New research based on more than
150,000 men and women shows that light drinking increases
the likelihood of cancer of the mouth, pharynx, oesophagus
and breast.One drink
a day increased the risk of cancer of the oesophagus by
almost a third, according to the study being reported in the
Annals of Oncology, which analysed data from more than 200
research projects. Low alcohol intake increased the risk of
oral cavity and pharynx cancer by 17 per cent, and breast
cancer in women by 5 per cent.
"Alcohol increases the risk
of cancer even at low doses," say the researchers. "Given
the high proportion of light drinkers in the population, and
the high prevalence of these tumours, especially of breast
cancer, even small increases in cancer risk are of great
public health relevance."
When it comes to enjoying
your favourite drink and looking after your health, advice
has often been complicated. Evidence suggests that drinking
in moderation may decrease the risk of heart disease, type-2
diabetes and dementia, leading many to believe a glass of
wine a day is good for you.
But the damaging effects of
drinking are well known. An estimated 2.2 million deaths a
year worldwide are linked to alcohol, according to the
report, and 3.6 per cent of all cancers are attributable to
drinking alcohol.
Until now, almost all the
evidence has come from studies that focused on people
drinking moderate or large amounts of alcohol, or binge
drinkers, and not those who drink less.
In the new study,
researchers from the University of Milan and other centres
in the US, France, Canada, Iran and Sweden, estimated that,
in one year alone, 24,000 deaths from oesophageal cancer,
5,000 from oral and pharyngeal, and 5,000 from breast
cancer, were due to light drinking.
The study defined light
drinking as up to one drink a day or 12.5g or less of
ethanol.
Data on 92,000 light
drinkers and 60,000 non-drinkers was used to calculate the
overall cancer risk.
No link was found with other
cancers that have been associated with heavier drinking,
including colon, liver and larynx.
Professor Peter Johnson,
Cancer Research UK's chief clinician, said: "This study adds
to the evidence linking alcohol consumption to several types
of cancer, and confirms that even light drinkers have a
small but definite increase in the risk, particularly for
those parts of the body, such as the throat and oesophagus,
that come into direct contact with alcohol.
"People who wish to minimise
their risk of cancer can help by cutting down on their
drinking."
Just why light intake
increases the risk of some cancers and not others, is
unclear. The researchers suggest that with cancer of the
mouth, pharynx and oesophagus it may be because the alcohol
comes into direct contact with the affected tissue. They
suggest the rise in risk for breast cancer may be associated
with increased levels of oestrogen, or higher levels of
insulin-like growth factors that are produced by the liver
after drinking alcohol.
