Alternative medicine systems discourage coffee consumption (but encourage coffee enemas). Sleeplessness and tremors are sure signs of overindulgence. There is a long-held belief that coffee consumption over some time is “bad.” The coffee is full of antioxidants that you can buy at health food stores for a lot of money.
A new study has found that coffee drinkers are less likely than others to die.
Wow! Great! The espresso machine is ready.
First, it’s a modest effect. You are 10% less likely to be killed if you drink six or more coffee cups a day. It’s just an association. We do not know if coffee drinking leads to a lower death rate or if coffee drinkers tend to do other things.
Ah, I should put away the espresso machine.
There is a lot of evidence to suggest that moderate coffee consumption may offer some protection against diseases like Parkinson’s Disease or Alzheimer’s Disease. (Again, we do not know if the coffee itself provides this protection, but rather something else coffee drinkers are doing). It’s also delicious.
The apparent health benefits from any food or drink should not be used as an excuse for overindulgence, such as the people who claim that drinking red wine in modest quantities is beneficial but then consume bottles of it at once.
While I’m getting the espresso going, tell me what the latest evidence is.
The team of researchers followed nearly 400,000 individuals for 14 years or until their death (whichever was first). The researchers asked the participants a series of questions about their coffee consumption, food intake, lifestyle, and health at the beginning of the study. After 14 years, they compared the death rates of coffee drinkers with non-coffee drinks.
More coffee drinkers die than ever before.
This is the problem of looking at these studies simplistically. Many other factors affect death rates. These are known as ” confounders ” (because they confuse interpretation). The increased mortality rate is due to the fact that many coffee drinkers smoke.
Researchers would have believed that coffee is bad for you if they hadn’t measured the smoking rates of the participants. The coffee drinking and less death association is also just an assumption. Even though many things were counted, something else is responsible for the longer life span.
How did they conclude that coffee is good for you?
In epidemiology, they say that “confounders were controlled”. Comparing smokers who do not drink coffee to those who do, the coffee-drinking smokers have a longer liver. It’s not as simple as this. You have to use clever maths to figure out how to combine all the measurements.
Is it a good course?
They did have a large group of people that they tracked for a long period. However, they only included people who were relatively healthy at the start of their study (so progression patterns of disease couldn’t affect things), and they looked at a wide range of lifestyle factors.
Researchers themselves admit that the problem was they only asked about coffee consumption when the study began. They had no idea if people increased or decreased their consumption or if they switched from decaf to regular coffee.
They did not measure the type of coffee. Apart from separating caffeinated and non-caffeinated, they only measured caffeine. We have no idea if the majority of people are drinking Heart Burtser espressos or Floor-Sweeping instant coffee.
This information is crucial if we are to generalize across populations. The strength of coffee in the US is different from that of Europe. I remember vividly visiting a friend in Seattle. The time was when I was a Berlin-based postdoctoral researcher. A filter coffee machine that was industrial strength was outside my lab, churning out black heart starters nearly 24/7. My friend took me to a street in Seattle, where he said the best coffee was served.
It tasted just like pinkelwasser. This is not a compliment.
Doesn’t sound inspiring, so what is the coffee doing to make people live longer?
Chlorogenic acid is a major antioxidant found in coffee. Ian Musgrave
We know what it isn’t doing. The caffeine is not the problem since decaffeinated or caffeinated drinks had similar effects (except in cases of injury and accident where caffeinated beverages were clearly superior).
Coffee contains antioxidant chemicals like polyphenols and chlorogenic acid. People who eat foods high in antioxidants live longer and have better outcomes. It is also known that giving people only antioxidant vitamins would be a waste of time. Theof a food may have nothing to do with health. Instead, it may indicate something else.
It’s not clear if it is the antioxidants found in coffee. It hasn’t prevented companies from adding antioxidants to instant espresso coffee (although this was done long before the study). It could be something totally unrelated, like people who drink coffee are more likely than not to walk to the coffee shop.