Is it Important to Delay Morning Caffeine Intake?

 

This idea has been popularized lately based on several physiological   mechanisms that support this idea.   First, is the fact that caffeine intake can definitely boost levels of cortisol which is already elevated in the morning. Cortisol is often labeled as being “bad” because it is a catabolic hormone that can have negative effects if chronically elevated.

Although this mechanism is real and caffeine can increase cortisol that is not the whole story!   If you are new to caffeine – it will definitely produce a big cortisol spike.    However, you quickly adapt to caffeine such that there is zero additional increase in cortisol.    In a study that looked at this they found that just 5 days of 300 – 600mg of caffeine the initial morning increased cortisol response was eliminated.

In addition, a strong morning cortisol response is important for several reasons:

It raises levels of blood glucose to provide the energy burst we need to wake up and go about our day!

Cortisol is essential for managing stressors – in fact if without cortisol you would die!

Cortisol stimulates the production of endogenous (internally produced) anti-oxidants such as Super Oxide Dismutase. 

High Cortisol is a problem if it is elevated all the time or at night because it can prevent sleep and breakdown body tissues.  Understanding if you have problems from cortisol is more about looking at your body’s cortisol rhythm – when is it high and low.  Cortisol is supposed to be high in the morning and low at night for example.

Another mechanism that has negative implications is that caffeine blocks the effects of a biochemical called Adenosine.   Adenosine build up throughout the day and is part of what makes us feel sleepy at night.  The thought is that by taking caffeine right away to block the affects of adenosine you will create a big crash when the caffeine wears off that could be avoided by delaying its intake.

However, is that what research on this subject has shown? 

According to a meta-analysis of over 200 studies just published in the Journal of the International Society of Sports Nutrition:   

“There is no evidence that caffeine ingestion upon waking is somehow responsible for the afternoon ‘crash’ or that delaying consumption would somehow prevent this if it did occur.”

The third mechanism cited is that caffeine causes dehydration.   Is that true and is the level of dehydration meaningful?   Even mild dehydration can reduce concentration, slow your reaction time, negatively impact short-term memory, and even negatively impact your mood.   As a metanalysis found the slight diuretic effect of caffeine may be minor or non-existent and proper fluid intake prevents dehydration.

So make sure you have plenty of fluids and dehydration from your morning caffeine is a non-issue!

In summary – common sense should prevail here.  Too much of anything is a bad idea and that includes caffeine – try to keep your intake at or under 400 milligrams per day.     

There are slow and fast caffeine metabolizers so pay attention to how you feel and adjust accordingly.   Also try not to have caffeine after Noon each day.

Like most substances caffeine does not agree with everyone and some people are very sensitive and find that even small amounts can cause anxiety, irritability and even heart palpitations. 

If you are taking any medication google caffeine and your medications to see if there are possible interactions and as always your physician is the best source of information!