Brewing Up Health Benefits for Coffee
New research gives coffee addicts a reason to keep drinking.
Tufts University Health & Nutrition Letter. New York: Jan 2008.
© Tufts Media LLC Jan 2008
1.
Most of us heard the dire warnings about coffee when we were growing up:
Drinking coffee would "stunt your growth," our mothers cautioned. The dark tone of
voice hinted that this was perhaps the least of coffee's health hazards.
2.
So our mothers would have been surprised to hear the experts assembled for a
panel at the 2007 Experimental Biology meeting in Washington, DC. They discussed a
wide range of possible health benefits from coffee consumption, ranging from reducing
the risk of a certain type of diabetes (type-2 diabetes) to helping prevent various
cancers. Since that session, hardly a month has gone by without some new study
suggesting that coffee – arguably the world's most widely consumed beverage, after
water – may be good for everything from your liver to your brain.
3.
Not that coffee consumption doesn't have its downsides. But the picture emerging
from recent research of coffee's health risks versus rewards is surprisingly more positive
than our mothers' view. "We're coming from a situation where coffee had a very
negative health image," said Dr. Rob van Dam, PhD, of the Harvard School of Public
Health, a panelist at the Experimental Biology session. He added, "It's not that we're
promoting coffee as the new health food and asking people who don't like coffee to
drink coffee for their health".
4.
If you are among the roughly 54% of Americans over 18 who drink coffee daily,
however, at least the latest science doesn't present any persuasive reason to quit.
Another 30% of the population occasionally drinks coffee, and among all coffee drinkers
the average “Java jolt” (caffeine from coffee) is a little over three cups a day. That puts
us behind many European nations, including Finland, Sweden, Switzerland, Germany,
France and Italy, as well as Brazil, although ahead of tea-drinking Japan and Britain.
Apart from the US, much of the research on coffee and health has originated from
nations at either extreme of this consumption scale, such as Finland, where one study
found benefits from gulping an astonishing 10 cups daily, and Japan, where it's easier to
isolate the coffee drinkers among the population.
I Love Coffee and Coffee Loves Me
5.
While researchers caution that none of their findings make a compelling case for
starting a coffee habit, a variety of studies do give coffee addicts reason to keep pouring
a cup every morning and not stop.
Type-2 Diabetes
6.
Since 2002, more than 20 studies have suggested that coffee somehow helps
ward off type-2 diabetes. According to the American Diabetes Association, "Drinking
brewed coffee in moderate amounts may be beneficial for reducing the chances of
getting diabetes. However, the presence of caffeine does not explain all of the effects.
There may be some other ingredient in brewed coffee that has healthful effects.”
Cancer
7.
At the Experimental Biology session, Dr. Lenore Arab, MSc, PhD, of UCLA
presented results of a review of nearly 400 studies concerning coffee and cancer risk.
While coffee may increase the risk of stomach cancer and especially leukemia, the
review found a protective effect against colon, rectal and liver cancer. Dr. Arab
suggested that, besides speeding the passage of stool (including any carcinogens from
food) through the colon, coffee might lower the buildup of cholesterol, sterol secretions
and bile acid in the colon.
8.
Another recent review, by Italian scientists, looked at 10 studies of coffee and liver
cancer and similarly found a benefit: Overall, an increase in coffee consumption of one
cup daily was associated with a 23% reduction in liver-cancer risk. Coffee drinkers
averaged a 41% reduced risk compared to non-drinkers, with the highest benefit (55%
reduced risk) among those drinking three or more cups a day.
9.
A new Japanese study supports the possible protection against colon cancer, at
least for women: Researchers at the Tokyo National Cancer Center analyzed data on
more than 96,000 men and women ages 40–69 over a 12-year span. They found that
women consuming at least three cups of coffee daily had only half the risk of colon
cancer of non-drinkers. No similar effect was seen for men, which the researchers
suggested could be due to the inability to adjust for the high rates of alcohol
consumption and smoking among Japanese males.
10. The most headline-grabbing recent research on coffee and cancer revealed
surprising teamwork between caffeine and exercise. Rutgers University researchers
found that both caffeine and exercise protected mice against skin cancer and that in
combination the effect was more than the sum of the two factors. The report led to many
late-night comics' jokes about jogging home from Starbucks.
Cardiovascular disease
11.
