Habitual coffee drinkers are able to detect the odor of coffee at lower thresholds and are also faster to identify it, according to new research published in Experimental and Clinical Psychopharmacology. The findings provide new insight into sensory changes that accompany drug consumption.
“Many years ago, I completed a PhD on the topic of caffeine and the general importance placed on the sensory (especially smell) aspects of coffee, which all planted the seed (or bean!) for a possible study. More recently, I begun thinking about the role of our sense of smell in drug consumption and addiction,” said study author Lorenzo Stafford, a senior lecturer in psychology at the University of Portsmouth.
“Most of the research in this area is dominated by visual processes, in particular showing how cues associated to drugs (e.g. packet of cigarettes, bottle of beer) become conditioned in such users. That work has been useful in explaining how in recovering addicts, long after the withdrawal symptoms have subsided, when exposed to such cues, they can nevertheless relapse to craving and consuming the drug. Hence, though a powerful driver, addiction is not just about reversing withdrawal symptoms.”
“However, most of our richer experiences are multisensory, so it seems likely that other senses must also play a role in the addictive process,” Stafford explained.
The researchers conducted two experiments to examine how well participants with varying levels of coffee consumption could detect coffee-related odors.
The first experiment, which included 62 participants, found that those who drank the most coffee were able to identify coffee at weaker concentrations and were faster to identify the odor. In addition, those who consumed more caffeine were more likely to indicate they had a stronger craving for caffeine.
“More interestingly, higher craving, specifically that which measured the ability of caffeine to reverse withdrawal symptoms such as fatigue, was related to greater sensitivity in the odor detection test,” Stafford said in a news release.
The second experiment, which included another 32 participants, found that caffeine consumers were more sensitive to the coffee odor but were not more sensitive to other odors.
Stafford told PsyPost that the findings show how “fairly basic processes in olfactory detection are linked to complex behavior such as drug consumption and addiction.”
“So, it was not just a case of more exposure to a smell (coffee) made people better at detecting that odor, but that their ability to detect the odor was related to their habitual consumption and craving.”
“In addition to further work needed in replicating these findings, particularly the craving aspect, I think it would be interesting to explore whether therapy could be developed to help people kick unwanted drug habits. Research from another laboratory has suggested that creating an aversive response to a specific odor is relatively quick and easy in humans, which offers a possible protocol of how a therapy could be developed,” Stafford added.
The study, “Higher Olfactory Sensitivity To Coffee Odour In Habitual Caffeine Users“, was authored by Lorenzo D. Stafford, Kit Damant, Sophie Ashurst, and Matt Parker.