Coffee: how much is too much?

Hmm coffee. There’s nothing I like more than my Kathmandu plunger of coffee in the morning. I’m probably like a lot of kiwis, and 54% of those in the US it turns out. Sixty five percent of whom claim they ‘need’ their coffee in the morning. Me? If I go happen to go without it, I feel mildly aggrieved that I wasn’t able to experience the pleasure of the first sip, which is preferable to the thumping headache others report experiencing if they miss it. It enhances my morning rather than controls it. Regardless of what camp you fall into, as New Zealander’s we are a proud coffee drinking nation, therefore it’s not surprising that one of the most commonly asked questions I get ‘am I drinking too much coffee*?’ And I have to say that’s like asking ‘how long is a piece of string?’ Like most things, we can’t look at caffeine consumption in isolation of other behavioural and physiological factors. We have to view it in context of the overall lifestyle for that person.


If this is you, take comfort in the fact that you are among friends. (Image stolen from Pinterest)

In fact, if you look at some of the media headlines which report consumption of coffee at a population level, it is all looking pretty good. It used to be frowned upon for its diuretic effect in the body, yet we now know that for habitual drinkers, around four cups per day does not cause dehydration.  Moderate consumption (of around 3-5 cups per day) places people at a lower risk for cardiovascular diseasereduced risk of type 2 diabeteslower risk of cirrhosis, non alcoholic fatty liver disease and hepatitis C. I know what you’re thinking: order me a Frappuccino and make it a Grande.

Not so fast.

When we look at studies of coffee consumption in the academic literature, we have to view it with the same light that we do the studies which conclude that saturated fat is associated with heart disease, or that red meat increases risk of cancer: these studies are observational and take a snapshot look at the population  – therefore the same inherent limitations exist: there is no cause and effect, it is just an association – when you ask a population once about their coffee intake you seldom get a clear picture of what they are drinking. Perhaps it IS a triple shot short black straight up from the café downstairs, or it’s a ½ teaspoon Moccona made with trim milk and hot water. In addition, we don’t always know the other lifestyle factors that occur in conjunction with the coffee consumption. Perhaps those with the lowest health risk who drink coffee are also people who are also regularly active, their body weight is within a healthy range for them, they may lead less stressful lives. Whilst these can be statistically adjusted in the studies, I tend to agree with those who argue that it’s always difficult to adjust away the accumulated affects of a healthy lifestyle.

Importantly, what studies like these are reporting are population averages. For example, if we track two groups of people over time (either those that consume coffee and those that don’t), we might find that in the group that drinks coffee, the actual intakes vary from two cups of coffee to eight cups of coffee a day. We might find that those who drink coffee have better sleep patterns than those that don’t. We would average out the intake and conclude that perhaps four drinks of coffee per day enhances sleep. However, it is highly likely there will be differences in those that drink two cups of coffee per day compared to those that drink eight cups. We also don’t know whether those that drink coffee have habitually done so, or have recently taken it up. Nor are we sure that those who don’t drink it have decided not to due to issues related to obtaining enough sleep. Further, among the group that actually do drink coffee, what is it about the lifestyles of the people in the study that drive them to drink eight cups of coffee in a day? These questions aren’t able to be addressed in population-based research in a way that is meaningful for the individual. In real life, we don’t work with the ‘average’ person, and at the individual level the coffee intake is not the problem – it’s the symptom of underlying issues that need addressing.

So what are the downsides of too much coffee? Coffee, or caffeine rather, is a stimulant. It elevates cortisol production (a stress hormone) which increases the load on the hypothalamic pituitary adrenal (HPA) axis, the regulatory system that is responsible (among other things) for regulating our thyroid metabolism, digestion, immune system and stress and sex hormone production. If you consume two espressos per day and feel more or less on top of everything from day to day, then this elevation in cortisol from the caffeine is more likely to be transient and if anything, the stress may well be good (after all, we need a certain amount of stress to thrive in everyday life). However, if you consume those two espressos on top of disrupted sleep, a rather heavy workload, a high training load (for an athlete) and might also be going through some relationship difficulty, then the accumulation of stressors will lead to a chronic elevation of adrenaline and cortisol. Over time this can cause disruption of the HPA axis, resulting in fatigue, increased susceptibility to illness, weight gain, and reduced ability to cope with further stress. None of these are desirable and, in fact, are becoming more common as our lifestyles are becoming busier. This collection of symptoms is referred to as adrenal fatigue, and while not always acknowledged as such in the medical arena, there are many people suffering the effects of burn out due to a chronic stress overload.

