Scientists have discovered that grape seed extract kills head and neck cancer cells while leaving healthy cells unharmed.

Researchers said that grape seed extract killed head and neck squamous cell carcinoma cells in experiments using cell lines and mouse models, but didn’t hurt healthy ones.

However, scientists say that this effect of GSE largely depended on the healthy cell’s ability to wait out damage.

Experts say that GSE works by creating conditions that are unfavorable for cell growth, and the study showed that GSE both damaged cancer cell’s DNA and stops pathways that allow repair, demonstrated by decreased levels of DNA repair molecules.

"Cancer cells are fast-growing cells," Rajesh Agarwal, investigator at the University of Colorado Cancer Center said in a statement. "Not only that, but they are necessarily fast growing. When conditions exist in which they can't grow, they die."

The study was published in the journal Carcinogenesis.

Researchers said that there were no observed cases of GSE toxicity in mice tested.

"I think the whole point is that cancer cells have a lot of defective pathways and they are very vulnerable if you target those pathways. The same is not true of healthy cells," Agarwal said.

Agarwal hopes to move forward to GSE clinical trials so that the seed extract could be used as an option in second-line therapies targeting head and neck squamous cell carcinomas that has failed a first treatment.

Head and neck cancers account for 3 percent of all cancers in the U.S., and these cancers are twice as common among men as they are among women, according to the National Cancer Institute.

The institute estimated more than 52,000 Americans were diagnosed with head and neck cancers in 2011.