Coffee: Healthy Or Bad For You?
When coffee was introduced to Europe the Pope was coerced by his advisors to label the new drink the ‘Bitter Invention of Satan’ but the Pope decided to taste the evil drop, and on doing so gave it his blessing.
CAN I GET A HALLELUJAH AND AN AMEN TO THAT?
We all know that coffee is sex in a cup, but what are the health benefits, how can coffee impact athletic performance, why does it make some people horny and can I please inject coffee straight into my veins?
I have examined all of these questions and more… just let me go and get a coffee first, and then we can get started.
THE HISTORY OF COFFEE:
It’s said a goat herder from Abyssinia (upper Egypt) named Khaldi discovered coffee after noticing his goats became quite agitated after eating fruit from a certain tree. The loyal goat herder ran (flock of goats in tow) straight to the monastery to tell the monks of this strange reaction. The monks tried the fruit for themselves. The monks were indeed affected by the fruit and became overwhelmed with feelings of joy.
The monks, up to their armpits in the exotic new fruit, began to party all night long with their robes tied in a fancy knot at the side to show off their geeky, yet well ahead of their time, roman sandals.
Eventually news of this magical, energising fruit began to spread around the world (1,2). Well at least, that’s how I imagine it. Although there are many accounts of coffee in history dating from to the ninth century and earlier, the earliest credible evidence of humans interacting with the coffee plant comes from the middle of the fifteenth century, when it was consumed in the monasteries of Yemen(1).
The Arabs were the first to cultivate and trade coffee and by the sixteenth century it was being cultivated in Persia, Egypt, Syria and Turkey, hitting Europe by the 17th century. And then…TO INFINITY AND BEYOND!
BEFORE IT GETS TO YOUR CUP:
Coffee is first planted and the seeds watered. So far so good. 3-4 years after plantation, the red fruit (called coffee cherry) is then harvested, mostly by hand. The cherry is processed using either the dry method (dried in the sun) or the wet method (fruit is pulped using water).
The processed fruit is then sent for drying, to prepare for storage. They then go through the process of milling, which includes hulling (to remove the endocarp layer), polishing (where the skin is removed), and then grading and sorting (sorted by weight and size and defective beans removed).
These beans, now referred to as “green coffee” (which is essentially the raw bean), are exported all over the world where the tasting process occurs. Tasting of the coffee bean is called “cupping” and is undertaken throughout the process of roasting to review the aesthetics, nose and taste. The green coffee then enters the roasting phase, and the magical green coffee is transformed in to the aromatic, brown beans we know so well (4). Ta-darh! Coffee is born and ready for me to grind and brew. Yummm!
IN YOUR BELLY:
99% of caffeine ingested is absorbed through the gastrointestinal tract and quickly moves through cellular membranes where it is metabolised by the liver. Caffeine has an average half life of 4 – 6 hours.
Coffee is known to block adenosine receptors, found throughout the body and brain, inhibiting the actions of adenosine (which I’ll go into below). It also binds to the receptors causing drowsiness by slowing down nerve cell activity.
So…to put it simply caffeine acts on these receptors to block the actions of adenosine, resulting IN…[take a breath]…an increase of your body’s use of fat (ya!), increased dopamine (activates the pleasure centre in the brain – wahoo!), increased adrenalin (further accelerating your body’s fat consumption – double ya!) and it tells the nerve cells to speed up, making you more awake and energetic. Also with the release of adrenalin, your airways open and your blood pressure rises.
The metabolism of caffeine results in the metabolites – paraxanthine (a psychoactive central system stimulant), theophylline (relaxes smooth muscle of bronchi) and theobromine (a diuretic, potential aphrodisiac, heart rate stimulant and dilates blood vessels) which is also found in chocolate (5,6).
Caffeine levels can appear in the bloodstream within 15-45 min of consumption, with the majority of the impact being a stimulatory effect on the central nervous system (CNS) (7).
