Heavy smokers are less likely to get cancer if they eat raw vegetables such as broccoli, cabbage, cauliflower, and Brussels sprouts. American researchers said Tuesday that the risk of getting the disease goes down by 20–50%.
The scientists quickly added that their research results were not yet enough to tell people how to eat. ”And if you smoke long enough, nothing can help,” nuanced Li Tang of the Roswell Park Cancer Institute in Buffalo.
The researchers found that eating vegetables reduced cancer risk, especially among people who smoke more than 20 cigarettes a day. People who used to smoke also benefit from the vegetables. The difference in decrease further depends on how often and what type of vegetable a person eats.
Tang and her colleagues studied 948 people with cancer and 1743 people without it.
According to information presented by the American Association for Cancer Research at its seventh annual international conference on Frontiers in Cancer Prevention Research, broccoli and other cruciferous vegetables seem to work best against cancer in smokers.
Many studies have shown that gross-flowered vegetables have protective effects, but this is the first comprehensive study to show a protective benefit in smokers, especially in ex-smokers, said Li Tang, Ph.D., a post-doctoral fellow at the Roswell Park Cancer Institute and the study’s lead author.
“Broccoli is not a therapeutic medicine, but for smokers who think they can’t quit and also can’t do anything about their risk, this is something positive,” Tang said. “People who quit smoking will definitely benefit more from the intake of cruciferous vegetables.”
Li and colleagues conducted a hospital-based, case-controlled study with lung cancer cases and controls matched on smoking status. The study included all commonly consumed cruciferous vegetables, and also took into account raw versus cooked form. The researchers performed statistical calculations to account for smoking status, duration and intensity.
“Broccoli is not a therapeutic medicine, but for smokers who think they can’t quit and also can’t do anything about their risk, this is something positive,” Tang said. “People who quit smoking will definitely benefit more from the intake of cruciferous vegetables.”
Li and his colleagues did a case-controlled study in a hospital with lung cancer patients and healthy people who did not smoke. The study included all commonly consumed cruciferous vegetables and also took into account raw versus cooked form. The researchers performed statistical calculations to account for smoking status, duration, and intensity.
reduced risk of lung cancer
The protective effect of eating cruciferous vegetables ranged from a 20% risk reduction to a 55% risk reduction in smokers, depending on which vegetable was eaten and how long and how much they smoked.
For example, only eating raw cruciferous vegetables was linked to a lower risk of lung cancer in people who still smoked.No significant results were found for the consumption of vegetables in general or fruits.
The researchers then broke their findings down into four types of lung cancer. They found that patients with squamous or small cell carcinoma had the biggest drop in risk. These two subtypes are more strongly associated with heavy smoking.
Special conclusion
“These findings are not yet strong enough to make a public health recommendation,” Li said. “But strong biological evidence supports this observation. These findings, along with others, suggest that cruciferous vegetables may play a more important role in cancer prevention in people exposed to cigarette smoking.”
We conducted a hospital-based case-control study with lung cancer cases and controls matched on smoking status and further corrected for smoking status, duration, and intensity in the multivariate models. A total of 948 cases and 1743 controls were included in the analysis.
Conclusions
Our results back up the idea that isothiocyanates, a group of phytochemicals that are only found in cruciferous vegetables, can change the way carcinogens affect people who smoke.Our data support the hypothesis that consumption of a diet rich in cruciferous vegetables may reduce the risk of lung cancer in smokers.
Lung cancer is the second most common form of cancer and is the leading cause of cancer death in both men and women. An estimated 29% of all cancer deaths in 2008 in the United States were due to lung cancer.
