Coffee could fight colon cancer (2004)
- 07/04/2004 - Coffee contains similar
levels of antioxidants to black tea and can be just as beneficial
to health, according to Scottish scientists that have found
coffee's antioxidants are highly absorbable by the human body.
Tea, particularly green tea, has received widespread
media coverage for studies revealing its health benefits but Professor
Alan Crozier from the University of Glasgow says that the new findings
show that coffee can also be considered a valuable source of antioxidants,
supplementing those obtained from fruit and vegetables.
Research
has already established the antioxidant activity of coffee and
confirmed its antioxidant components - chlorogenic
acid, also found in fruits, such as apples.
But Professor Crozier's
research demonstrated for the first time the high bioavailability
of such antioxidants when consumed in coffee.
Investigating
the absorption of chlorogenic acid in the ileum, part of the
small intestine, of volunteers, the researchers found that more
than 75 per cent of the antioxidant had disappeared, being absorbed
into the bloodstream before reaching the ileum.
The remaining
25 per cent would pass from the small to the large intestine
where it may offer protection against colon cancer, Crozier told
NutraIngredients.com.
"This is higher absorption than I've seen with
other antioxidants," he said. "With green tea about 30 per cent
of the antioxidants are absorbed altogether, but they shouldn't
be regarded as competing with each other. More importantly it shows
that all of these beverages are a useful supplement to the diet."
He
cautioned however that producing such antioxidants in supplement
form raises the risk of side effects as the natural ingredient
is taken out of its normal matrix.
"It's important to eat a varied diet of fruit
and vegetables so that your body can absorb a range of antioxidants.
If you rely on supplements, with one tablet you could, for instance,
be consuming the equivalent of 2 kilos of onions - not a very natural
thing to do."
High doses of chlorogenic acid have been shown
to raise concentrations of homocysteine in plasma, thought to
be a marker for heart disease risk. But the antioxidant has also
been shown to be a potent anti-inflammatory agent.
The findings
were presented last week at the Society for Experimental Biology's
annual meeting at Heriot-Watt University in Edinburgh and will
be submitted for publication in a scientific journal.
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