What if I told you that one of the greatest nutrition myths we’ve told ourselves is that caffeine impacts our ADHD (either negatively or positively)?

Well, buckle up, because what you’re about to learn is going to blow your mind.

Let’s chat caffeine.

I admit it - I used to drink WAY too much caffeine myself. From nights where I chugged about six cans of Mountain Dew back in college to drinking over my fair share of coffee the morning after, I am well familiar with the ADHD love for caffeine.

According to the research, you probably are too.

People with ADHD - as well as people with depression and anxiety - drink significantly more caffeine than the general population. We are also at a higher risk for developing Caffeine Use Disorder, or CUD. CUD is an extreme version of caffeine dependence: essentially, caffeine use disorder happens when we want to cut down on our caffeine consumption because we notice it is giving us problems, but we are unable to due to significant withdrawal symptoms.

Interestingly, that study that found people with ADHD are at a higher risk of developing CUD? They found that caffeine consumption itself isn’t related to ADHD severity.

I know what you’re thinking - that makes absolutely no sense. But it will. Trust me.

How Caffeine Impacts Your Brain

Let’s backtrack a little bit to make sure we understand what caffeine does to our brains. When we drink caffeine, it travels to our brain and shoves out a neurochemical called adenosine. Adenosine is crucial for regulating our sleep-wake cycle. When we wake up, it starts increasing more and more until it hits night, and then it reduces. This is actually why many people benefit from a mid-day nap! When we take a short nap, it clears excess adenosine, allowing for an increase in focus.

That being said, caffeine can do something similar. However, instead of reducing the overall adenosine, it simply makes our brain pretend they don’t exist.

Over time, when we consume a lot of caffeine, it can actually increase the amount of adenosine receptors in the brain. Essentially, think of it this way:

Caffeine also impacts dopamine, but it’s more of a secondary interaction whereas the adenosine push is its primary function.

The Caffeine-ADHD Connection

Ok, so based on all of that, are we sure it doesn’t impact ADHD? Because for a lot of people, it definitely makes us feel like it’s helping. Considering how it impacts the brain, it also might make sense that it could worsen ADHD in the long run too!

Here’s the thing. Sometimes, conventional wisdom and logic don’t translate to real life.

In fact, we have quite a large number of studies proving that caffeine, simply put, doesn’t impact ADHD (big win for y’all who have about 3 different drinks with caffeine on your desk right now). For instance, this 2023 meta-analysis found no statistical impact on ADHD in children and this 2022 review found the same for adults.

And then, remember how I talked about how caffeine use disorder is associated with ADHD but not the caffeine itself? Well, that study also found that quality of life was important here. Essentially, caffeine use disorder is more associated with how well a person feels rather than with ADHD symptoms. Meaning, the more positively you view your life, the less impactful caffeine might be on your general health!

It’s also important to look at genetics as well.  There is a specific gene polymorphism that is connected with a higher risk of developing CUD, AND people with ADHD are more likely to have that than the general population. Also, guess what: that gene polymorphism is also associated with caffeine affecting sleep - which we know that people with ADHD already have issues with statistically. At the end of the day, as with nearly everything, it comes down to both genetics and our environment.

Caffeine and Sleep in ADHD

One question many people wonder about is the impact of caffeine on sleep. Interestingly, there is a huge range of experiences with sleep and caffeine. Some people actually fall asleep quickly after drinking caffeine, and some people experience sleep disturbances. However, this study found that even though the kids with ADHD felt like they got worse sleep, they didn’t actually. There’s a lot of work to be done in this area, but the current consensus in the caffeine-sleep field is that, for some unknown reason, some people’s sleep aren’t affected by caffeine and some people are. (The likely reason is genetics).

This is where I personally take a conservative approach and recommend not consuming caffeine past noon. Until we get more solid research on the subject, I believe in erring on the “it may likely negatively impact our sleep.” Considering sleep quality is one of the top reasons for ADHD exacerbation (second to stress, in my opinion), I do recommend just being safe about it.

What About the TYPE of Caffeine?

If we want to make everything a bit more complicated, there is also the interaction of the type of caffeine we consume. For example, energy drinks can contain little-to-no health benefit whereas coffee and tea can contain incredible phytonutrients that could actually improve ADHD and mental health in general.

Take, for example, green tea. You might remember that article on matcha I did a while back (here’s a link to read it) that found it could help ADHD symptoms.

Another common one? Coffee. This study actually found that drinking 2-3 cups of coffee a day might have a protective effect on both anxiety and depression, which a lot of people with ADHD experience. The study also found the effect was significantly diminished if the coffee was sugar-sweetened, so (again) please be sure to decrease your purchases from Starbucks if you want the best benefits.

How Much is TOO Much?

The dietary guidelines recommend we consume at maximum 400mg of caffeine per day. This is because more than that has been associated with many negatives, including increasing anxiety severity, cardiovascular risk, diabetes II risk, and more. In fact, this study found that drinking more than 6 cups of coffee a day is associated with 53% increased risk of dementia compared to drinking 1-2 cups a day!

It seems that the sweet spot for optimal functioning is about 120-250mg of caffeine per day for adults. Keep in mind that some foods also contain caffeine, such as cocoa powder (which is something I take every day myself). I encourage you to take a good look at what you’re drinking and see how you can reduce it, if necessary.

Last, remember: Adults are DIFFERENT from kids. It’s recommended from a public health standpoint to eliminate caffeine (or consume less than 20mg, if in food form) if they are under the age of 6, and then between 6-14y consuming no more than 80-100mg of caffeine a day. One of the biggest reasons for this is actually how it can increase risk of mental health conditions in the future, such as this study on caffeine consumption in kids and developing anxiety later on.

What Does This Mean For You?

Overall, here are the main takeaways:

1. Caffeine does not impact ADHD

2. Moderate consumption of caffeine seems to have a neuroprotective effect in adults (120-250mg per day)

3. Ideally caffeine consumption should be from sugar-free or low-sugar versions of plant-based caffeine: think coffee, tea, and cocoa powder

4. Overconsumption of caffeine can harm our overall health, so ensure you are drinking at maximum 400mg per day

5. Children should be closely monitored regarding their caffeine intake as it can actually harm them rather than help them (like what we see with adults)

And last, just listen to your body! You know yourself the best. For me, I simply don’t drink much caffeine at all as it has the tendency to make me feel either too jittery or it makes me crash. If I do, I always drink it with food to help with the jitters, prioritizing protein.

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Thanks for reading!

If you have any thoughts, questions, or comments, be sure to shoot me a DM on Instagram @Nutrimindcoach or simply reply to this email. I LOVE hearing from you!

Last week I dropped the episode on what can actually make ADHD worse - check out the YouTube or Podcast episode below!