Consuming cannabis every day could delay at-risk youth from moving on to injecting more dangerous drugs, according to a new study that casts doubt upon the age-old assumption that marijuana acts as a gateway for teens to try other more harmful substances. The research, from scientists at the BC Centre on Substance Use, also adds to other work that has suggested marijuana could be used as a substitute for people addicted to opioids. Researchers repeatedly interviewed 481 homeless young people in Vancouver’s downtown core who had never injected any drugs and found - over a decade of tracking this at-risk cohort - that daily cannabis use was associated with a 34 per cent decrease in the rate people started injecting drugs.