We sure love our coffee. Even during lockdown lots of us managed to keep buying our daily flat white or Americano. So all of us should be happy to hear those drinks may actually have helped to keep us healthy. The latest assessments of the health effects of coffee and caffeine, its main active ingredient, are reassuring indeed. Their consumption has been linked to a reduced risk of all kinds of ailments, including Parkinson’s disease, heart disease, type-2 diabetes, gallstones, depression, suicide, cirrhosis, liver cancer, melanoma and prostate cancer.
In fact, in numerous studies around the world, consuming enough coffee to provide 400mg of caffeine a day has been associated with reduced death rates. That’s about four or five cups of regular coffee. In takeway terms, an espresso shot contains 60-65mg of caffeine, and a latte, cappuccino or flat white usually contains at least one or two shots. (At Starbucks, you’ll get 150mg of caffeine from a Grande cappuccino and 225mg from a Venti cappuccino.)
Overall, despite various concerns that have cropped up over the years, coffee is remarkably safe and has a number of important potential benefits
In a study of more than 200,000 participants followed for up to 30 years, those who drank three to five cups of coffee a day, with or without caffeine, were 15 per cent less likely to die early from all causes than were people who shunned coffee. Perhaps most dramatic was a 50 per cent reduction in the risk of suicide among both men and women who were moderate coffee drinkers, perhaps by boosting production of brain chemicals that have antidepressant effects.
As a report published last summer by a research team at the Harvard school of public health concluded, although current evidence may not warrant recommending coffee or caffeine to prevent disease, drinking coffee in moderation “can be part of a healthy lifestyle” for most people.
It wasn't always thus. I've lived through decades of sporadic warnings that coffee could be a health hazard. Over the years, coffee's been deemed a cause of conditions such as heart disease, stroke, type-2 diabetes, pancreatic cancer, anxiety disorder, nutrient deficiencies, gastric-reflux disease, migraine, insomnia and premature death. As recently as 1991, the World Health Organisation listed coffee as a possible carcinogen. In some of the now-discredited studies, smoking, not coffee drinking (the two often went hand in hand), was responsible for the purported hazard.
"These periodic scares have given the public a very distorted view," says Dr Walter C Willett, professor of nutrition and epidemiology at the Harvard TH Chan school of public health. "Overall, despite various concerns that have cropped up over the years, coffee is remarkably safe and has a number of important potential benefits."
Even if you can fall asleep readily after an evening coffee, it may disrupt your ability to get adequate deep sleep
That’s not to say coffee warrants a totally clean bill of health. Caffeine crosses the placenta into the foetus, and drinking coffee during pregnancy can increase the risk of miscarriage, low birth weight and premature birth. Pregnancy alters how the body metabolises caffeine, and women who are pregnant or nursing are advised to abstain entirely, stick to decaf or at the very least limit their caffeine intake to less than 200mg a day.
The most common ill effect associated with caffeinated coffee is sleep disturbance. Caffeine locks into the same receptor in the brain as the neurotransmitter adenosine, a natural sedative. Dr Willett, a coauthor of the Harvard report, says, “I really do love coffee, but I have it only occasionally, because otherwise I don’t sleep very well. Lots of people with sleep problems don’t recognise the connection to coffee.”
In discussing his audiobook on caffeine with Terry Gross on US National Public Radio last winter, Michael Pollan called caffeine "the enemy of good sleep" because it interferes with deep sleep. He confessed that after the challenging task of weaning himself from coffee, he "was sleeping like a teenager again".
Willett, who is now 75, says, “You don’t have to get to zero consumption to minimise the impact on sleep,” but he acknowledges that a person’s sensitivity to caffeine “probably increases with age”. People also vary widely in how rapidly they metabolise caffeine, enabling some to sleep soundly after drinking caffeinated coffee at dinner while others have trouble sleeping if they have coffee at lunch. But even if you can fall asleep readily after an evening coffee, it may disrupt your ability to get adequate deep sleep, Pollan writes in his forthcoming book, This Is Your Mind on Plants.
Willett says it’s possible to develop a degree of tolerance to caffeine’s effect on sleep. My 75-year-old brother, an inveterate imbiber of caffeinated coffee, claims it has no effect on him. However, acquiring a tolerance to caffeine could blunt its benefit if, say, you wanted it to help you stay alert and focused while driving or taking a test.
All the things people put into coffee can result in a junk food with as many as 500 to 600 calories
Caffeine is one of more than 1,000 chemicals in coffee, not all of which are beneficial. Among others with positive effects are polyphenols and antioxidants. Polyphenols can inhibit the growth of cancer cells and lower the risk of type-2 diabetes; antioxidants, which have anti-inflammatory effects, can counter heart disease and cancer, both leading killers.
None of this means coffee is beneficial regardless of how it’s prepared. When brewed without a paper filter, as in French press, Norwegian boiled coffee, espresso or Turkish coffee, oily chemicals called diterpenes come through that can raise artery-damaging LDL cholesterol. However, these chemicals are virtually absent in both filtered and instant coffee. Knowing I have a cholesterol problem, I dissected a coffee pod and found a paper filter lining the plastic cup. Phew!
Also countering the potential health benefits of coffee are popular additions some people use, such as cream and sweet syrups, that can convert this calorie-free beverage into a calorie-rich dessert. “All the things people put into coffee can result in a junk food with as many as 500 to 600 calories,” Dr Willett says. A Grande Starbucks Mocha Frappuccino, for example, has about 36.8g of sugar, 16.3g of fat (11.5 of them saturated) and 312 calories.
With iced-coffee season approaching, more people are likely to turn to cold-brew coffee. Now rising in popularity, cold brew counters coffee’s natural acidity and the bitterness that results when boiling water is poured over the grounds. Cold brew is made by steeping the grounds in cold water for several hours, then straining the liquid through a paper filter to remove the grounds and harmful diterpenes and keep the flavour and caffeine for you to enjoy. Cold brew can also be made with decaffeinated coffee.
Decaf is not totally without health benefits. As with caffeinated coffee, the polyphenols it contains have anti-inflammatory properties that may lower the risk of type-2 diabetes and cancer. – New York Times