Theoretical Explanation for Reduced Body Mass Index and Obesity Rates in Cannabis Users
Thomas M. Clark, Jessica M. Jones, Alexis G. Hall, Sara A. Tabner, and Rebecca L. Kmiec
Cannabis and Cannabinoid Research, 2018, Volume 3.1, 259-272
Doi : 10.1089/can.2018.0045
Introduction : Obesity is treatment-resistant, and is linked with a number of serious, chronic diseases. Adult obesity rates in the United States have tripled since the early 1960s. Recent reviews show that an increased ratio of omega-6 to omega-3 fatty acids contributes to obesity rates by increasing levels of the endocannabinoid signals AEA and 2-AG, overstimulating CB1R and leading to increased caloric intake, reduced metabolic rates, and weight gain. Cannabis, or THC, also stimulates CB1R and increases caloric intake during acute exposures.
Goals : To establish the relationship between Cannabis use and body mass index, and to provide a theoretical explanation for this relationship.
Results : The present meta-analysis reveals significantly reduced body mass index and rates of obesity in Cannabis users, in conjunction with increased caloric intake.
Theoretical explanation : We provide for the first time a causative explanation for this paradox, in which rapid and long-lasting downregulation of CB1R following acute Cannabis consumption reduces energy storage and increases metabolic rates, thus reversing the impact on body mass index of elevated dietary omega-6/omega- 3 ratios.
Keywords : Cannabis; body mass index; obesity; omega-6 fatty acid; theory
The current review and meta-analysis establishes the impact of Cannabis use on body mass index (BMI) and obesity rates, and provides a well-supported physiological, causative explanation for this impact. Cannabis use appears to reverse the impact of the modern American diet on health by reducing the effects of an elevated ratio of omega-6/omega-3 fatty acids on endocannabinoid (eCB) tone. It is therefore necessary to understand how diet impacts health to understand the health impact of Cannabis use.
Diet is the main cause of premature death and disability in the United States. The modern western diet is
proinflammatory and obesogenic.1,2 Diseases associated with inflammation and obesity include cancer, cardiovascular disease, diabetes mellitus (DM), Alzheimer’s disease, mood disorders, autoimmune disorders, liver and kidney disease, and musculoskeletal disabilities.1–12
A significant dietary factor contributing to these health problems is an increased ratio of omega-6 (linoleic acid, LA) to omega-3 (a-linolenic acid, ALA) fatty acids,2,10,13–21 especially in the context of a high glycemic load and reduced physical activity. Recent reviews show that dysregulation of the eCB system plays a major role in development of obesity and metabolic disorders, and strongly implicate the elevated omega-6/omega-3 ratio as a primary cause of this dysregulation.15,18,19,22–29 Omega-6 fatty acids are precursors of the eCBs N-arachidonoylethanolamide (AEA, or anandamide) and 2-arachidonoylglycerol (2- AG). These eCB signals act via receptors, including CB1R andCB2R, and CB1R plays a primary role in energy homeostasis. An elevated dietary omega-6/omega-3 ratio therefore leads to elevated levels of AEA and 2-AG, overstimulation of CB1R, and dysregulation of energy homeostasis leading to weight gain.21–23,25,29–32