Can Grapefruit Raise Your Risk of Breast Cancer?

How to Make Sense of Conflicting Reports in the Media

Halved pink grapefruit, close-up
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Can eating grapefruit really raise the risk of developing breast cancer?  News about breast cancer research makes international headlines and appears to be the latest truth about this disease. But are the headlines always completely accurate? Is grapefruit actually deadly? 

Check out these conflicting headlines!

Grapefruit May Raise Your Risk of Breast Cancer

Researchers at the University of Southern California and University of Hawaii have done the only study that takes a look at a possible link between grapefruit consumption and breast cancer risk.

The authors of the study, which surveyed 50,000 postmenopausal women, have concluded that "grapefruit intake may increase the risk of breast cancer among postmenopausal women."  In this "positive" study, it was found that, on average, women who ate at least a fourth of a grapefruit per day were 30% more likely to develop breast cancer.

In contrast, studies done in 2008 and 2009 found no association between the consumption of grapefruit and breast cancer risk.

Grapefruit Could Help Cure Your Breast Cancer

Only a week after the "grapefruit scare," researchers at the University of Chicago reported that patients taking lapatinib, a breast cancer drug, with a fatty meal and grapefruit juice, could get five times the benefit of the drug, because the food and grapefruit juice aids its absorption. But don’t change your medicine habits based on that one scholarly paper. More tests are needed before definitive results can be reached.

Grapefruit Raises Estrogen Levels

A 2013 study decided to see what happens to estrogen levels in a woman's body when she eats grapefruit.  It was found that the woman who ate more grapefruit had higher estrogen levels.

Grapefruit May Inhibit Breast Cancer Cells

Going back a few years, to 1998, it was found that naringenin, a compound found in grapefruit, inhibited breast cancer cells that were grown in the lab.

And What About the Grapefruit Diet?

On the fad diet front, the grapefruit diet has its many admirers, who either eat the fruit or drink the juice before each meal, hoping to lose weight by tapping into the power of special enzymes in the fruit. This diet has been popular since the 1920s and 1930s among people who wanted to burn fat, exercise only a little, and drop their extra pounds. But sticking to this diet also requires sticking to an intake of only 800 calories a day, and being very choosy about the foods you eat while on the diet. And there's been little research in this area.

Confusing indeed! So, should you panic?

News Coverage vs. Medical Experts

Researchers will tell you that if only one study has been done, it makes a fine headline, but it isn’t the final word in health science. Medical research is carefully done, and is a long process that allows for challenge and validation. Studies on breast cancer risks, treatments, and survival get great news coverage, but also frighten many people, because of the way the research results are reported.

If only one or two studies proclaim a new hazard or a new cure, don’t panic. Wait until a well-respected authority, such as the National Cancer Institute puts its stamp of approval on the definitive answer, then you can respond.

Take Home Message

Don't panic if one or two new medical stories make news. Wait to hear what the whole medical community agrees on.  Check out these common myths about breast cancer.  Meanwhile, you can still eat grapefruit and drink its juice. Just practice Aristotle's doctrine: "Moderation in all things." 

Sources:
Prospective study of grapefruit intake and risk of breast cancer in postmenopausal women: the Multiethnic Cohort Study, K R Monroe, S P Murphy, L N Kolonel and M C Pike, British Journal of Cancer (online),

Breast cancer drug works better on a full stomach, Medical Research News, Published: Tuesday, 17-Jul-2007 http://www.news-medical.net/?id=27692

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