Fruits and Veggies Cut Cancer Risks
Studies Offer New Insights Into How Plant-Rich Diets Can Offer Protection
Fruit, Vegetables Lower Head and Neck Cancer Risk
While several studies have suggested that fruits and vegetables may lower the risk of head and neck cancer, many suffered from poor design as they asked people who had already developed cancer to recall their dietary habits years before, says Kristal, who moderated a news conference on the findings.
To help settle the issue, National Cancer Institute researchers asked 490,802 AARP members about their typical dietary habits and then followed them for five years. During that time, 787 of them developed head and neck cancer.
Results showed that participants who ate about 12 servings of fruit and vegetables per day were 29% less likely to develop the cancer than those who ate three servings per day. Increasing consumption by just two servings of fruit or vegetables per day was associated with a 6% reduction in head and neck cancer risk, researcher Neal Freedman, PhD, a cancer prevention fellow, tells WebMD.
One serving equals approximately one medium-sized fresh fruit, 1/2 cup of cut fruit, 6 ounces of fruit juice, 1 cup of leafy vegetables, or 1/2 cup of other vegetables.
Broccoli Curbs Breast Cancer Spread
While studies have shown that broccoli and soy offer protection against breast and ovarian cancer, how this occurs has not been well understood, says Erin Hsu, MS, a molecular toxicologist at the University of California, Los Angeles.
Her team's laboratory experiments offer one potential clue, showing that diindolylmethane (DIM), a compound resulting from digestion of cruciferous vegetables, and genistein, a major isoflavone in soy, reduce production of two proteins whose attraction to each other is necessary for the spread of both cancers.
In the experiments, the researchers exposed breast and ovarian cancer cells to purified DIM or genistein. Levels of two proteins known as CXCR4 and CXCL12 that promote breast and ovarian cancer spread dropped.
"In other words, DIM and genistein make the cancers more treatable," Hsu tells WebMD.
Both DIM and genistein are being developed for use in the prevention and treatment for breast cancer, although more extensive toxicological studies are necessary, she says.