Caffeine has long been a lively topic of discussion among scientists, health professionals, and the general public as to its possible risks and benefits to health. Caffeine has been lauded for its positive effects on mental acuity and physical performance only to be subsequently vilified for its possible harmful effects on the heart and nervous system. Tens of thousands of research studies have now identified and clarified the effects of this widely consumed substance and have helped settle a number of questions about it. While the “final word” on the topic is undoubtedly far from being written, we are now armed with an abundance of reliable information about caffeine’s safety and efficacy in human health.
Caffeine was first isolated from coffee seeds (beans) nearly two hundred years ago although its consumption dates back many millennia prior to that. It is now regarded as the world’s most widely used psychoactive compound with an estimated 120,000 tons of it consumed annually around the globe. This equates to one 50 milligram serving every day of the year for every man, woman, and child on Earth! The most widely used natural sources of caffeine include coffee, tea, kola nut, yerba mate, guarana and cocoa/chocolate. Products by PURE use natural sources of caffeine. Those products, and their estimated caffeine content per serving, include: PURE Café (150mg), GPS Energize (110mg), ENERGY (120mg), 360 Complete Shake (35mg), Metabolic ONE (88mg), Green Coffee Bean (<16mg), Matcha Vegan Shake (45-50mg).*
Close to 99% of the caffeine that we ingest is absorbed into the bloodstream within about forty-five minutes. Its half-life, (the time it takes to eliminate half of what is consumed), averages about five hours but can be more or less depending upon genetics and activity. That means that your 7:00 a.m. serving of caffeine is still in your system at half-strength when the clock strikes noon. This also means that caffeine is probably best avoided about five hours prior to bedtime – more about that in bit.
For those of you whose eyes glaze over when you read technical science, you can skip this paragraph as it describes the underlying physiology of caffeine in the body. Four notable physiological effects occur with the consumption of caffeine: 1) it blocks adenosine, (a normal central nervous system depressant in the body), thereby increasing nerve activity and creating a more energetic, wide-awake feeling; 2) it causes blood vessels in the brain to constrict slightly which helps prevent drowsiness; 3) it increases dopamine production – dopamine being a neurotransmitter that activates the “pleasure centers” in the brain; and 4) it increases cyclic-AMP levels which leads to greater fat-burning. In addition, caffeine positively influences the release of other neuroactive compounds such as adrenalin, noradrenalin, serotonin, acetylcholine and GABA. The net physiological effect of these biochemical activities is greater mental alertness, increased blood flow to the heart, smooth muscle relaxation in the lungs (which eases breathing), increased muscle energy and work capacity and better body composition.
The widely accepted safe consumption level of caffeine for healthy adults is 400 milligrams per day (US FDA, Health Canada, Mayo Clinic). For pregnant or nursing mothers, the recommended maximum is 200-300 milligrams daily. Consumption of caffeine in excess of 400 milligrams may cause nervousness, insomnia, irritability, migraines, slightly increased heart rate and/or stomach upset in sensitive individuals.* For particularly sensitive individuals, (who comprise a very small percentage of the population), a much lower intake can elicit these same issues. It’s worth noting that caffeine is not considered an addictive substance, (it doesn’t activate pathways in the brain related to addiction), and while slightly diuretic, caffeine has little or no impact on hydration levels in the body, particularly during exercise!
So, here is the general list of benefits that can be derived from caffeine consumption, as identified by thousands of scientific research studies.
- Increased alertness and attention
- Improved sports performance and exercise/training – both endurance and strength
- Weight loss – through appetite suppression, increased fat-burning (lipolysis), and stimulation of thermogenesis (production of heat through calorie burning)
- Reduced risk of Alzheimer’s disease and Parkinson’s disease
- Improved long-term memory
- Decreased risk of liver disease, gallstones, and kidney stones
- Enhanced protection of eyes from cataract formation
Here is the general list of risks identified in the other scientific research studies.
- Increased levels of anxiety and depression, especially in adolescents consuming “adult quantities” of caffeine
- Slight rise in blood glucose levels in Type 2 diabetes
- High intake may trigger gout attacks for those individuals with the condition
- May cause insomnia, if consumed three to six hours prior to bedtime
- See above (paragraph 5) for undesirable effects experienced with excessive consumption of caffeine
Finally, here is a list of specific takeaways that are found throughout the scientific research literature.
Caffeine and the Heart
- May slightly elevate heart rate
- Protects heart muscle from oxidative damage
- Regular coffee drinkers have a lower incidence of new-onset atrial fibrillation (a-fib) than non-drinkers
Caffeine and the Brain – Mood/Cognitive Function
- Improves reaction time, vigilance, memory, attention, and cognitive function
- Benefits short-term performance and improves mood
- Can increase anxiety
- Partially prevents fatigue-related cognitive decline
- Increases information processing activity of the brain
- Enhances verbal IQ and reasoning abilities
- Raises levels of “brain entropy” resulting in higher activity throughout the entire cerebral cortex
Caffeine and Physical Performance
- Increases speed and power
- Improves amount of weight lifted in resistance-trained individuals
- Increases endurance and preserves muscle glycogen stores through fat mobilization and burning
- Lowers perceived exertion during activity
Healthful hero or vitality villain?
Maybe caffeine is a little bit of both. The overwhelming consensus in scientific circles, however, is that caffeine has been shown to be harmless for all but a very small percentage of adults and has been validated to be beneficial for a very large percentage. The fact that 90% of the adult population consumes caffeine in one or more forms is a testament to its mental and mood benefits. Coupling that with the health and performance benefits realized from caffeine use and the scales are tipped strongly toward it being a health hero. As I said at the beginning, the “final word” isn’t yet written for caffeine but, for the present, the “manuscript” does support the view that consuming it at recommended levels is both safe and advantageous.
By Rich Scheckenbach, PURE Wellness Advisory Board Member – May 2018
Rich Scheckenbach received his baccalaureate degree from the University of California, Los Angeles (UCLA) with Bacteriology as his major field of study. He pursued his doctoral studies in Microbiology/Biochemistry at Oregon State University. Areas of expertise include product research and development, proprietary formulation, market assessment, product promotion, FDA and FTC compliance, and nutritional biochemistry.
*Do not exceed 4 servings per day of ENERGY, GPS Energize, Metabolic ONE or PURE Café in any combination, to prevent potential undesirable effects of too much caffeine.