Watercress extract was shown to reduce the activation of carcinogens caused by smoking by 7.7%, in a new randomized trial. The plant extract was also shown to increase detoxification of benzene by 24.6% and acrolein by 15.1%, both substances found in cigarette smoke.

Researcher’s at the University of Pittsburgh Cancer Institute enrolled 82 cigarette smokers in the Phase II randomized clinical trial. The participants either took a mixture of 10mg of watercress extract and 1mL of olive oil, 4 times a day for 1 week or placebo. The first week of treatment was followed by a week of washout, after which participants switched their treatment from the first week.

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Specifically, the extract lessened the activation of the carcinogen known as nicotine-derived nitrosamine ketone, by 7.7% after 1 week. The effects were noticeably greater for people who lack two genes involved in a genetic pathway which aids the antioxidant glutathione in removing carcinogens and toxicants from the body. For this population the detoxification of benzene was increased by 95.4%, and for acrolein by 32.7%. Also increasing detoxification of crotonaldehyde by 29.8%.

Lead author of the study, Jian-Min Yaun, MD PhD, cited the difficulty of quitting smoking, and highlighted the importance discovering a carcinogen inhibitor could have saying, “Having a tolerable, nontoxic treatment, like watercress extract, that can protect smokers against cancer would be an incredibly valuable tool in our cancer-fighting arsenal.”

Dr. Yuan said that while eating watercress and broccoli is good for people, they are unlikely to have the same pronounced effect as the extract. A Phase 3 study that includes hundreds of people would need to be initiated before a real recommendation can be made.

For more information visit UPMC.com