Guest Post: What you need to know about coffee

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I have been emotionally addicted to coffee for a few years now, ever since I got a coffee machine for Christmas. I love the taste, I like making it in the morning and enjoy the whole experience of drinking coffee – the texture, the smell of coffee brewing, and the moment of peace followed by becoming less hungry and/or more alert. And this is funny, since for years I’ve been totally against coffee, seeing people addicted to it, saying they have headaches if they don’t have their coffee fix in the morning – and I am massively against all addictions. So why did I start drinking coffee in the first place? It wasn’t the coffee machine. Primarily it was an essay I was assigned to do during my Masters degree. It was called “Impact of non-nutritive components – The focus on coffee”. I was to analyse everything that is in coffee and is not a macro- or micronutrient and state what influence it has on us, the consumers of coffee. And while researching this, I found out a few very interesting things.


Coffee has antioxidants

I am sure everyone knows that. But, just to recap, antioxidants in coffee belong to the group of polyphenols, and are 6-12% of coffee powder. They contribute to colour and bitterness of coffee, so the more bitter or astringent your coffee, the more antioxidants it potentially contains. These antioxidants serve us as protection from free radicals that wreak all sorts of havoc in our bodies and cause cancer and aging of our cells. Polyphenols in coffee apparently can also be anti-microbial and anti-viral, protecting us from bacteria and also, HIV! Now I am not saying that coffee cures AIDS here – but there might be some small degree of protection. There are also bad sides to polyphenols – they make casein, milk and gelatin less absorbable so they make it harder to digest some of your dietary protein, and also, they bind plant iron. Iron binding by coffee is especially important for vegetarians – if you are one, do not drink coffee with your meals, and also, make sure that you take in plenty of vitamin C, which can counteract this negative effect of coffee on iron. Finally, just to put antioxidant ability of tea versus coffee into perspective – coffee’s antioxidant activity is about 6 times higher than that of tea. Coffee is also a source of a vitamin called niacin, a member of B vitamins. Beware though – decaffeinated coffee will contain much less of this vitamin.


You can really drink a lot of coffee!

Research shows that consuming less than 1000 mg of caffeine per day poses no risk on human health. That corresponds to approximately 6 cups of boiled coffee, or 10 espresso shots! What is even more interesting, people above 60 years of age that were drinking more than 400 mg of caffeine per day were shown to have lower occurrence of memory problems, dementia or Parkinson’s disease. Just to put caffeine content of coffee in perspective, boiled coffee contains up to 177 mg caffeine per cup, filtered – up to 160 mg, espresso – 100 mg and instant coffee has about 30-40mg per cup. As you may or may not know, caffeine causes awesome things such as increased alertness, being less sleepy, higher resting energy expenditure (you burn more calories while resting, so basically increased metabolism), higher endurance and performance during physical activity and increased mental energy. Other positive effects include enhancement of cognitive functioning (thinking, basically), increased coordination and improving your mood. On the bad side, caffeine was found to increase blood pressure, but mostly on its own (caffeine pills), and in very small proportions through coffee drinking.


Coffee and coffee is not equal

I already mentioned different content of caffeine in different coffees. There are also other factors involved. Coffee can also contain cholesterol-like molecules called kafestol and kahweol. These can increase your LDL or “bad cholesterol” up to 10%! Coffee brews with a lot of fats contain these and this varies according to a preparation method – filtered coffee contains less than 7 mg of fat, while espresso coffee can reach up to 160 mg. That is of course not a tragedy when it comes to your calorie intake, but these fats are mostly in the form of “cholesterol”. So, in general, the coffee that is creamy, and has rich foam on top – unfortunately, that coffee can also be risky when it comes to your cholesterol levels.


… But, there are also risks

Unpleasant short-term side effects of caffeine include palpitations, stomach upsets, anxiety, increased blood pressure and insomnia. Coffee is not good for pregnant women and may cause lower fertility, smaller babies and even miscarriages. Caffeine is also potentially addictive and it can cause withdrawal effects. It is due to increased dopamine in the brain after drinking coffee – makes you happy so you want to keep on drinking it. That effect is similar to an effect of some drugs, however those would also act on parts of your brain that affect motivation and decision making – caffeine does not.


An important issue are the long term effects of caffeine such as a risk of developing heart disease. People that consumed 3-4 cups a day had a risk for coronary heart disease, and a high association was found for people consuming more than 4 cups of coffee a day. BUT! There was no increase in heart disease risk for people that consumed 2 or less cups of coffee per day.


The take home message?

As a strong antagonist of coffee before I wrote that essay a few years ago, I was quite surprised by the positive findings. So yes, there are negative effects to coffee drinking – but these usually do not apply for drinking less than 2 cups per day, or drinking filtered coffee. With caution, coffee can be drunk without fear, and there are tons of benefits! The only bad side to what I found is that it is my favourite brew, espresso, that causes most of the cholesterol trouble, and that is the type of coffee mostly found in all cappuccinos and coffees in coffee places like Starbucks, Costa or Insomnia.


Finally, there have been several new meta-analyses (studies of different scientific articles that summarize their findings) that link coffee consumption with lower risk of Parkinson’s disease, lower risk of diabetes type 2 (that stands for coffee, decaf, and tea), and lower risk of liver cancer! The exact cause of these positive effects is not known, and decaf seems to work as well as caffeinated coffee. I am definitely looking forward to finding out more in the future!


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