Lack of appetite: the only indication where research contradicts common opinion

What do studies say about cannabis in cases of lack of appetite?

No improvement was observed. A systematic review with meta-analysis on cancer cachexia (PMID:34881518) gathered ten studies, four with randomization and six without, and for appetite received a result of minus 0.02 standard deviations with a confidence interval from minus 0.51 to 0.46, based on very low-quality evidence.

The same work separately assessed quality of life, this time based on moderate quality evidence, and the result was unfavorable for the studied preparations: minus 0.25 with a range from minus 0.43 to minus 0.07. Improvements in appetite were reported by patients in studies without randomization.

A second systematic review, limited to randomized studies in oncology (PMID:33666957), included six studies from the past twenty years. None showed improvement in appetite, food intake, or body weight; there was also no change in the perception of taste and smell or quality of life measured through the lens of appetite. The authors concluded that the collected material does not justify changing the guideline of the European Society for Clinical Nutrition from 2016, according to which there is insufficient data to recommend cannabinoids for taste disorders and anorexia in cancer patients.

This is the only indication described here where the evidence goes directly against common belief. The meta-analysis found no significant improvement in appetite, and in one comparison, the quality of life of individuals taking cannabinoids was worse than in the control group. Improvement in appetite appears in patient reports from studies without randomization, meaning where the expectation of effect was not separated from the preparation itself. The nutritional guideline does not recommend cannabinoids for this indication, and after twenty years of research, there is still no basis to change that.

Where does the belief that cannabis stimulates appetite come from?

From observations where no one separated expectation from the preparation. Increased appetite after cannabis has been reported for decades, but in the material collected for cancer cachexia, such reports come from studies without randomization, meaning from a setup where both the patient and the researcher know what was administered.

The physiology itself is not disputed here. Type 1 cannabinoid receptors are densely distributed in the hypothalamus and the reward system, and stimulating this pathway shifts the signaling of hunger and satiety. However, this description does not imply that in a person suffering from cancer cachexia, it will translate into a meal consumed. The mechanism suggests that something is possible. A randomized study indicates whether it occurred more frequently than in the control group.

The discrepancy between the two layers of the same review is instructive. Studies without randomization provided reports of improvement, while studies with randomization did not confirm this improvement, and the quality of life comparison was unfavorable for cannabinoids. When the result depends on how the patient assesses their own appetite, the mere knowledge of having taken the preparation is enough to shift the assessment. Hence, ravenous hunger is a cultural certainty, yet it is not visible in clinical studies. This same discrepancy is also often seen in other areas of medicine wherever the endpoint is a feeling reported by the patient, rather than a quantity measured by a device.

What strain characteristics are important here?

None. In both reviews, preparations were studied based on the content of active substances, not the name of the cultivar: synthetic derivatives of tetrahydrocannabinol and extracts with a fixed ratio of components. There is no study that randomly assigns patients to two strains and compares their effects on appetite or body weight.

What can be said about the raw material itself pertains to the chemotype, meaning which phytocannabinoid predominates in a given registration entry. Entries with a predominance of tetrahydrocannabinol, balanced entries, and those with a predominance of cannabidiol are often treated separately in the literature because they differ in their action profiles. However, this does not turn the chemotype into a criterion for selection in cases of appetite loss: for this indication, the starting point remains negative regardless of which compound predominates.

The terpene profile is an even weaker premise. The composition of volatile components is sometimes provided by two independent sources, which can report different information for the same position, and none of the studies on appetite recorded the profile of the provided raw material. Thus, correlating terpene with craving would be adding a link that is not present in this material. Separate pages of this compilation are dedicated to individual volatile compounds, for example, the description of limonene, and there it states what is known about them.

What does the doctor decide, and what does the patient decide?

The attending physician decides everything related to treatment. Dried flower is a pharmaceutical raw material dispensed by prescription in the Rpw category, so neither the indication, nor the dosage, nor the route of administration is a matter of choice in the store. The patient brings to this conversation a description of their own symptoms and the course of previous treatments.

In cases of appetite loss, determining the cause takes precedence over everything else. Weight loss can be a result of the underlying disease, cancer treatment, pain, swallowing disorders, or low mood, and each of these causes has its own management. Nutritional care has guidelines based on evidence in this area, and cannabinoids have no recommendations in them.

On the patient's side remains observation and its reliable communication. Recording how much one manages to eat, how body weight changes, and what symptoms occur after taking the preparation is information that the doctor cannot reconstruct from documentation. Tolerance to the preparation can be a separate question from efficacy in this indication, because the evidence of efficacy is negative here, and symptoms occur regardless of it.

The method of dispensing remains a separate issue. A prescription for raw material from the Rpw category is fulfilled at a pharmacy, and the availability of individual entries changes over time with decisions on approval and what the manufacturer currently imports. A person reading a strain description from a year ago may thus have before them an entry that is no longer available on the market, and this is also a conversation to be had with the doctor, not a determination to be made independently.

What adverse effects have been reported in studies on this indication?

They were reported in nine out of ten studies collected in a systematic review with meta-analysis (PMID:34881518), but in randomized studies, they did not differ significantly from the control group, and in studies without randomization, the description was inconsistent and the relationship with treatment remained unclear. Frequencies for the dried flower from this material cannot be read.

