CBD boosts sleep quality and immune function: Study
A team of U.S. researchers investigated the effects of either 50 mg daily oral CBD or placebo on mental health, immune cell function and sleep quantity and quality in 28 healthy individuals over a study period of eight weeks.
Results showed that daily consumption of hemp-derived CBD resulted in improvements in the overall perceived quality of sleep and enhanced NK cell cytotoxicity.
“CBD supplementation may offer benefits in enhancing sleep quality in humans and improving immunosurveillance,” they wrote.
CBD and sleep
Cannabis-derived phytocannabinoids interact with the body's endocannabinoid system, which includes two cannabinoid receptors (CB1 and CB2), endogenous ligands and their synthetic enzymes.
These components are present in the nervous and immune systems, among others, and are considered the main targets for CBD and other external cannabinoids. CBD is believed to act as an agonist mainly on CB2 receptors.
Previous studies have shown that CBD has anxiolytic (anxiety-reducing) effects by affecting the limbic and paralimbic brain regions. In addition, CBD interacts with the serotonin 1a receptor, which influences mood, anxiety, depression and immune function.
The immune system is crucial for mental health and sleep regulation, and immune cells, particularly natural killer (NK) cells, show high CB2 expression.
One rat study found that circulating NK cell numbers were increased following CBD administration, however, these effects on human NK cells remain unverified.
Sleep quality and immune function
The participants were randomized to receive either oral capsules of 50 mg of CBD or a calorie-matched placebo daily.
They completed pre- and post-intervention assessments, including anthropometric measurements, mental health surveys and sleep analysis.
Blood samples were also collected pre- and post-intervention from all participants to determine immunophenotype and cytotoxic function.
At the eight-week intervention, the study reported no significant differences between placebo and intervention groups with respect to mental health measures, sleep quantity or circulating immunophenotype. There were also no significant changes in body weight, BMI or body fat percentage
However, the CBD group experienced significant improvements in sleep quality measured objectively using a sleep questionnaire and enhanced Natural Killer (NK) immune cell function assessed in situ.
The researchers hypothesized that improved perceived sleep quality might be due to CBD's effects on the central nervous system, particularly through the downregulation of the hypothalamic-pituitary-adrenal (HPA) axis. However, actigraphy (a non-invasive technique used to assess cycles of activity and rest over several days to several weeks) did not detect changes in sleep duration.
“The current investigation sets the stage for additional future investigations regarding CBD effects on sleep and immunological function,” they concluded. “The improvements seen in perceived sleep quality following CBD administration are promising, and future work using PSG following CBD administration would be innovative in uncovering the effects of CBD on sleep architecture.”
Journal: Nutrients
“Eight Weeks of Daily Cannabidiol Supplementation Improves Sleep Quality and Immune Cell Cytotoxicity.”
doi: 10.3390/nu15194173
Authors: Kisiolek, J. Et al.
