Weight-Loss Surgery May Have Benefits Beyond the Scale

November 18, 2019

A pair of recent studies show that there appears to be benefits to weight-loss surgery that go beyond looking great in a pair of jeans.

One study, published recently in the journal Surgery, showed that patients who underwent bariatric surgery were 38 percent less likely to develop a new colon lesion in the next five to 10 years, compared to other obese patients who did not have the surgery.

A second study, published online in JAMA, shows that major cardiac events, such as a heart attack, decreased after weight loss surgery in obese people who had diabetes.

While many people may seek weight loss surgery to look and feel better, these studies underscore the long-term value in bariatric surgery as a means to improve health, says Leena Khaitan, MD, MPH, Director of the Bariatric Surgery Program at University Hospitals.

“It’s not the weight loss surgery that gives the benefits, it’s getting back to a normal, healthy weight,” she says. “The surgery is the mechanism – it’s the way to get to these health benefits.”

Bariatric Surgery and Colon Cancer Risk

In the first study, researchers reviewed the medical records of 4,462 people who had gastric bypass, sleeve gastrectomy or gastric banding between 1985 and 2015. Their information was compared to a group of obese people who did not have weight loss surgery.

Results showed that while people who had weight loss surgery did indeed lose weight, they also developed fewer precancerous colorectal lesions than those who did not have the surgery.

Obesity is a risk factor for colorectal cancer. While weight-loss surgery usually results in weight loss, up to now there has been no scientific evidence that colorectal cancer risk goes down with the number on the scales after the surgery.

Bariatric Surgery and Cardiovascular Disease

In the second study, researchers compared medical records of 13,722 obese adults with Type 2 diabetes, 2,287 of whom had weight loss surgery, between 1998 and 2017.

Results show that those who had weight loss surgery had significantly fewer cardiovascular events. Cardiovascular events include heart attacks, stroke, heart failure, kidney disease involving the small blood vessels and atrial fibrillation.

Building the Body of Evidence

The studies were observational, in which researchers observe behavior, and not randomized clinical trials, the gold standard for proving cause and effect, Dr. Khaitan says. But the results are nonetheless compelling.

“While weight loss is the nice thing that happens, really the main reason for weight loss surgery is metabolic benefit,” Dr. Khaitan says. “In fact there is a movement to reterm weight loss surgery metabolic surgery to reflect this concept. Studies like these build the body of evidence.

“There’s a lot of negative stigma about weight loss surgery and its benefits,” Dr. Khaitan says. “The body of literature is beginning to show the long-term advantages of weight loss surgery.”