Why you should choose cannabis based on smell, not THC levels – study

Aroma is more important than THC potency when it comes to having a pleasant experience with cannabis flower, according to a new paper. 

A new study is the first to demonstrate that a pleasant aroma – as opposed to THC potency, dose or terpene expression – is associated with a more positive experience with inhaled cannabis flower.

The report, ‘The Nose Knows: Aroma, but Not THC, Mediates The Subjective Effects of Smoked and Vaporized Cannabis Flower’ was published this month in the journal Psychoactives, led by Adrianne R Wilson-Poe and co-authored by Dr Ethan Russo.

Consumers always want access to good quality cannabis and previous analysis suggests that they are willing to pay more for it. But what is ‘quality’ cannabis? So far it is yet to be defined, although THC potency and terpene content are often cited as indicators by consumers. 

In their study, Dr Russo and colleagues aimed to identify which features of cannabis contribute to its appealing subjective effects.

In a randomised double-blind process, commercially available cannabis flower products were given to ‘healthy’ volunteers, who then completed an anonymous survey about their effects. 

The data was then analysed by independent researchers.

It’s all in the aroma

They found that it was not terpene expression, THC potency, or THC dose, which were positively correlated with pleasant subjective effects, rather a ‘pleasant subjective aroma’.

“These results suggest that, unlike THC potency, pleasant aroma is predictive of pleasant subjective effects,” says the paper.

“Similar to other agricultural commodities such as coffee and tea, aroma appears to be a robust indicator of the quality of cannabis inflorescence.”

Less is more?

It also appears that less could be more when it comes to cannabis consumption.

Researchers found a negative association between the amount of cannabis consumed and overall appeal, with those who consumed smaller amounts reporting a greater appeal.

Cannabis was also more enjoyable for those who used it less frequently. According to the findings, people who reported a typical consumption frequency of once a week or less were the most likely to report higher appeal scores. 

The vast majority of volunteers (88%) had adhered to the guidance of taking a 48 hour tolerance break prior to consuming the samples.

As the authors put it: ‘Impairment and enjoyment are unrelated phenomena…High-THC cannabis may cause people to feel high, but high‐THC cannabis is not always enjoyable’.

The differing effects of THC

Researchers also recorded some interesting results in relation to how THC affects different demographics.

In the study, males were more likely to report appealing effects of high-THC flower, suggesting that women are more sensitive to the effects of THC. Meanwhile volunteers aged 60 and older reported the greatest overall appeal, compared to other age groups. 

THC potency was not associated with commonly reported adverse effects such as dry eye, dry mouth, or increased appetite, however, it was modestly associated with tachycardia.

Public health implications

These results could have important public health implications, given the ‘well-established health risks of THC overuse’ say the authors. 

In jurisdictions where cannabis has been legalised for adult-use, high-THC products make up a large share of the market and are often perceived to be in higher demand than products containing less THC. 

As a result of their higher monetary value and consumer demand (potency remains a major factor in purchasing decisions according to studies), producers feel pressure to breed more potent strains. 

However, as previous research has shown, frequent exposure to high-THC cannabis can have a detrimental effect, increasing the risk for negative outcomes such as psychosis, cannabinoid hyperemesis, and cannabis use disorder.

Consumer safety 

Dr Russo and colleagues argue that these findings could help consumers make safer and more responsible choices when it comes to choosing cannabis products.

“With a constantly growing worldwide legal cannabis consumer base, there is a great need for consumer education about how to consume safely and responsibly,” they write in the paper’s conclusion.

“Aligned with harm reduction approaches, these blinded, unbiased results suggest that optimal recreational enjoyment may be achieved by the use of small amounts of low-potency cannabis with a pleasant aroma, particularly when used once per week or less.

“The results of this study may help support consumers in making evidence-based decisions that can support subjective enjoyment while decreasing health risks.”

They also recommend that aroma should be considered ‘primary criterion’ when assessing product quality, that products should be regulated in a way that allows consumers to smell before they buy and that the market should be ‘diversified’ to offer a wider range of products containing less than 20% THC.

They add: “These evidence-based practices would have important public health implications by minimising THC as the primary driver of market demand and thus reducing the risks associated with THC overconsumption.”

• How to hide the smell of cannabis
• Germany’s plans for cannabis legalisation – what it means for consumers
• Medical cannabis patients at ‘low risk’ of hospitalisation from mental disorders – study
• How to mitigate the side effects of cannabis
• Cannabis-dependent patients may be at risk of post-surgery complications – study