Right…I don’t know about you, but I need to take a coffee break, so lets all go play this highly pertinant and addictive online coffee making game
Coffee intake is associated with a reduced incidence of major diseases such as cancer, cardiovascular disease, diabetes, and inflammatory disease. It is associated with reduced incidence of human bladder and colorectal cancer, gallstone, Parkinson’s disease, liver cirrhosis, and type 2 diabetes. This protective effect is thought related to compounds in the coffee that reduce oxidative stress.(7) It does however increase circulating cortisol concentrations, which is known to increase blood sugar.
Just a side note, a lot of the research about coffee, is actually about caffeine as an isolated constituent and not an actual cup of coffee. Therefore, all of the research needs to be taken with a pinch of salt, or a pinch of caffeine in this instance!
Caffeine has antioxidant properties and has been demonstrated to reduce early-onset familial alzheimers in mouse models.(8)
- Antioxidant action
Coffee contains polyphenols, compounds that have anti-oxidative effects and can reduce oxidative cell damage. Note – The espresso method of extraction yields higher antioxidant activity than other brewing methods.
High coffee consumption has been associated with better glucose tolerance and a substantially lower risk of type 2 diabetes. One such study of 88,259 US women with a high coffee intake, reported an association with a lower risk of type 2 diabetes. (10)
Some studies have shown depression rates among women decrease with increased consumption of coffee, along with decreased rates of suicide, of which is linked to depression (11).
Coffee consumption appears to have beneficial effects on inflammation and oxidative stress, thought due to the blockage of adenosine (12)
- Weight Loss & Thermogenesis
A study examining the effects of coffee on metabolic rate in normal and obese subjects, found that metabolic rate increased significantly during the 3 hours after caffeine ingestion. In one of the trials coffee was consumed with a 3080 kJ meal resulting in the free fatty acid levels increasing, accompanied by a significant increase in fat oxidation.(13)
The thermic effect of the meal (that is, the rate at which the metabolism is increased above the normal metabolic resting rate) was significantly greater after coffee, than after decaffeinated coffee and fat oxidation (breaking down fat for energy) was significantly greater after coffee. Furthermore, caffeine consumption at a dose of 100mg resulted in a significant thermogenic effect even on subjects who had a habitual caffeine intake.
So if you are like my mum and have had 25 coffees a day for the last 25 years, you will still reap the rewards! Just kidding of course. Thats naughty Mum. Tsk, tsk.
- Sex Drive
One study on rats found that caffeinated female rats were more inclined to return to the male rat post intercourse, suggesting that caffeine increases sexual motivation(14). So ladies, next time that guy in your office brings you a coffee, you know why! [Insert Barry White music here]
- Smarty Pants
By blocking the inhibitory neurotransmitter, adenosine (we talked about adenosine at the start), the brain increases neuronal firing which means you are firing on all cylinders. A very good time to take an exam, yesiree!
- Weight Loss
Caffeine, partly due to its stimulant effect on the central nervous system, both raises metabolism and increases the oxidation of fatty acids. It is therefore considered an advantage to those following a weight loss program (13).
- Fatty liver
One study noted that coffee drinking is associated with a reduced risk of non-alcohol related fatty liver and cirrhosis. They also stated that more research is required to understand whether it’s the coffee itself that contains protective substances, or its the lifestyle related tendencies of coffee drinkers (15).
Animal studies have demonstrated that caffeine can inhibit UVB-induced cancer. One study examined this theory and found caffeine functioned almost as a sunscreen and additionally enhanced UVB-induced cell death (apoptosis) and also cell death (remember, apoptosis) in UVB-induced tumours (16).
COFFEE ON ATHLETIC PERFORMANCE:
Caffeine is also considered to be ergogenic, a substance that improves the capacity to do work or exercise. Findings suggest that during exercise caffeine acts to decrease reliance on glycogen utilisation and increase dependence on free fatty acid mobilisation.(17) So your performance may improve due to the increased fat oxidation, not to mention the increase of adrenalin which results in increased energy and improved blood flow.
In two separate meta-analyses caffeine was found to increase exercise performance by 11-12% on average, particularly for endurance testing (18). Another meta-analysis examined the effects of caffeine on ratings of perceived exertion (RPE). The results demonstrated that caffeine reduced RPE during exercise (19). It is also thought to reduce muscle pain due to the blockage of adenosine and its link to inflammation.
