr. Gary Giovino, professor and chair of community health and health behavior at UB, and Dr. Shen-Chih Chang from UCLA, also contributed to this research.