Researcher details role of apples in inhibiting breast cancer

ITHACA, N.Y. — Six studies published in the past year by a Cornell researcher add to growing evidence that an apple a day — as well as daily helpings of other fruits and vegetables — can help keep the breast cancer doctor away.

Fresh apple extracts

In one of his recent papers, published in the Journal of Agricultural and Food Chemistry, Rui Hai Liu, Cornell associate professor of food science and a member of Cornell’s Institute for Comparative and Environmental Toxicology, reports fresh apple extracts significantly inhibited the size of mammary tumors in rats — and the more extracts they were given, the greater the inhibition.

“We not only observed the treated animals had fewer tumors, but the tumors were smaller, less malignant and grew more slowly compared with the tumors in the untreated rats,” said Liu, pointing out the study confirmed the findings of his preliminary study in rats published in 2007.

In his latest study, for example, he found a type of adenocarcinoma — a highly malignant tumor and the main cause of death of breast-cancer patients, as well as of animals with mammary cancer — was evident in 81 percent of tumors in the control animals.

However, it developed in only 57 percent, 50 percent and 23 percent of the rats fed low, middle and high doses of apple extracts (the equivalent of one, three and six apples a day in humans), respectively, during the 24-week study.

Phytochemicals

The studies highlight the important role of phytochemicals, known as phenolics or flavonoids, found in apples and other fruits and vegetables.

Of the top 25 fruits consumed in the U.S., Liu reported in the same journal that apples provide 33 percent of the phenolics Americans consume annually.

New phenolic compounds

In a study of apple peel published in the same journal, Liu reported on a variety of new phenolic compounds he discovered that also have “potent antioxidant and anti-proliferative activities” on tumors.

And in yet another study in the same journal, he reported on his discovery of the specific modulation effects that apple extracts have on cell cycle machinery.

Recently, Liu’s group also reported the finding that apple phytochemicals inhibit an important inflammation pathway, NFkB, in human breast cancer cells.

Breast cancer is the most frequently diagnosed invasive cancer and the second leading cause of cancer deaths in women in the U.S., said Liu.

The studies were supported, in part, by the American Institute for Cancer Research, the Ngan Foundation and the U.S. Apple Association.