The ups and downs of coffee remain debatable

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The ups and downs of coffee remain

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October 28 2004 at 04:16PM

 

By Cherry Maslen

 

Coffee is more addictive than previously thought,and it is suspected

that too much coffee can trigger an irregular heartbeat (heart arrhythmia)

in those prone to the condition, which affects around two percent of the

population. The problem is believed to be caused by the stimulant caffeine.

 

However, the British Heart Foundation says that drinking moderate

amounts is unlikely to increase the risk of developing arrhythmia in

those not already susceptible to it.

 

Research into whether caffeine raises blood pressure took a new turn

in 2003, when a team at Edinburgh University tested its effect on arteries

around the heart - rather than in the arm as normal.

Coffee contains antioxidants

 

After the caffeine equivalent of four to five cups of coffee,

volunteers' blood pressure rose sharply, even though the arteries in the arm

showed no change.

 

This hidden rise may explain why previous studies regarding caffeine

and high blood pressure have been inconclusive.

 

The long-term effects on the cardiovascular system are still unknown.

 

Coffee does not cause ulcers but could aggravate existing ones,

because it stimulates the stomach's acid secretions.

 

Two reports this year have shown different views on caffeine and Type

2 diabetes, which is controlled by diet and drugs rather than insulin

injections.

 

American research found a link between coffee at mealtimes and

increased blood sugar, indicating that caffeine could make this form of

diabetes worse by interfering with blood sugar control.

 

Diabetes United Kingdom, however, felt the study was too small (14

people) to make any recommendations, other than encouraging diabetics to

check their blood sugar regularly so that they are aware of fluctuations.

 

Conversely, research by Helsinki's National Public Health Institute

found that coffee appeared to protect people from developing Type 2 diabetes

in the first place.

 

This is backed up by a report from the Harvard School of Public

Health, which also suggests it is minerals in coffee - rather than the

caffeine it contains - that have a protective effect.

 

There seems little doubt that coffee is a diuretic, encouraging the

body to lose fluid, though some studies, including one published by the

National Academy of Sciences in America, claim the effects are negligible.

 

Coffee has long been listed as a possible trigger for migraine.

 

This is thought to be due to compounds called amines in coffee, which

stimulate blood platelets in the brain to clump together, releasing

serotonin and so triggering a migraine.

 

Caffeine inhibits the body's absorption of iron and other nutrients,

and causes calcium to be expelled from the body in urine.

 

There has been concern that this could increase the risk of

osteoporosis.

 

However, research is inconclusive, according to a British government

report on nutrition and bone health, and in any case, most people drink

coffee with milk, increasing their overall calcium intake.

 

Caffeine has been associated with low fertility. One study maintained

that three or more cups a day was enough to reduce the chances of

conceiving, though the results were partly based on what women could

remember about their coffee consumption 10 years previously. But researchers

at Sao Paulo University in Brazil discovered that men who regularly drank

coffee had stronger sperm than men who did not.

It is thought that caffeine has a stimulating effect on sperm, just as

it does on the central nervous system.

 

The Food Standards Agency issued a warning to pregnant women earlier

this year after research suggested caffeine could be harmful to an unborn

child.

 

Pregnancy also slows down the elimination of caffeine.

 

The recommended daily limit for pregnant women is 300mg of caffeine,

roughly equivalent to four cups of instant coffee, or three cups of freshly

brewed.

 

Like both black and green tea, coffee contains antioxidants, which can

help prevent the cell mutation which may lead to cancer.

 

Surprisingly - given that it can be a migraine trigger - the caffeine

in coffee can also help to cure headaches.

 

It is one of the ingredients in some headache pills because it

increases the power of aspirin and other painkillers by as much as 40

percent.

As coffee is a stimulant, it can help with concentration.

 

Earlier this year, Dr Chiara Trombetti, of the Humanitas Gavazzeni

Institute in Italy, went as far as suggesting a morning cup of milky coffee

could get sleepy schoolchildren off to a good start.

 

However, that is unlikely to be echoed by nutritionists, who recommend

sufficient sleep and good diet.

 

Doctors cannot explain the link, but several studies have shown that

coffee drinkers are less likely to develop liver disease, including

cirrhosis of the liver.

 

Women are twice as likely as men to develop gallstones. In one study,

women who drank four cups of coffee a day were 25 percent less likely to

need surgery for gallstones than women who are non-drinkers.

 

In one study, caffeine appeared to improve microcirculation when

applied to the skin, making cellulite look better.< br>

 

 

a.. This article was originally published on page 0 of The Star on

October 28, 2004