Cannabis use is associated with sustained reductions in analgesia and improvements in glycemic control in patients suffering from diabetic neuropathy, according to longitudinal data published in the journal Biomedicines.

Israeli researchers assessed the adjunctive use of inhaled cannabis in a cohort of 50 patients suffering from treatment-resistant diabetic neuropathy. Study participants inhaled standardized, medical-grade cannabis flower (20 percent THC | 1 percent CBD) for five years.

Patients reported significant decreases in their pain scores, as well reductions in their use of opioids and other prescription analgesics, over the span of the study. Specifically, participants decreased their morphine-equivalent doses by more than 90 percent, their gabapentin doses by 97 percent, duloxetine by 93 percent, and pregabalin by 79 percent without developing rebound pain. Patients’ pain severity decreased from a mean of nine to two on a numerical rating scale.

Study participants also exhibited improvements in their A1c scores (glucose levels) following their sustained use of cannabis — a finding that is consistent with other studies assessing the impact of cannabinoids on glycemic control.

No serious adverse events occurred during the trial period.

“The present longitudinal observational study demonstrates the potential long-term benefits of inhaled cannabis as an adjunctive therapy for painful diabetic neuropathy,” the study’s authors concluded. “Over a 5-year follow-up period, patients exhibited significant reductions in pain severity, pain interference, and neuropathic symptoms, alongside marked improvements in pain relief. These symptomatic improvements were accompanied by enhanced glycemic control (HbA1c reduced from 9.77 percent to 7.79 percent) substantial tapering of concurrent analgesics, and no major adverse events attributable to cannabis. … Inhaled cannabis is both safe and effective for treating refractory painful DN [diabetic neuropathy] because it provides pain relief as well as metabolic advantages and allows for reduced medication use.”

The findings are consistent with those of prior clinical trials concluding that both vaporized cannabis and the transdermal application of cannabinoids significantly reduce diabetic neuropathy.

Commenting on the study, NORML’s Deputy Director Paul Armentano said: “This study is the latest in a growing body of research indicating that cannabis effectively mitigates hard-to-treat neuropathic pain while also providing metabolic benefits, particularly for those with or at risk of adult-onset diabetes.”

According to a meta-analysis involving over 478,000 subjects, cannabinoids may possess “protective effects” against the development of type 2 diabetes. Researchers reported, “[T]he odds of developing T2DM [type 2 diabetes] in individuals exposed to cannabis was 0.48 times lower than in those without cannabis exposure.” 

The full text of the study, “Long-term efficacy and safety of inhaled cannabis therapy for painful diabetic neuropathy: A 5-year longitudinal observational study,” appears in Biomedicines. Additional information on cannabinoids and neuropathy is available from NORML.