Boost from the garden can help activate the body’s own toxic waste disposal system.
U. S. and Japanese scientists have discovered how to trigger the body’s natural defenses against cancer and are working on a drug that could boost protection against all forms of disease. The researchers at Johns Hopkins Medical Institutions in Baltimore have believed for many years that the body has a toxic waste disposal system that gets rid of chemicals, such as those in cigarette smoke, that can cause cancer. Now, they say they have proven in detail how the system works.
Working with researchers at the University of Japan, they have discovered the protein that triggers the production of an army of toxic clean-up molecules. These waste-disposal enzymes, known as Phase II enzymes, either neutralize cancer-causing chemicals or help the body excrete them.
It has been 10 years since the researchers discovered that substances in such vegetables as broccoli, kale, cabbage, and cauliflower raise levels of these clean-up enzymes, which is one of the reasons doctors consider them an important part of a healthy diet.
Now they say they have found exactly how the anti-cancer system gets activated, sometimes with help from the vegetable patch. Chemicals like sulforaphane in broccoli cause the release of a key protein known as Nrf2, which then switches on the production of a dozen or more toxic-busting enzymes.
“We have evidence that we can increase the system’s level of protection in people and are planning long-term studies that would reveal any lowered incidence of cancer,” said Thomas Kensler, an environmental toxicologist, who is overseeing clinical trials of a new drug in China. The team’s findings are published in the most recent edition of the Proceedings of National Academy of Sciences.
Carcinogens can lead to cancer by causing mutations in the genetic material of a cell, a long, silent process that can take 10 years before it leads to a tumor.
The researchers at Johns Hopkins believe a key in the war against cancer is learning how to stop the disease before it begins. They say they are not looking for a cure, just a way to help the body protect itself.
The researchers took a big step forward with the help of Japanese biologist Masayuki Yamamoto, who genetically engineered a group of mice so they could not produce any of the Nrf2 trigger protein. Levels of waste disposal enzymes dropped dramatically. They then exposed both the genetically altered and normal mice to benzypyrene, a cancer-causing chemical in cigarette smoke. The mice, who could not produce the trigger protein, had significantly more tumors. They then gave both the altered and normal mice a drug called Oltipraz, which, like broccoli has been shown to raise levels of the clean-up enzymes and reduce the risk of cancer. Both groups were exposed to the carcinogen again, but the Oltipraz worked only on the normal mice. The altered mice that could not turn on their detoxification system were still riddled with tumors.
Although the experiments were done in mice, the researchers believe the system is common to many animals, including humans. Boosting the natural anti-cancer system could thus increase resistance to the disease.
