You eat right, exercise, stay out of the sun, get plenty of sleep, and take your vitamins — all in an effort to stay healthy and avoid disease. But a new study has found that many cancers occur more as a result of bad luck than bad lifestyle choices.  

Researchers at Johns Hopkins University recently looked at 31 different types of cancer (breast cancer and prostate cancer were not part of the study) and concluded that only nine of them could be linked to genetics or lifestyle choices. The remaining 22 occurred simply because of bad luck during cell division.

The study, which was published in a recent issue of Science, concluded that the most common cause of the development of cancer cells are random mutations that occur during cell division. For two-thirds of the cancers that they studied, lifestyle choices such as diet, exercise, and even smoking did not play as large of a role as researchers had previously thought, particularly in cancers such as pancreatic, leukemia, bone, testicular, ovarian and brain cancer. Researchers also noted that cancer rates were higher in parts of the body where cell division occurs most often, thereby creating more random mutations. 

Of course, this isn't a free pass to pick up any bad habits. Dr. Cristian Tomasetti, an assistant professor of oncology at Johns Hopkins and one of the study's authors, told the Wall Street Journal that the study shouldn't be viewed as permission to smoke, drink, or hang out in the sun. Lung and skin cancer, for example, are clearly tied to lifestyle choices such as smoking and sun exposure, Tomasetti said. 

But the authors did argue that more effort and expense should be used on early detection of cancer rather than prevention for the cancers that may not be attributed to genetics or lifestyle choices.

So keep following that healthy diet and doing everything else you do to stay healthy — just make sure you add an annual checkup with your health care provider to the list.

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