Studies needed on effects of cannabis use on physical health of children

McMaster University researchers say there is an urgent need for studies on the physical health effects of cannabis use, including its impact on puberty.

The call comes following a systematic review of existing literature that identified an absence of such research. The results of the review were published in Adolescent Health, Medicine and Therapeutics.

"While the effects of cannabis on neuropsychological and cognitive outcomes in children have been studied, there's a need to understand the physical health effects of cannabis," said lead author M. Constantine Samaan, an associate professor of the Department of Pediatrics at McMaster University and a pediatric endocrinologist with Hamilton Health Sciences' McMaster Children's Hospital.

"As puberty is a critical window of physical growth and development, it is critical to fully understand what impact cannabis consumption can have."

Animals studies have shown that chronic cannabis use leads to delayed sexual maturation.

"With legalization, including here in Canada in October, the usage of cannabis among youth will likely increase and there is a need to understand how it will impact their physical health," said Samaan. "While cannabis is not legalized for use by children under 18, this has not limited access by this group. A disruption during puberty can have lifelong implications on growth, metabolism and accumulation of bone mass."

Samaan and his research team at McMaster set out to find studies on boys and girls under age 18 with exposure to recreational or medicinal cannabis. The use of cannabis included smoked, ingested and other modes of exposure to cannabis products. A minimum of 10 study participants were required for the study to be considered eligible for inclusion.

Using these criteria, the team reviewed several databases of medical and scientific journals as well as additional literature sources. The review identified 759 records. A total of 29 full-text papers were assessed for eligibility. However, all studies were excluded as they did not meet the eligibility criteria.

"Adequately powered longitudinal studies are urgently needed to provide pediatricians and other health care providers with high-quality information on the potential effects of cannabis on the physical health of children," said Samaan. "If cannabis affects the physical health in children, clear approaches to prevention and screening for physical health effects are needed."