Coffee may be the perfect morning pick-me-up, but a new study suggests drinking too much can compromise our brain health over time.
Researchers in Australia have found that high coffee consumption is associated with smaller total brain volumes and a 53 percent increased risk of dementia.
The experts offer no explanation for the surprising link, which follows multiple previous studies showing that drinking coffee in moderation can actually prevent dementia.
The new study also follows a wealth of previous evidence that drinking coffee has other health benefits over time — as long as it’s not consumed in excess.
While excessive coffee consumption was not specifically found to cause dementia, the authors of this new study caution against high consumption of the black stuff, which they define as more than six cups a day.
It’s easy to down several coffees throughout the day without keeping track of how much we’ve been drinking. Now, new research from the University of South Australia shows that too much can affect brain health over time
DAILY COFFEE INTAKE: WHAT IS THE OFFICIAL ADVICE?
According to US federal dietary guidelines, three to five 8-ounce cups of coffee per day can be part of a healthy diet — but this guideline only applies to regular black coffee.
An 8 ounce cup is equivalent to about 240 ml – just under half a pint – and is about the capacity of a small serving of coffee in the UK.
According to the British Dietetic Association (BDA), an average cup of coffee contains about 90 mg of caffeine, depending on the type of coffee and how it’s made.
“A double espresso, the typical base for many coffee shop coffees, contains about 125 mg, and the more shots you have in your coffee, the more caffeine you’re taking in,” says the BDA.
Health organizations around the world suggest that most people can safely consume up to 300mg of caffeine per day.
In addition, despite its benefits, research has shown that caffeine can also be dangerous if consumed in excess.
The American Academy of Pediatrics recommends that children generally avoid coffee and all drinks with caffeine in them.
The American Heart Association also warns that popular coffee-based drinks like lattes and macchiatos are often high in calories, added sugar and fat — effectively canceling out any of the black stuff’s benefits.
The study, published in Nutritional Neuroscience, is led by experts from the University of South Australia (UniSA), along with academics from other institutions, including the University of Cambridge and the University of Exeter.
‘Coffee is one of the most popular drinks in the world. But with global consumption exceeding nine billion kilograms per year, it is critical that we understand all the potential health implications,” said study author Kitty Pham of UniSA.
‘This is the most comprehensive study into the links between coffee, brain volume measurements, the risk of dementia and the risk of stroke.
“It is also the largest study that takes into account volumetric imaging data of the brain and a wide range of confounding factors.”
‘Taking into account all possible permutations, we consistently found that higher coffee consumption was significantly associated with reduced brain volume.
“Essentially, drinking more than six cups of coffee a day can put you at risk for brain diseases like dementia and stroke.”
According to the European Food Safety Authority, we should drink a maximum of 400 mg of coffee per day, about four to five cups, although the daily maximum for pregnant women is only 200 mg.
“Typical daily coffee consumption is somewhere between one and two standard cups of coffee,” says study author Professor Elina Hyppönen.
“Although the unit sizes may vary, a few cups of coffee a day is generally fine.
“However, if you find that your coffee consumption is moving towards more than six cups a day, it’s time to reconsider your next drink.”
The experts assessed the effects of coffee on the brain in 17,702 UK Biobank participants, aged between 37 and 73.
Those who drank more than six cups of coffee a day were 53 percent more likely to develop dementia than those who drank one to two cups a day.
Drinking more than six cups of coffee was also associated with a 17 percent increased risk of stroke.
About 50 million people are diagnosed with dementia worldwide, and in Australia, dementia is the second leading cause of death, with an estimated 250 people diagnosed every day.
In a stroke, the blood supply to the brain is disrupted, resulting in lack of oxygen, brain damage and loss of function.
If your coffee consumption is moving towards more than six cups a day, ‘it’s time you reconsidered your next drink,’ study suggests
COFFEE AND DEMENTIA: PREVIOUS STUDIES
2018: Krembil Brain Institute, Canada
Drinking coffee can protect you from developing both Alzheimer’s and Parkinson’s disease
2018: Rutgers University, USA
Two compounds in caffeine prevent the build-up of a toxic protein, alpha-synuclein, which is associated with dementia with Lewy bodies.
