A Cochrane review of 81 randomized controlled trials (6971 participants) examined whether meditation, especially mindfulness-based interventions (MBIs) and transcendental meditation (TM), helps prevent cardiovascular disease (CVD). Compared with no intervention or usual care, MBIs reduced systolic and diastolic blood pressure, anxiety, depression, and perceived stress, but the evidence was low-certainty and heterogeneity was substantial. TM reduced systolic blood pressure compared with active controls (moderate-certainty evidence) and reduced blood pressure, anxiety, and depression compared with non-active controls (low- to very-low-certainty evidence). Neither meditation type consistently improved smoking cessation or well-being. Few trials reported CVD clinical events or adverse events. The authors conclude that the evidence is limited and uncertain, with many small studies at unclear risk of bias.
Chronic pain with a nerve-damage component affects 6–10% of the population, and current drugs help only a minority. Cannabis is widely promoted as a treatment. This updated Cochrane review analyzed 21 randomized, double-blind trials with 2,187 adults suffering from chronic neuropathic pain. For THC-dominant cannabis, there was no clear evidence of at least 50% pain relief or meaningful improvement on a global scale, though nervous system side effects (e.g., dizziness, drowsiness) were increased. Balanced THC/CBD medicines may slightly increase global improvement ratings and pain relief of at least 30%, but these effects were not clinically meaningful and also raised the risk of side effects.