Examining cognitive health benefits and stigma of surgery as weight management tool

09 Jan 2024 --- As obesity rates in the US continue to increase, there is a growing demand and offer of weight management solutions, from diet and lifestyle changes to weight loss drugs and surgery. A new study highlights additional benefits of bariatric weight loss surgery, suggesting that it may mitigate cognitive decline associated with obesity, though randomized controlled trials are needed to confirm the findings.

“We do not know all of the reasons that lead from obesity to brain injury. Our research has shown that the same metabolic factors that lead to brain injury also lead to peripheral nerve injury. A better understanding of the precise mechanisms has the chance to lead to new treatments in addition to those we have for weight loss,” the study’s senior author, Brian Callaghan, MD, a neurologist at the University of Michigan Health, tells Nutrition Insight.

At the same time, a national survey by Orlando Health indicates that 60% of US citizens see bariatric surgery — including gastric bypass, sleeve gastrectomy, gastric band and duodenal switch surgeries — as a shortcut to losing weight. 

“Bariatric surgery is by no means an easy way out. If you have the courage to ask for help and commit to doing the hard work of changing your diet and improving your life, you’re a champion in my book,” notes Dr. Andre Teixeira, medical director and bariatric surgeon at the Orlando Health Weight Loss and Bariatric Surgery Institute. 

“Surgery is simply a tool to jumpstart that change. After surgery, it is up to the patient to learn how to eat well, implement exercise into their routine and shift their mindset to maintain their health for the rest of their lives.” 

Countering cognitive decline  
Research published in the Journal of Nutrition, Health & Aging reveals that people with obesity who underwent bariatric surgery had a stable cognition two years later. 

“Since individuals with obesity experience more rapid cognitive decline than those without, stable cognition two years after bariatric surgery may be considered a success against historical trends, yet future controlled trials are needed to test this,” says first author Evan Reynolds, Ph.D., lead statistician for the NeuroNetwork for Emerging Therapies at Michigan Medicine. 

The most extensive study to assess changes after surgery included 87 patients with a body mass index (BMI) of 35 or higher. The research team used a combination of memory and language tests developed by the National Institutes of Health and the Rey Auditory Verbal Learning test. 

Two years after the surgery, patients also experienced improvements in metabolic risk factors and diabetes complications, such as peripheral neuropathy, chronic kidney disease and retinopathy. However, these were not associated with improved cognition, nor was the reduced waist circumference of participants. 

Very few clinically eligible people undergo surgical obesity treatment due to stigmas around obesity and surgery.While a secondary measurement of executive function improved, a measure of memory declined two years after surgery. Callaghan adds: “Future studies are needed to confirm whether there are differences between the effect of bariatric surgery on executive function and memory.”

In addition, the study’s results conflict with previous studies that found improved memory and executive functioning among similar patients. 

Reynolds explains: “That study was primarily made up of patients who received gastric bypass, while our study was made up primarily of individuals that completed a sleeve gastrectomy.” 

“To provide the best evidence on the effectiveness of bariatric surgery on cognition and potential differences between surgery types, we must conduct larger observational studies or randomized, controlled trials.”

“Last resort” 
The Orlando Health survey reveals that 79% of US citizens believe weight loss surgery should only be pursued as a last resort. Moreover, 61% of respondents believe exercise and diet should be enough. 

The survey was conducted online and included 1,017 US participants over 18. 

While bariatric surgery is “less invasive and safer than ever” due to advancements in laparoscopic and robotic surgery techniques, and access to the surgery has recently been expanded with new guidelines, very few clinically eligible people undergo surgical obesity treatment. 

“Because of the stigma around obesity and bariatric surgery, so many of my patients feel defeated if they can’t lose weight on their own,” says Muhammad Ghanem, MD, a bariatric surgeon at Orlando Health Weight Loss and Bariatric Surgery Institute. 

“But when I tell them obesity is a disease and many of its causes are outside their control, you can see their relief. They often shed a tear because they’ve struggled with their weight all their lives and finally have some validation.”

Surgery is one potential weight management tool, in addition to lifestyle and diet changes, medication and counseling.Nutrition for weight loss  
Lifestyle changes such as weight loss diets or increased exercise are commonly used weight management tools. For example, researchers recently highlighted plant-based diets’ weight loss and cholesterol reduction benefits. 

Obesity drugs are also growing in popularity, although experts note these may not be sustainable alternatives over time due to their high costs. 

Additionally, companies increasingly offer products to support weight loss, such as Nestlé Health Science’s Optifast meal replacement program, which a clinical trial found led to more significant weight loss, and reductions in blood pressure, cholesterol and estimated cardiovascular disease risk than a low-calorie diet. 

Callaghan notes that further studies are needed to compare the different weight management interventions. “Bariatric surgery leads to more weight loss than dietary interventions or medications. However, we do not know whether the difference in weight loss between these interventions leads to different outcomes and/or if the same weight loss from two different interventions leads to the same effect.”

While the Orlando Health team agrees that lifestyle changes, medication and counseling are all useful obesity treatment tools, the experts are concerned that stigmas around surgery may deter those who qualify to pursue the treatment they need. 

“If someone’s decision is affected by those who think they don’t need surgery or that make them feel like a failure if they have surgery, that greatly diminishes their chances of losing weight and maintaining a healthy lifestyle long term,” says Teixeira. 

He explains that bariatric surgery is one of the elements in obesity treatment plans, which are tailored to each patient based on BMI and existing medical conditions. 

“By taking this personalized approach, we are extremely successful in reversing health issues caused by obesity, from diabetes to heart disease.”  

By Jolanda van Hal