Rui Hai Liu, MD, PhD
Rui Hai Liu, MD, PhD, is an associate professor in the department of food science at Cornell University in Ithaca, New York.
An apple a day may not only keep the doctor away — new research shows that it may specifically be helpful in protecting against breast cancer.
At Cornell University’s department of food science and Institute for Comparative and Environmental Toxicology, researchers randomly divided rats treated with a known mammary carcinogen into different groups, feeding them either low, middle or high doses of Red Delicious apple extracts (the equivalent of one, three and six apples a day in humans, respectively) or a control extract. Rats fed the strongest apple extract experienced the lowest cancer rate (40% developed cancer)… followed by the group fed middle-strength extract (43%)… and the lowest strength extract (59%). In comparison, 71% of those fed the apple-free control extract developed mammary cancer over the 24-week study period. The study appeared in the December 10, 2008, online edition of Journal of Agricultural and Food Chemistry.
According to researcher Rui Hai Liu, MD, PhD, associate professor of food science at Cornell University, the study demonstrated not only that apple extracts effectively inhibited the growth of mammary tumors in the rats but that the more administered, the greater the anticancer effect. “Not only did animals treated with apple extract have fewer tumors overall, the tumors were smaller, less likely to be malignant and grew more slowly when compared with tumors in the untreated animals,” he said.
Why are apples so powerful against breast cancer, I wondered? Dr. Liu explained to me that apples are one of the best sources of phenolics and flavonoids, which are phytochemicals (bioactive compounds) that have powerful antioxidant and anti-proliferative (antigrowth) effects in the body. In two previous studies, Dr. Liu and his colleagues discovered that phytochemicals from apples effectively inhibited the growth of human breast cancer cells. In another study, Dr. Liu found that phytochemicals from apple peels inhibited an important inflammation pathway, NFkB, in human breast cancer cells, thereby reducing the proliferation of the cancer.
Dr. Liu told me that although other fruits and vegetables also contain phenolics and flavonoids, apples are one of the best dietary sources of fruit phenolics. In fact, of the top 25 fruits consumed in the US, apples provide 33% of the phenolics that Americans consume annually. “Americans love to eat apples, so it makes sense to encourage them as part of a balanced diet for optimal health,” he said, adding that this doesn’t mean anyone should forsake other fruits and vegetables. “It’s clear that regular consumption of fruits, vegetables and whole grains can help to prevent chronic diseases, such as heart disease and cancer,” Dr. Liu said.