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If you cook meat too long, at too high a temperature, the chemical reaction that creates tasty flavor and aroma compounds keeps going, creating other compounds. Some of those compounds can be carcinogenic when we consume them in high-enough concentrations. Morgan McCloy/NPR hide caption

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Addiction counselor John Fisher says prescriptions for medicines to help people wean themselves from opioid drugs are part of the appeal of the clinic he operates in Blountville, Tenn. Blake Farmer/NPR hide caption

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Gretchen Burns-Bergman (center) speaks Wednesday at a rally in front of the White House about ending mass incarceration of drug users. Angus Chen/NPR hide caption

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Breast cancer drug Herceptin is one of the medicines that are typically covered by insurers but often at a high out-of-pocket cost for patients. Jeff J Mitchell/Getty Images hide caption

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Jessica Roberts and her father, Alan Roberts, who has struggled with addiction himself. They are both clean and hope to break the cycle of addiction with the newest generation of their family. Mallory Yu/NPR hide caption

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A group at MIT built this tiny package of sensors to collect vital signs as it travels through the digestive system. Albert Swiston/MIT hide caption

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Testing for prostate cancer has declined after a recommendation in 2012 said it shouldn't be routine. iStockphoto hide caption

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People who drank three to five cups of coffee per day had a lower risk of premature death than those who didn't drink, a new study finds. iStockphoto hide caption

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An image from the Allen Institute's Brain Explorer shows gene expression across the human brain. Courtesy of Allen Institute For Brain Science hide caption

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Four pregnant women sit in lotus position. Thomas Northcut/Getty Images hide caption

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