Key Takeaways
Caffeine and its breakdown products exhibit invigorating effects. They are responsible for the diminution of fatigue induced by adenosine by blocking its specific receptors. Caffeine, due to its performance-enhancing properties, is frequently utilized by athletes (which is confirmed by the frequency of detection in the urine of professionals). In 2004, it was removed from the list of banned doping substances by the World Anti-Doping Agency (WADA). Characteristic consequences associated with caffeine intake can even occur under the influence of the mere awareness of its consumption, which is referred to as the placebo effect of caffeine.
The placebo effect of caffeine and psychoactive performance
Some studies show that consuming 1-2 cups of coffee per day contributes to improving cognitive impairments (L. Wu et al. 2017). Coffee can have a positive effect on the prevention of Alzheimer's, although, as P. London et al. describe, some studies in this area provide uncertain outcomes. However, caffeine and thus coffee itself have many benefits. It is widely believed that coffee has a positive effect on the treatment of cognitive impairments, especially in individuals who require concentration and strengthening. An example of this is that decaffeinated coffee significantly enhances the motor skills of individuals who reported expecting this effect (I. Kirsch and L. Weixel). A study published in the journal "Human Psychopharmacology" also confirms the existence of this phenomenon. Participants who believed that they had received coffee with caffeine (though they had actually received a decaffeinated beverage) performed much better in a test assessing psychomotor vigilance than those who knew what they were drinking.
The placebo effect associated with caffeine and the fat oxidation process
Twelve men were put through a three-day effort test with a gradual increase in difficulty level. On the first day they received caffeine (3 mg/kg), on the second day a placebo, and on the third day also a placebo, although they were informed that they were receiving caffeine. The process of fat oxidation was emphasized on the first and third day. No significant difference was noted between the first and third day (J. Gutiérrez-Hellín et al, 2021). Could the placebo effect of caffeine also impact the effectiveness of exercises during weight loss? The study results suggest that caffeine worked similarly to the belief in its consumption, but researchers were not always able to observe such an effect. The placebo effect of caffeine was not observed in a study published in 'Nutrients' (A. Filip-Stachnik et al, 2020). In women who typically consumed moderate amounts of caffeine (an average of 4.1 mg caffeine/kg per day), it was not shown that the belief in consuming 6 mg caffeine/kg body weight before strength training (weightlifting) affected the effectiveness of the workout and increased the number of repetitions. Researchers explain that if someone drinks coffee more often and in larger quantities, they may become less sensitive to its actual effect, and thus the belief in its stimulating properties also decreases. It is not excluded that the effect of caffeine decreases with increased consumption. The placebo effect of caffeine may be unnoticed in people accustomed to daily coffee consumption. Nevertheless, the withdrawal symptoms of coffee can be painful for some.
Caffeine foam
The effects of caffeine withdrawal have been observed in many individuals who frequently consume coffee. Headache, fatigue, decreased concentration - these are the most common. Reintroduction of caffeine results in alleviation of these symptoms. The placebo effect of caffeine may also play a role in the intensification of these symptoms (L. M. Juliano et al. 2019). Regular coffee drinkers who abstained for at least 16 hours before the study were divided into two groups, which were then divided into two smaller subgroups.
Group: Participants were given coffee without the stimulant
1 a – They were informed that the coffee they received was devoid of the stimulant 1 b – They were notified that the coffee contained the stimulant.
Group: Participants were given a caffeinated coffee beverage
2 a - They were notified that they had consumed a decaffeinated coffee beverage 2 b - They were informed that they had received a caffeinated coffee beverage. 45 minutes after consuming the beverages, the participants were asked to complete a questionnaire assessing the intensity of symptoms such as headache, fatigue, decreased concentration, irritability. The fewest symptoms were reported by individuals in group 2 b. The highest number of symptoms was recorded in group 1 a - the one that received a decaffeinated coffee beverage and was informed about it. Interestingly, individuals who drank a caffeinated coffee beverage but believed it was decaffeinated (2 a) experienced stronger symptoms than those who drank a decaffeinated coffee beverage but were certain it contained caffeine (1 b). This is an excellent example of how the belief that one is drinking a caffeinated coffee beverage can influence well-being. However, this effect only applies to the initial impressions. By the end of the day, those who had received caffeine felt significantly better than those in the decaffeinated group (regardless of the information they received). Caffeine is a psychoactive substance. The effects of its consumption are generally perceived as positive, and it has also been proven to promote not only physical performance but also health. Attitude can also have an impact on psychological well-being.