In a recent study published in the Nutrients Journal, researchers evaluated the effects of oral cannabidiol (CBD) administration on the health and fitness of healthy adults.
Study: Effects of Oral Cannabidiol on Health and Fitness in Healthy Adults: An 8-Week Randomized Trial. Image Credit: KimberlyBoyles/Shutterstock.com
Background
CBD, a non-intoxicating phytocannabinoid extracted from Cannabis sativa L., has shown significant therapeutic benefits in managing neuroinflammatory disorders, including anxiety, depression, Alzheimer's disease, and Parkinson's disease.
Regular CBD usage has been encouraged to improve fitness. Studies have reported that CBD may alter body composition by impacting glucose metabolism and can increase maximal oxygen consumption (VO2 max) with no impact on other parameters of cardiovascular health.
CBD use has also improved learning and memory and increased blood flow in the cerebrum of individuals with cognitive decay. CBD can also reduce interleukin-6 (IL-6) levels among adults with cocaine usage disorders and lower pro-inflammatory gene expression and C-reactive protein (CRP) levels among individuals infected with the human immunodeficiency virus (HIV).
However, contradictory findings have been reported, warranting further research, including randomized controlled trials (RCTs).
About the study
In the present double-blinded, placebo-controlled RCT, researchers investigated the impact of oral CBD use over eight weeks on the health of adult individuals, particularly on health-associated fitness, cognitive health, body composition, physical exercise patterns, psychological well-being, and C-reactive protein (CRP) levels.
The trial included 48 individuals aged 18 to 50 years, who were randomly allocated to receive oral capsules of 50.0 milligrams of CBD (n=23) or 225.0 milligrams of medium-chain triglyceride (MCT) as a placebo (n=25) daily over eight weeks post-dinner and before sleeping.
The individuals completed four visits before and after the intervention, and assessments, including eight-hour fasted blood draws, fitness, body composition, physical exercise, and self-documented surveys, were performed.
All individuals were provided wearable activity trackers (Fitbits) to assess physical activity. The peak value for uptake of oxygen (VO2 peak) in relative terms was calculated on the second visit to evaluate aerobic fitness; a 30.0-second Wingate test was performed to assess power output and evaluate anaerobic fitness on the third visit; and bench press and back squat one-repetition maximums (1RMs) were performed during the fourth visit to assess muscle strength.
Adverse events (AEs) were documented. Primary study outcomes included relative VO2 peak, body fat percentage (BF%), body mass (BM) and lean BM (LBM), peak power (PP) and relative PP (RPP), anaerobic fatigue (AF), mean power (MP), relative MP (RMP), bench press and back squat 1RM, a one-week mean daily step count, self-documented psychological well-being and cognitive function scores, and serological CRP concentrations.
Individuals who abstained from cannabis [CBD and/or tetrahydrocannabinol (THC)] use for six weeks before study initiation and had no history of chronic alcohol consumption or drug usage were included.
Individuals diagnosed with metabolic, neurological, cardiovascular, or mood disorders; pregnant or lactating mothers; and individuals who could not adhere to the intervention for eight weeks were excluded from the analysis.
Cognitive function was evaluated using the National Institute of Health (NIH) Patient-Reported Outcomes Measurement Information System (PROMIS) Cognitive Function-Abilities-Short Form 8a.
Serological CRP levels were determined using enzyme-linked immunosorbent assays (ELISA). Muscular strength was assessed using the National Strength and Conditioning Association (NSCA) guidelines.
Results
The mean values for participant age, height, and BM were 25 years, 171 cm, and 73 kg, respectively. No significant differences were observed between groups regarding body composition, aerobic fitness, muscular strength, physical activity, cognitive health, psychological well-being, or serological resting CRP concentrations.
However, the placebo group experienced a 9.6% reduction in PP and a 6.6% reduction in RPP compared to the intervention group participants.
In contrast, CBD recipients experienced no changes in PP or RPP. No severe adverse events were reported. Combining both groups showed LBM ranging between 37 and 84 kg, BF% ranging between 8.2% and 40%, relative VO2 peak ranging between 28 and 62 mL/kg/min, bench press 1RM ranging between 25 and 161 kg, and back squat 1RM ranging between 39 and 166 kg.
Further, PP ranged between 372 and 1148 W, RPP ranged between 6.0 and 13 W/kg, MP ranged between 288 and 804 W, RMP ranged between 4.2 and 8.3 W/kg, and AF ranged between 43 and 71%. The one-week mean daily step count was 11,415 steps. Cognitive function T-scores ranged between 30 and 64, and cognitive function ability T-scores ranged between 37 and 67.
Concerning psychological well-being, autonomy scores ranged between 8.0 and 21.0; environmental mastery scores ranged between 7.0 and 21.0; personal growth scores ranged between 15.0 and 21.0; scores for positive relations with others ranged between 10.0 and 21.0; purpose in life scores ranged between 11.0 and 21.0; and self-acceptance scores ranged between 8.0 and 21.0. The mean CRP level in serum was 1.40 mg per liter, ranging between 0.10 and 8.8 mg per liter.
Conclusions
Overall, the study findings showed that the regular intake of 50.0 mg of CBD for eight weeks may prevent reductions in anaerobic power with time, likely due to an increase in the levels of antioxidants such as glutathione peroxidase and superoxide dismutase and a decrease in free radicals such as reactive oxygen species (ROS).
However, long-term CBD use did not improve aerobic fitness, body composition, mental health, physical activity, inflammation, or psychological well-being among adults.
Everyday physical activity provides immediate benefits for brain health