Reports of adverse effects are collected for medicinal products with a batch number, not for the strain name, so the following pertains to hemp dried flower as a group of raw materials. The most frequently reported symptoms are dry mouth, red eyes, and increased heart rate. Dizziness upon rapid standing, daytime drowsiness, and temporary worsening of short-term memory are less frequently described, as well as anxiety that increases with dosage. A separate issue is medications taken concurrently, especially sedatives and those affecting coagulation: their assessment requires knowledge of the entire list of preparations, not just the description of the plant. We do not provide the frequency of these symptoms numerically, as public compilations for hemp dried flower in Poland do not separate them by individual products.

For the nutritional indication, one more thing is significant. Some symptoms described after cannabinoids affect the same area as the symptom that would be alleviated: daytime drowsiness and dry mouth do not facilitate eating. In the quality of life comparison, the group taking cannabinoids performed worse than the control group, and this is a statistically significant result, going in the opposite direction to what was expected.

How long does the effect last and what does it depend on?

On the route of administration, not on the strain name. In cases of appetite loss, this has practical implications because a meal is an event at a specific time, and an ingested preparation and a vaporized preparation distribute their effects over time quite differently. The following ranges are described for the route of administration, not for a single pharmacy entry.

The route of administration determines the course more than the variety itself. After vaporization, the substance passes from the lungs to the blood almost immediately, so the first sensations appear after a few minutes, the intensity increases for another ten to thirty minutes, and the whole effect lasts for two to four hours. After ingestion, the raw material first passes through the intestine and liver, so the first sensations are awaited from half an hour to two hours, and the episode can last six, sometimes eight hours. Hence the most common mistake with oral administration: anyone who thinks nothing is happening after thirty minutes and takes another dose will receive both doses at once. The above ranges describe the route of administration, not this variety; pharmacokinetic studies for a single cultivar have not been published.

For the nutritional indication, caution arises from transferring results. The studies gathered in both reviews were primarily based on preparations taken orally, so extending their results to vaporization is a guess, not a conclusion.

Is the mere increase in appetite enough to stop weight loss?

No. Cancer cachexia is a metabolic syndrome in which weight loss and muscle wasting occur despite food intake, so merely improving appetite does not resolve the issue. Therefore, reviews assess not only appetite but also body weight and quality of life, and only the complete set of these points provides insight into the indication.

This difference explains why the results of reviews can be perceived as contradictory to experience. Someone who ate more than usual after taking a product is correct about their own evening. The point evaluated in the study is different: whether the average change in appetite in the cannabinoid group exceeded the change in the control group throughout the observation period. The answer is: it did not exceed.

The scope of this material is narrow. Both studies concern cancer patients, so appetite loss due to other diseases, in older age, or with eating disorders is not included. The conclusion does not extend beyond the population from which it was obtained, and there is simply no data outside of it. This does not mean that cannabinoids act differently in those situations. It only means that no one has verified this in such collected material, and transferring a negative result can be as risky as transferring a positive one.

How to read strain descriptions that link them to appetite?

In such a way that the strain description cannot promise what has not been confirmed. Comparisons are often labeled as indications, and this label comes from sales descriptions and user reports, not from clinical studies. The value of such a description ends with the characteristics of the raw material itself and who supplies it.

What can be verified at the source has a different nature: the registration name, manufacturer, and declared content of the active substance. Such data is collected in the current list of medical marijuana strains maintained on this site, updated when the availability of items in pharmacies changes.

Besides the nutritional indication, there are other axes of this compilation: separate pages describe the state of evidence regarding sleep disorders oraz przy chronic pain. List of items with dried flower in this store is, however, a catalog of the assortment and does not refer to any indication.

It is worth distinguishing between two types of statements that stand next to each other in such descriptions. The statement about the raw material can be verified: the registration name comes from the document allowing the item to be marketed, and the content of the active substance from the manufacturer's declaration. The statement about the effect requires a study in which someone administered this item to patients and compared it with a control group. For appetite loss, there is no such study for any strain, so every statement about the effect is added rather than measured.

Frequently Asked Questions

Do hemp products stimulate appetite?

Randomized studies have not confirmed this. In a meta-analysis on cancer cachexia, the change in appetite in the cannabinoid group did not differ significantly from the control group, and improvements are often described in studies without randomization, where the expectation of effect was not separated from the product.

Can a doctor prescribe dried hemp for lack of appetite?

The indication is determined by the attending physician, and the raw material is dispensed by prescription in category Rpw. This text describes the state of evidence and does not replace such a conversation. The nutritional guideline in oncology does not recommend cannabinoids for this indication.

Which strain works best for appetite?

None have been tested for this purpose. The studies collected in both reviews concerned products described by the content of active substances, not by cultivar names, so comparing strains with each other has no basis in this material.

Where does the belief in ravenous hunger after using hemp come from?

From common observations and from studies where no one concealed group assignments. Receptor physiology describes a possible mechanism, but the mechanism is not the result: verification in a randomized system did not show improvement.

Do cannabinoids prevent weight loss in cancer?

The collected evidence does not show this. Reviews did not demonstrate improvements in body weight or food intake, and in terms of quality of life, the result was unfavorable for cannabinoids compared to the control group.

Do the studies on appetite indicate anything about adverse effects?

Reports appeared in nine out of ten included studies, but in randomized studies, they did not differ significantly from the control group. Frequencies for the dried flower itself cannot be derived from this material.

Do these results also apply to people without cancer?

No. Both studies involve cancer patients, so appetite loss from other causes remains outside their scope, and this material does not provide data for it.

The material is for informational purposes only and does not substitute for medical advice nor does it constitute a recommendation for the use of any product. Redakcja ubucha.pl