'RETOX' A WORRY IF YOU GO OFF THE GRASS

REFORMED cannabis users opting for a crash diet and gruelling exercise
regime stand a greater chance of "retoxifying" than coming clean, a
study has found.

An Australian finding, published in the British Journal of
Pharmacology, found that stress or extreme dieting could trigger a
release of THC, the psychoactive cannabis ingredient stored in fat,
back into the bloodstream.

Co-author Jonathon Arnold, a senior lecturer in pharmacology from the
University of Sydney, said the researchers studied rats after noticing
unusual results in humans. "I had a case where a guy swears blind that
he hadn't consumed cannabis," he said.

"But he'd gone on a vigorous weight-loss regime, lost four kilograms
within a week and got this exceptionally high cannabinoid level that
he couldn't really explain."

Dr Arnold and colleague Iain McGregor injected rats with a
THC-equivalent of smoking between five and 10 cannabis cigarettes a
day for 10 days, before sending them cold turkey and exposing them to
a stress hormone or depriving them of food.

In the hungry rats, the THC reading was more than double that of the
control group. There was a statistically significant increase in
stressed rats.

Dr Arnold said the implications for humans were being
studied.

"You could potentially kick your grass habit and a couple of weeks
later go on a rigorous diet and exercise regime and it is
theoretically possible, based on this paper, that the THC could flood
out and lead that person to being re-intoxicated," he said.

This potentially also had yet-to-be studied implications for fuctional
impairment under certain situations, such as for those who follow up a
weekend binge by skipping breakfast and heading to the gym on a Monday
morning, where "it could possibly lead them to say some silly things
in a meeting", he said.

Jan Copeland of the National Cannabis Prevention and Information
Centre said it was a case of user beware.

"Frequent cannabis users who make health lifestyle choices that
include quitting cannabis in association with a diet and exercise
regime need to be aware that they may still test positive for cannabis
for ... up to four weeks or even longer," she said.

"Those for whom a negative test is critical should have a confidential
test done by their GP."

But Edward Wray-Bliss a lecturer at the University of Technology who
has studied the use of drug testing in workplaces, said tests using
hair rather than urine could return a positive result up to a year
after a heavy cannabis user had taken the drug.

Dr Wray-Bliss said that, in most cases, this represented a massive
overreach of the rights of the employer over the lifestyles of their
staff.

"It's a real problem for the legitimacy of drug testing in the
workplace because it doesn't measure impairment, it only measures some
historic useage at some point in the past," he said.