It should come as no surprise that there is a connection between marijuana and appetite. The question is, what causes such ravenous hunger when high? Scientists are just beginning to figure out what happens in the body when you smoke pot and the answer to that has the potential to change the way we look at weight loss. 

Marijuana and Olfactory Processes 

A discussion of marijuana and appetite entails that we delve deeper into what role cannabinoids, specifically THC, play in our olfactory process.

Research conducted in 2014 on mice found that THC fits into the receptors in the brain’s Olfactory bulb, increasing the animals ability to smell food, leading them to eat more of it. The research indicated that THC may enhance your smell and taste receptors thereby stimulating your appetite. Although, to understand why THC affects us on such a profound level we need to understand the origins of this cannabinoid.

Scientists have long surmised that THC may have been produced by marijuana plants as self defense against herbivores who might feel disoriented after eating the plant and avoid it in the future. The surprising thing is that THC fits into the brain’s natural endocannabinoid system, which helps to control emotions, memory, pain sensitivity and appetite.

Marijuana and the Endocannabinoid system 

The Endocannabinoid system is one of the body’s largest neurotransmitter networks. Its function is to maintain homeostasis, which means maintaining a stable internal environment despite external environment changes. This network is composed of messengers and receptors which work together to balance the internal environment. ECS is responsible for keeping tabs on, 

  • Fertility, pregnancy and reproductive systems 
  • Appetite, hunger and digestive systems 
  • Sleep 
  • Motor Control
  • Pain and Pleasure 
  • Immune Functions 
  • Temperature
  • Mood and Memory 

The brain naturally produces endocannabinoid molecules (like anandamide and 2-arachidonoylglycerol, or 2-AG), which are home-grown messengers that can be found in your brain, organs, connective tissues, glands, and immune cells. There are two main types of receptors CB1 and CB2 with the latter found mainly in the immune system and the former located in the brain and nervous system along with the lungs, liver and kidneys. 

The cannabinoids in weed bind with these receptors. For instance , the THC in Cannabis binds with CB1 which results in pain relief, nausea relief and mood changes. The CBD interacts with CB2 and is involved in the regulation of appetite along with managing pain and inflammation. 

Scientists have found that the cannabinoid THC increases your appetite by binding with the CB1 receptor. In the different body tissues it occupies, CB1 acts in slightly different ways, several of which increase appetite. CB1 can be found in, 

  • The basal ganglia, where it may enhance eating pleasure.
  • The limbic forebrain, where it may enhance food palatability.
  • The stomach and small intestine, which both regulate ghrelin (an appetite-stimulating hormone that speeds digestion).
  • The hypothalamus and rhombencephalon, two sections of the brain that help regulate food intake.

By activating CB1, THC increases appetite through the below observed mechanisms. 

  • It may decrease your levels of Peptide Tyrosine Tyrosine (PYY), thus increasing your levels of hormone ghrelin, which increases your appetite. 
  • It activates the mTOR (Mammalian target of rapamycin) pathway, thus increasing your levels of hormone ghrelin which increases your appetite. 
  • It activates a subset of neurons called proopiomelanocortin neurons (POMCs). These neurons can suppress hunger (primary pathway) and/or increase appetite (secondary pathway) to various degrees. 

These exciting findings hints at how THC manipulates the body’s natural system, it mimics sensations felt when we are deprived of food. The findings also support previous research conducted into marijuana and appetite.

In a 2005 study, scientists found that Cannabis use rendered specific neurons in the brain “more excitable” and inhibited the appetite suppressing hormone, leptin.

A 2009 study conducted in Japan found that marijuana may, interact with taste receptors to enhance the sweet taste in food, thus boosting cravings especially for sweet foods. All this research points to a strong connection between marijuana and appetite, particularly through the interaction of exogenous cannabinoids with our endocannabinoid system.

The Exciting future of Cannabis Medication 

Cancer patients and people suffering from HIV already use the link between marijuana and appetite to their benefit, but exciting research in this space could pave the way for breakthrough drugs and pills, to jumpstart hunger which could be a boon for patients undergoing chemotherapy who often complain of nausea and loss of appetite.

Even more exciting could be the new approaches to treating obesity, that may arrive once scientists deepen their understanding of the Endocannabinoid system. For instance, by understanding how to block certain receptors in the brain, scientists could develop a cure for obesity which would have far reaching implications for the future of marijuana and public health.

CB1 receptors the key to weight loss

Since activating CB1 increases appetite, it isn’t surprising  that blocking this receptor has the opposite effect. Studies have shown that blocking CB1 increases the production of adiponectin, an anti inflammatory hormone negatively associated with obesity. 

Researchers used Endocannabinoid antagonists (compounds that block CB1) to treat obesity as a result by compulsive bringing or cravings. Rats given the anti-obesity drug rimonabant, an endocannabinoid antagonist, lost weight and experienced a reduction in their blood levels of insulin. Human trials of the same drug showed weight losses of 2.6–6.3 kg (5.7–13.7 lb) above placebo. Most of these trials lasted over a year, including one that saw a plateau at 9 months.

Yet in spite of these successes, rimonabant failed to earn approval from the U.S. Food and Drug Administration (FDA) and was withdrawn from the European market, due to side effects that include nausea, dizziness, severe depression, and suicidal thoughts.

Still, in the future safer Endocannabinoid antagonists ( compounds that block CB1 receptors) may play a role in treating obesity by blocking CB1 in order to increase adiponectin production and reduce appetite. 

Authorship

Malcolm Pinto.