Will Californians approve Proposition 19 in the Nov. 2 election? That’s the measure that would regulate and tax the legal sale of medical marijuana.

Back in February we told you about the results of a study by the state’s Center for Medicinal Cannabis Research, which found that pot, even in low doses, can alleviate pain and other symptoms.

A field of study that is short on hard science got some more evidence in marijuana’s favor this week, when Canadian researchers that found the highest dosage of marijuana can reduce the pain levelreported by sufferers of neuropathic, or nerve, pain.

The research, published in the Canadian Medical Association Journal, examined 21 men and women whose average age was 45. Three potencies of marijuana were used: one with 9.4 percent tetrahydrocannabinol (THC, the active ingredient in pot), 6 percent and 2 percent, as well as a placebo. (“Street” marijuana is much stronger, at 10-15 percent.) Each of the subjects smoked all four substances, holding in a single puff for 10 seconds, three times a day for five days each.

The patients then then rated their pain level on a scale from 1-10, with 10 being the worst. After the highest concentration of marijuana, 9.4 percent, subjects reported pain levels of 5.4, compared with 6.1 for the placebo. That doesn’t sound like much, but researchers said the patients had found little relief with other medications.

Last Saturday more than 1,000 people gathered at the Anaheim Convention Center for the Know Your Rights Expo, a medical-marijuana conference. Among the booths promoting literature and pot paraphernalia was a mother of an autistic, terminally ill son who says she helped him get relief, and put on weight, thanks to medical marijuana.

You can read Scott Martindale’s story about the confab, here. And listen to the mother’s story in the video above.