To add to this, caffeine is an adenosine antagonist, which means that it takes the place of adenosine on receptors in the brain and blocks its activity. Adenosine is responsible for producing a more relaxed state and preparing us to get ready to wind down. Caffeine blocks this and therefore the neurotransmitters responsible for invoking an alert state are allowed to continue on, making you feel less sleepy after taking it. Useful if looking for a second wind later on in the day. However, given that caffeine has a half life of around 6 hours (meaning it takes that long to metabolise), when consumed in large amounts later in the day it is going to impact on sleep, regardless of how convinced you are that this isn’t the case for you. While you might not have any trouble getting to sleep, certainly the quality of sleep is compromised. This lack of restorative sleep not only impacts physiologically (increasing insulin resistance), but increases cortisol levels and the likelihood of reaching for foods and stimulants to level out energy levels the following day.

So…are YOU drinking too much?  If it leaves you feeling relaxed and calm then it probably only makes you more awesome. If it leaves you feeling a bit jittery and wired, or you use it to get through the day, perhaps you need to evaluate whether that long black is contributing to your health or stealthily removing it. Only you can determine that.

*the only thing I can say with almost certainty is that coffee made from Jungle Beans (or its derivative Zee) is best avoided regardless of context.

Anyone for a short black?

Coffee. Mmmm. Even those people who don’t drink coffee can enjoy the pleasurable sensory satisfaction of freshly ground coffee beans. Coffee drinkers that don’t have their morning / post lunch / pre-bed espresso can feel just a little bit less than human. Actually for some, that’s being polite. Like someone falling off the edge of a glucose cliff, they can turn into the worst version of themselves if they haven’t slammed their triple shot short black, hold the glass. There is a reason why we turn our nose up at Starbucks or McCafe when there is a small local espresso stand just down the road. As a rule, New Zealand has GREAT coffee and even the less seasoned drinkers can wax lyrical about coffee machines, a well roasted coffee bean, or a good crema on top of our espresso. We trump Australia in the coffee stakes and are as proud of that as we are of the All Blacks.

And what’s not to love? Now that it is pretty much undisputed that, for regular consumers, coffee isn’t going to dehydrate you, it can also boast about being protective against risk of type 2 diabetes and cardiovascular disease. It is known for its performance enhancing effects for athletes due to the effect of caffeine on the central nervous system. But really, these are almost positive byproducts of consumption  for most people. Coffee, with it’s stimulant effect, helps us get out of bed in the morning, gets us through the two hour meeting (which, like most meetings, could be over and done with in half an hour), gives us something to do at 3pm when we feel like we are going to crash, and helps us unwind at the end of a busy day. While some of these are more psychological (particularly the last one), the others are to do with the effect that caffeine has in the brain. Caffeine has the ability to take the place of adenosine in our brain, an inhibitory neurotransmitter released by neurons to help promote sleep by binding to adenosine receptors and causing the release of dopamine. Caffeine is perfectly shaped to take place of the adenosine in certain adenosine receptors and take up residence instead. This allows the brain to function as normal instead of it preparing for rest, increasing alertness and offsetting any drowsiness we might be experiencing particularly when we are lacking in sleep. For some, operating in this sleep deprivation/fatigued state is pretty much how life rolls at certain times of the week or year.  While some notice the effects of caffeine more than others, most will build up a tolerance over time so its stimulant effect will be harder and harder to come by without upping our dose of caffeine. It has a half-life of around 6 hours (i.e. it takes this long to eliminate half the caffeine dose from our system) which means that your body can still be in a state of alert well into the night if you typically enjoy a long black after dinner (or, to a lesser extent, an afternoon coffee). Despite assertions from people that the post-dinner caffeine hit doesn’t affect their sleep, research shows it can affect the time it takes to get to sleep, the amount of time we sleep in total and the amount of quality restorative sleep we are able to get. This could be the start of a vicious cycle where the pleasurable cup (or three) of coffee in the morning starts becoming a necessity to keep you feeling awake or alert. The ‘tired but wired’ feeling typically experienced comes from the effect that caffeine has on the pituitary gland, causing the release of adrenaline. I’ve talked before about the short (and long) term effects of this stress hormone response, and imagine many out there can relate to the exhaustion that comes from the sleep deprivation and blood sugar disregulation that can come from too much coffee.

