Scientists have studied the effect of the smell of fresh coffee on mood

Five minutes next to freshly brewed coffee was accompanied by an improvement in self-esteem and mood among participants in a small study. After the experiment, they reported less fatigue, tension, and confusion, and the device recorded a change in brain activity, which the authors associate with relaxation. At the same time, the heart rate did not change significantly. The researchers warn that without a control group, it is impossible to determine whether it was the aroma of coffee that caused the changes. About how the work was carried out and what its results mean, see the "Izvestia" material.

How the experiment was conducted

The authors of the study invited 20 healthy adults aged 20 to 29 years. They were interested in whether three groups of indicators change simultaneously after short-term exposure to the aroma of coffee: assessments of one's own mood, electrical activity of the brain and heart function.

The researchers prepared a fresh portion of the drink for each participant.: 20 g of ground Sumatran coffee was brewed with 400 ml of water at a temperature of 85 degrees through a paper filter. The coffee container was placed about half a meter from the seated person. He breathed calmly for five minutes, feeling the smell spreading through the room. The participants did not drink coffee.

Immediately before and after these five minutes, the researchers assessed the condition of each volunteer using the POMS mood questionnaire, electroencephalography, and heart rate measurements. Thus, they compared the performance of the same person at two points in time.

This approach has the advantage of not having to explain the difference between participants who were initially in different moods. But there is also a significant limitation. All the volunteers underwent the coffee-scented procedure; there was no group in the study that would have spent the same five minutes without it. Therefore, the observed change cannot be confidently attributed to flavor.

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How the mood has changed

After the experiment, the overall rate of adverse conditions in the POMS questionnaire decreased. On average, participants reported less fatigue, tension and anxiety, confusion, as well as lower scores on the depression scale. At the same time, the indicator of vigor and activity did not significantly change.

It is important to distinguish between the mood scale and the medical diagnosis. A decrease in depression scores means a change in participants' responses about how they felt at the time of the measurement. The study did not examine the treatment of depression and does not show that the smell of coffee reduces the symptoms of a clinical disorder.

The overall indicator of adverse conditions decreased by an average of 20.54 points according to the method used. This is the difference between the scores before and after the procedure, not the percentage of improvement in mood, or an indicator of how long the effect lasted: the authors did not conduct follow-up.

What did the brain and heart measurements show?

In addition to the answers in the questionnaire, the researchers studied an electroencephalogram, a record of the electrical activity of the brain. The relaxation index calculated by her after five minutes increased from about 0.74 to 0.78. The difference was statistically significant in this group, but such an index by itself does not show how much a person felt calmer in an everyday sense.

Measurements of heart function did not reveal statistically significant changes in either heart rate or heart rate variability. Therefore, the results do not confirm that in five minutes next to coffee, the body went into a distinctly different state according to these cardiovascular indicators.

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The scientists also checked whether the changes were the same for individual people. For example, whether the mood improved more in those who had a more noticeable increase in the EEG index. They did not find significant links between individual changes in mood, brain activity, and cardiac parameters. This does not prove that the reactions are completely independent: with the participation of only 20 people, the study might not have enough data to identify such a connection.

Is it possible to talk about the effect of coffee flavor

The study focuses specifically on the smell that the participants felt without drinking the drink. Therefore, the observations cannot be explained by the usual effects of caffeine after a cup of coffee. However, the lack of coffee does not prove that the changes were caused only by odorous substances.

The volunteers could feel better thanks to a five-minute rest, expectation of a pleasant effect, or habitual associations with coffee. The answers could also be affected by re-filling out the questionnaire. To separate the influence of smell from these factors, a control group is needed: for example, participants who will spend the same amount of time without the smell of coffee or next to another aroma.

In addition, the work involved a small group of healthy young people. The authors did not compare the reactions of people who like and dislike coffee, and did not systematically evaluate their habitual consumption of the drink and their individual sensitivity to odors. It is not known whether people of a different age or in a familiar environment would have achieved the same results.

Thus, the study recorded short-term changes after contact with the aroma of fresh coffee, primarily in self-assessment of mood. It provides a basis for a more rigorous experiment, but it does not yet confirm that the smell of coffee by itself improves mood or helps to cope with anxiety and depression.