Odds are you are familiar with caffeine. Even if you aren’t a regular consumer of tea, coffee, soda or energy drinks, you have no doubt heard of caffeine and likely know someone who can’t seem to function without it.
Every few years, social media and news outlets talk about the antioxidants in coffee and suggest that these disease-fighting phytonutrients negate the possible negative effects of the caffeine. While that might be true for some people, the only way for you to know if its worth it for you is to figure out how the caffeine is affecting you.
By the end of this article, I hope you will have the information you need to make that decision.
What exactly is caffeine?
Caffeine is a naturally occurring stimulant from a group of substances called methylxanthines. It is one of the end products of nitrogen metabolism in the seeds, leaves or stems of more than 60 plant species, including the coffee bean, tea leaves, cacao beans, kola nuts and yerba mate leaves.
Where is caffeine found?
Caffeine is found in a wide range of food, drinks, supplements and medications. The obvious sources are those made from the aforementioned plants like coffee, espresso, black tea, green tea, yerba mate and chocolate. Depending on the level of processing, the end product may retain some of the other nutrients from the source (like antioxidants), but this isn’t a guarantee.
As well, the caffeine can be extracted from the plant and used in other products or supplements. In these cases, it likely won’t be accompanied by any of the other nutritional goodness that plants give us, like antioxidants and other phytonutrients.
People looking for a jolt of energy may choose to get it from capsule or powder caffeine supplements, sodas, energy shots or energy drinks. Less obvious sources of caffeine include those to which it is added for its stimulating effect, like jelly beans, sports chews and diet pills.
What does caffeine do in the body?
Obviously, you know that caffeine is a stimulant (even without me mentioning it above, I’m sure!). Presumably, it works by lowering the threshold required for neurons in the brain to reach the excitatory state. This means that caffeine makes the neuron fire with less stimulation, so more neurons fire more often while caffeine is present.
This increased activity in the brain causes a cascade of events in the body that include the release of adrenaline (the “fight or flight” hormone) by the adrenal glands. Adrenaline increases the heartbeat, constricts blood vessels which raises blood pressure, slows digestion by diverting blood flow, and releases sugar from the liver to provide more energy to the body. In fact, caffeine increases most people’s blood pressure, but in those with hypertension, the increase has been shown to be significantly higher.
(By the way, although the research I found doesn’t make a direct connection, we know that a slow digestive system can lead to its own problems, including heartburn, an upset stomach and bloating.)
Caffeine also increases cortisol levels and prevents cortisol levels from falling, as part of the normal circadian rhythm that this hormone follows. And it may not be a temporary effect. Ping et al found that caffeine seems to have an epigenetic effect by demethylating the gene in adrenal cells that control how much cortisol is produced. In their experiment, the caffeine-exposed cells continued to produce more cortisol than controls even after the caffeine was removed.
Another effect of caffeine is an increase in the excretion of calcium in urine and bile. Although the amounts excreted may be minimal, for those who are at risk for bone loss or do not consume a lot of calcium in their diets, it is something to be mindful of.
Finally, although this isn’t applicable to most of us, caffeine inhibits the breakdown of glycogen in endurance athletes. It spares glycogen by getting in the way of the enzyme that needs to attach to the glycogen molecule in order to release glucose. (I say it’s not applicable to most of us as caffeine has not been shown to have this effect in those who are not endurance athletes. But in the event that you are training for endurance events and you wondered why your coach said to include some caffeine in your training and race day food plans, now you’ll know why.)
I feel like I could go on and on about the potential negative impacts as caffeine has been linked with reactive hypoglycemia, heartburn/GERD, diarrhea, IBS, ulcerative colitis, anxiety, PMS, infertility, fibrocystic breasts, arrhythmias, elevated triglyceride and homocysteine levels, migraines, restless leg syndrome, muscle spams, tremors, back pain, urticaria/hives, Meniere’s disease and teeth grinding.
On the flip side, some observational studies have shown caffeine reduces the risk of gallbladder disease, Parkinson’s disease, and type 2 diabetes. And some people think the increased alertness is harmless. (Which I suppose it is, if you aren’t experiencing any of the other fall out.)
Should you avoid caffeine (and, therefore, coffee, tea and chocolate)?
Well, the answer (of course) is, it depends.
If you are currently experiencing or have an increased risk for any of the above conditions, then I encourage you to avoid it… or at least keep your intake to a minimum. Perhaps switch from drip coffee (163 mg caffeine in 8 ounces) to green tea (25 mg in 8 ounces) or decaf drip coffee (6 mg caffeine in 8 ounces). And, definitely, stop using caffeine supplements, energy shots and energy drinks, unless you have a true medical reason and you and your healthcare practitioner are in agreement on this topic.
If you don’t have any of the above conditions, I suggest that you give up caffeine for 1 week just to see what could be happening in your body without your awareness. You see, caffeine is an addictive substance, meaning that our bodies change how they function when regularly exposed to caffeine. Over time, it becomes difficult for our bodies to function normally without the caffeine, and that’s not a good thing because of all the possible negative effects that come with regular exposure.
If you can’t give up caffeine without experiencing the symptoms of withdrawal (which includes headaches, sleepiness, depression, lethargy, irritability and insomnia), then you are likely sensitive to it. And it could be causing mild forms of the above conditions or setting you up to experience them down the road.
By the way, it can take 6+ weeks for your body to change its behavior once you give up caffeine, or any other food for that matter. One man I know gave up caffeine in an attempt to fix the stomach issues he had been plagued with for years. Going caffeine-free was the only change he made, and right at the 6 week mark, his symptoms all but disappeared.
Now, before you start to think of me as the “caffeine nazi”, I want you to know that I enjoy a cup of green tea and a good box of chocolate as much as anybody.
That being said, my goal for you is that you use food to your advantage. And, if caffeine is causing you to experience discomfort, pain, emotional disturbance or anything else, then I want you to be able to stop it. Because you deserve to feel awesome!
So, give it a try. Give up caffeine for awhile and see what happens. In the mean time, you can get the antioxidants you need from other places. (Hint: eat some berries, nuts, dark green veggies, sweet potatoes, beans or fish.)
— Chan Q, Brown I, Tzoulaki I, et al. Abstract P393: Relationship of Caffeine Consumption to Blood Pressure: The INTERMAP Study. Circulation. 2013; 127(12 Supplement): AP393.
— Chesley A, Howlett RA, Heigenhauser GJ, et al. Regulation of muscle glycogenolytic flux during intense aerobic exercise after caffeine ingestion. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 1998; 275(2): R596-R603.
— Gaby AR. Nutritional Medicine. Concord, NH: Fritz Perlberg; 2011.
— Gropper SS, Smith JL. Advanced Nutrition and Human Metabolism. 6th ed. Belmont, CA: Wadsworth Cengage Learning; 2013.
— Hall J. Guyton and Hall Textbook of Medical Physiology. 12th ed. Philadelphia, PA: Saunders Elsevier; 2011.
— Nichols H. What is caffeine? How does caffeine work? Accessed October 7, 2015.
— Ping J, Lei YY, Liu L, et al. Inheritable stimulatory effects of caffeine on steroidogenic acute regulatory protein expression and cortisol production in human adrenocortical cells. Chemico-biological Interactions. 2012; 195(1): 68-75.