You may either be obsessed with your “Starbucks run” or know someone who is - likely a combination of the two. Many polled consumers state that they drink coffee to socialize, enjoy a tasty drink, or gain perceived health benefits (Samoggia et al., 2019). However, in society and introspection, coffee’s main incentive is its caffeine. Despite this, framing caffeine as the ‘number one drug in the world’ may have scared many into a decaf variation, of which more than 90% of caffeine is removed from an average cup of coffee. But is caffeine really anxiogenic (anxiety causing) like some other drugs? If so, what type of coffee should you drink?
DOES CAFFEINE CAUSE ANXIETY?
Caffeine is most commonly known to keep us awake for a long day (or night). How does caffeine achieve such a result? Put simply, caffeine inhibits adenosine receptors in our brain that are responsible for inducing sleep, (Klevebrant et al., 2023) Additionally, caffeine also acts as a stimulant. Thus, the antagonism coupled with the stimulatory effect leads our hearts to beat faster, our blood pressure to increase, an increased respiratory rate, and a restless feeling. With symptoms mimicking the cultural perception of anxiety, a consumer cognitively labels these physiological changes as a feeling of anxiety, in turn feeling anxious. Additionally, caffeine increases cortisol secretion, leading to a coupled effect from cortisol stress (Lovallo et al., 2006). Similarly, some consumers consider the effects of caffeine as a panic attack (Klevebrant et al., 2023).
WHAT DO THE STUDIES SHOW?
So is the solution to cut out caffeine completely? Not quite. In a study conducted by the UK Biobank, 146,566 participants mentioned their choice of coffee: instant/ground (caffeinated) or decaffeinated coffee. They were given the GAD-7 questionnaire (a reputable anxiety scale) to compare their anxiety scores to a baseline made up of self-reports, PHQ-4 scores (a briefer anxiety questionnaire), and hospital evaluations (Min et al., 2023). For both coffee types, low consumption of coffee (1 cup [ 250mL]) results in higher levels of anxiety than more moderate amounts (2-3 cups), with a trend that the more coffee one consumes of any type, the more anxious they will feel.
Results per coffee type, however, shows helpful results for decaf coffee drinkers. For 4-5 cups, decaf drinkers were lowest in anxiety comparisons, as well as for 6-7 cups. For 8-9 cups, decaf drinkers were out-calmed by instant/ground coffee drinkers, but reclaimed the throne for 10 cups and above (Min et al., 2023). Unexpectedly, however, is that decaf subscribers who drink 1 to 3 cups of coffee are more anxious than caffeinated coffee drinkers who drink the same amount.
Compared to other studies, it’s replicated that the more caffeine one consumes, the higher their GAD-7 score. For example, researchers found a weak positive correlation between caffeine consumption and and GAD-7 scores among 144 college students at Florida State University (Bertasi et al., 2021). In a longitudinal study, over 3000 secondary school students showed that ‘total weekly caffeine intake remained a significant predictor of ‘anxiety’ (Richards et al., 2015). Is this enough to conclude you should stick to decaf coffee?
NUANCE
While coffee enthusiasts who drink multiple cups on end may benefit from lower anxiety, the average American won’t notice a drastic difference with their 1-3 cups per day (Statista, 2023), simply because that there is a high variability in anxiety levels caused by any type of coffee when it is limited to 1-3 cups. This is because each individual has a different sensitivity to caffeine. Variations in the genes CYP1A2 and ADORA2A can lead to faster or slower caffeine metabolism and thus lead to a high or low caffeine sensitivity (Kapellou et al., 2023). In addition, one can acquire tolerance to caffeine after high doses; more adenosine receptors are created, reducing the effects of caffeine in small doses. (Boulanger et al., 1983).
CONCLUSION
While some evidence shows a link between caffeine and stress, switching to decaf likely won’t help the average coffee drinker in America. One, two, or three cups of coffee aren’t likely to contribute to feelings of anxiety. The main aspect of the caffeine to stress pipeline is the cognitive label of the physiological response one is having to the caffeine. Therefore, in trying to limit anxiety, it's imperative to consider individual caffeine sensitivity and its physiological impact, recognizing moderate consumption of both caffeinated and decaffeinated coffee as potentially beneficial for reducing anxiety compared to extremes in intake. Above all, caffeine is no simple player, and it must be studied further to examine its interactions with other parts of the brain and body. Anxiety can’t be limited to one thing, and despite there being an ‘average’ American coffee drinker, there isn’t an average ‘anxious person’. However, when you start thinking about your Starbucks run in a more scientific way, it might be a fast step in the right direction.
Written by Amin Belhadj and edited by Dr. Aldrin Gomes, PhD
References
Bertasi, Raphael A O et al. “Caffeine Intake and Mental Health in College Students.” Cureus vol. 13,4 e14313. 5 Apr. 2021, doi:10.7759/cureus.14313
Boulenger, J P et al. “Chronic caffeine consumption increases the number of brain adenosine receptors.” Life sciences vol. 32,10 (1983): 1135-42. doi:10.1016/0024-3205(83)90119-4
Kapellou, Angeliki et al. “Genetics of caffeine and brain-related outcomes - a systematic review of observational studies and randomized trials.” Nutrition reviews vol. 81,12 (2023): 1571-1598. doi:10.1093/nutrit/nuad029
Klevebrant, Lisa, and Andreas Frick. “Effects of caffeine on anxiety and panic attacks in patients with panic disorder: A systematic review and meta-analysis.” General hospital psychiatry vol. 74 (2022): 22-31. doi:10.1016/j.genhosppsych.2021.11.005
Lovallo, William R et al. “Cortisol responses to mental stress, exercise, and meals following caffeine intake in men and women.” Pharmacology, biochemistry, and behavior vol. 83,3 (2006): 441-7. doi:10.1016/j.pbb.2006.03.005
Min, Jiahao et al. “The association between coffee consumption and risk of incident depression and anxiety: Exploring the benefits of moderate intake.” Psychiatry research vol. 326 (2023): 115307. doi:10.1016/j.psychres.2023.115307
Richards, Gareth, and Andrew Smith. “Caffeine consumption and self-assessed stress, anxiety, and depression in secondary school children.” Journal of psychopharmacology (Oxford, England) vol. 29,12 (2015): 1236-47. doi:10.1177/0269881115612404
Samoggia, Antonella, and Bettina Riedel. “Consumers' Perceptions of Coffee Health Benefits and Motives for Coffee Consumption and Purchasing.” Nutrients vol. 11,3 653. 18 Mar. 2019, doi:10.3390/nu11030653
Statista Consumer Insights (2023, January 17th) How Many Cups of Coffee Do Americans Drink Each Day? [Infographic]. Statista. https://www.statista.com/chart/19524/cups-of-coffee-drunk-by-americans-per-day/
Комментарии