Cortisol is a natural steroid hormone that is released into the body from your adrenal glands during a stress response. Stress can be from things like getting stuck in traffic, a big presentation coming up, having an argument with your partner, a cut to our finger and even exercise to some degree. Cortisol is crucial for your body to respond to stress and repair itself. Without it, we wouldn’t generate an inflammatory response when we hurt ourselves and we wouldn’t start that repair process of our own tissues. Cortisol follows a rhythm that is naturally high in the morning when we wake up, it then starts to decline throughout the morning and continues to drop all the way until we go to sleep. These cortisol patterns are seen in healthy individuals and also follows your circadian rhythm (your bodies natural body clock). As you wake up and are surrounded by sunlight, cortisol levels rise to make you feel more awake and ready for the day. As the day progresses and sunlight starts to decline, cortisol levels reduce, and this prepares you for rest and sleep. The problem is when it is elevated all the time and cortisol deviates from this pattern. It can lead to suppression of your immune system, increased blood sugar levels, unexplained weight gain, changes in your hormone levels and affect your sleep. Sounds scary!
Caffeine has been shown in many studies that it increases cortisol secretion in both men and women by stimulating the central nervous system. It also further enhanced cortisol release in people who were already undergoing stressful events. For most people, the main sources of our caffeine are going to be coming coffee and tea. For a standard 2 shot espresso coffee, there is roughly 145mg and for a teaspoon serving of matcha green tea, this ranges about 75-90mg of caffeine. However, how your body responds to the caffeine and release of cortisol can be very different. Read below.
Starting the morning with a cup of coffee on an empty stomach can shoot up your cortisol levels as the caffeine is rapidly absorbed in the small intestines into the blood and then crossing the blood brain barrier. The caffeine affect tends to peak at 30minutes after having your coffee and then starts to wear off just as quickly leaving us feeling like we have crashed. This is when we might reach for our second cup of coffee. Our cortisol levels are no longer following that natural circadian cycle we discussed about earlier.
Starting your morning with Matcha green tea, we can see a different effect. Matcha contains an amino acid called l-theanine and is actually one of the richest food sources of this compound. L-theanine also crosses the brain-blood barrier around 30 minutes of drinking Matcha. This starts to act on the receptors and chemical messengers in the brain to dampen the cortisol stress response and promote relaxation. When this is combined with the caffeine in Matcha, we see a steady and slow increase in caffeine to help promote focus and concentration which lasts longer than coffee and less of a cortisol stress response. There is also a slower drop of the caffeine level in our systems so we don’t feel such a crash that coffee would give us. This is why I love to start my morning rituals with a Matcha latte and save coffee for those weekend outings at a cafe.
References:
- The role of cortisol in the body https://www.healthdirect.gov.au/the-role-of-cortisol-in-the-body
- Cortisol responses to mental stress, exercise, and meals following caffeine intake in men and women https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2249754/
- Caffeine Stimulation of Cortisol Secretion Across the Waking Hours in Relation to Caffeine Intake Levels https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2257922/
- What is caffeine? Alcohol and Drug Foundation https://adf.org.au/drug-facts/caffeine/
- Caffeine as a Factor Influencing the Functioning of the Human Body—Friend or Foe? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8467199/
- How does the tea L-theanine buffer stress and anxiety https://www.sciencedirect.com/science/article/pii/S2213453021001324
- Anti-Stress, Behavioural and Magnetoencephalography Effects of an l-Theanine-Based Nutrient Drink: A Randomised, Double-Blind, Placebo-Controlled, Crossover Trial https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4728665/