- Marie Belzile-Davidson, MS Nutrition Student
The Love-Hate Relationship Between Caffeine and Cortisol
Updated: Oct 26, 2020
When you hear “caffeine,” what’s the first thing that comes to mind? Chances are, you’re thinking about that fresh cup of morning coffee, that afternoon pick-me-up when energy is running low, or that substance that we hear conflicting information about in the news every few months.
Caffeine is in many commonly consumed beverages and some foods, like coffee, tea, and chocolate. In fact, it’s the most widely used psychoactive drug in the world (1). Caffeine consumption, for many Americans, is part of a daily routine. If you’re like me, you wake up to welcome the day and immediately proceed downstairs to make a delicious cup of coffee. Consuming caffeine can be something enjoyable, like savoring a couple squares of dark chocolate, or it can be for necessity: maybe you just need that boost of energy to get through the day.
While caffeine comes with some benefits, like increasing our alertness, helping us feel less fatigued, and possibly having some neuroprotective effects, too much of it can be detrimental to our bodies and overall health (1,2). One major way in which caffeine impacts our general wellness is through its relationship with cortisol. Several studies have shown that caffeine generally increases our cortisol levels (3-5).
Cortisol, while often portrayed as “bad,” is actually quite an important hormone, just in the right quantities. This stress hormone is a major player in energy balance and our levels of cortisol change throughout the day (4,6). In an otherwise healthy individual, cortisol levels are highest in the morning when waking up and reach their lowest levels during the early phases of sleep (4). Cortisol is also critical to our natural response to danger, allowing us to act as necessary when an oncoming car is drifting left of center or your child is running too close to the street (6).
Just as with caffeine though, too much cortisol can have negative impacts on our health. Over time, elevated cortisol can lead to anxiety, trouble sleeping, digestive issues, depression, weight gain, and more.6 While cortisol levels are only temporarily increased from caffeine consumption, the impact still matters because chronic stress is prevalent in our society, and more stress equals more cortisol. In fact, a 2019 survey by the American Psychological Association showed that Americans are “experiencing higher average levels of stress than they feel is healthy (7).” Add on a global pandemic and you’ve got a recipe for high cortisol levels.
This relationship between caffeine and cortisol isn’t one-sided though. While caffeine increases cortisol levels, increased cortisol can create situations where we feel the “need” for more caffeine. If cortisol levels are high enough to mess with sleep, we may not get the true rest we need every night, even if we spend eight to nine hours in bed. Unfortunately, our daily responsibilities don’t adjust themselves to match how rested we are so the fatigue from a poor night’s sleep can bring us to pour one cup of coffee after another. Or maybe the little stressors in our day quickly add up to an overwhelming amount, mindlessly leading us to the bag of chocolate.
So how do we break this vicious cycle between caffeine and cortisol? An effective way can be to tackle the root cause of our chronic stress levels (that is another blog post...or twelve), and manage our caffeine intake! Don’t worry, this doesn’t mean you have to forever forego that latte, because caffeine can be part of a balanced life, we just need to be mindful of how much we are consuming.
While there are many factors that can impact how well our bodies process caffeine, such as genetic variances, medications, and routine caffeine consumption, a general guideline for safe caffeine consumption is less than 400 mg per day (8,9). Recent data has shown that 85% of Americans have an average daily intake of 180mg of caffeine, which is equivalent to two cups of coffee (9). However, two cups can quickly become more if that cup is topped off a few times, or an extra shot of espresso is added.
Now you might have a better understanding of how much caffeine you’re taking in on a daily basis, but is there anything else you can do to help minimize the impacts of caffeine on cortisol? Absolutely!
One obvious way is to reduce your caffeine consumption slowly over time. This can be cutting back from four cups of coffee per day to three and a half, then three and a half cups to three, gradually over several weeks until you’re down to a reasonable amount. Another way to blunt the caffeine-cortisol impact is minimizing caffeine intake after lunch. This will allow your cortisol levels to drop as they should around bedtime. So maybe that afternoon coffee is eventually eliminated or that post-dinner dark chocolate is moved up to a mid-morning treat. You could also opt for a cup of green or herbal tea instead of another cup of coffee throughout the day. An additional strategy for you might be “microdosing,” or spreading your caffeine intake across several hours, instead of quickly knocking back a cup of coffee before tackling the day (11).
As with all aspects of nutrition, caffeine consumption is an individualized thing. What’s best for someone else may not be what’s best for you. The easiest way to get the personalized approach you need is to talk with your registered dietitian about what healthy caffeine consumption looks like for you!
N. Rieth NV-R, C. Buisson, C. Jaffré, K. Collomp. Caffeine and saliva steroids in young healthy recreationally trained women: impact of regular caffeine intake. Endocrine. 2016(52):391-394.
Nour Zibdeh MS, RDN. Can't Give Up Your Coffee? Here Are 8 Ways To Make It More Gut-Friendly.mindbodygreen.com: Mind Body Green; 2019.
William R. Lovallo P, Thomas L. Whitsett, MD, Mustafa al'Absi, PhD, Bong Hee Sung, PhD, Andrea S. Vincent, PhD, Michael F. Wilson, MD. Caffeine Stimulation of Cortisol Secretion Across the Waking Hours in Relation to Caffeine Intake Levels. Psychosom Med. 2005(67).
Staff MC. Caffeine: How much is too much? https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678. Published 2020. Updated 03/06/2020. Accessed 07/24/2020, 2020.
Michael D. Patz HEWD, Andrew Burow, Serge Campeau. Modulation of the hypothalamo-pituitary-adrenocortical axis by caffeine. Psychoneuroendocrinology. 2006(31):493-500.
Taylor M. What Is Cortisol & What Causes High Levels Of This Stress Hormone. In: Sheeva Talebian MD, ed. Integrative Health. Vol 2020. mindbodygreen.com: Mind Body Green; 2020.
Association AP. Stress in AmericaTM. American Psychological Association;2019.
Staff MC. Caffeine Content for Coffee, Tea, Soda, and More. Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20049372. Published 2020. Updated 02/29/2020. Accessed 07/24/2020, 2020.
Jennifer L. Temple CB, Steven E. Lipshultz, Jason D. Czachor, Joslyn A. Westphal, Miriam A. Mestre. The Safety of Ingested Caffeine: A Comprehensive Review. Front Psychiatry. 2017.
Moore A. Does Chocolate Really Contain Caffeine? Amount & Effects From Dark, Milk & White Chocolate. In. Functional Food. Vol 2020. mindbodygreen.com: Mind Body Green; 2020.
Marvin Singh MD. How to Consume Caffeine In The Healthiest Way, According To A Gut Health Expert. In. Integrative Health. Vol 2020. mindbodygreen.com: Mind Body Green; 2020.