Effect Of Caffeine On Cognitive Functions

Abstract

Consumption of caffeinated products has always been questionable since it's related to many health benefits and at the same time the overuse of these products can cause a lot of harm to the vital organs. The daily use of caffeine for increasing alertness is a common behaviour worldwide, but recently some studies have demonstrated that other non-caffeine components in caffeinated products such as coffee seem to have a significant effect on behaviour, which in turn indicate that these components aid in this "alertness" effect of caffeine. 

Searching for the effects of coffee without caffeine, regular coffee, and placebo on mood and cognition a recent double-blind, randomized study was conducted on individuals of different ages and sexes where age and sex were contributing factors (Haskell-Ramsay et al., 2018). 

When comparing caffeinated coffee with placebo, the influence of increased alertness and decreased reaction time was in favour of the caffeinated coffee. Surprisingly, when decaffeinated coffee was compared to a placebo, it showed a result of decreased tiredness and heading rates, indicating that other components than caffeine must have contributed to these effects. Factors of age and sex were found to be interfering with treatment when an increased rate of anxiety was noticed after regular coffee intake in older males and younger females.

Effect Of Caffeine On Cognitive Functions

Some studies have linked many health benefits to coffee consumption, including reduced risk of type 2 diabetes mellitus (Jiang et al., 2014), lower incidence of cardiovascular disease (Rodriguez-Artalejo et al., 2017), and lower death rates from inflammatory diseases (Andersen et al., 2006). Some studies have shown a confirmed relation between higher consumption of coffee and achieving better in cognitive tests in adults (Jarvis et al., 1993) and (Araujo et al., 2015).

Materials and Methods

Design

The study’s design was double-blind, randomized, and controlled by placebo. Northumbria university’s faculty of health and life sciences ethics committee has approved the study on 26 February 2016.

Participants

A total number of seventy-two participants was selected around the area of Newcastle.  The older group (61-80) years represented half the number of participants, 18 of which are males, the younger group whose ages range from 20 to 34 years (18 males) represented the other half of participants. All participants were native English speakers, healthy, non-smokers, and take no medications except the older group of participants who used medications for hypertension, arthritis, and high cholesterol.

Treatment

Three kinds of drinks were to be administered: 

1- 220 mL caffeinated coffee with 100 mg caffeine (without sugar or milk).

2- 220 mL decaffeinated coffee with 5 mg caffeine (without sugar or milk).

3- 220 mL water + 2.5 g coffee flavor (placebo).

An allocation generated by computer was used to indicate in what sequence the participants should have each drink. The caffeine flavour used for placebo consisted of: (0.1 g dark roast, 0.1 g mild roast, 0.04 coffee natural and 2.26 maltodextrin).  

Cognitive and mood measures

A software application called COMPASS (Computerized Mental Performance Assessment System) was used to deliver mood and cognitive functions. This evaluation system has already shown a significant degree of sensitivity to nutritional interference (Kennedy et al., 2010), (Stonehouse et al., 2013) including caffeine (Dodd et al., 2015).

Discussion 

When evaluating the processing tasks of quick visual information and digit vigilance, faster responses were noticed due to regular coffee compared to decaffeinated coffee. Also, when compared to placebo, regular coffee intake showed higher overall mood, rates of alertness, and decreased levels of mental fatigue. 

Conclusion

Coffee is considered one of the most consumable drinks worldwide due to its numerous benefits including increased alertness, lower levels of mental fatigue and headaches. Now, studies are directed to discover the potential benefits of other non-caffeine components in coffee that also affect mood and cognition. To achieve accurate results, the effects of regular coffee are compared to those resulting from decaffeinated coffee and placebo.   

References

• Haskell-Ramsay, C., Jackson, P., Forster, J., Dodd, F., Bowerbank, S., & Kennedy, D. (2018). The Acute Effects of Caffeinated Black Coffee on Cognition and Mood in Healthy Young and Older Adults. Nutrients, 10(10), 1386.

• Jiang, X., Zhang, D., & Jiang, W. (2014). Coffee and caffeine intake and incidence of type 2 diabetes mellitus: a meta-analysis of prospective studies. European journal of nutrition, 53(1), 25-38.

• Rodríguez-Artalejo, F., & López-García, E. (2017). Coffee consumption and cardiovascular disease: A condensed review of epidemiological evidence and mechanisms. Journal of agricultural and food chemistry, 66(21), 5257-5263.

• Andersen, L. F., Jacobs Jr, D. R., Carlsen, M. H., & Blomhoff, R. (2006). Consumption of coffee is associated with reduced risk of death attributed to inflammatory and cardiovascular diseases in the Iowa Women’s Health Study–. The American journal of clinical nutrition, 83(5), 1039-1046.

• Jarvis, M. J. (1993). Does caffeine intake enhance absolute levels of cognitive performance?. Psychopharmacology, 110(1-2), 45-52.

• Araújo, L. F., Giatti, L., Reis, R. C., Goulart, A. C., Schmidt, M. I., Duncan, B. B., ... & Barreto, S. M. (2015). Inconsistency of association between coffee consumption and cognitive function in adults and elderly in a cross-sectional study (ELSA-Brasil). Nutrients, 7(11), 9590-9601.

• Kennedy, D. O., Wightman, E. L., Reay, J. L., Lietz, G., Okello, E. J., Wilde, A., & Haskell, C. F. (2010). Effects of resveratrol on cerebral blood flow variables and cognitive performance in humans: a double-blind, placebo-controlled, crossover investigation–. The American journal of clinical nutrition, 91(6), 1590-1597.

• Stonehouse, W., Conlon, C. A., Podd, J., Hill, S. R., Minihane, A. M., Haskell, C., & Kennedy, D. (2013). DHA supplementation improved both memory and reaction time in healthy young adults: a randomized controlled trial–. The American of Clinical Nutrition, 97(5), 1134-1143.

• Dodd, F. L., Kennedy, D. O., Riby, L. M., & Haskell-Ramsay, C. F. (2015). A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology, 232(14), 2563-2576.