Her visiting card has an imprint of the familiar five-bladed leaf of the cannabis plant on both sides, leaving no room for doubt about the cause she espouses. Dr Uma Dhanabalan is trained in family medicine, with a Masters in public health from Harvard University, but over the past four years, she has been on a mission to educate people about the therapeutic benefits of cannabis (marijuana).In her home state Massachusetts, she does medical marijuana authorisations and is involved in efforts to reform US government policy on marijuana. Stopping over in Bengaluru after attending an ayurveda conference in Kolkata, she talks about her mission with Indulekha Aravind. Edited excerpts:I was in Kolkata for the World Ayurveda Congress to present a paper on the endocannabinoid system and therapeutic use of cannabis. It’s been an “Aha” moment for me — cannabis was introduced to the US by a gentleman named Dr William (Brooke) O’Shaughnessy who had come to Bengal in 1833 to learn about ayurveda. That’s when he learnt about cannabis. And here I was, 183 years later, coming to West Bengal to talk about cannabis at an ayurveda conference!It is one of the five essential plants mentioned in the vedas , along with soma and barley. It is part of our medicinal and spiritual culture. In ayurveda, it was used to improve memory, against leprosy, and many other things.There was a lot of curiosity but also caution because it is still illegal. I sensed a feeling of fear when these people even talk to me! And that’s kind of interesting because it’s the same stigma as in the US. India was the origin of cannabis as medicine, we need to bring it back. And I would love to come back to India for this. I believe I’ve planted at least a few seeds on this trip.From India, O’Shaughnessy went to Afghanistan and Nepal to learn about cannabis and took that knowledge to the US and Europe. In 1850, it was part of the US Pharmacopeial Convention (which sets standards) and prescribed by doctors from 1850 to 1942. Those are the facts! Now why did this change? The evidence points not to facts, but propaganda. It began in the 1930s, when they began to call it marijuana, to change the connotations and associate it with Mexicans, blacks and musicians. Movies like Reefer Madness were released. At that time, cannabis was being used as food (hemp seeds), in paper, building material, medicine… The people who had an agenda were the Hearsts, who had paper mills and the power of yellow journalism, DuPont with patents in polyester and nylon, Rockefeller and Carnegie who had pharmaceutical companies. These are the people who changed the face of cannabis. And a man called Harry ( J) Anslinger (Bureau of Narcotics commissioner) was their mouthpiece. Cannabis began to be called the “gateway drug”. They made statements like “Marijuana is the most violent drug in the history of mankind”. Then in 1937, they imposed the Marijuana Tax Act.Cannabis is in Schedule 1 (of the Drug Enforcement Administration) along with heroin and LSD (lysergic acid diethylamide). Schedule 1 drugs are those that have no medical use, no medical research in the US and have the highest potential for abuse. On a federal level, it is still illegal but there are 28 states where you can use medical marijuana. There are nine states where it is now legal for full recreational use. What I’m fighting for is for it to be descheduled and treated like alcohol and tobacco, which means it can be taxed but will be available to people over the age of 21. If it goes into Schedule 2 or 3, it will go into the hands of Big Pharma. Cannabis is not for everybody. But I believe it should be a first-line option, not a last resort.My mother was diagnosed with a condition called idiopathic pulmonary fibrosis — fancy term for we don’t know what caused your lung disease. After she died in 2012, I realised I’d been lied to. I learnt the implications of how this medicine could have been used to help her. That’s when I started learning about it, and became passionate about it. I said this two years ago: Cannabis is not an entrance drug — it’s an exit drug from pharmaceuticals and narcotics. Now, I don’t contribute at all to the opioid epidemic in the US — I haven’t written an opioid prescription in six years. I have over 800 patients, from 18-year-olds to a 96-year-old. I’m getting them to improve their lives, patients are using this to make sure their cancer never returns. Cannabis works for so many ailments because of the endocannabinoid system in the body, which has receptors everywhere to accept cannabinoids such as tetrahydrocannabinol (the cannabis plant has over 80 cannabinoids, a unique compound). We need more doctors to understand that the stigma is purely because of politics, not because of evidence. There are zero fatalities due to cannabis use — what part of that evidence of zero fatalities don’t people get?California recently legalised it... I was very involved with the legalisation of cannabis in both Massachusetts, where I live, and in Maine, my neighbouring state. Medicinally, it has been legalised in 2012 but we didn’t have stores till 2014. The stigma is still there. Even my own society of clinicians had a lot of pushback against what I’m doing. But it passed. Massachusetts, Maine, Nevada and California were the four states in which it became legalised. We are facing a huge opioid epidemic in the US. The US has 5% of the world’s population but we consume 80% of the world’s opioid prescription. That’s not acceptable.We need more education and research. We already have over 25,000 research articles on cannabis and endocannabinoids but we need to learn more. What we’ve learnt is that in the states that have had legalisation and medicinal use, we have a 25% decrease in opioid consumption in two years. That becomes 33% in five years. There’s decrease in alcohol consumption, opioid overdose, and a saving of $165 million in medicare expenses.This is a medicine, and it has to be treated as such. We need to do that through education, proper information. We need to stop alienating patients who want to use this. In the US, most doctors will not write the recommendation (for cannabis) because they like their paycheck. Right now, it is still illegal at the federal level and doctors who work in universities and hospitals still get a paycheck from the federal government, so why bite the hand that feeds you.Regardless of that, this is what we have to do. I’m always an optimist. I will go anywhere for this, just as I came to India. Nobody else paid for my trip. I’ve come on my own behalf. No one supports me other than my own patients.