Thursday, July 21, 2011
Regular readers will recall my recent posts on the notion that the benefits of regular exercise on body weight are largely mediated by the positive impact on caloric intake rather than by the number of calories burnt.
This notion is based on the idea that exercise modulates eating behaviour by reducing stress, improving mood, and perhaps, even by reducing the ‘reward’ response of palatable foods.
The latter assumption, is supported by a recent stud by Maciej Buchowski and colleagues from Vanderbilt University, Nashville, Tennessee, published in PLoS.
The study was conducted in 12 sedentary or minimally active non-treatment seeking cannabis-dependent adults, who attended 10 supervised 30-min treadmill exercise sessions standardized using heart rate (HR) monitoring (60-70% HR reserve) over 2 weeks.
Self-reported drug use reduced from about 6 joints per day to less than 3 joints a day during the exercise intervention and remained at 4 joints per day 2 weeks after the end of the study.
Average Marijuana Craving Questionnaire factor scores for the pre- and post-exercise craving assessments were also markedly reduced for compulsivity, emotionality, expectancy, and purposefulness.
As the authors discuss:
“Consistent with the changes in cannabis use reported by participants, subjective cravings elicited by cannabis cues were also significantly reduced by exercise, suggesting the possibility that the potential therapeutic effect of exercise may be mediated via brain mechanisms responsible for cue-induced craving.
These same brain mechanisms have been invoked in behavioral addictions involving non-drug rewards, as is observed in overeating and obesity, problematic hypersexuality, and pathological gambling. Analogously, it has been reported that exercise activates some of the same reward pathways as are activated by addictive drugs. For instance, acute bouts of exercise increase central dopamine concentrations and chronic exercise leads to sustained increases in dopamine concentrations and compensatory alterations in dopamine binding proteins in brain regions relevant to reward.”
Thus, the findings from this rather small study provides the basis for conducting a much larger and longer-term study on the use of exercise as a treatment for marijuana addiction.
On the other hand, given important role of the brain’s reward circuitry for food in take, it may not be expected if such a study also demonstrates a positive effect on overconsumption of highly palatable foods.
AMS
Dushesnay, Quebec
Buchowski MS, Meade NN, Charboneau E, Park S, Dietrich MS, Cowan RL, & Martin PR (2011). Aerobic exercise training reduces cannabis craving and use in non-treatment seeking cannabis-dependent adults. PloS one, 6 (3) PMID: 21408154
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