Can coffee really keep the doctor away?
While recent
findings have been encouraging, there is still a long way before these prove
conclusive.
By Michael Lim
Not all coffees are the same
The universe of
research data on coffee is dotted with contradictions on outcomes. Other than
methodology and size of studies, some of these differences may be due to the
different ways in which coffee is prepared.
Unfiltered coffee contains chemicals called diterpenes such as kahweol and cafestol,
which are associated with an increase in 'bad' cholesterol and hence an
increase in risk of heart disease. Some studies suggest that drinking
unfiltered boiled coffee can increase cholesterol by as much as 10 per cent.
These chemicals
can be removed with a paper filter. The most well-known chemical in coffee is caffeine.
On the average,
one cup of brewed or one shot of espresso
has about 100mg of caffeine.
Decaffeinated coffee contains a few mg in each cup. The equivalent of
a lethal dose of caffeine will be akin to drinking 100 cups of coffee.
Will my heart skip a beat?
It is a common
perception that drinking coffee can cause your heart to skip a beat. Perception
appears to be different from reality. A Canadian study published in the Annals
of Internal Medicine in January 1991 reviewed five studies of people with
abnormal heart rhythms and found that drinking up to five cups of coffee a day
did not worsen the heart rhythm.
Interestingly,
a study of about 130,000 Kaiser Permanente health insurance members showed that
those who were drinking up to three cups of coffee a day were 20% less likely
to be hospitalized for abnormal heart rhythms than non-drinkers.
While the
Harvard study on 45,000 healthy men in the
Health Professionals Follow-Up Study published in the New England Journal of
Medicine in 1990, found that coffee drinking had no effect on the risk of heart
attack or stroke, studies in the last few years have put a positive spin on coffee.
A more recent
study of more than 81,000 men and women in Japan published in the Journal of
Epidemiology and Community Health showed that drinking one or two cups of
coffee a day was associated with up to a 23% risk reduction of death from heart
disease.
Another large 2008
Spanish study in the Annals of Internal Medicine that tracked 129,000 men and
women over two decades found that
- women
who drank four to five cups per day were 34 per cent less likely to
die of heart disease, while
- men who had more than five
cups a day were 44 per cent less
likely to die.
Is coffee good for my brain?
It appears that
the benefits on the heart seen in recent large trials appear to extend to the
brain as well.
A 2009 Harvard
study of 83,000 women published in the journal Circulation showed those who drank
two to four cups of coffee a day had a 19 to 20% lower risk of stroke
than women who drank less than one cup a month.
The data was
supported by a 2011 Swedish study of 34,670 women published in Stroke journal
that found women who drank more than a cup of coffee each day had a 22
to 25% lower risk of stroke than women who drank less coffee.
This benefit is not gender-specific and a 2008
Finnish study of more than 26,000 male smokers found that the men who drank eight
or more cups of coffee a day had a 23% lower risk of stroke than the men who drank little or no coffee.
Coffee and other health
benefits
Possible
benefits that appear to be associated with regular coffee drinking include
lower risk of developing
- diabetes mellitus,
- gallstones, liver damage,
- dementia,
- Parkinson's disease and
- colon cancer.
In addition, it
also appears to be associated with
- improved cognitive function and
- performance in physical endurance activities.
Should I start drinking coffee?
Before you
start recommending coffee to your friends as a health drink, you will need to
answer this question: Can coffee be harmful to health?
Most of the
purported benefits of regular coffee consumption are statistical associations and
researchers have yet to be able to
produce definite evidence that coffee has a direct causative effect for these
benefits.
