A study helmed by UCSB researchers has determined that certain vegetables have the potential to help shield humans from cancer.

Although research has previously shown that eating cruciferous vegetables — such as broccoli and cauliflower — can combat cancer, the team’s findings revealed for the first time exactly how these vegetables inhibit cell proliferation. The study, published in the December issue of the journal Carcinogenesis, shows how cruciferous vegetables contain high amounts of isothiocyanate compounds, which possess anticancer properties.

According to Leslie Wilson, a professor of biochemistry and pharmacology at UCSB and co-author of the study, these compounds may effectively prevent cancer.

“[The sulforaphane compound] may be an effective cancer preventive agent because it inhibits the proliferation and kills precancerous cells,” Wilson said in a press release.

Olga Azarenko, the first author of the study and a UCSB graduate student, said in a press release that the study centered on a single compound and how it affected breast cancer cells.

“Our paper focuses on the anti-cancer activity of one of these compounds called sulforaphane, or SFN,” Azarenko said. “It has already been shown to reduce the incidence and rate of chemically induced mammary tumors in animals. It inhibits the growth of cultured human breast cancer cells, leading to cell death.”

However, while breast cancer was the study’s target, those at risk of contracting other forms of cancer may also benefit from SFN. The study found that SFN inhibits the function of microtubules – tubelike strands of proteins used to separate the cell’s chromosomes. Therefore, by preventing cell mitosis, Azarenko said, SFN ensures that cancer cells cannot reproduce and tumors cannot grow.

“Cancer cells divide more rapidly than regular cells [as a] tumor grows, [but SFN] affects the cells so they can’t divide anymore. If it can’t divide, the cell will die,” Azarenko said.

According to Azarenko, although SFN is similar to current anti-mitotic cancer drugs, it is much less toxic.

“The drugs used currently are very, very toxic, there are multiple side effects, [such as] hair loss and nausea,” Azarenko said. “We were looking at these compounds and seeing how much was needed for the same effect… chemicals in plants that we eat are not as toxic as the drugs used to treat breast cancer, [while] the mechanisms are similar.” Azarenko said the cancer preventative qualities of isothiocyanate compounds are useful since prevention can be achieved through dietary means.

“Since we are eating [vegetables] all the time, we kill the cells that are on the verge of becoming cancerous,” Azarenko said. “It is important to treat [cancer], but to prevent it would be better.”

For the future, Azarenko said, she plans to continue the study by ascertaining why the compound does not affect healthy cells as much as it affects cancer cells. In addition, her studies will expand scientific knowledge about the metabolism of isothiocyanates by testing the compounds in larger biological systems.