Episode 119 Transcript – Do You Need to Wait 1-2 Hours After Waking Before Consuming Caffeine

Leah:


Hello and welcome to the Ideal Nutrition Podcast. I’m Leah Higl and I’m here with my co -host Aidan Muir. And today’s episode, we will be discussing a pretty popular topic at the moment. And that is, do you need to wait one to two hours after waking before consuming caffeine? This is something that I have seen popping up all over TikTok and Instagram and it seems to be kind of a bit of a thing at the moment. And the proposed mechanism that these influences and other people are talking about has to do with certain hormones. So mainly cortisol and adenosine. So we’ll go through that.

But basically they both of these hormones are fairly low upon waking, which theoretically would reduce the effects of caffeine. So by timing it one to two times after waking at one to two hours after waking, we may be able to see more of a benefit from the caffeine than if we were to take it straight away.

Aidan:

So I’m gonna talk about the three main mechanisms that are proposed. I’m gonna try and not give my thoughts on it. I’m just gonna talk about them as how they’re proposed and then we’ll talk through them. So the mechanisms, two of the ones you kind of mentioned, cortisol and adenosine. And then also the third mechanism is like avoiding an afternoon crash. It will be related to that.

So talking through, first one, cortisol. So cortisol levels typically peak around 45 minutes after waking, depending on the source. Some will say a little bit longer, some will say a little bit less. After that point, whatever point they pick up, they typically start to decrease a little bit. Theoretically, adding caffeine while cortisol is already increasing would not further increase it much because caffeine based on this mechanism is also increasing cortisol as well. And that cortisol makes you more alert.

So the goal based on this mechanism is to get it higher to make you feel more alert. The logic then is instead if you waited until cortisol levels started to drop, you could offset that drop and get a further increase instead. So that’s the logic behind waiting one to two hours before having caffeine.

The adenosine one is that adenosine is something that makes us feel tired. Caffeine blocks adenosine by attaching itself to adenosine receptors. When we wake, as you mentioned, adenosine levels are low and typically they rise throughout the day. Therefore, one of caffeine’s main benefits of blocking adenosine isn’t really relevant directly after waking because they haven’t risen at all.


And then that third thing about avoiding the afternoon crash is only really relevant if you’re consuming caffeine only once per day, because if you consumed it once per day, it probably wouldn’t really be in play around 2 or 3 pm for example, when you might be experiencing that crash. Whereas if you timed it a bit later, for example, two hours after waking, it might be a little bit more likely to be in play slightly later and helping prevent that crash is the logic there.

Leah:

Something that I think is pretty crazy is the fact that influences people are talking about cortisol in a positive light where we usually always hear cortisol in a very negative light

Aidan:

Yeah, it’s the only space I say that hey.

Leah:

Yeah, sually we hear cortisol as being the stress hormone and the fat storing hormone Which obviously both of those things sound kind of bad and that’s usually the context we hear cortisol in but obviously that’s an oversimplification of what cortisol actually does in the body. We know it does have both positive and negative functions, but it is mostly talked about in the negative context.

But from a positive perspective, cortisol does make us feel more alert. It increases glucose metabolism and it can reduce inflammation, which are the impacts of cortisol that lay the foundation of the proposed mechanism with delayed caffeine intake. So talking about cortisol a little bit more and how it relates to this. The concept of cortisol increasing after waking and then like dropping throughout the day seems pretty consistent in the research, like that does appear to be something that does happen. There is also plenty of research showing that caffeine increases cortisol levels.

However, one thing that is often not factored in is that a large percentage of these studies are done on people that have not been habitually consuming caffeine in the lead -in or prior to this testing. So it may not have a lot of crossover to people that are habitual caffeine consumers, and it may not necessarily be the same.

Aidan:

So looking at research on habitual caffeine consumers and the effect on cortisol, to the best of my knowledge, there is only one study on this topic. I’m open to being wrong. And maybe there is more because as you can imagine, it’s kind of hard to find this because it’s like, you could theoretically find any study on caffeine and cortisol could be like a side thing that was measured. I don’t know if that exists. I haven’t seen anyone talking about that. I couldn’t find anything beyond this one study. So I’m just going to talk about one study.

So one study had 96 participants, roughly an equal split of men and women. They got them to do various dosages of caffeine leading into the experiment ranging from zero to 600 milligrams per day. Just putting context around that 600 milligrams is just over the equivalent of about six shots of coffee. So that’s the top end of this range is quite high. So zero to 600 milligrams per day in a double blind crossover study. Then for the experiment, they took 250 milligrams of caffeine or placebo at 9am 1pm and 6pm. The key finding and the one that obviously matters is that there was no difference in cortisol response after the 9am dosage of either caffeine or placebo in those who are habitual consumers of caffeine, the people who have been having caffeine. They found no difference.

And this really, really undermines the cortisol logic being like, as I said, there’s only one study, but if this finding was replicated or a consistent finding, you would come to the conclusion that’s like, okay, well then the effect of caffeine on cortisol is blunted, kind of doesn’t really matter. That’s not really a logical argument.

Few quick notes. Cortisol actually did increase a little bit in the 1pm and 6pm dosages. So as I said, in 9am there’s actually no increase in comparison to placebo. In the later dosages throughout the day, there was a little bit of an increase, but it was still blunted in comparison to where it was for the people who were not habitual consumers. So interesting study based on what we’ve got, it kind of really undermines that kind of cortisol thing. But I also keep an open mind about being like, what if five more studies were done like this and was the outlier finding. Like I still have like a little bit of an open mind from that perspective too.

Leah:

So let’s talk about the non cortisol stuff. In relation to adenosine, the theory makes a lot of sense. As adenosine rises throughout the day, we can use caffeine to offset the feelings of tiredness that come along with that rise in adenosine. But that also doesn’t make having a coffee upon waking entirely useless. It’s still going to have an effect in regards to perceived tiredness, perceived effort and alertness. Not to mention that caffeine does stay in our system for several hours and we can also use multiple caffeine dosages across the day. So it’s really only an issue if you’re limiting yourself to one caffeine dosage in the day. Like maybe if you want to optimize it, potentially wait a little bit until adenosine starts to rise. so you’re kind of counteracting that rise in adenosine, but you’re also, you know, not limited to one bout of caffeine across the day.

As for the two to 3 PM crash thing, that is also only relevant if you’re limiting it to like one dose per day. So you could always have a coffee upon waking and then a coffee around that kind of afternoon slump time. That would be a solution as well.

Aidan:

Or even like a few hours after the first one and have it still be in your system.

Leah:

Yeah, exactly. So if you’re kind of consuming caffeine throughout the day, this all of a sudden doesn’t really matter.

Aidan:

Yeah. And if you’re concerned about like the total dosage going up, you could just use less. You could like split the dosage over two, two occasions and that way it still would work out.

As a bit of a summary, I think, for most people, this topic probably doesn’t really matter that much. I think it is something that if you are regularly consuming caffeine, it’s kind of enough to say that it probably doesn’t matter. You probably don’t need to wait. It could just be a preferencing if you wanted to. You could come back to that total kind of thing about being a cat. The second you woke up, it probably increased the likelihood that you have more total caffeine. If you’re trying to reduce your caffeine, then maybe you would want to change that. But overall, I don’t think this really matters for many people.

Leah:

This has been episode 120 of the Ideal Nutrition Podcast. If you haven’t yet left a rating or review, it would be greatly appreciated for you to do so. But otherwise, thanks for tuning in.