Three cups a day: The sweet spot for coffee’s health benefits
Overall the researchers give coffee the thumbs up, finding that caffeine reduces all-cause mortality. Photo: Getty
Coffee is good or coffee is bad? The argument has been raging for hundreds of years.
Johann Sebastian Bach wrote a mini-opera called The Coffee Cantata in which a disgruntled father threatens to ruin his daughter’s life if she doesn’t give up drinking coffee.
In response, the girl turns into a ruthless schemer – the implication being that coffee makes you crazy, whether you drink it or not.
The story was a satire of 18th century Leipzig where coffee mania was in full swing. As it is today – from Austria to Australia.
OK, but is coffee safe? And what is a healthy amount?
Overall, coffee (caffeine) appears to be safe and good for us.
A 2017 study in the British Medical Journal found coffee consumption was “consistently associated with a lower risk of mortality from all causes of cardiovascular disease, coronary heart disease and stroke”.
The researchers found the “largest reduction in relative risk” came from drinking three cups a day.
But, as demonstrated in a new comprehensive review in the New England Journal of Medicine, paradoxes abound.
On the one hand, caffeine may reduce foetal growth and increase the risk of pregnancy loss.
On the other hand, it has proven to be effective for treating apnea (cessation of breathing) in premature infants – and slightly improves lung function in adults.
What caffeine does to your body
The heart: Caffeine increases blood pressure in the short term, until the body gets used to it. Partial tolerance, at the least, develops with habitual intake.
The brain: This is where most of the action happens. On the upside, caffeine increases mental performance and vigilance owing to greater alertness.
It may reduce the risk of depression and Parkinson’s disease.
It can augment the effect of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen, for treating headache and
other causes of pain.
But it contributes to insomnia and induces anxiety, particularly at high doses and in susceptible people.
Liver: May reduce the risk of liver fibrosis, cirrhosis and cancer.
Endocrine system: Caffeine reduces skeletal muscle insulin
sensitivity in the short term, but again, tolerance appears to develop with
habitual intake.
Kidneys and urinary tract: High doses of caffeine can have a diuretic effect, but habitual moderate intake does not cause dehydration. Consistency is the key.
But coffee can kill you, can’t it?
Very high doses of caffeine can be fatal, but you’d need to drink about 100 standard cups in a very short amount of time.
By the same token, you could kill yourself by drinking too much water.
A shot of espresso contains 63 milligrams of caffeine.
You’d need to drink 20 shots in short order to suffer toxic effects – about 1.2 grams of caffeine.
Ten to 14 grams – more than 200 shots – is thought to be fatal.
So … stick to three cups.