In two new studies, researchers report that bariatric surgery—also known as gastric bypass or gastric banding—can help obese people live longer (Sjoström et al., NEJM 2007; 357:741, and Adams et al., NEJM 2007; 357:753). It’s common knowledge that such surgeries are extremely effective in helping obese people lose weight, and that the massive weight loss that results is often associated with a decreased risk of diabetes and heart disease. Until now, however, there were few reliable data to show that bariatric surgery can improve the quantity as well as the quality of life.
Sjoström and colleagues from several Swedish centers followed 2010 obese persons who underwent one of three types of bariatric surgery, and 2037 similarly obese people who did not for an average of 10.9 years. In order to be included, participants had to have a BMI (see Definition and Classification of Obesity and Are Our Athletes Really Fat?) of at least 34 (men) or 38 (women), so they would all be classified as at least moderately obese. After 10 years, the groups had lost from 14 to 25 percent of their baseline body weight. Overall, the surgery significantly decreased the risk of dying by over 25 percent. As expected, the risk of dying from cardiovascular disease and diabetes declined, and surprisingly, so was the risk of dying from cancer.
Dr. TD Adams of the University of Utah School of Medicine led the second study, which examined the effect of only one type of surgery—gastric bypass—on longevity. The gastric bypass procedure essentially makes part of the small intestine non-functional and thus decreases the amount of nutrients (and calories) that can be absorbed from food. These researchers examined the death rates of nearly 10,000 surgical patients approximately 7 years post-surgery. Those rates were compared with those of a similar number of severely obese persons (BMI of at least 35) who had not had the surgery. Surgical patients had a 40 per cent lower death rate overall than did non-operated patients. Further, the surgery decreased the risk of death from coronary artery disease (by 56 percent), from diabetes (by 92 percent), and from cancer (by 60 percent).
In a editorial accompanying these reports, Dr. George Bray noted that the results of these two studies might well inspire the National Institutes of Health (NIH) to reexamine their BMI cutoff points for recommending bariatric surgery. Current guidelines state that if a person’s BMI is over 40 he or she is a candidate for such surgeries (or a BMI over 35 for those with coexisting ailments such as diabetes). He stated “the question as to whether intentional weight loss improves lifespan has been answered, and the answer appears to be a resounding yes.”
If his suggestion is followed, and the BMI cutoff points are lowered, coverage by insurance companies would likely expand accordingly, which would result in many more bariatric surgeries, although extreme obesity is the form that has been increasing the fastest .
Ruth Kava, Ph.D., R.D., is Director of Nutrition at the American Council on Science and Health (ACSH.org, HealthFactsAndFears.com).