SO COFFEE IS ALL GOOD THEN?
These are some of the contraindications and adverse reactions some people can experience if they consume too much, or if they are more susceptible to caffeine.
- Psychological effects and sleep changes
Everyone who has had one too many coffees, knows what I mean when I say “coffee jitters”. This can also cause anxiety and irritability, along with insomnia.
According to one report, caffeine does not cause dehydration or act as a diuretic when consumed in moderation (under five cups a day), suggesting that coffee intake also adds to the body’s daily fluid.(20)
Caffeine molecules are small enough to penetrate the placenta and pass into the baby’s blood circulation. Foetuses are not capable of metabolising caffeine and excreting it, so it is therefore in their system ten times longer than in adults. There is, however, no evidence that coffee intake causes miscarriage or malformations. Further, maternal coffee intake has shown caffeine present in breast milk (21).
- Iron Absorption
Coffee can interfere with the absorption of iron. One study looked at the comparison of water, tea and coffee on iron absorption when consumed with a hamburger meal. Water with the meal resulted in a 3.71% of the iron absorption, black tea (which is a major iron inhibitor) saw absorption rates fall by 64% and black coffee 39%. Iron absorption was most significantly inhibited when the coffee was taken with the meal or 1 hour later, but no or little inhibition was seen if taken 1 hour before the meal. Coffee with milk was even more iron inhibiting that just black coffee (22).
Caffeine should not be mixed with Panadol (paracetamol / acetaminophen) as it may cause damage to the liver.
- Insulin Sensitivity
There is mixed research on this one. Basically, glucose uptake is somewhat decreased due to the free fatty acids that are flowing around your body (remember security not letting in the due with bad shoes i.e. the blockage of adenosine, that releases fatty acids to be used for energy). So because there is a lot of available energy by way of fatty acids, insulin sensitivity is decreased to allow the body to use the fat instead of the glucose. But that makes perfect sense if you are trying to use fat for energy instead of glucose. (23).
- Gluten Cross Reactivity
Coffee comes from a seed which means it comes with armour to protect it from being digested meaning it may irritate the gastrointestinal tract. So for those who have sensitive tummies and IBS, perhaps keep it to a minimum. Whats more, in gluten sensitive individuals (isn’t that all of us?!) coffee has been shown as one of the most gluten cross reactive foods – meaning it can still cause issues for your gut, immune system and overall health even though it is gluten free. Hmmm….
HOW MUCH CAN I DRINK:
One to two cups a day should be your maximum as massive amounts of coffee are bad for you. Everything in moderation. Although, if you are sensitive (like I am) and you start to lose sleep, or you experience anxiety, then stick to one cup or none (boo!).
And remember one cup of coffee does not mean an extra, extra grande sized coffee with 3 sugars, whipped cream and sprinkles.
The neater your coffee, the better. So just go black and learn to enjoy the natural flavour of the coffee as opposed to adding crap. If you are a real coffee lover, then you needn’t add anything else to your black cup of heaven. Keep it NAKED and enjoy!
Also, make sure you avoid decaf coffee as it seems that caffeine protects the bean from mould. It’s through the decaffeination process that new toxins are introduced and may contribute to mould.
THE FINAL WORD
Coffee is one of the most commonly consumed beverages in the world. Although there are many health benefits, consuming too much coffee (like more than two a day) has been linked with other negative habits such as smoking, eating crappy food and lack of exercise. Therefore, control your coffee intake and reap the rewards.
Also, please make sure you ONLY buy fair trade coffee so that the farmers who work their arses off to provide us with something that takes 2 seconds to make and consume (often without any thought to the process beforehand) get a fair deal. You can read and SHOULD read more about that here if you are not familiar with the topic.
So I’m very happy to conclude that on the most part a daily consumption of one cup of black coffee a day, is fairly healthy for me.
BRING IT ON! Coffee anyone?
How do you like to have your coffee? Do you have a specific brand or bean that you like? What are your thoughts on Bulletproof coffee?