2016: University of Coimbra in Portugal
Moderate coffee consumption may reduce the risk of developing Alzheimer’s disease by up to 27 percent
2014: Institute for Scientific Information on Coffee
Drinking three to five cups a day can reduce the chance of developing Alzheimer’s disease by up to 20 percent.
Worldwide, one in four adults over the age of 25 will have a stroke in their lifetime. Data suggests 13.7 million people will have a stroke this year, resulting in 5.5 million deaths.
‘This research provides essential insights into heavy coffee consumption and brain health, but as with many things in life, moderation is key,’ says Professor Hyppönen.
‘Along with other genetic evidence and a randomized controlled trial, these data strongly suggest that high coffee consumption may adversely affect brain health.
“While the exact mechanisms aren’t known, one simple thing we can do is to stay hydrated and remember to drink a little water in addition to that cup of coffee.”
Earlier this year, Swiss researchers found that regular caffeine intake reduces the volume of gray matter in the brain, suggesting that coffee intake could impair our information processing capacity.
The experts gave volunteers three 150 mg servings of caffeine per day for 10 days — a caffeine intake equivalent to about four or five small cups of brewed coffee per day, or seven single espressos.
They found a reduction in gray matter, which is usually found on the outer layer of the brain, or cortex, and serves to process information.
UniSA has consistently researched the effects of coffee – one of Australia’s favorite beverages – on human health.
In February, the team revealed that long-term, heavy coffee consumption — six or more cups a day — can increase the amount of fats in your blood, increasing your risk of cardiovascular disease (CVD)..
‘There is certainly a lot of scientific discussion about the pros and cons of coffee,’ Professor Hyppönen said at the time.
“But while it may seem like we’re walking down ancient paths, it’s essential to fully understand how one of the world’s most consumed beverages can affect our health.”
Professor Hyppönen and her colleague Ang Zhou looked at genetic and phenotypic associations between coffee intake and plasma lipid profiles – the cholesterols and fats in the blood.
The study, published in Clinical Nutrition, used data from 362,571 UK Biobank participants, aged between 37 and 73 years.
Not only did they find a link between the two, they also found causal evidence that regular coffee consumption contributes to an unfavorable lipid (fat) profile.
Coffee beans contain a very potent cholesterol-raising compound called cafestol, which is mainly present in unfiltered brews, such as French press, Turkish and Greek coffee, as well as espressos.
Espressos are the foundation for most barista-made coffees, including lattes and cappuccinos. If you order a coffee on the high street, you will probably be served an espresso, whether with or without milk.
It is therefore wise to choose filtered coffee whenever possible and be wary of excessive drinking, even if it helps us through the working day.
Just one cup of coffee a day during pregnancy may increase stillbirth risk, study suggests
3D illustration of a caffeine molecule. Caffeine consumption during pregnancy has been an ongoing topic of discussion
Just one daily cup of coffee during pregnancy may increase the risk of stillbirth, research published in 2020 suggests.
The British study of more than 1,000 pregnant women, including 290 who had stillbirths, looked at daily caffeine intake.
Every 100 mg of caffeine per day during pregnancy — the equivalent of one mug of filter coffee — was associated with a 27 percent higher risk of stillbirth.
Caffeine is believed to constrict the blood vessels of the placenta, which can reduce oxygen reaching an unborn baby.
Babies in the womb clear caffeine about a third as fast as their mothers, and it can result in an irregular heartbeat.
Professor Alexander Heazell, lead author of the study and director of Tommy’s Maternal and Fetal Health Research Center at the University of Manchester, said: ‘This is a relatively small risk, so people shouldn’t worry about the occasional cup of coffee.
“But our research has found that even a fairly small amount of daily caffeine is linked to a greater risk of stillbirth.”
Read more: A cup of coffee a day may increase stillbirth risk, study suggests