Reading this with a mug of coffee in your hand? Then you have permission to feel smug.
The latest pan-European research, led by epidemiologist Marc Gunter of Imperial College, London – following a study of more than 500,000 people over 16 years – has shown that those who drank the most coffee had a reduced risk of premature death from any cause.
But what if you’re reaching for a tea instead? Don’t panic: a compound in black tea could help gut bacteria fight infections and prevent severe influenza, say scientists at the Washington University School of Medicine in the latest issue of the journal, Science.
It’s good to know that our two favourite hot drinks can be healthy – but which one would be best for you?
BEST FOR… LONGER LIFE? TEA
If you want to live longer, pop the kettle on. The latest study on coffee backs up evidence from the National Institutes of Health, published in the New England Journal of Medicine in 2012, which reported that, compared with men who did not drink coffee, men who drank six or more cups per day had a 10 per cent lower risk of death, whereas women in this category of consumption had a 15 per cent lower risk.
But regular tea drinkers have also been found to live longer than average. An Australian study published in The Journal of Clinical Nutrition in 2015 showed that women in their 70s and 80s lived longer if they had the equivalent of two cuppas a day. This may be due to a unique compound in tea that can change the body’s genetic code.
Weronica Ek, from Uppsala University, whose study was published in Human Molecular Genetics in May, found that drinking tea (but not coffee) regularly is associated with epigenetic changes in 28 different gene regions known to interact with cancer or oestrogen metabolism.
BEST FOR… ANTIOXIDANTS? COFFEE
Both coffee and tea contain lots of antioxidants called polyphenols, nutrients that can help to reduce inflammation and repair cellular damage.
Bob Arnot, whose latest bestseller The Coffee Lover’s Diet (HarperCollins) reveals how to get the most health benefits from the drink, explains: “We know now that the driving force behind many illnesses such as heart disease and stroke is inflammation, which is something polyphenols can help with. And coffee contains two-and-a-half times more polyphenols than tea on average.”
But he also warns that there is a staggering difference between brands, thanks to methods of roasting – and even among types of beans from different countries.
“If you want to get the most polyphenols (and thus the most benefit) from drinking coffee, choose beans grown at high altitude, such as Nyeri in Kenya.”
“Better still is dark Greek or Turkish roast, as these retain higher levels of polyphenols than lighter French or Italian roasts,” says Arnot. “But for the very best health, you want varieties of polyphenols. So do drink tea, too.”
BEST FOR… HEART HEALTH? TEA
Be still your (rapidly beating) heart: both coffee and tea have been linked with reduced cardiovascular diseases.
Dutch research, published in Arteriosclerosis, Thrombosis, and Vascular Biology: Journal of the American Heart Association in 2010, found that drinking more than six cups of tea per day was associated with a 36 per cent lower risk of heart disease compared to those who drank less than a single cup of tea per day.
Coffee drinkers with a modest two-to-four cups per day had a 20 per cent lower risk of heart disease compared to those drinking less than two or more than four cups.
“The polyphenols may help your heart,” says Arnot, “but if you are a slow caffeine metaboliser, it can lead to increased blood pressure and a higher pulse rate. Know your caffeine tolerance level and how much goes into the average shop-bought coffee.
“No-one should have more than 400mg of caffeine a day (equivalent to four espressos). Anyone who finds that caffeine particularly affects them – ie, that it disturbs their sleep – should have no more than 200mg a day.”
BEST FOR… THE DIGESTIVE SYSTEM? COFFEE
“We found the more coffee consumed, the lower the risk,” said Stephen Gruber, director of USC Norris and senior author of the study. The indication of decreased risk was seen across all types of coffee, both caffeinated and decaffeinated.
BEST FOR… WEIGHT LOSS? TEA (AS LONG AS IT’S GREEN…)
If you’ve swallowed fitness magazine advice to neck an espresso before a fat-burning workout, this might give you pause for thought. Black coffee has been the staple of many a dieter’s regime, but it may be doing more harm than good.
An April 2011 study from the University of Guelph reveals not only that a healthy person’s blood sugar levels spike after eating a high-fat meal, but that the spike doubles after having both a fatty meal and caffeinated coffee – jumping to levels similar to those of people at risk for diabetes.
Ultimately, said researchers in the Journal of Nutrition, saturated fat and fat combined with caffeinated coffee hinder the body’s ability to clear sugar from the blood, and having high blood sugar levels can take a toll on our body’s organs.
There are a number of small studies that indicate the use of green tea in supporting weight management, says Euan MacLennan, a medical herbalist with a central London NHS General Practice.
“In a study carried out with 35 obese men and women, it was found that those who drank four cups of green tea daily for two months lost significantly more weight than those who consumed a placebo. Green tea may support weight loss in several ways: increasing thermogenesis (kilojoule-burning), increasing fat oxidation (burning of fat for energy), reducing fat absorption and even reducing appetite.”
BEST FOR… LOWERING CHOLESTEROL? TEA
Drinking coffee may be raising your cholesterol. According to US research from the Baylor College of Medicine published in the July 2007 edition of journal Molecular Endocrinology, a compound found in coffee called cafestol elevates cholesterol by hijacking a receptor in an intestinal pathway critical to its regulation.
French press coffee, boiled Scandinavian-style brew and espresso contain the highest levels of the compound, which is removed by paper filters used in most other brewing processes.
BEST FOR… ALERTNESS? TEA
We drink coffee to pep us up, but that feeling may be an illusion, say researchers from the University of Bristol. A June 2010 study, published in Neuropsychopharmacology, reports that frequent coffee drinkers develop a tolerance to both the anxiety-producing effects and the stimulatory effects of caffeine.
Frequent consumers may feel alert after coffee, but the evidence suggests that this is the reversal of the fatiguing effects of acute caffeine withdrawal. And given the increased propensity to anxiety and raised blood pressure induced by caffeine consumption, there is no net benefit.
However, MacLennan, who is herbal director at Pukka Herbs, quotes Portuguese research published in Frontiers in Bioscience in 2011, which suggested that compounds found in green tea can cross the brain-blood barrier to reach neural tissue.
“They can help to protect neurons (nerve cells),” he says “and reduce the decline in brain function. Studies also suggest that L-theanine, the ‘relaxing’ amino acid in green and matcha tea, may have benefits for memory and reducing the decline in cognitive function as we get older.”
BEST FOR… IMPROVING BONE STRENGTH? TEA
Thanks to caffeine’s slight “blocking” effect on calcium absorption, coffee is often mistakenly pilloried as contributing to weakened bone density. (In fact, any such effects of caffeine on calcium absorption is so small it is fully offset by the tiniest splash of milk.)
Conversely, studies have long linked black tea with improved bone strength – but, says MacLennan, the benefits of green tea may be even greater.
He cites research from Texas, published in 2013 in the American Journal of Clinical Nutrition: “It found that the epigallocatechin (EGCG) compound, which is abundant in green tea, can decrease the numbers of osteoclasts in the body – these are the cells that break down bone – and increase the numbers and activity of osteoblasts, the cells that build bone.
“Green tea may also be helpful if you need to speed up the healing process of a broken bone.”
Coffee may not boost bone strength, but according to a report by the Society for Experimental Biology, by sports scientists at Coventry University in June 2012, caffeine does help boost the power of older muscles.
So, a cup of coffee could help elderly people to maintain their strength, reducing the incidence of falls and injuries.