world cancer report - iarc
world cancer report - iarc
world cancer report - iarc
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ALCOHOL DRINKING<br />
SUMMARY<br />
> Heavy alcohol drinking causes <strong>cancer</strong> of<br />
the oral cavity, pharynx, larynx, oesophagus,<br />
and liver, and may increase the<br />
risk of breast and colorectal <strong>cancer</strong>.<br />
> Risk is linearly related to the mean daily<br />
consumption.<br />
> Low levels of consumption appear to<br />
exert a protective effect against cardiovascular<br />
disease.<br />
> In the oral cavity, pharynx, larynx and<br />
oesophagus, the risk is greatly<br />
increased by concurrent smoking.<br />
Beverages containing alcohol (the common<br />
name for ethanol) as the product of<br />
the fermentation of carbohydrates have<br />
been produced in most human societies<br />
since ancient times. Despite great variety,<br />
most alcoholic beverages can be grouped<br />
as either beers (brewed by fermenting<br />
malted barley and typically containing 5%<br />
volume of alcohol), wines (made by fermenting<br />
grape juice or crushed grapes,<br />
containing 12% alcohol) or spirits (made<br />
by distilling fermented products of a variety<br />
of cereals, vegetables and fruits, containing<br />
40% alcohol). Beverages that are<br />
less common and which are often limited<br />
to particular regions include cider, fortified<br />
wines and flavoured wines.<br />
On a global scale, the consumption of<br />
alcoholic beverages by adults as calculated<br />
from official figures is equivalent to 4 L<br />
of alcohol per year (or 9 g/day), corresponding<br />
to approximately 3% of the average<br />
total intake of calories [1]. Unofficial<br />
consumption, however, is estimated to<br />
account for an additional amount corresponding<br />
to 20-100% of the official<br />
figures, depending on the country. Most<br />
“unofficial” alcohol is either sold illegally<br />
on the black market (usually to avoid taxation)<br />
or produced for private consumption.<br />
There is strong regional variability in<br />
consumption levels, with a minimum<br />
(12 L/year) in Central and Southern<br />
Europe. The distribution between each<br />
major type of beverage is also countryspecific<br />
(Fig. 2.10). Official figures show a<br />
decrease in alcohol consumption in more<br />
developed countries and, over recent<br />
years, an increase in consumption in less<br />
developed countries.<br />
Cancers caused<br />
Through analytical epidemiological studies<br />
of cohort and case-control type conducted<br />
in many populations with different<br />
levels of consumption, the causal association<br />
of drinking alcohol has been definitely<br />
established in respect of oral,<br />
oesophageal, liver and other <strong>cancer</strong>s [2].<br />
In particular, studies of <strong>cancer</strong> risk in<br />
brewery workers and in alcoholic patients<br />
have provided important evidence on the<br />
carcinogenic role of alcohol. A causal<br />
association is also established in the case<br />
of breast <strong>cancer</strong> and is probable for colon<br />
and rectal <strong>cancer</strong> [2,3]. There have been<br />
suggestions of a possible carcinogenic<br />
effect of alcohol drinking on other organs,<br />
such as the lung, but the evidence is still<br />
inconclusive [4]. An association between<br />
alcohol intake and risk of head and neck<br />
<strong>cancer</strong> is indicated by the geographical<br />
pattern of these neoplasms; countries<br />
(and regions within countries) with heavy<br />
alcohol consumption are among those<br />
with the highest incidence of these neoplasms.<br />
For all <strong>cancer</strong>s caused by drinking alcohol,<br />
the risk of <strong>cancer</strong> is a linear function of<br />
the level of consumption, up to an intake<br />
of about 80 g/day (one litre of wine, a<br />
quarter of a litre of spirits), above which<br />
Mean alcohol Relative risk<br />
consumption (95% confidence)<br />
No alcohol 1<br />
> 0 to 30 g/day 1.2 (0.4–3.4)<br />
> 30 to 60 g/day 3.2 (1.0–10.1)<br />
> 60 g/day 9.2 (2.8–31.0)<br />
*Adjusted for follow-up time, sex, education, body mass<br />
index (BMI), vegetable and fruit consumption, tobacco<br />
smoking and energy intake<br />
Table 2.4 Consumption of alcohol increases the<br />
risk of <strong>cancer</strong> of the upper gastrointestinal tract.<br />
Fig. 2.10 Patterns of alcohol drinking, expressed as mean equivalent volumes of pure ethanol, in selected<br />
countries, 1996.<br />
Alcohol drinking 29