By Zuzanna Boguslawska 

The disruption in education caused by the COVID-19 outbreak has led us, students to face many challenges in learning. From speaking to my peers there is a feeling of uncertainty, studying in isolation, and lack of resources have affected our ability to focus on learning, sometimes decreasing academic performance.  

Although the cognitive manifestations associated with experiencing the global pandemic and going through the infection are still unknown, I think we all have faced issues with memory and productivity (1). It’s been almost a year since the coronavirus outbreak, and during this time students have been exposed to the overlap of stress and anxiety. A large study (2) shows that overwhelming, worrying thoughts disrupt the cognitive performance in non-depressed adults.  

Many strategies might help with excessive worrying, like meditation, better sleep, or reducing social media. However, the experience of the ongoing COVID-19 outbreak combined with my interests as a nutrition student, got me thinking about another approach: dietary supplements. These are the products that provide additional nutrients that might be missing in our diet (3). According to NHS, most people do not need to take supplements, as vitamins and minerals can be obtained from a healthy, balanced diet. Anyhow, there are more types of supplements, like creatine for bodybuilders or herbs used in alternative medicine. The group of substances that drew my attention due to their beneficial effect on brain function in healthy people are nootropic supplements.  

A nootropic or brain booster is a compound (drug or supplement) that improves one’s cognitive functions including memory, creativity, motivation, and attention (4). There is a whole variety of natural stimulants that enhance cognitive performance, and you might be surprised, but caffeine is one of the most popular ones. It is a bitter compound that acts on the central nervous system. Caffeine is rapidly absorbed following oral consumption, with peak plasma levels being reached within 30 minutes. It easily crosses the blood-brain barrier and, once in the brain it increases acetylcholine and dopamine transmission (5). This mechanism of action causes the well-known feeling of wakefulness and alertness. As students, we tend to consume coffee in excessive amounts, causing ourselves sleepless nights, nervousness, and anxiety  everything to enhance academic performance. Many of us might not realise how long caffeine stays in our body. Its half-life, so the time is taken for the body to eliminate one-half of the caffeine ranges between 3-6 hours. It means that if you have a cup of coffee late in the afternoon, half of the caffeine is still present in your blood at midnight. That could cause difficulties in falling asleep or staying asleep during the night. Then, you wake up the next day feeling tired, drinking coffee throughout the day, and struggling to get to sleep – a vicious cycle. Caffeine is not addictive scientifically speaking, but its regular use can lead to physical dependence. 

Coffee has about twice as much caffeine as black tea, but the latter contains another secret ingredient: l-theanine. L-theanine is a non-protein amino acid found in tea leaves. The substance itself is believed to cause a sense of relaxation and mental alertness by increasing alpha wave activity in the brain. These are normally produced when we are resting (6). Therefore, there are two psychostimulants present in a cup of black tea and scientists have been looking at their combined effect on cognitive performance. Studies show that co-consumption of l-theanine and caffeine improves reaction time, but also the speed of numeric working memory and word recognition (5). Another study looked at the effects of tea on psychophysiological stress responsivity and found that drinking the equivalent of four cups of black tea per day leads to lower post-stress cortisol (7). What is interesting, is that l-theanine and caffeine work better together than in isolation.  

Both tea and coffee share similar benefits of enhancing cognitive performance, and some differences in the amount of caffeine present. Excessive intake of caffeine can lead to insomnia; therefore, it is important to consume the substance in moderation. The awareness of its action can help with choosing a cup of tea over coffee after lunchtime. By doing so you can improve your sleep quality and feel more energised during the daytime.

About the Blog Post Author:

Zuzanna Boguslawska or Suzie for short, is a 3rd year Human Biology & Nutrition student at the University of Glasgow. Her passion for science started at a very young age when she used to binge Animal Planet and National Geographic documentaries, thinking she’d become a vet in Africa. However, Suzie’s interests changed, and she started training karate in Poland (that’s where she’s from). Since then, she became passionate about the human body and how it works- from the importance of diet in sports to the muscle structure. Last year, she travelled to Central America, where she had the opportunity to experience authentic yoga practice. This motivated her to explore a holistic approach to health and wellness, which involves physical exercises, mediation, and a balanced diet. She believes that incorporating mindfulness into everyday life improves the brain’s ability to handle stress, which makes a real difference in academic performance. She writes about alternative medicine for qmunicate magazine and as a part of TILE network, she will be looking for ways to enhance students’ learning experience. Outside of university, you can find Suzie boxing at the gym or streaming online DJ sets.

TILE Student Voice

This is a new section of the TILE Network that features the student voice in learning and teaching. We want to shine a light on the student perspective when it comes to teaching and learning practice and what better way to do this than letting the students express this themselves. This series also aims to give students to opportunity to engage in science communication and writing. Broadcasting scientific findings to a wider audience is a valuable skill and TILE provides students with the platform to practice that skill.

If you are a student and interested in contributing to the TILE Student Voice section, get in touch:



  1. Almeria, M., Cejudo, J. C., Sotoca, J., Deus, J., & Krupinski, J. (2020). Cognitive profile following COVID-19 infection: Clinical predictors leading to neuropsychological impairment. Brain, behavior, & immunity-health9, 100163. 
  2. Lukasik, K. M., Waris, O., Soveri, A., Lehtonen, M., & Laine, M. (2019). The relationship of anxiety and stress with working memory performance in a large non-depressed sample. Frontiers in psychology10, 4. 
  3. Do I need vitamin supplements?. Retrieved 17 January 2021, from 
  4. Suliman, N. A., Mat Taib, C. N., Mohd Moklas, M. A., Adenan, M. I., Hidayat Baharuldin, M. T., & Basir, R. (2016). Establishing natural nootropics: recent molecular enhancement influenced by natural nootropic. Evidence-based complementary and alternative medicine2016. 
  5. Owen, G. N., Parnell, H., De Bruin, E. A., & Rycroft, J. A. (2008). The combined effects of L-theanine and caffeine on cognitive performance and mood. Nutritional neuroscience11(4), 193-198. 
  6. Mason, R. (2001). 200 mg of Zen: L-theanine boosts alpha waves, promotes alert relaxation. Alternative & Complementary Therapies7(2), 91-95. 
  7. Steptoe, A., Gibson, E. L., Vounonvirta, R., Williams, E. D., Hamer, M., Rycroft, J. A., … & Wardle, J. (2007). The effects of tea on psychophysiological stress responsivity and post-stress recovery: a randomised double-blind trial. Psychopharmacology190(1), 81-89.