By Jaime Lee Tartar
via O2X
Caffeine is the most consumed psychoactive substance in the world. It is found in popular foods and beverages, including coffee, tea, soda, and chocolate. Coffee consumption became widespread in the 15th century and tea in the 18th century—and both have been securely nestled in our daily routines and cultures ever since. Given its popularity, caffeine undoubtedly has beneficial effects on mental and physical states. Regrettably, however, this benefit does not come without cost.
Caffeine: How Do You Do What You Do?
Caffeins’ popularity stems from its ability to improve focus and enhance alertness. The effects of caffeine on the body and brain can be attributed to its ability to work on a receptor for a natural sleep-promoting chemical in our body called adenosine. Caffeine also increases dopamine and adrenaline activity. Combined, the effects of these chemicals result in increased wakefulness, increased motor activity, and enhanced cognition. The benefit of cognition is largely limited to what can be considered “lower” cognitive functions. This would include simple cognitive tasks like attention and reaction time. The ability of caffeine to improve more complex or “higher” cognitive processes is less certain. This would include tasks like problem-solving and making decisions. Recent research also supports the general health benefits of moderate caffeine use. These include reduced risk for neurodegenerative disease, stroke, Type 2 diabetes, heart disease, and some cancers.
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The Wonders of Caffeine Are Not Without Cost
Importantly, all the benefits of caffeine are not without cost. Unwanted side effects include potential increases in anxiety, increased tension, rapid heartbeat, headaches, and jitteriness. In addition, caffeine use close to bedtime decreases total sleep time and reduces deep sleep, which is essential to restoration and recovery. For most people, 400 mg of daily caffeine (about four cups of coffee) is considered safe. Frequent use of higher doses of caffeine (e.g. over 600 mg) can not only result in unwanted short-term effects, but can result in chronic effects such as insomnia, increased anxiety, and ingestion difficulties.
Timing and Dose Considerations
To avoid unwanted effects from caffeine, it is helpful to consider the dose and timing of caffeine. Following ingestion, the effects of caffeine peak at about 45 minutes, and the half-life of caffeine is five hours (on average). This means the wanted effects of caffeine will peak about an hour after it is taken, but caffeine will still be active in the body for some time. For example, 150 mg of caffeine (one cup of coffee) at 5:00 p.m. would mean that there is still ~75 mg of caffeine in your system at 10:00 p.m. The dose of caffeine also matters for its ability to improve performance. In general, caffeine doses from 32 to 300 mg can improve cognitive and physical performance. However, like the majority of biological processes, caffeine is subject to an “inverted U-shaped” function. This is why caffeine can both improve or impair mental states and performance. Although low arousal is associated with poor performance, increased arousal through caffeine use can improve physiological or mental arousal…but only up to a point, beyond which higher doses can deteriorate performance. Lastly, it is important to recognize that individual differences in our genetic makeups can also influence how quickly caffeine is metabolized from the body. Individual sensitivity to caffeine should always be a consideration.
Bottom Line
Caffeine is not intrinsically “good” or “bad.” Caffeine holds the potential for deleterious side effects when the consumption is too high or when it is taken too late in the day. Caffeine can be useful for improved mental and physical performance and appears to have multiple health benefits. However, it is critical to understand the effects of caffeine on you as an individual and be a cautious user who is aware of the potential negative side effects.
Jaime Lee Tartar, Ph.D., is an accomplished O2X Sleep & Fatigue Management Specialist and a professor of neuroscience at Nova Southeastern University (NSU). With extensive credentials, she serves as the neuroscience program director and research director for the NSU College of Psychology. Dr. Tartar holds a Bachelor of Science degree in psychology from NSU, a Master of Arts degree in psychology from Florida Atlantic University, and a Ph.D. in Behavioral Neuroscience from the University of Florida. Her research background includes investigating neurobiological pathways involved in stress responses and studying the neurological consequences of sleep perturbations. Dr. Tartar’s expertise in sleep and fatigue management has earned her recognition and awards, including an Honorary Doctorate from NSU and being named NSU Professor of the Year. She has published numerous research articles, collaborated with professional athletes, and served as a speaker and scientific advisor for esteemed organizations such as NASA. Currently, her research focuses on the relationship between stress, sleep, and athletic performance in humans.
O2X Human Performance provides comprehensive, science-backed programs to hundreds of public safety departments, federal agencies, and the military. O2X works with clients to elevate culture, improve mental and physical wellbeing, support healthy lifestyles, and reduce healthcare costs associated with injuries and illnesses. Driven by results and cutting-edge research, O2X programs are designed and delivered by a team of Special Operations veterans, high-level athletes, and hundreds of leading experts in their respective fields of human performance.
