X-Ray Danger for Obese People — More Radiation, More Cancer Risk

Published Dec 20, 2018

We know that obesity can lead to many health issues, including an increased risk of developing cancer. But now, a new study from the University of Exeter and Musgrove Park Hospital, Taunton, is suggesting that people who are overweight have a higher risk of getting radiation-linked cancer from X-rays.

The study looked at people who are considered extremely obese (with a body mass index of up to 50) and found that because higher doses of radiation were needed when these individuals got X-rays, their cancer risk was increased. Researchers looked at 630 people with an available history of radiation dose received in X-rays between 2007 and 2015. All of the people involved in the study had undergone procedures such as the fitting of gastric bands, gastric sleeves, or gastric bypasses at Musgrave Park Hospital in Northern Ireland.

The study, published in the Journal of Radiological Protection, found that the overall risk of cancer caused by the extra radiation was more than double (153%) the risk for people considered average weight. This is likely due to the fact that heavier patients receive higher doses of radiation because of the increased amount of tissue to be imaged.

Study authors concluded that, “radiation-related lifetime cancer risk is increased in patients with obesity as a result of medical radiation exposures. This indicates more dose [optimization] research is needed in this group of patients to reduce dose rate and variation.” Lead study author Saeed Al-Qahtani said that the increased risks indicate that there needs to be more rigid regulations when it comes to radiation doses.

But just how worried should we be about X-rays and increased cancer risk? X-rays and gamma rays are known carcinogens, according to the American Cancer Society, but it’s difficult to measure exactly how much low levels of exposure — like the levels a person would get during an X-ray examination — increase cancer risk.

The Exeter study noted that in 2015 and 2016, 22.6 million X-rays were performed in England, and only 280 cases of cancer have been linked to an X-ray radiation dose. And, X-rays are still a very important diagnostic tool that have saved countless lives. “Although the risk of cancer from X-ray is very low, we urgently need more research in patients who are overweight and obese, so we can understand how to [minimize] doses in this group and feed into far more robust guidelines around radiation,” said Karen Knapp, who oversaw the Exeter study.

Obesity has been linked to an increased cancer risk in several other ways as well. Being overweight can increase the risk of developing endometrial cancer, colorectal cancer, prostate cancer, and a host of other cancers. Dr. Stephen Freedland, of Cedars-Sinai Medical Center, said that obesity doesn’t just increase a man’s risk of getting prostate cancer — but also increases his risk of dying from the disease.

“Obese men are about 35% more likely to die from prostate cancer,” Dr. Freedland said. “So it may seem modest, but when we think about how a third of the [U.S.] is obese, and we think about prostate cancer being the most common cancer among men, the now third most lethal cancer among men … the 35% increase actually amounts to thousands of men, every year, dying simply because they had an extra few pounds.”

The Exeter study didn’t mention exactly which types of cancer obese patients would be at the highest risk of getting.

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