Another reason to love coffee…

Love your coffee? Here’s another reason to pour yourself a cup. A recently published study should the consumption of a dark roasted coffee brew (500ml) daily for one month resulted in a 23 percent reduction in DNA damage to white blood cells compared to baseline levels. The protective feature of coffee is thought to be the polyphenols that are found in coffee. These bioactive ingredients (such as caffeic acid, catechol, hydroxyhydroquinone, trigonelline and the alkylpyridinium compounds) have been studied for their antioxidant and anti-inflammatory properties. They are able to mop up reactive oxidative stress (ROS) molecules that are the byproduct of metabolism. Obviously a small amount of ROS is necessary, however too much can overwhelm our anti-inflammatory and antioxidant system, causing increased inflammation and the reduction in the ability for these pathways to function, causing DNA damage.

DNA damage accelerates ageing and is the underlying cause of the growth of carcinogenic cells in the body. It leads to telomere shortening – telomeres are like small caps on the end of your DNA chromosomes, protecting them from damage, and are used as a biomarker for ageing. The study was a randomised controlled trial; therefore, it is able to establish causation (unlike a lot of nutrition research, which is largely observational in nature).It is consistent with other studies that show a reduction in DNA damage after even short term exposure (such as this study, where healthy volunteers showed a reduction in damage after only 2h of drinking coffee). The current research was conducted in both healthy men and women, and the 500ml of coffee per day equated to around 372mg caffeine daily – equal to around four cups of espresso. That sounds like a lot of coffee (and it is!) however this is consistent with other observational and clinical trial research that has shown a reduction in cardiovascular disease risk, cancer incidence and all-cause mortality for people who habitually consume around 4-5 cups of coffee per day. This latest study adds to a body of knowledge regarding the health benefits of coffee. The polyphenols mentioned above help protect us from type 2 diabetes, stroke and cardiovascular disease, with improvements being seen in glucose and insulin metabolism (important for blood sugar control), blood pressure and markers of inflammation in the body.

I’ve talked before on the health benefits we see in coffee, and though this is great news for coffee drinkers, let’s not forget there is a fairly substantial proportion of people who are sensitive to the caffeine in the coffee and can’t tolerate its stimulant effects. Caffeine is metabolised in the liver, with the CYP1A2 enzyme responsible for detoxifying most of the caffeine. Our ability to produce this enzyme is coded by our genes, and there is variation as to how active this is for each individual. Those that have an active gene are able to metabolise caffeine efficiently, therefore the stimulating effects of caffeine are mild and short-acting. This may affect their enjoyment of caffeine and clearly their ability to tolerate it. The opposite is also true – someone with reduced activity of the gene will metabolise caffeine more slowly and its effects will be longer lasting and more noticeable. You can find out your genetic ability to tolerate caffeine through a Fitgenes DNA test(PM me for more information).  In addition to the genetic differences, environmental elements also influence our ability to tolerate caffeine. Even if you are a fast metaboliser, stress and lack of sleep can impact on caffeine’s effects – ramping up cortisol levels and with it anxiety and blood sugar dysregulation. Three coffees a day when on holiday and in a relaxed state may not be a problem, however when a work deadline is looming and you’ve been running on little more than petrol fumes rather than sleep, it is a different story.

With the present research, as the health benefits are from polyphenols present in the coffee, rather than the caffeine, the reduction in DNA damage may well be seen in decaffeinated coffee too, with previous research finding benefits with regards to type 2 diabetes and liver damage when consuming both decaffeinated and caffeinated coffee. has found health benefits from drinking this. However, without clinical trials to confirm this, at this stage it is unknown.

Coffee cup with saucer and beans on wooden table.

Obligatory cup of coffee (PC:stockphotos)

Coffee: your friend or foe?

