Can apples help prevent cancer?

Research indicates that apples may inhibit the growth of tumors

Turns out, an apple a day may keep the oncologist away. A researcher at Cornell University has found that fruit, especially apples, substantially inhibits breast tumor growth. “The apple is a magical fruit,” says Rui Hai Liu, a professor of food science. The magic, he explains, lies in the apple’s high concentration of phytochemicals, which pack many disease-fighting properties.

Liu’s research shows that among rats fed apple extract during a 24-week stretch, a type of adenocarcinoma—the deadliest kind of breast cancer tumor—was less prevalent. The more apple extract the rats received, the better: tumors were found in 57 per cent of rats fed a low dose of apple extract, compared to 50 per cent and 23 per cent in rats given medium and high doses, respectively—that’s like a human eating one, three or six apples daily.

That’s not to say we should be eating half a dozen apples a day, explains Liu, who receives some funding from the U.S. Apple Association. One is enough, he says, as long as it’s part of a diet that includes other fruits and vegetables. “Phytochemicals in fruits and vegetables work [together] to help optimal nutrition,” he says. This assertion is backed up by other research. A 2007 article in the Journal of the American Medical Association found that “a diet high in vegetables and fruit probably decreases breast cancer risk.”

Liu says of the 25 most popular fruits and vegetables in the U.S., apples are the source of 33.1 per cent of the phenolics (a type of phytochemical) that Americans consume annually. That’s more than any other fruit. Oranges (14 per cent), grapes (12.8 per cent), strawberries (9.8 per cent) and plums (7.3 per cent) round out the top five. He says the same is likely true in Canada.

Next, Liu will look into whether the apple can have a curative effect as profound as its preventative impact. (The JAMA study found that eating five fruits and vegetables a day didn’t prevent breast cancer in previously treated people, nor did it slow down the progression of the disease.) In the meantime, his best advice is for people to eat several fruits and vegetables every day to stave off disease. And there’s one more incentive, he adds: “They’re delicious.”

Looking for more?

Get the Best of Maclean's sent straight to your inbox. Sign up for news, commentary and analysis.