Caffeine and Sleep

 

Sleep is crucial for overall health and well-being, playing a vital role in physical and mental recovery. Despite the overall health benefits associated with coffee consumption (such as being a valuable contributor of antioxidants and fibre to the diet), its caffeine content can negatively impact sleep quality. Understanding the effects of caffeine on sleep is essential for making informed choices about coffee consumption.

 

What is Caffeine?

Caffeine is a natural stimulant most commonly found in coffee, tea, and cacao plants. It works primarily by blocking the action of adenosine, a neurotransmitter that promotes sleep and relaxation. This blockage prevents adenosine from binding to its receptors, resulting in increased alertness and wakefulness. While this can be beneficial for short-term focus and energy, it can have negative impacts on sleep, especially when consumed later in the day.

 

How Much Caffeine is in Coffee?

The amount of caffeine in a coffee beverage varies significantly depending on several factors, including the species and variety of coffee, the brewing method, and the amount of coffee used. For example, a filter coffee brewed using a typical specialty arabica coffee typically contains around 200 mg of caffeine, which is half the recommended daily limit for adults. A standard double espresso using the same coffee will contain approximately 125 mg of caffeine. Some varieties of arabica coffee have naturally less caffeine will have around 60% of the caffeine content. The coffee variety Robusta on the other hand has significantly more caffeine. You can read more about caffeine in coffee in our post here.

 

How Does Caffeine Affect Sleep?

Caffeine affects sleep in several ways, primarily by interfering with adenosine and influencing other physiological processes.

Blocks Signals of Tiredness: Caffeine attaches to adenosine receptors in the brain, preventing the neurotransmitter from signalling tiredness. When caffeine is metabolized, there is often an accumulation of adenosine, leading to a "caffeine crash" where individuals feel an abrupt onset of fatigue once the stimulant wears off.

Increases Feelings of Anxiety: Caffeine can increase heart rate and body temperature due to the release of adrenaline. This "fight or flight" response prepares the body for physical exertion but can also heighten feelings of anxiety. The increased heart rate, dilated air passages, and raised blood pressure can contribute to a sense of unease or nervousness.

Reduces Quality Deep Sleep: Caffeine reduces the amount of deep sleep by blocking adenosine, which is crucial for entering and maintaining deep sleep stages. Deep sleep, also known as slow-wave sleep (SWS), is essential for physical and mental recovery. By disrupting this stage, caffeine leads to lighter, more fragmented sleep and increased wakefulness during the night.

 

How Long Does Caffeine Stay in the System?

For the average person, caffeine has a half-life of about 5-6 hours, meaning that half of the consumed caffeine remains in the body after this period. This equates to a quarter-life of caffeine of 10-12 hours. So if you drink a filter coffee containing 200mg of caffeine at noon, around 50mg of caffeine will still be in your system by 10 PM, roughly equivalent to the caffeine content of a can of coke. This residual caffeine can interfere with your ability to fall asleep and stay asleep. It should be noted the half life of caffeine varies significantly for different people.

 

Health Benefits of Coffee

While the caffeine component of coffee can have a negative impact on sleep - drinking coffee has several significant health benefits (so don’t stop drinking coffee!).

Some of the positive impacts of coffee consumption:

Contribution of antioxidants to the diet: Coffee is rich in antioxidants, which help protect cells from damage caused by free radicals. These antioxidants can reduce inflammation and lower the risk of various chronic diseases.

Contribution of fibre to the diet: Coffee contains soluble fibre, which can aid in digestion and promote a healthy gut microbiome. This fibre can help regulate blood sugar levels and improve overall digestive health.

When coffee is decaffeinated it retains its fibre and antioxidants - so these health benefits are also present in decaffeinated coffee. This makes decaf a suitable option for those who want to enjoy the health benefits of coffee without the caffeine-related sleep disturbances.

 

How to Improve Your Sleep and Still Enjoy Coffee

If you love coffee but are concerned about its impact on your sleep, there are several strategies you can employ to enjoy your favourite beverage without compromising your rest:

Set a Caffeine Cut-off Time: Establishing a cut-off time for your last coffee of the day can significantly improve sleep quality. The earlier the cut-off time, the more effective it will be. For many people, this might be mid-afternoon or even noon.

Try Low Caf or Half Caf Coffees: These options provide some caffeine but in lower amounts, allowing your body to clear it more effectively by the end of the day. This can help maintain alertness without severely impacting sleep.

Opt for Decaf Coffees in the Afternoon or Evening: Decaf coffee allows you to enjoy the taste and ritual of coffee without the caffeine. This can be a great option for the latter part of the day to avoid sleep disruptions.

 

Summary 

Understanding the relationship between caffeine and sleep is essential for balancing the benefits of coffee with the need for quality rest. By making informed choices about when and how much caffeine to consume, you can enjoy your coffee while maintaining healthy sleep patterns. Whether by setting a caffeine cut-off time, choosing low caffeine options, or switching to decaf in the afternoons, you can find a strategy that works for you.

Interested in trying some lower caffeine coffee to help improve your sleep? Have a look at our decaf coffees if you want minimal caffeine, or we have naturally low caffeine coffees and half caf blends for those who want around half of the caffeine typically found in specialty arabica coffee.

 

References

- Drake, C., Roehrs, T., Shambroom, J., & Roth, T. (2013). Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. *Journal of Clinical Sleep Medicine*, 9(11), 1195-1200.

Gardiner, C., Weakley, J., Burke, L.M., Roach, G.D., Sargent, C., Maniar, N., Townshend, A., and Halson, S.L., 2023. The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Journal of Sleep Research. Available online 6 February 2023.

Bartlett, S. (Host), 2023. 'Matthew Walker: The World's No.1 Sleep Expert (The 6 Sleep Hacks You NEED!)', The Diary Of A CEO, 6 February. Available at: https://podcasts.apple.com/au/podcast/matthew-walker-the-worlds-no-1-sleep-expert-the-6/id1291423644?i=1000603402611 (Accessed: [06/08/2024]).