Weight loss surgery linked to significantly lower risk of cancer and death, new study suggests

• Weight loss surgery is linked to significantly lower risk of getting cancer and dying from it, study finds.
• Surgical patients lost about 55 pounds more, on average, and more weight lost was linked to lower risk.

Weight loss surgery is linked to significantly lower risk of getting several types of cancer, and of dying from cancer, for people with obesity, according a study published June 3 in The Journal of the American Medical Association.

Researchers from Cleveland Clinic looked at data from more than 30,000 adults with obesity, 5,053 of which had undergone weight loss surgery, and compared their rates of cancer and cancer-related death over a median of six years of follow-up.

They found that surgery patients were about 32% less likely to develop cancer, and 48% less likely to die from it, than participants who didn't have surgery.

The researchers found that on average, surgery patients lost about 55 pounds more than those who didn't have surgery, and greater weight loss was linked to more reduction in cancer risk.

The findings are supported by previous research suggesting weight loss surgery is linked to lower risk of cancer.

While the study authors speculate that non-surgical weight loss may reduce cancer risk too, they also noted that significant, long-term weight loss through lifestyle changes is difficult. Previous research suggests that while a variety of diets may be effective in the short term for weight loss, the benefits don't last over time.

And, while the study shows a link between weight loss surgery and lower cancer risk, it doesn't directly show what caused the reduced risk. Other factors may also play a role — for instance, surgery patients may have made other lifestyle changes such as reducing alcohol and tobacco use, exercising more, or eating more nutritious foods that may help explain the benefits.

The link between obesity and cancer isn't well understood, either, although factors like inflammation, insulin levels, and other hormones may all play a role, according to the researchers.

Weight stigma, which evidence suggests can worsen long-term health outcomes, may also make high-quality healthcare more difficult to access for people in large bodies, which may explain the higher risk of chronic illnesses. For instance, studies have found people with obesity are less likely to get screened for cancer, which could lead to worse outcomes by preventing early diagnosis and treatment.

Weight loss surgery also has risks. Around 20% of bariatric surgery patients experience complications, according to one study, which can include nutritional deficiencies, blood clots, leakages, hernias, and sometimes infection and death.