Coffee. It’s like the world’s favourite elixir. Mine included. For an athlete, there are many studies supporting its use as an ergogenic aid for athletes – helping reduce rates of perceived pain and effort, improving muscle fibre recruitment and enhancing glycogen repletion post-workout. These benefits are individual, however, and while research suggests that genetic differences in our ability to detoxify caffeine could account for this, it is not a universal finding. This is something true for athletes and non-athletes alike.

Other features of coffee are also salient for all individuals. Caffeine is ketogenic; not only can it help mobilise fatty acids to be used for energy, it increases the presence of ketones in the bloodstream – hence it is a good pre-workout fuel to help elicit fatty acid oxidation pathways and provide fuel for the workout in the absence of glucose. This doesn’t necessarily translate in additional body fat loss (more important lifestyle strategies are required for that, such as a caloric deficit, resistance training, reduction in stress etc), but can encourage these energy pathways to be upregulated, helping in the process of becoming adapted to a lower carb dietary approach.

Coffee improves insulin sensitivity and glucose tolerance (potentially related to the polyphenols present, though the mechanism is currently unclear), therefore enhancing the effects of both a lower carb approach, or a plan that includes fasting (either intermittent fasting, super-fasting, or a 5:2 approach such as the one in my fat-loss plans). Further, anyone doing my accelerated fat loss plans who have that 16h intermittent fast on the ‘fasting mimicking’ days could experience a more potent effect from the fast by including black coffee alongside water as their beverages of choice.

Autophagy, where our body starts to clear out damaged cells from the liver, heart and muscle tissue, is one of the benefits of fasting as you know. In mice models it might take just 16 hours for this to occur, in humans it is likely to take a lot longer given the differences in our metabolic rate (a mouse has a faster metabolism). Consuming caffeine on an empty stomach (or as part of a fast) promotes autophagy, which theoretically would shorten the time that is required to fast to stimulate this process. It also triggers AMPK, an enzyme that inhibits fat storage, promotes fat burning and activates antioxidant networks. These properties are thought to underpin much of the purported health benefits of drinking coffee.

It IS a balance though – if you’re following a fasting protocol, working out, and reading this at 3.30am in the morning, it’s a good sign that your brain is wired – raising cortisol to the extent that it’s (quite obviously) disrupting sleep. When we fast, like exercise, it places a stress on the body – this is where many benefits come from, as your body responds and adapts, becoming more resilient. However, too much of anything is too much! If coffee on top of your fasting regime or exercise program (or, life in general) is causing this stress response, then it is worth dialling it back a bit (or go 1/2 and 1/2 with decaf) to see if this changes your stress response.

Caffeine (or coffee), though, may not be good for anyone with gut issues. As it can stimulate the stomach cells to release more gastric juices, aiding in digestion, we often hear that too much coffee promotes a highly acidic environment and as such, could increase the risk of damage to the cells and subsequent gut issues. The literature, though, reports that caffeine does not negatively impact gastric or duodenal ulcers, and in fact when administered in vitro, could help repair cells damaged by inflammatory bowel conditions such as ulcerative colitis, and is also protective for the mucosal layer of the gut. Research suggests this is because caffeine increases blood flow to the gastrointestinal tract. Conversely, caffeine can lower the tone of the oesophageal sphincter – the valve that controls the release of stomach acid into the oesophagus, thus may promote heartburn and reflux.

With all research studies, it’s important to remember you are your own best investigator when it comes to how coffee affects you. I’ve said this before, but a good point to reiterate. The best advice, then, is to pay attention to how you feel when you drink coffee. Does drinking coffee make you more wired, especially when you fast, indicating it stimulates your stress (or cortisol) response? Does it give you reflux or heartburn? Does it upset your digestive tract more than settle it? Everyone has a different tolerance level to coffee, and further, our ability to detoxify it may also be different. If you feel great when you have coffee, and you don’t have any gut-related issues, then it is likely absolutely fine for you. If you notice an irritated gut, or you feel a bit wired, then it isn’t worth persevering with coffee for the purported health benefits – in your case, it might be making things worse.


Ahhh… coffee 🙂

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.