Coffee
can produce anxiety in excess, but what are its benefits? The good news
is that the picture of caffeine and health is not all bad, and not
completely one sided.
Caffeine, like chocolate, often receives bad publicity. Whilst in some
instances, and in excess, these can have negative effects on our body,
they can also be quite beneficial.
I am not disputing that some people are more sensitive to the negative
effects of either caffeine or chocolate. For example, excess caffeine
can create anxiety, nausea (particularly if taken on an empty stomach),
an increase in heart rate, and even depression in some people. And
chocolate is certainly not something that should form the mainstay of
one's diet. If struggling with sugar addiction, or wanting to lose
weight, there are more nutritionally complete foods that are available.
But scientists have turned up some interesting facts on caffeine. For
example, caffeine actually blocks the effects of a neurotransmitter in
the brain (adenosine) that otherwise makes us feel tired. This is why
it works so well to keep us awake. It also encourages the release of
another brain chemical, dopamine (as well as adrenaline). Dopamine
contributes to a feeling of well being.
Two studies, one a population based study (which are not as specific or
rigorously defined as other types of studies, but nonetheless valuable
indicators) found that drinking caffeine containing drinks like coffee
and tea had a protective effect for those at risk of developing liver
disease. Issues that the study participants had that increased their
risk of liver disease included alcoholism, hepatitis B or C, obesity,
or other complications.
And the results indicated that people who drank more than 2 cups of
coffee a day had a 44% lower chance of showing actual liver damage
compared to those who drank no caffeine. This was not a clinical trial,
and the reason why coffee and tea had such an effect is not known.
Coffee and tea contain a range of plant chemicals (phytonutrients) that
could be responsible for this. A 2005 Norwegian study also found
similar benefits for coffee with regards liver disease. This study
found that drinking 3 cups of coffee a day could lower the risk of
death from liver cirrhosis.
Even if you're not at risk of liver disease, caffeine still has some
advantages. Recent research from Austria showed that caffeine may
actually enhance short term memory. Researchers found that there was an
increase in brain activity (as measured by functional magnetic
resonance imaging) in the parts of the brain that were associated with
memory and attention. These parts of the brain were the frontal lobe
and the anterior cingulum. This was a placebo controlled study, meaning
that some people were not given any caffeine. Another, earlier study
(2004) found that caffeine did support short term memory, but only when
it was in relation to a topic that people were already thinking about.
This study found that when testing coffee's effects on unrelated
subjects, short term recall was actually inhibited.
Everything does have a flip side though. Adenosine, which is blocked by
coffee, is also calming. This could be why it can also cause anxiety in
excess, and in some individuals. After all, the balance of our brain
chemistry is unique. And when we are addicted to stimulants like
caffeine, we lose the sensitivity to our own natural stimulants
(dopamine and adrenaline).
