Are Stress and Obesity Related?
New research may prove the long-suspected link between stress and metabolism.
Posted Oct 12, 2016
Obesity continues to be one of the leading causes of preventable death around the world. And it's a problem that is steadily growing worse.
Typically defined as a medical condition in which excess body fat has increased to the point of having a negative impact on health, obesity has been linked to heart disease, type 2 diabetes, sleep apnea, osteoarthritis, and some forms of cancer. In the United States alone, obesity and diabetes are both epidemic, with some estimates putting the percentage of Americans with some form of metabolic problem as high as 35 percent.
Though the main causes of obesity are high food intake, lack of adequate exercise, and genetic susceptibility, researchers have long suspected that stress may play a role as well. Along with the familiar phenomenon of "stress eating" and binging, stress is also believed to affect the body's metabolism, including those processes underlying how our bodies process nutrients. Despite various attempts at determining the exact mechanism linking stress and metabolism however, researchers have had little success. But a new study by researchers at the Hebrew University of Jerusalem may change all that.
Headed by Professor Hermona Soreq of the university's Edmond and Lily Safra Center for Brain Sciences, the research team has identified key molecular elements, known as microRNA, which may act as a bridge between anxiety and metabolism. First isolated in the 1990s, microRNA is found in a wide range of plants, animals, and some viruses. Originally considered to be "junk DNA," microRNA has since been found to play an important role in regulating protein production and the production of acetylcholine and other essential neurotransmitters. One exciting finding is that the way chronic stress and anxiety affect inflammation in the brain and gut and may help explain how stress can affect conditions such as Crohn's disease and arthritis.
“In the present study, we added obesity to the equation," Dr. Soreq said in a recent interview. "We revealed that some anxiety-induced microRNA are not only capable of suppressing inflammation but can also potentiate metabolic syndrome-related processes. We also found that their expression level is different in diverse tissues and cells, depending on heredity and exposure to stressful situations."
The latest research paper, recently published in the journal Trends in Molecular Medicine, provides evidence that microRNA pathways share regulatory networks for metabolic disorders as well as anxiety spectrum disorders such as posttraumatic stress disorder, obsessive-compulsive disorder, and phobia. This includes the regulation of acetylcholine signaling in the central nervous system and related molecular mechanisms.
Not only might this discovery provide new ways of diagnosing anxiety disorders, but it could also lead to radical new treatments for metabolic disorders (including obesity), as well as psychiatric symptoms linked to stress.
“The discovery has a diagnostic value and practical implications, because the activity of microRNAs can be manipulated by DNA-based drugs,” concluded Soreq. “It also offers an opportunity to reclassify ‘healthy’ and ‘unhealthy’ anxiety and metabolic-prone states, and inform putative strategies to treat these disorders.”