Caffeine & Sleep – Reviewing The Latest Research

As a regular caffeine consumer and overall nutrition nerd there are few topics that intrigue both myself and my clients more than how to optimize caffeine’s joys and benefits while minimizing concerns around sleep disturbance.

Given that March is Caffeine Awareness Month, there is simply no better time to review the latest research on caffeine and sleep science.

Today’s article is sponsored by the Canadian Beverage Association, but the key messages and interpretation of the referenced science is my own.

My goal is to offer new and valuable insights into caffeine and sleep that go above and beyond what I’ve explored in the past.

With that said, let’s get to the good stuff.

Sleep Stats in Canada

Before we explore caffeine’s role in the bigger picture, let’s start by reviewing some important sleep statistics in the Canadian context.

For this I turn to a recently published report by Statistics Canada which used 2020 Canadian Community Health Survey data from nearly 10,000 respondents.

Here’s what they found:

  1. ~75% of Canadian adults aged 18-64 meet current sleep recommendations (7-9 hours).
  2. ~66% of Canadians report having high quality sleep.

The importance of this data for today’s purposes is to really outline the fact that while there is room for improvement in the quality and quantity of Canadian’s sleep, the majority of Canadians are sleeping well.

 Caffeine Content of Common Foods & Beverages

To best understand the data I’ll be referencing next, it will be helpful to review the caffeine content of commonly consumed foods and beverages.

As a friendly reminder, the physiological and structural properties of caffeine are identical whether they are natural (ie: coffee) or synthetic (ie: energy/soft drinks).

Keep these values in mind as we head into the next section!

 Caffeine & Sleep – New Evidence

It won’t surprise anyone to hear that, for some, consuming caffeine too close to bedtime can compromise the ability to fall asleep as well as the nature, quality and duration of sleep.

I believe it is both reasonable and strongly advisable that regular caffeine consumers understand the latest evidence surrounding caffeine use and sleep quality/duration.

For more information, let’s turn to a recent systematic review and meta-analysis which includes 24 different studies on the effects of caffeine on sleep.

The goal of this particular review is to provide insights into caffeine consumption in relation to quantity and timing of consumption, and what is least likely to result in disturbances in any aspect of sleep duration and quality.

Their general findings:

The effect of caffeine on sleep is dependent on both dosage and timing, meaning that large doses later in the day have the greatest potential to influence sleep.

Their recommendations:

1. When consuming moderate doses of caffeine (about 100 mg) – consumption approximately 9 hours before bed will most fully reduce your risk of caffeine disturbing your sleep quantity or quality.

2. When consuming larger doses of caffeine (about 215 mg)  – consumption approximately 13 hours before bed will most fully reduce your risk of caffeine disturbing your sleep quantity or quality.

3. When consuming smaller doses of caffeine (about 40-50 mg)   this amount appears to have much less potential to disturb sleep, regardless of when it is consumed.

No firm guidelines are offered by this review on this level of consumption.

A theoretical example:

Let’s imagine we have a person who consumes two coffee shop coffees a day and wants to apply these findings to their life.

They consume one medium coffee (approximately 160-200 mg caffeine) and one small coffee (approximately 80-100 mg caffeine) daily or any caffeine equivalent from tea, pre-workout or energy drinks, as per their preference.

In this case, the individual should aim to have the larger medium cup of coffee within a few hours of waking up in the early morning and have that second smaller cup of coffee in the early afternoon, in order to minimize the impact to sleep.

Caffeine Effects Everyone Differently

Caffeine is metabolized very differently by different people, and it is likely that the effect of caffeine quantity and timing will impact different  people’s sleep in a different ways.

The caffeine cut-off recommendations that this particular review has arrived at can be seen as a general guideline, but does not need to be taken as a hard rule by those who are confident in their sleep behaviours despite consuming caffeine in a manner that is not in alignment with the findings presented.

For those who are regular caffeine consumers with less confidence in their sleep, the guidelines provided may prove important focal points.

Foods With Added Are Now “Supplemented Foods”

You may have noticed that some of your favourite products that contain added caffeine are sporting new “Supplemented Food Facts” tables identifying the supplemental ingredients and their quantities.

Products with 1 or more added supplemental ingredient can fall under new labelling regulation.

The regulations for these labels were published by Health Canada in 2022 and all supplemented foods must have them by January 1st, 2026, with the primary goal of allowing consumers to make more informed decisions.

As it relates to caffeine added products, these labels will make it much easier for people to determine how much they are getting and really allow them to make strategic decisions around product choice and timing of use.

Caffeine isn’t the only example of a supplemental ingredient though, as various vitamins and minerals are also added to different types of foods and beverages.

Certain supplemented foods will also have a supplemented food caution identifier on the front label.

The presence of this label indicates that a caution box will be present on the back or side of the package.

These caution boxes provide further insight into the safe and appropriate use of the product, but let’s take a closer look at why Health Canada decided to add these statements to products.

Why Do Some Supplemented Foods Contain Additional Statements?

So glad you asked!

It is the case that certain supplemented foods contain ingredients that can be of concern in specific contexts such as when:

  • Consumed in excess by the general population
  • Consumed by people who are:
    • Under the age of 14
    • Pregnant or breastfeeding
    • Sensitive to caffeine

Supplemented foods that fall into this category will contain the additional front of pack caution identifier and the caution box identified in the previous section.

Caffeinated energy drinks are an example of such a product, and as a result will contain certain labels to help consumers understand how to use them in the most suitable way.

All caffeinated energy drinks must have:

  • The statement “high caffeine content”
  • A supplemented food caution identifier
  • The cautionary statements:
    • “Not recommended for those under 14 years old, pregnant or breastfeeding women or individuals sensitive to caffeine”

Working with so many people over the years I know the important roles various supplemented foods play in our daily lives and the level of enjoyment they bring to many of us.

That is precisely why I wanted to close today’s article by reviewing these new labelling regulations to ensure you can approach them from a place of understanding as to their role in guiding your choices.

Until next time,

Andy De Santis RD MPH