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.
Shaking the habitual: Many can't start the day without a cup of tea or coffee, but it's been proven that caffeine doesn't actually jump start your brain
'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
Addiction: Experts say that the ubiquitous morning cup of coffee or tea is a sign of mass drug dependency
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.
Buzzin': Coffee doesn't increase alertness, concentration, or reaction time, but it will keep you awake
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.
'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.