|
By
Caroline Kanaiza and Marjorie Volege
Coffee
is a widely consumed beverage in the world. Coffee contains phenolic compounds which
are known to exhibit antioxidant activity, a property believed to decrease the
susceptibility of LDL to oxidation. The phytochemicals in coffee include caffeic,
ferulic and p-coumaric acids. Consumption
of coffee increases the total blood antioxidant status in humans.
A
number of studies have demonstrated a positive correlation between coffee
intake and cardiovascular disease (CVD). Nonetheless, the association of coffee
consumption with CVD remains to be contradictory.
Oxidized
low density lipo-protein (LDL cholesterol ) is linked with atherosclerosis, a cardiovascular
disease risk. It causes formation of lesions and plaques in blood vessels.
Susceptibility of low density lipo-protein (LDL) to oxidative modification can
be influenced by diet. For example, diet rich in fruits and vegetables can
reduce the vulnerability of LDL to oxidation and its disease effects.
A
group of Italian researchers at the National Institute for Food and Nutrition, Italy, reported that intake of coffee increases resistance of LDL to oxidation.
Their study was conducted on 10 (5 males and 5
females) healthy moderate coffee drinking volunteers aged between 24 and 35
years. They evaluated the effect of coffee consumption on the reduction/oxidation
status of LDL as modulated by the possible incorporation of phenolic acid into
LDL. The subjects acted as their own controls and were instructed to avoid
coffee and other beverages that are rich in phenolic acids for two days before
the experiment. After an overnight (10-12 hours) fast, the subjects drank 200ml
of freshly prepared American–style coffee.
Low
density lipo-protein (LDL) reduction/oxidation analysis was
done on venous blood sample taken before and 30 and 60 minutes after coffee
consumption.
The researchers found that consumption of 200 ml
coffee was associated with increased resistance of LDL to oxidation. The phenolic
acids, such as caffeic acid, in coffee are incorporated into the LDL and
protected the LDL from oxidation.
Consumption of coffee, however, did not have any
benefit in terms of reducing the proportion of LDL in the blood.
The researchers suggested that phenolic acids in coffee,
because of their antioxidant properties, can represent one of the positive
contributors to the beneficial effects of coffee in CVD prevention and
management.
The study was published in the American Journal of
Clinical Nutrition (2007, Vol 86: 604-609).
Natella, F., Nardini, M., Belelli, F.,
and Scaccini, C. Coffee drinking induces
incorporation of phenolic acids into LDL and increases the resistance of LDL to
ex vivo oxidation in humans. Am J Clin Nutr 2007;86:604 –9.
|
