An extract from broccoli sprouts has been demonstrated to protect mice from oral cancer and was successfully tolerated when taken by a small group of human volunteers.
It's said to be a safe, natural molecule that works by protecting the oral lining upon which oral cancers form.
The next step, say members of the research team at the University of Pittsburgh Cancer Institute (UPCI) where the experiment was conducted, is a human clinical trial for which they plan to recruit those at risk for head and neck cancer recurrence.
"People who are cured of head and neck cancer are still at very high risk for a second cancer in their mouth or throat, and, unfortunately, these second cancers are commonly fatal," says lead author Julie Bauman, M.D., M.P.H., co-director of the UPMC Head and Neck Cancer Center of Excellence.
Research conducted in China suggests cruciferous vegetables such as broccoli, cabbage and garden cress have a high concentration of sulforaphane that can neutralise the effects of environmental carcinogens.
The mice in Dr Bauman's lab were predisposed to oral cancer, yet the sulforaphane reduced the number of them who fell ill.
She then treated 10 healthy volunteers to a smoothie containing fruit juice and sulforaphane-rich broccoli sprout extract.
They experienced no side effects and in observation of the lining of their mouths indicated the extract was absorbed and helped bolster the at-risk tissue.
The human clinical trial would involve 40 participants who have undergone head and neck cancer and been treated.
In the trial, capsules containing broccoli seed powder will be used instead of the smoothie.
"We call this 'green chemoprevention,' where simple seed preparations or plant extracts are used to prevent disease," says Dr Bauman. "Green chemoprevention requires less money and fewer resources than a traditional pharmaceutical study, and could be more easily disseminated in developing countries where head and neck cancer is a significant problem."
Dr Bauman's colleague Daniel E. Johnson, Ph.D., professor of medicine at Pitt and a senior scientist in the UPCI Head and Neck Cancer Program, says sulforaphane could be important for people chronically exposed to environmental pollutants and carcinogens.
Broccoli has long been thought to contain carcinogen-fighting elements. Last year, broccoli sprouts were mixed into a smoothie that helped detoxify, flushing out the carcinogen benzene in 300 Chinese men and women who participated in the study.
"This study points to a frugal, simple and safe means that can be taken by individuals to possibly reduce some of the long-term health risks associated with air pollution," notes Thomas Kensler, PhD, professor at the Johns Hopkins Bloomberg School and one of that study's co-authors.