·
Coffee-drinkers aren't more alert than their caffeine-free
counterparts
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What's more, regular consumption of tea and coffee leads
to
dependency
Every
morning, millions of people perform an essential daily ritual - having their
first cup of tea or coffee. It concentrates the mind and acts as a pick-me-up.
Or does it? The latest research suggests that familiar buzz
doesn't so much as give us a lift, but fights the caffeine withdrawal symptoms
- fatigue, mental fogginess and a dull headache - that have kicked in since our
last cup.
Indeed, experts suggest that this morning ritual is actually a
sign of mass drug dependency.
'People
who consume caffeine regularly will become dependent on it - if you take
caffeine away from them, they will function below par,' says Peter Rogers,
professor of biological psychology at Bristol University and a leading expert
on caffeine.
'They just don't function normally without the drug on board. If
it's your first tea or coffee of the day, it gets you back to normal, but
beyond that you don't get much more of a kick.'
Professor Rogers has studied coffee and its effects for more
than 20 years and, as a result, he and other members of his team have given up
caffeine.
'On balance, caffeine is not particularly helpful. It triggers
withdrawal and increases your blood pressure, which is not a good thing,' he
says.
'I sometimes think one of the biggest effects of my research work has been
on my department. Four or five colleagues have given up caffeine, and we're all
on decaf.'
WHY COFFEE
DOESN'T GIVE YOU A BOOST
The idea that caffeine doesn't perk up your brain might sound
absurd, but that's what Professor Roger's research shows.
In one key study, around 300 volunteers - half had a moderate to
high caffeine intake, the others had a low intake - were asked to stop drinking
coffee for 16 hours before undergoing tests.
The volunteers were randomly split into two groups and given a
placebo or coffee. The results, in the journal Neuropsychopharmacology, were
intriguing.
Though the regular coffee drinkers did have an increase in
alertness following the coffee, this only made them as alert as non-coffee
drinkers who had the placebo.
In other words, drinking coffee doesn't make us any more
alert than non-coffee drinkers.
...BUT WHY
YOU THINK IT DOES
Caffeine stops a brain chemical known as adenosine having an
effect.
Normally, adenosine helps slow down reactions in the body. As
caffeine effectively stops adenosine latching onto cells, it means that when we
drink it our body is constantly on the accelerator, not the brake.
Then within a few hours of stopping drinking coffee, the
withdrawal effects start to kick in. In some cases, they can even cause
flu-like symptoms.
Our body experiences a flood of adenosine, leading to fatigue.
Many will also experience a dull headache.
This is because caffeine narrows blood vessels in the brain,
says Professor Rogers, so when we stop drinking it, there is an increase in
blood flow, which triggers a headache.
'On the rare occasions I have drunk coffee for a few days, when
I stop I start to feel under the weather and think I am coming down with a
cold,' says Professor Rogers.
'But then I remember - this is what caffeine withdrawal feels
like.'
IT WON'T
IMPROVE CONCENTRATION
Another recent study by Professor Rogers involving 300
volunteers found coffee doesn't increase alertness, concentration or reaction
time, but it will keep you awake.
'I have coffee when I'm driving across Europe, as I know it will
keep me awake. But it wouldn't be helpful if I was trying to write a
scientific paper late at night as it doesn't help focus or thinking.'
IS
CAFFEINE GOOD OR BAD FOR THE HEART?
Aside from triggering a physical dependency, what other effects
does caffeine have on our health?
One week we read a report showing caffeine is good for us; the
next that it is bad. The experts are fiercely divided.
'It is a well-established and reliable fact that caffeine
increases blood pressure,' says caffeine researcher Jack James, professor of psychology
at Reykjavik University.
'The increase is modest, but likely to be clinically significant
over the course of a lifetime of consuming caffeine.
'I'm confident that in time caffeine consumption will be
regarded as a risk to cardiovascular health.'
One paper by Professor James, who is also editor of the Journal
of Caffeine Research, suggests regular caffeine may account for 14 per cent of
premature deaths due to coronary heart disease and 20 per cent of premature
deaths due to stroke.
And in a study published just a few weeks ago, Australian
researchers suggested a chemical in coffee called chlorogenic acid may increase
the risk of diabetes and even lead to the body storing excess fat.
The study, published in the Journal of Agriculture and Food
Chemistry, showed that when mice were given high amounts of this compound, the
equivalent of drinking five or six cups a day, their bodies struggled to
control blood sugar and they developed insulin resistance. They were also less
likely to lose weight.
However, other research has shown that regular coffee and tea
intake reduces the risk of stroke and heart disease, as well as
neurodegenerative diseases such as Parkinson's.
Indeed, one large study undertaken by Harvard researchers, and
published last year in the journal Circulation, suggested that moderate coffee
intake (four cups a day) reduced the risk of heart failure.
The team looked at research from five studies, involving more than 140,000 people.
The team looked at research from five studies, involving more than 140,000 people.
'There is a growing body of research suggesting coffee is
beneficial and this paper added to this,' says Dr Elizabeth Mostofsky, a
post-doctoral research fellow and lead researcher of the paper.
Coffee consumption has also been linked to a lower risk of type
2 diabetes and some forms of cancer.
However, as with everything, moderation is best. Drinking
more than ten cups a day 'may be harmful', says Dr Mostofsky.
She suggests that patients who are at risk of stroke and not
regular coffee drinkers may want to consider avoiding it. Some of her earlier
research suggests the peak in blood pressure immediately after having coffee
may briefly increase stroke risk (the effect was not seen for tea).
But, overall, Dr Mostofsky believes the effects are positive.
'It's nice to know there may be health benefits from the number one drug
consumed,' she says.
SHOULD YOU
SWITCH TO DECAF?
So what are we to make of this wealth of apparently conflicting
evidence?
Professor Rogers suggests that, in fact, the benefits of coffee
and tea lie in the antioxidants that they contain - compounds that work to
lower inflammation in the body.
Inflammation has been linked to a host of diseases such as
stroke, cardiovascular disease and cancer, and so antioxidants consumed in tea
and coffee may reduce the risk of these diseases.
This is why he still drinks decaffeinated tea and coffee (five
cups of tea and one cup of coffee a day).
But he says the effect would not be seen with caffeine-filled
energy drinks.
'Compounds in tea and coffee may be producing beneficial
effects, but in other drinks, such as energy drinks, there aren't these
naturally occurring compounds to balance out the effect of caffeine.'
And he believes that the rise in caffeine products will only
fuel our dependency.
'I suspect caffeine intake will increase, and on balance that's
not a good thing,' he adds.
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