The key
element appears to be the greater amount of polyphenols
contained in red wines. Polyphenols
are known to act as antioxidants,
which reduce the speed and level at which our bodies suffer
from oxidative stress, which in turn kills cells and triggers
diseases, especially cancer. The term "polyphenol" encompasses
certain compounds derived from plants. Other important sources
of polyphenols include fresh fruits and raw vegetables, tea,
grains and seeds.
Full-bodied young reds average 0.14 ounces of polyphenols
per liter of wine, or 10 times more than white wines, according
to Joseph Vercauteren, a Bordeaux university professor who
is a leading expert on polyphenols. Reds form complex polyphenols
during winemaking and aging. Grape tannins make up 35 percent
of total phenolics in reds, and anthocyanin pigments (the
color) about 20 percent. Whites lack tannins and anthocyanin
(though they do contain lesser amounts of other polyphenols).
Research confirms the superiority of red wines over whites
in terms of health benefits. In a 1998 study published in
the American Journal of Clinical Nutrition, some volunteers
drank half a bottle of red wine daily for two weeks, while
others drank the same amount of white wine. The antioxidant
capacity recorded in the plasma of the volunteers peaked
within half an hour or so after drinking the red wine and
stayed in the body for two to four hours. "White wine
consumption didn't have any effect," reported researcher
Shailja Nigdikar and colleagues.
Similar results emerged from a study of 44 young men from
Chile. Federico Leighton, a biologist at Universidad Católica
de Chile, in Casilla, fed his volunteers a high-fat diet
similar to that consumed by many people living in Western,
industrialized countries. Then, in subsequent three-week
periods, he complemented this unhealthy diet with a daily
glass of white wine, then a daily glass of red wine, and
finally, with an additional eight servings daily of fruit
and vegetables, but no alcohol.
The study showed that both the white and red wine increased
the high-density lipoproteins -- HDLs or "good cholesterol" --
that tend to clean up arteries. This was further proof that
drinking a moderate amount of alcohol protects against heart
disease. But red wine was slightly more effective.
Compared with the Chilean volunteers who ate only the high-fat
diet, those who added a glass of red wine a day increased
their level of good cholesterol by 14 percent. The HDL level
went up 9 percent with a daily glass of white wine and up
5 percent with the additional servings of fruit and vegetables
(without wine).
Leighton also measured the oxidative damage to the volunteers'
DNA caused by the high-fat diet. When the volunteers drank
red wine, they reduced the high-fat diet's oxidative damage
to their DNA by 50 percent. White wine lowered the damage
by 16 percent. The fruit and vegetable addition reduced the
DNA damage by 42 percent.
The free flow of blood is good for our health, and Leighton
measured changes in the diameter of the volunteers' vessels.
A glass of white wine didn't make a difference. But a glass
of red wine markedly enlarged the volunteers' arterial diameter,
improving their endothelial function -- essentially, their
arterial health. The fruit and vegetable servings had almost
the same positive effect as the red wine.
"Moderate wine consumption
and additional servings of fruits and vegetables lower
cardiovascular risk, and
red wine provides
additional benefits probably due to its antioxidant properties," concluded
Leighton.
This article appeared in the Dec. 15, 2001, issue of Wine
Spectator magazine, page 53.
©2003
Wine Spectator