Coffee's long-term effect on blood pressure has long been debated, and should
be weighed against any possible benefits. In 2006, Norwegian researchers found that
older women drinking one to three cups of coffee daily were 24% less likely to die of
cardiovascular disease than non-drinkers. Another study in 2007 found that older
people (age 65 and over) who consume four or more servings of caffeine daily had a
lower risk of death from heart disease.
12.
On the other hand, because caffeine has a short-term elevating effect on blood
pressure, people who drink one cup after another may keep their blood pressure high
for periods long enough to risk heart trouble.
Parkinson's disease
13.
The coffee-loving Finns recently found evidence that their high level of
consumption – 10 cups a day or more -- might protect against Parkinson's disease.
Following 6,710 men and women ages 50 to 79 for 22 years, researchers at Finland's
National Public Health Institute concluded that the heaviest coffee drinkers were at 84%
reduced risk of developing the disease.
Cognitive decline
14.
Anybody who has experienced coffee's morning wake-up call to the brain
knows that it can temporarily help sharpen thinking. But coffee may also boost brain
function in more permanent ways: A European study of 676 healthy men, published in
2006 found that those consuming three cups of coffee daily suffered significantly less
cognitive decline over 10 years than non-drinkers. And in 2007, a French study
concluded that older women who drank at least three cups of coffee daily were 18%
less likely to develop problems with verbal recall and 33% less prone to memory
problems. The four-year study of 7,017 people age 65 and older failed to find similar
benefits in men. Similar results were seen for tea, leading researchers to identify
caffeine as the source of the benefit.
A Cup of Caution
15.
Before you rush out to buy an extra-large coffeepot, however, be aware
that coffee has negatives. Pregnant women are often advised to avoid or limit
coffee and other sources of caffeine because of possible harm to the fetus and
risk of miscarriage with high intakes. Coffee brewed in French-press pots has
been found higher in oils that are mostly filtered out by other brewing methods.
These oils affect the liver, raising unhealthy LDL cholesterol levels. You may also
want to watch your coffee consumption if you take certain medications. Some
drugs, when combined with caffeine, may exaggerate the effects of the caffeine.
Weight Watchers Beware
16.
The specialty-coffee trend like Starbucks and Aroma, which have swept
America, have also added calories to our coffee cups. Only 35% of Americans drink
their coffee black, meaning the rest of us have to be careful that what we add to our
cups doesn't outweigh any possible health benefits from the coffee. Cream and sugar?
Extra calories and saturated fat. If you must add to your coffee, choose carefully. Many
coffeehouses now offer 1% or low-fat milk. Cinnamon and other spices don't add
calories or fat. Artificial sweeteners let you sweeten coffee without calories .
17.
Nutritionally, the consequences of the wrong coffee choices can be disastrous.
At Starbucks, for example, a grande (16-ounce / ½-liter) Caffe Americano has a mere
15 calories, 10 milligrams of sodium and zero fat. But the same size White Chocolate
Mocha made with whole milk (with 8.5 grams of fat) has a whopping 500 calories – a
quarter of what many people should consume in an entire day – and 22 grams of fat, 14
grams of it saturated fat, plus 240 milligrams of sodium .
More Good News
18.
Most coffee drinkers think of their morning cup of coffee as containing little more
than hot water, caffeine and coffee flavor. It's true that caffeine is responsible for many
of coffee's health effects, both good and ill. But that's hardly the whole story; there are
other beneficial ingredients in coffee. In 2005, for example, newspaper headlines
promoted the finding that coffee is the number-one source of antioxidants in the US diet.
That's not because coffee is the best source of antioxidants ounce per ounce, however,
as many media reports interpreted the study, but rather because Americans drink so
much coffee.
19.
Less publicized was the more recent finding that for most US adults, coffee is the
main dietary source of many minerals, including the trace element boron. An essential
nutrient for plants, boron may also prove beneficial to humans; one study in rats found
that dietary boron reduced the amount of insulin in the blood required to maintain proper
glucose levels.
Coffee is also a surprising source of more familiar minerals and
nutrients, including chromium, magnesium and niacin. A cup of coffee contains about
one-third as much potassium as found in a small banana.
20.
So what can we conclude about the question that coffee may "stunt your
growth"? This concern originally arose from research suggesting caffeine might
negatively affect calcium absorption. This made it of potential concern not only to
growing children but also to adults at risk for osteoporosis. But subsequent studies have
shown that the real worry is substituting caffeinated beverages for those containing
calcium. Make sure you're getting adequate calcium and you can enjoy coffee – in
moderation – and even gain some benefit from it.