#10: Sleep & Caffeine – Part 1

12/06/21 • 11 min

1 Listener

In today's episode, Matt unpacks the world of coffee, and caffeine in the first of a two-part series on caffeine. Matt describes the numerous health benefits associated with coffee, the fact that Matt has even changed his tune a little and advocates a morning cup for some. Matt may not have anything to do with caffeine itself, with more details on that in part 2. In part 1, Matt then takes a deep dive into the different ways in which caffeine negatively impacts your sleep, some of which you may be less familiar with.

The first is that caffeine makes it harder for you to fall asleep. Due to activation of the nervous system, caffeine can lead to that unpleasant experience of a racing mind that won't shut off in bed—almost a Rolodex of anxiety that leads to ruminating and therefore catastrophizing.

The second impact is that caffeine makes it more difficult for you to stay asleep soundly across the night. This is due, in part, to the fact that caffeine makes your sleep more unstable and fragile, so up more frequently at night. The consequence is something that scientists and doctors call sleep fragmentation, meaning that your overall sleep efficiency, or the consistent quality of your sleep, becomes significantly worse when you have caffeine on board.

The third feature that Matt points out centers on caffeine’s duration of action. Caffeine has a half-life of between five to six hours in the average adult. This means that, after five to six hours, 50% of that caffeine is still in your system. What this also means is that caffeine has a quarter-life of approximately 10 to 12 hours for a typical adult.

Here, Matt gives us some context: if you have a cup of coffee at 2 PM, a quarter or more of that caffeine could still be circulating in your brain at midnight. Meaning, if you have a cup of coffee at 2 PM, it may be the equivalent of getting into bed at midnight, and just before you turn the lights out, you swig a quarter of a cup of coffee and you hope for a good night of sleep.

Matt, however, points out that the 10 to 12 hours quarter-life of caffeine is for the average adult, but this varies significantly from one person to the next. He explains in detail why this is the case: based on differences in genetics, different people will have a more or less efficient version of an enzyme that clears caffeine from their system. Some people will have a version of that enzyme that allows them to remove the caffeine from their system very quickly, whereas other people will have a version of the enzyme that is much slower in its speed of clearing caffeine.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.The good people at InsideTracker are the sponsors of this week’s episode, and they are generously offering 25% off any one of their programs for anyone who uses the above link. InsideTracker is essentially a personalized biometric platform that analyzes your blood and your DNA to better understand what's happening inside of you and also offers suggestions regarding things that you can do to better try and adjust some of those numbers, optimize them, and, as a result, optimize you.

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Previous Episode

#09: Sleep & Alcohol - Part 2

On last week’s episode, we learned about the three main ways alcohol can harm our sleep: 1) alcohol results in sedation rather than naturalistic sleep, 2) alcohol causes sleep fragmentation, and 3) alcohol impairs REM sleep.

Today, Matt dives into each of these negative impacts, explaining exactly how and why alcohol disrupts our sleep in these specific ways.

First, alcohol is a class of chemicals called “the sedatives,” and sedation is not natural sleep. Healthy sleep is a very active, highly coordinated event within the brain, unlike sedation. As a result, alcohol can result in you waking up and feeling unrestored and unrefreshed by that non-normal sleep.

Second, we normally need to shut off our fight-or-flight branch of the nervous system, called the sympathetic nervous system, and shift over to the calming, parasympathetic nervous system, in order to stay asleep soundly across the night. However, alcohol reactivates the fight-or-flight nervous system, forcing the brain and body back into a more hyper-alert state.

This increases the chances of you waking up and staying awake, causing your sleep to become more fragile and prone to fragmented awakenings throughout the night. Alcohol also triggers the release of several stress-related chemicals, including cortisol. This stimulates the fight-or-flight nervous system and emotional centers in the brain, also making it more likely that you will wake up and stay awake.

Finally, alcohol significantly reduces the amount of REM sleep the brain can produce. Specifically, the metabolic byproducts of alcohol degradation within the body disrupts and impairs the generation of REM sleep. Without that REM sleep, we can suffer impairments to our cognitive brain function and emotional stability. We can also experience a heightened amount of negative moods, such as anxiety. REM sleep is also the time when we hit our peak in the release of important hormones, like testosterone, which is critical for both men and women.

While Matt acknowledges that this news may not be especially encouraging or popular, he closes out today’s show with a reminder that life is to be lived. It is not his intention to tell anyone how to live their life. Instead, Matt’s goal is to simply lay out the scientific evidence regarding the relationship between sleep and alcohol, so that you can make an informed decision about how to best structure your own sleep schedule and find an enjoyable life balance.

Please note that Matt is not a medical doctor and none of the content in this podcast should be considered as medical advice in any way, shape or form, nor prescriptive in any way.

The episode is sponsored by the wonderful folks over at Athletic Greens, who are providing a discount and free product if you use the link above. Athletic Greens is a comprehensive daily nutritional beverage containing 75 vitamins, minerals, and whole food-sourced ingredients, including a multivitamin, multimineral, probiotic.

So, head on over to Athletic Greens www.athleticgreens.com/mattwalker and get a free year supply of Vitamin D and 5 free travel packs today. Finally, if you have thoughts or feedback you’d like to share, please reach out on Instagram @drmattwalker.

Next Episode

#11: Sleep & Caffeine – Part 2

In this week’s episode, Matt continues his discussion of sleep and caffeine. Here, we learn about the paradox of coffee, one in which coffee provides health benefits, despite its negative impact on sleep.
Before addressing that, however, Matt speaks about one last sleep consequence of caffeine: regardless of your sensitivity to caffeine, it can still disrupt the quantity and electric quality of your deep non-REM sleep.
This can lead to a cycle of caffeine dependency 1) you drink more coffee the next morning to compensate for your poor-quality, unrestorative sleep the night before, which then 2) degrades the quality of your subsequently night's sleep even more, which leads to 3) your potentially reaching for even more sups of coffee the following day, etc, etc .

Matt’s advice to still drink coffee (if you want) is due to the many health benefits associated with coffee. How is it possible that coffee has such health benefits, despite the harmful impact of caffeine on sleep?
Matt points out that the coffee bean itself contains a sizable blast of antioxidants in every cup. In fact, because of the state of the standard Western diet, coffee is the biggest source of antioxidants for many people in developed nations. However, it is possible to get these benefits without drinking caffeine – many health benefits are similarly associated with drinking decaffeinated coffee since that too contains antioxidants.
Therefore, it is the antioxidants in the coffee bean, not the caffeine, that carries the health-related advantages.
But Matt is also clear to speak about the fact that when it comes to coffee, the dose , and the timing make the poison. His advice: try to limit it to one to three (at the max) cups in the morning, remembering the quarter-life of caffeine is around 10-12 hours for the average adult.
By following these steps, you can maintain a healthy relationship between caffeine, coffee, and this beautiful thing we call sleep at night.

Please note that Matt is not a medical doctor, and none of the content in this podcast should be considered medical advice in any way, shape, or form, nor prescriptive in any way.

The episode is sponsored by the incredible folks over at Athletic Greens, who are providing a discount and free product if you use the link above. Athletic Greens is a comprehensive daily nutritional beverage containing 75 vitamins, minerals, and whole food-sourced ingredients, including a multivitamin, multimineral, probiotic.