When I chat to clients about their coffee intake they are often anxious that I will suggest they need to drop all coffee immediately. But that’s not my default position. If you aren’t experiencing any digestive issues, symptoms of liver toxin overload, sleep deprivation or any problems with anxiety, then there may be no reason to do cut back. However, if you recognise that your coffee intake is higher than it should be, and you’re using it as a crux to get you through the day, then cutting back on coffee is one strategy among other dietary and lifestyle modifications that help bring you back into balance. Some people can quit drinking coffee and experience no physical symptoms. Here are a few things that I’ve recommended to clients to help them reduce their intake and potentially limit those withdrawal symptoms:

  • Warm water with lemon in the morning: this can help support liver function and reduce symptoms of sluggishness related to metabolising nutrients and toxins in the body.
  • Higher protein content at breakfast:  this helps support a normal cortisol level (another stress hormone which helps maintain energy and concentration and should be higher in the morning and decreases over the course of the day. This isn’t possible with increased adrenaline). A higher protein breakfast will also help keep you fuller for longer. This is important if you notice that the 10am coffee is in lieu of a snack because you’ve had a cereal-based breakfast that has barely touched the sides.
  • Ensure you are drinking enough water during the day. This will help you remain hydrated and reduce any dehydration-related fatigue.
  • Quit the coffee after lunch. Find a substitute. This will help restore restorative sleep patterns which will obviously reduce fatigue throughout the day. Combined with a better breakfast, your concentration and energy levels will be a lot higher, negating that 3pm coffee.
  • Which of your four morning coffees are a necessity for you and which are merely a distraction from what you should be doing? Gradually reducing your intake and setting a timeline around this can be helpful. You will feel good about achieving your short-term goals, and it will may make it easier to cut back further if need be. By substituting one of these for a brisk walk up and down the stairs you will increase your blood flow and level of alertness without the caffeine hit.
  • Find another beverage. If you’re not a fan of herbal teas then I can relate. I don’t like a herbal tea bag as they promise SO much more than they deliver. However a visit to a specialised tea shop uncovered some great options in the form of leaf tea which, surprisingly (to me) provided just as much pleasure as an afternoon long macchiato. Once I got my head around it.
  • Jumping in a cold shower for a few minutes can also increase your alertness, as the shock factor from the cold water will increase your deep breathing and deliver oxygen (i.e. energy) to your muscles. Your heart rate will also increase and blood will pump through your body faster. Of course, this is pretty impractical for all but a few of us, so try splashing your face with cold water throughout the day for the same effect.
  • Drink green tea: while this contains some caffeine, it is a lot less than your standard cup of coffee (25 mg versus 150 mg, though obviously this will vary). There is a compound in green tea called l-theanine that works to increase alertness, particularly in the presence of the small amount of caffeine in it.
  • Put your feet up… literally. Putting your legs up against the wall for a few mintues will increase the blood flow to your head and can eliminate brain fog. Try it.
  • When you feel a craving come on, actively busy yourself with another task – i.e. Take your mind off it. Research shows that this can help suppress your craving for coffee.

Do you need to reduce your intake? You might not need a nutritionist to answer that. Be honest with yourself about how much you are consuming and hopefully some of these strategies listed above will help you if you do. It’s likely that, after a period of time, you’ll rediscover the real feeling of pleasure that is derived from a perfect cup of coffee, which may be somewhat diluted if you’re overloading your system.