Rimonabant’s Suppression of Chocolate Intake Persisted After Its Chow Effect Faded in Rats
Rimonabant reduced chocolate-flavored beverage intake throughout a twenty-one-day rat experiment, while its reduction of ordinary food intake was smaller and short-lived. The same treatment therefore showed different adaptation patterns for different available foods.
Food choices were available concurrently
Rats had continuous access to a chocolate-flavored beverage, regular pellets and water. They received daily rimonabant, a CB1 antagonist/inverse agonist, or control treatment. Comparing intake within that arrangement helped distinguish the response to a highly palatable option from the response to ordinary chow.
Persistence differed between endpoints
The dose-dependent beverage reduction lasted throughout treatment without apparent tolerance. The pellet-intake effect was largely limited to the first few days. Calling the drug simply tolerant or non-tolerant would conceal this divergence. Duration of one food-related effect did not determine duration of another in the same experiment.
The hedonic explanation was an interpretation
The authors suggested a stronger influence on hedonic than nutritive properties of the diet. That is a mechanistic interpretation of an intake pattern, not a direct measurement of human pleasure or addiction. Differences in observed consumption do not independently establish improved health, nutritional adequacy or a safe long-term weight-loss treatment.
Interpreting the evidence
The study makes food type part of the tolerance question. Its rat feeding results should not be turned into a claim that blocking CB1 is a clinically suitable way to manage appetite or cannabis-associated eating.
Related reading: consequences of changing endocannabinoid breakdown.
Research reference
Gessa GL; Orrù A; Lai P; et al. (2006). Lack of tolerance to the suppressing effect of rimonabant on chocolate intake in rats. Psychopharmacology. doi:10.1007/s00213-006-0327-1. Evidence basis: study abstract.
