Caffeine
What is Caffeine?
Caffeine is a naturally occurring compound, specifically a bitter, white crystalline purine known as a methylxanthine alkaloid. It shares chemical similarities with adenine and guanine, two integral components of DNA (1). This substance primarily acts as a central nervous system (CNS) stimulant within the methylxanthine class, elevating activity across the brain and nervous system (2)(4). Natural sources of caffeine encompass leaves and fruits from particular plants, inclusive of coffee beans, tea leaves, kola nuts, and cacao pods (2)(4). Additionally, caffeine finds its way into certain medications, foods, and beverages, such as pain medications, cold remedies, energy drinks, and specific snacks and gums intended to boost energy (4).
Dosage
The caffeine content in beverages varies significantly. However, for most healthy adults, a safe upper limit stands at around 400 milligrams (mg) per day (3)(6). Individual sensitivities to caffeine do exist, and some may encounter side effects even at lower doses (2).
Side Effects
Generally speaking, moderate caffeine consumption is benign, though it can induce adverse effects in certain individuals (2)(4)(5). Potential caffeine-induced side effects encompass insomnia, unease, restlessness, nausea, accelerated heart rate, and headaches (2)(5). Higher dosages might instigate anxiety, chest discomfort, and heart palpitations (5). Notably, caffeine functions as a diuretic, prompting the body to excrete surplus salt and water through urination (4).
Interactions
Interactions between caffeine and specific drugs, such as MAOIs, are a possibility. Moreover, individuals with particular health conditions, including anxiety disorders and cardiovascular issues, should exercise caution when consuming caffeine (2)(4). A prior discussion with a healthcare professional is advisable before amalgamating caffeine with other medicines or supplements.
Time of Day and With or Without Food
While caffeine is amenable to consumption at any juncture of the day, intake during late afternoon or evening might disturb sleep and is usually discouraged (2). Ingesting caffeine alongside food is generally recommended to mitigate the possibility of gastric discomfort (2).
Human Studies
Human studies extensively probe the impacts of caffeine on metabolic activities, including its capacity to invigorate the CNS, heighten respiratory and cardiac rates, and actuate diuresis (3)(4). Investigations also spotlight its prospective benefits like enhancing mental alertness, sports performance, and memory retention (5). Nonetheless, exhaustive research is pivotal to comprehend the complete therapeutic potential of caffeine.
To encapsulate, Caffeine, a CNS stimulant under the methylxanthine class, augments cerebral and nervous system activity. Naturally residing in particular plants like coffee beans and tea leaves, it is also an additive in specific medications and edibles. For the average healthy adult, daily caffeine intake up to 400mg is generally safe. However, caffeine might evoke side effects in certain individuals and may interact with some medications. Although consuming caffeine doesn't have a strict timing, late-day intake can disrupt sleep. Thorough human studies on caffeine delineate its physiological effects and potential health benefits, but further research is essential for a holistic understanding.
Citations:
(1) https://en.wikipedia.org/wiki/Caffeine
(2) https://www.betterhealth.vic.gov.au/health/healthyliving/caffeine
(3) https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20049372
(4) https://medlineplus.gov/caffeine.html
(5) https://www.webmd.com/vitamins/ai/ingredientmono-979/caffeine
(6) https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678