A team of U.S. researchers investigated the effects of either 50 mg daily oral CBD or placebo on mental health, immune cellย function and sleep quantity and qualityย in 28 healthy individuals over a study period of eight weeks.
Results showed that daily consumption of hemp-derived CBDย resulted in improvements inย the overall perceived quality ofย sleep and enhanced NK cell cytotoxicity.
โCBD supplementation may offer benefits in enhancing sleep quality in humans and improving immunosurveillance,โย they wrote.
CBD and sleepโ
Cannabis-derived phytocannabinoids interact with theย body’sย 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 theย mainย targets for CBD and other external cannabinoids. CBDย is believedย to act as an agonist mainly on CB2 receptors.
Previous studiesโย 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 forย mental health and sleep regulationโ, and immune cells, particularly natural killer (NK) cells,ย show high CB2 expressionโ.
Oneย rat studyโย found that circulating NK cell numbers were increased following CBD administration, however, these effects on human NK cells remain unverified.
Sleep quality and immune functionโ
The participantsย were randomizedย 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.ย
Blood samples were also collected pre- and post-intervention from all participants to determine immunophenotype and cytotoxic function.ย
At the eight-week intervention, the study reported no significant differences between placebo and intervention groupsย with respect toย mental health measures, sleep quantity or circulating immunophenotype.ย 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 toย CBD’sย effects on the central nervous system,ย particularlyย 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.
โThe current investigation sets the stage for additional future investigations regarding CBD effects on sleep and immunological function,โย they concluded.ย โThe 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.โ
Journal:ย Nutrientsโ
โEight Weeks of Daily Cannabidiol Supplementation Improves Sleep Quality and Immune Cell Cytotoxicity.โ
doi:ย 10.3390/nu15194173โ
Authors: Kisiolek, J. Et al.ย