In a study published in the journal Experimental and Clinical Psychopharmacology, a team of researchers found that habitual coffee consumers were more sensitive to a coffee odor than non-consumers, which increased with level of caffeine craving.
Regular coffee consumers can sniff out even small amounts of coffee and are faster at recognizing the aroma. Image credit: StockSnap.
“We wanted to examine if there were any differences in the ability of people to smell and respond to the odor of coffee, depending on whether or not they were big coffee drinkers,” said lead author Dr. Lorenzo Stafford, an olfactory expert in the Department of Psychology at the University of Portsmouth, and colleagues.
“The results point firmly to a link, with heavy coffee drinkers being more sensitive to the smell of coffee, and the smell being linked to their cravings.”
In one experiment, 62 men and women were divided into those who never drank anything containing caffeine; those who consumed moderate amounts (70-250 mg, equivalent to 1-3.5 cups of instant coffee a day); and those who consumed a high amount (300 mg, equivalent to 4 or more cups of instant coffee a day).
Each person was blindfolded and, to test their sensitivity to the smell of coffee, they were asked to differentiate very small amounts of the coffee odor from odor blanks, which have no smell.
For the odor recognition test, they were asked to identify as quickly as possible the scent of real coffee and, separately, the essential oil of lavender.
Those who drank the most coffee were able to identify coffee at weaker concentrations and were faster to identify the odor.
Each person was also asked to complete a caffeine-craving questionnaire. Predictably, the results showed that the more caffeine a person usually consumed, the stronger their craving for caffeine.
In a second experiment, 32 people not involved in the first experiment were divided into those who drink coffee and those who do not and they were tested using the same odor detection test for coffee odor, and with a separate test for a control, using a non-food odor.
Again, the results showed the caffeine consumers were more sensitive to the coffee odor but crucially, did not differ in sensitivity to the non-food odor.
“We found the higher the caffeine use, the quicker a person recognized the odor of coffee,” Dr. Stafford said.
“We also found that those higher caffeine users were able to detect the odor of a heavily diluted coffee chemical at much lower concentrations, and this ability increased with their level of craving. So, the more they desired caffeine, the better their sense of smell for coffee.”
“Caffeine is the most widely consumed psychoactive drug and these findings suggest sensitivity to smell and its links to craving could be used to help break some drug use behaviors, including addiction to tobacco or reliance on cannabis.”
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L.D. Stafford et al. Higher olfactory sensitivity to coffee odour in habitual caffeine users. Experimental and Clinical Psychopharmacology, published online May 9, 2019; doi: 10.1037/pha0000293
