Your Internal Weapon: GLP-1
By Cynthia K. Buffington, PhD
I want to tell you about a hormone in your body that you’ve probably never heard of before, that’s doing wonderful things for you right now. In fact, if you’ve had a bariatric procedure, then consider this an eye-opener about its importance to your health and your weight.
Research on changes that occur in the body following bariatric surgery has led scientists to believe that these operations do a lot more than cause weight loss. For instance, most bariatric surgeries alter production of gut hormones that have an array of biological functions. One of these is GLP-1 (glucagon-like-peptide one). This gut hormone is produced by cells in the lower gut in response to a meal. Certain bariatric procedures, including the gastric bypass, sleeve gastrectomy, biliopancreatic diversion and duodenal switch, cause hypersecretion of GLP-1 following a meal. In fact, with these surgeries, GLP-1 may increase to levels in the blood that are 5 to 20 times above normal.
The exceptionally high increase in production of GLP-1 with surgery has a variety of health benefits. GLP-1 interacts with the appetite centers in the brain to reduce appetite and increase satiety which reduces the amount of food consumed at any given meal. It also causes feelings of fullness for a longer period of time after the meal. In addition, GLP-1 is believed to reduce the desire for certain foods, such as fatty foods and sweets. Some investigators suggest that high levels of GLP-1 may even affect sweet taste, causing sweet foods to taste too sweet.
The exaggerated increase in GLP-1 with surgery is also believed to play a role in improving or causing early remission of type 2 diabetes. Surgeries that increase GLP-1 result in remission or improvement of diabetes before significant weight loss has occurred. GLP-1 lowers blood sugar levels by increasing the hormone insulin and by improving the body’s sensitivity to this hormone, causing it to move out of the blood and into tissues. In this way, GLP-1, helps to keep blood sugar levels under control.
Improvement in psoriasis may be another benefit of GLP-1. Gastric bypass causes early remission or improvement of psoriasis and does so prior to significant weight reduction. Improvement of psoriasis has been attributed to the exaggerated increase in GLP-1 that occurs early following gastric bypass (and various other procedures). GLP-1 improves psoriasis because this skin disease is an inflammatory condition and GLP-1 has anti-inflammatory actions. The possibility exists that the exaggerated increases in GLP-1 with bariatric surgery may also help to improve other inflammatory conditions.
Recent studies find that GLP-1 may help to improve Alzheimer’s disease in experimental models. GLP-1 protects brain tissue from toxins, reduces memory loss and helps prevent degenerative conditions in the brain that lead to Alzheimer’s disease. Medications that ‘mimic’ GLP-1 actions improve brain communication and cognitive (thought) processes resulting in significant improvement in learning and memory. Presently, there are no reports of the effects of those bariatric surgeries that cause hypersecretion of GLP-1 in Alzheimer’s disease. There also are no studies of the effects of these surgeries on the prevalence of the disease as patients age. It is tempting to speculate, however, that bariatric surgery could improve Alzheimer’s disease or possibly reduce the risk for future occurrence of the disease in bariatric patients.
Bariatric surgery, then, may cause a multitude of changes in the body, including the hypersecretion of GLP-1, that may have numerous health benefits, in addition to weight loss alone. Studies have only scratched the surface of knowledge regarding the many additional benefits provided by bariatric surgery.