Abstract
A large number of prospective studies have observed
an inverse relationship between a moderate intake
of alcohol and coronary heart disease morbidity and
mortality. Concerning death from all-causes, results
are not unanimous. Alcohol intake was associated with
a protection of all-cause mortality in England and
USA physicians and the large study of the American
Cancer Society. None of these studies separated the
effects of different alcoholic beverages.
In our prospective studies in France on 35 000 middle-aged
men, we observed that only wine at moderate intake,
was associated with a protective effect on all-cause
mortality. The reason was that in addition to the
known effect on cardiovascular diseases, a very moderate
intake of wine, protected also from cancer and other
causes as confirmed by Gronbaek in Denmark. Our recent
results also indicate that the protective effect of
a moderate intake of wine on all-cause mortality is
observed at all levels of blood pressure and serum
cholesterol.
Key words: Alcohol, mortality, wine.
Abbreviations : BMI : body mass index; CHD: coronary
heart disease.
Introduction
A large number of studies have reported that amoderate
intake of alcohol is associated with a lower risk
of morbidity and mortality (1, 2) from coronary heart
disease (CHD), more efficient on morbidity. These
results however, do not imply that longevity is increased
in alcohol drinkers. In Great Britain, Shaper et al.
reported (3) in a prospective study on 7735 middle
aged men, that in moderate drinkers there was a 34
% lower mortality rate from CHD but no benefit in
total cardiovascular and all-cause mortality. Another
study concluded: “Our results are inconsistent
with the belief that daily consumption of a few glasses
of wine has salutary effects” (4). In that study,
they did not evaluate wine drinkers but rather beer
and spirit drinkers. Thus, they anticipated that the
effect of wine could not be different from that of
other alcoholic beverages.
Alcohol and
all-cause mortality.
Do we have further indications that moderate alcohol
drinking does not lower death from all causes? In
1994, the same year of the Shaper study (3) Sir Richard
Doll et al. (5), also in Great Britain, in their study
on British physicians, reported that a moderate intake
of alcohol (21 units/week) reduced by more than 20%
mortality from all causes, in addition to the usual
protective effect on CHD mortality.
In USA, a prospective study on 22 701 men, also physicians,
reported that the consumption of 2 to 6 drinks of
alcohol per week lowered mortality from all causes
by 21 to 28 % (6).
The question raised by these two studies involves
the kind of alcoholic beverage drank by these physicians.
Could it be that they normally drank more wine than
the general population? However, in USA, in the largest
study ever performed on the effect of alcohol (238
206 subjects) (7) on mortality, but in motivated subjects,
very moderate drinkers, a 20% reduction in the mortality
from all causes was registered, for 1 to 3 drinks
per day, a result similar to that observed in the
British (5) and American physicians (6).
Thus, at least three large prospective studies have
observed a similar reduction in mortality from all
causes for a moderate intake of alcohol. The question
raised is why large studies have observed a similar
protective effect of alcohol on all-cause mortality
and not the previous smaller
studies? Such a discrepancy could be due to the size
of the cohort or/and possibly the type of alcoholic
beverage consumed.
Unfortunately, none of these prospective studies have
evaluated the type of the alcoholic beverage consumed.
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Type
ok alcohol and all-cause mortality
The first prospective study suggesting that the type
of alcoholic beverage in addition to its quantity,
could be important for the protective effect on mortality,
was that of Gronbaek (8).
In that study, for 3 to 5 drinks per day cardiovascular
mortality was reduced by 47% in the wine drinkers,
but the other causes were also 50% lower. An important
issue was that the other causes were not reduced in
the drinkers of beer and spirits.
Since French males are considered the largest consumers
of wine in the world, we conducted a study in Eastern
France that included 34 014 middle-aged men (40 -
60 years at baseline) in which we evaluated mortality
in relation to their alcohol intake, with a follow-up
of 10 - 15 years (9), In that study, every social
class consumed wine, and the largest consumers were
workers and tradesmen (48.9 and 47.6 g/ day respectively).
Higher classes such as high-level managers consumed
only 36.2 g/day of wine. In that cohort, wine was
the main alcohol consumed (82% of the total alcoholic
beverages). A moderate intake of wine (2 - 3 glasses
per day) was associated with a 24 - 31% reduction
in all-cause mortality, in smokers, ex-smokers and
nonsmokers.
In a subsequent study (10) with 36 250
men, we evaluated separately the effect of wine, beer,
and of wine + beer. Significant lower all-cause mortality
was observed only
with wine at a moderate intake (1 to 5 glasses/day).
With beer, either representing more than 40 % of alcohol
or less, there was no reduction of the all-cause mortality,
at any level of alcohol consumption. The reduction
of all-cause mortality in moderate wine drinkers could
be attributed to a lower
death from cancer (by 20%) and from other causes (by
28 to 42 %) shown in Figure 1.
The specificity of wine for lowering the risk of all-cause
mortality and cancer has been confirmed recently by
Gronbaek et al. (11). It was only in wine drinkers
that the all-cause mortality was lowered by more than
20% for an intake of up to 3 drinks per day. They
also found that it was only wine but not spirits or
beer that reduced cancer mortality by up to 20% (3
glasses of wine/day). As for cancer, the subsequent
question was to evaluate on what types of cancer wine
may have protective effects.
Gronbaek et al. have already shown that wine drinking
does not increase the risk of upper digestive tract
cancer (12) as compared to beer or spirits.
In our cohort from Eastern France mentioned above,
in 946 cases of cancer we evaluated the effect of
wine drinking compared to abstainers (Fig. 2). The
risk of both lung cancer and of other cancers was
lowered by about the same extent for 1 - 3 glasses
of wine (other cancers), and for 3 - 5 glasses (lung
cancers). Above 5 glasses /day the risk of cancer
was increased by 50 %.
Since it is only wine that offers some
protection on the risk of cancer, that protection
does not seem to be due to alcohol per se. Among the
phenolic substances contained in wine, resveratrol
is one substance that has been extensivelys tudied
in relation to cancer and other problems (13). It
has been shown that resveratrol modulates lipoprotein
metabolism, presents antioxidant and antiinflammatory
activities, inhibits platelet aggregation and cellular
events associated with cancer i.e. initiation, promotion
and progression (13).
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