Coffee is more than a stimulant – it can protect you from chronic disease and extend your life. Here’s why doctors recommend coffee as part of healthy diet.
Is coffee good for you? Or can it damage your heart, cause insomnia or lead to heartburn? Huge swathes of the internet are devoted to this most contested of debates. It’s not hard to see why, given how much we consume. An estimated 75 per cent of Australians drink at least one cup of coffee a day and more than one in four people say they can’t survive the day without it, according to a survey by social research firm McCrindle. Anecdotally, coffee consumption is thought to be even higher among sleep-deprived legal people.
The good news for coffee drinkers is an emerging and solid evidence base suggests coffee may have health benefits. Even better, those benefits come from drinking more than one cup a day.
Being alert and aware
Ponder the effects of coffee and your brain likely makes a fast segue to caffeine, a drug that stimulates your brain and nervous system. We often associate caffeine with negative health impacts like heart palpitations and infertility, but in moderation it can be beneficial, explains accredited practising dietitian Joel Feren from The Nutrition Guy and a spokesperson for Dietitians Australia.
“Caffeine is actually quite useful for us as it helps to increase our awareness and alertness,” he says. “It does so by inhibiting a neurotransmitter in the brain called adenosine.
“It can also increase reaction times, so it’s got a place for people who might be a little bit tired or need an energy hit to increase alertness in the office.”
Living a longer, healthier life
The most powerful benefits of coffee are likely derived not from caffeine but from the in excess of 100 biologically active components contained in the beverage. One of the most potent is compounds called polyphenols.
“There’s a whole raft of research coming out now showing the benefit of polyphenols, from everything from mood health and gut health to heart health,” Feren says. “A lot of the benefits of coffee are actually attributed to these antioxidants, and specifically these polyphenols.”
Research shows coffee may offer some protection against type 2 diabetes, liver disease, Parkinson’s disease, bowel cancer, depression and cardiovascular events like heart attack and stroke.
Drinking two to three cups of coffee a day is linked with a longer lifespan and lower risk of cardiovascular disease compared with avoiding coffee, according to recent research published in the European Journal of Preventive Cardiology.
Crucially, it doesn’t much matter if you buy a fancy barista-made latte or make do with the contents of the office pantry, as the findings applied to ground, instant and decaffeinated varieties.
“Polyphenols can improve the body’s metabolism, increase the body’s sensitivity to insulin and improve the gut bacteria,” explains lead author Dr David Chieng, a cardiac electrophysiology fellow at the Alfred Hospital in Melbourne. “All these effects are likely to explain the reductions in the risk of cardiovascular disease.”
Finding the sweet spot
Research suggests that consuming 400mg per day of caffeine – equivalent to four standard coffees – is a safe amount. “Anything more can increase things like heart palpitations, increase irritability and it can affect sleep as well,” Feren says. He recommends having your last coffee 10-12 hours before bed to prevent disruptions to sleep.
Dr Chieng says drinking fewer than the two to three cups of coffee recommended in his research likely inhibits “the health benefits of the biologic compounds in coffee”.
“Conversely, higher levels of coffee intake can result in significant activation of the sympathetic [nervous] system, along with feelings of anxiety, restlessness, insomnia and psychomotor agitation. As with most food and drink consumption, moderation seems to be the way to go.”
Likewise, Feren says, despite the benefits of coffee it’s important to moderate consumption of “liquid calories”. “Milk, sugar and potentially sugary syrup can all add up,” he says. “I’m a big advocate of dairy – it’s a wonderful source of protein and calcium – but it’s important not to overdo it.”
Coffee is beneficial for most people, but if you’re troubled by digestive issues, Feren says it’s best to cut back or even cut it out. “It’s probably not so great for people with IBS as it can increase some of those unwelcome symptoms like bloating and cramping,” he says.
“Coffee is also not great for people with reflux, because it relaxes the lower part of the oesophagus. You can get acid coming back up the oesophagus and get that that sensation of heartburn.”
If you’re low in iron or iron deficient, Feren recommends waiting about half an hour after a meal before drinking coffee. “Coffee can inhibit iron absorption. Pregnant women and older women, in particular, need to make sure their body is absorbing all the iron they can get.”
As such, if you’re pregnant it’s recommended to limit your caffeine consumption to 200mg a day – equivalent to two standard coffees.
For non-drinkers, Dr Cheing says it’s still unclear whether the health benefits are so great that you should take up the habit. But for everyone else, “we would certainly recommend that current coffee drinkers continue at mild to moderate levels as part of a healthy lifestyle.”