Anorexia nervosa is a devastating eating disorder that often endangers the lives of sufferers. The causes of the condition are not fully understood, making it extremely difficult to treat, although there is some evidence to suggest that cannabis may play a role in helping people deal with certain aspects of anorexia.
Cannabis, Cannabinoids, Anorexia And Appetite
The fact that cannabis is so synonymous with the munchies has led to the suggestion that smoking weed may help to combat anorexia by stimulating the appetite. In reality, however, the condition entails much more than a simple lack of hunger and is underpinned by complex psychological issues such as body dysmorphia, low self-esteem and obsessive behaviours.
Cannabis alone is therefore unlikely to be enough to bring about recovery from anorexia, yet it may be a useful tool in the quest to increase eating and gain weight. The hormone leptin, for example, is heavily involved in appetite suppression and is greatly influenced by the activation of the cannabinoid 1 (CB1) receptor. In studies on mice, the inactivation of this receptor significantly disrupted the function of leptin, hinting at a role for cannabinoids in the treatment of eating disorders[i].
Further animal research has revealed that CB1 receptor signalling mediates the link between smell and hunger. When mice were treated with cannabinoids, they became more responsive to the aroma of certain foods and increased their intake[ii]. Similarly, patients with cachexia – or appetite loss – following cancer or HIV treatment tend to eat more and gain weight when given CB1 agonists[iii].
Such findings do not amount to evidence that cannabis treats anorexia but do imply that cannabinoids may help underweight patients put on some extra pounds. Given that severe weight loss is one of the most dangerous symptoms of anorexia, this fast-acting appetite stimulator could be a life-saver for those seeking treatment.
Does Cannabis Actually Work For Anorexia?
There are hardly any proper studies involving the use of cannabis to treat anorexia. Of the two small-scale studies that do exist, one has been criticised for its poor design and methodology, leaving only one credible trial[iv].
Conducted at a specialised centre for the treatment of eating disorders between 2008 and 2011, the study involved 24 women with severe anorexia nervosa. Participants took 2.5 milligrams of synthetic THC twice a day for four weeks, followed by a month-long break and a subsequent four-week course of a placebo.
THC treatment brought about an average extra weight gain of 0.73 kilograms per patient compared to the placebo. Importantly, the dosage used was so low that most of the women in the trial were unable to tell if they had received the cannabinoid or the placebo[v]. In contrast, the aforementioned problematic study used much higher doses of THC, causing many of the participants to withdraw from the trial after getting a little too stoned[vi].
According to the study authors, 82 per cent of this weight gain was directly attributable to the THC, indicating that cannabis may help women with anorexia to increase their food intake and attain a healthier physique.
Though there are no studies into the efficacy of different cannabis strains for anorexia, Indica varieties are renowned for their capacity to stimulate the appetite. Anyone looking to gain weight may therefore want to try cultivars like OG Kush or Skywalker OG.
It’s vital to remember, however, that in the absence of other therapies, cannabis is unlikely to treat the underlying causes of anorexia, even if it can help with that initial increase in food intake.
[i] Cristino L, Becker T, Di Marzo V (2014) Endocannabinoids and energy homeostasis: an update. BioFactors 40(4):389–397. https://iubmb.onlinelibrary.wiley.com/doi/10.1002/biof.1168
[ii] Soria-Gómez E, Bellocchio L, Reguero L, Lepousez G, Martin C, Bendahmane M, Ruehle S, Remmers F, Desprez T, Matias I, Wiesner T. The endocannabinoid system controls food intake via olfactory processes. Nature neuroscience. 2014 Mar;17(3):407-15. – https://www.nature.com/articles/nn.3647
[iii] Nelson K, Walsh D, Deeter P, Sheehan F (1994) A phase II study of delta-9-tetrahydrocannabinol for appetite stimulation in cancer-associated anorexia. J Palliat Care 10(1):14–18. https://journals.sagepub.com/doi/10.1177/082585979401000105
[iv] Rosager EV, Møller C, Sjögren M. Treatment studies with cannabinoids in anorexia nervosa: a systematic review. Eating and Weight Disorders-Studies on Anorexia, Bulimia and Obesity. 2021 Mar;26(2):407-15. – https://link.springer.com/article/10.1007/s40519-020-00891-x
[v] Andries A, Frystyk J, Flyvbjerg A, Støving RK. Dronabinol in severe, enduring anorexia nervosa: a randomized controlled trial. International Journal of Eating Disorders. 2014 Jan;47(1):18-23. – https://onlinelibrary.wiley.com/doi/abs/10.1002/eat.22173
[vi] Gross H, Ebert MH, Faden VB, Goldberg SC, Kaye WH, Caine ED, et al. A double-blind trial of delta 9-tetrahydrocannabinol in primary anorexia nervosa. J Clin Psychopharmacol. 1983;3:165–171. – https://journals.lww.com/psychopharmacology/abstract/1983/06000/a_double_blind_trial_of.4.aspx.