The Positive and Negative Effects of Caffeine Consumption

by | Jun 26, 2023 | Caffeine

Written by Taylor Woosley, Staff Writer. Clinical research has associated caffeine consumption with improved brain health, cardiovascular function, and has been linked to a lower risk of all-cause mortality. However, overconsumption can lead to negative effects on nervous system and cardiovascular health.

Coffee and tea are two of the most popular beverages consumed around the world and both commonly feature caffeine. It can also be found in energy drinks, gums, supplements, chocolate, and soft drinks. Caffeine is a xanthine alkaloid compound which, when consumed, triggers alertness and improves mood1. The average caffeine consumption in the United States is approximately 210-238 mg per person, averaging out to around 2-3 cups of coffee or 4 cups of caffeinated tea a day2. Around 90% of adults around the world consume caffeine daily.

Caffeine has been consumed since ancient times but is still considered a controversial substance. Many people choose to avoid caffeine due to its addictive nature and the potential dependency that could develop. However, for those who do regularly consume it, there are many positive effects it can provide.

Positive Effects

Caffeine is a highly researched psychoactive substance with neuroprotective properties. It is both water and fat soluble and can cross the blood-brain barrier. Current studies suggest that caffeine intake may be associated with a lower risk of cognitive impairment and cognitive decline3. This may be because it is a short-acting neurostimulator through the mobilization of intracellular calcium, antagonism of adenosine receptors, and modulation of GABA receptor function4. By blocking the adenosine receptors, caffeine prevents adenosine from acting and conversely influences the central nervous system5.

Data also suggests that caffeine has various anti-inflammatory and antioxidant mechanisms6. Plus, caffeine has the ability to decrease oxidative stress7. A recent systemic review concluded that caffeinated coffee consumption was significantly associated with a reduced risk of all-cause and cardiovascular disease mortality8.

The benefits of caffeine include improved sports performance and focus. This is most often achieved through consuming energy drinks or pre-workout. Small to moderate benefits of caffeine use include muscular endurance, improved movement velocity, and overall improved physical performance9. These enhanced results were best shown when consuming caffeine 60 minutes prior to athletic activities.

Negative Effects

There is a “coffee paradox” that consists of the fact that caffeine raises blood pressure, but research has indicated that regular caffeine consumption is associated with a lower risk of hypertension10. However, meta-analysis research indicates that irregular or occasional caffeinated coffee consumption is associated with an increase in blood pressure and may result in an increased risk of arterial hypertension11.

The safety of caffeine has long been researched and studies purport that the upper limit of safe consumption is less than 400 mg per day (around 4-5 cups of coffee or 5-6 cups of tea) and that high doses of caffeine can cause significant metabolic changes that can be detrimental12. For example, over consumption of highly caffeinated energy drinks or supplements can interact with the sympathetic nervous system and cause serious negative effects to the cardiovascular system13.

Furthermore, consumption of caffeine during pregnancy has long been discussed for its potential negative effects. Caffeine can freely transfer across the blood-placental barrier and epidemiological studies have shown that caffeine consumption during pregnancy can lead to low birth weight, along with other complications14.

The amount of caffeine consumed is important to note. While there are many benefits to regular moderate caffeine intake, overconsumption can result in negative outcomes that should be avoided.

References:

  1. Barcelos RP, Lima FD, Carvalho NR, Bresciani G, Royes LF. Caffeine effects on systemic metabolism, oxidative-inflammatory pathways, and exercise performance. Nutrition research (New York, NY). Aug 2020;80:1-17. doi:10.1016/j.nutres.2020.05.005
  2. Rodak K, Kokot I, Kratz EM. Caffeine as a Factor Influencing the Functioning of the Human Body-Friend or Foe? Nutrients. Sep 2 2021;13(9)doi:10.3390/nu13093088
  3. Zhou X, Zhang L. The Neuroprotective Effects of Moderate and Regular Caffeine Consumption in Alzheimer’s Disease. Oxid Med Cell Longev. 2021;2021:5568011. doi:10.1155/2021/5568011
  4. YM MY, Waldvogel HJ, Faull RLM, Kwakowsky A. Neuroprotective Effect of Caffeine in Alzheimer’s Disease. Molecules. Jun 10 2022;27(12)doi:10.3390/molecules27123737
  5. Herden L, Weissert R. The Effect of Coffee and Caffeine Consumption on Patients with Multiple Sclerosis-Related Fatigue. Nutrients. Jul 28 2020;12(8)doi:10.3390/nu12082262
  6. Rodas L, Riera-Sampol A, Aguilo A, Martínez S, Tauler P. Effects of Habitual Caffeine Intake, Physical Activity Levels, and Sedentary Behavior on the Inflammatory Status in a Healthy Population. Nutrients. Aug 3 2020;12(8)doi:10.3390/nu12082325
  7. Ősz BE, Jîtcă G, Ștefănescu RE, Pușcaș A, Tero-Vescan A, Vari CE. Caffeine and Its Antioxidant Properties-It Is All about Dose and Source. Int J Mol Sci. Oct 28 2022;23(21)doi:10.3390/ijms232113074
  8. Neves JS, Leitão L, Magriço R, et al. Caffeine Consumption and Mortality in Diabetes: An Analysis of NHANES 1999-2010. Front Endocrinol (Lausanne). 2018;9:547. doi:10.3389/fendo.2018.00547
  9. Guest NS, VanDusseldorp TA, Nelson MT, et al. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. Jan 2 2021;18(1):1. doi:10.1186/s12970-020-00383-4
  10. Iriondo-DeHond A, Uranga JA, Del Castillo MD, Abalo R. Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain-Gut Axis. Nutrients. Dec 29 2020;13(1)doi:10.3390/nu13010088
  11. Surma S, Oparil S. Coffee and Arterial Hypertension. Curr Hypertens Rep. Aug 9 2021;23(7):38. doi:10.1007/s11906-021-01156-3
  12. Hamed E. Caffeine Toxicity Following Ingestion of an Exercise Supplement by a Patient with Type 1 Diabetes. Eur J Case Rep Intern Med. 2018;5(10):000957. doi:10.12890/2018_000957
  13. Domaszewski P. Gender Differences in the Frequency of Positive and Negative Effects after Acute Caffeine Consumption. Nutrients. Mar 7 2023;15(6)doi:10.3390/nu15061318
  14. Qian J, Chen Q, Ward SM, Duan E, Zhang Y. Impacts of Caffeine during Pregnancy. Trends in endocrinology and metabolism: TEM. Mar 2020;31(3):218-227. doi:10.1016/j.tem.2019.11.004