Coffee
is one of the most commonly consumed beverages worldwide. Two
thirds of Americans drink at least one cup of coffee a day, with the
average consumption at 3.1 cups of coffee per day. In the US that’s
400 million cups of coffee a day or 146 billion cups of coffee per
year.
Although
that is a lot of beans, we are not even close to being a leader in
per capita consumption. Finland comes in first at 12 kg of coffee per
person per year with the other scandinavian countries - Sweden,
Norway, and Denmark - close behind. The US places a distant 25th at
4.2 kg per person per year.
Which
brings up the question as to whether all this coffee is affecting our
health. Is Starbucks vying with fast food as a leading
contributor to our country’s declining longevity?
Roasted
coffee is a complex mixture of more than 1000 bioactive compounds
including caffeine and a number of antioxidants. For those who
drink coffee, it provides more of their daily dietary antioxidants
than tea, fruit, and vegetables.
A
2017 analysis of over 200 individual studies documented a health
benefit for coffee drinkers and the more cups a day, the greater the
reduction in all cause mortality. There was a decrease in heart
disease and cancer as well as a number of neurologic conditions.
Decaffeinated coffee was as beneficial as caffeinated coffee in its
health impact.
The
longevity benefit (approximately 3% per cup) was greatest for the
first four cups but even a fifth and sixth cup added an additional
boost. The final numbers are impressive. A 17% reduction in all cause
mortality, an almost 20% reduction in cardiovascular disease, and a
similar reduction in cancer.
The
liver fared even better with a 29% lower risk of non-alcoholic fatty
liver disease and a 39% lower risk for liver cirrhosis (scarring).
As
did the brain. Coffee drinkers have a lower rate of developing
Parkinson’s disease, a decreased risk of depression, and an amazing
25% decrease in the incidence of Alzheimer’s disease.
Interestingly,
a single randomized study focused on Parkinsonism, there was an
improvement in movement symptoms after just three weeks of two cups
of coffee a day.
Even
the current diabetic epidemic was impacted positively with a 25% risk
reduction.
Athletes
have long taken advantage of the improvement in athletic performance
with just a single cup of coffee - runners
randomized to drink coffee shaved about six seconds per mile off
their times while weightlifters could squat more weight.
What
about risks?
There
is a marginal increase in complaints of esophageal reflux (heartburn
and indigestion).
Fracture
risk is increased in women (only) - one percent with one cup a
day rising to 14% at higher daily intakes.
Interestingly
there was one cancer that is statistically more common in regular
coffee drinkers - ovarian cancer. The reason is not clear and this
may be a statistical blip.
Coffee
has a cholesterol raising effect which parallels increasing intake of
unfiltered coffee. It is speculated that an oily substance in the
bean, removed with a paper filter, is the culprit. The
implications of this observation are uncertain as increasing coffee
consumption is not associated with more adverse cardiovascular
outcomes, including myocardial infarction.
Coffee
should be avoided in pregnancy based on a well documented association
with low birth weight, preterm birth, and miscarriage. Most
obstetricians suggest pregnant women limit their caffeine intake to
200 milligrams (one small cup of coffee) a day.
Although
most of us have heard about the risk of extra heart beats
(palpitations and atrial fibrillation) from too much coffee, data
shows the opposite to be true. Caffeine does not increase the
risk of atrial fibrillation. And low doses of caffeine, defined in
the study as less than five cups of coffee a day, may even have a
protective effect.
Finally,
let’s not forget those with insomnia who are especially sensitive
to the effects of caffeine.
Where
does this leave us? My take aways:
1)
If you are pregnant, cut back your coffee.
2)
If you have a history of osteoporosis with its increased risk of
fractures, cut back on your coffee.
3)
Otherwise drink as many cups a day as you’d like, the more the
better. We’re not yet at the point of prescribing coffee for
specific diseases, but like aspirin it is a readily available, over
the counter product, with surprising health benefits.
References:
References:
