Alcohol 39Cancer.Most laboratory tests give no indication that alcohol has a potential
for causing cancer. Nonetheless, mice experimentation indicates that long-term
use of alcohol can cause liver cancer. Human reports indicate an increased
risk for prostate cancer. Women who take more than two drinks a day have
an increased risk of breast cancer. A study of 8,006 Japanese men in Hawaii
found an association between alcohol and cancer of the lungs and rectum, but
“association” is not the same as cause and effect. Evidence indicates that saliva
might transform alcohol in ways that promote oral cancer.
Pregnancy.A study of 430 couples in Denmark found fertility to decline
among women as their alcohol consumption increased, but no effect was ob-
served on male fertility. In contrast, a study of farm couples in Canada found
no difference in fertility between women who did or did not drink alcohol.
Still another study, in the Netherlands, found male alcohol consumers to have
higher fertility as consumption increased, with no difference in fertility rate
between women who drank different amounts. Such findings of sometimes
yes, sometimes no, are a classic sign of an “invalid variable,” which in this
case would mean that no difference in fertility can be attributed to alcohol
(although more studies would be needed to reach a firm conclusion, and some
authorities say the trend of research indicates that alcohol does reduce female
fertility).
A study found that premature infants were more likely among pregnant
teenagers who drank alcohol than among those who did not. That effect was
not seen among older pregnant women who drank. Other research has noted
lower birthweights among children delivered by pregnant alcohol consumers.
A human experiment documented fetal response to two glasses of wine
drunk by women whose pregnancies were close to time of delivery: In that
experiment fetal respiration and sleep were disturbed—which did not surprise
researchers because heavy consumers of alcohol frequently give birth to in-
fants having sleep difficulties. Such newborns may also have tremors and poor
reflexes and cry more than normal. Children can be born dependent on the
drug.
Alcohol is a well-known cause of birth defects. In mice the substance is
known to cause a facial deformity called holoprosencephaly, and a human
case report suggests that heavy dosage can do the same in humans. Less dra-
matic facial characteristics are common after substantial prenatal exposure to
alcohol. Other human birth defects attributed to alcohol include kidney, heart,
and brain trouble. More subtle damage has been measured as a slight decline
in IQ among schoolchildren of mothers who took two or more drinks a day
during pregnancy. Male exposure to some drugs can produce birth defects,
and researchers have found problems in behavior and thinking skills among
children of alcoholic fathers as well as among offspring of pregnant alcoholics.
Fetal alcohol syndrome (FAS) is a collection of afflictions observed in children
typically born to women who had six or more drinks a day while pregnant.
The syndrome may include low birthweight, defective vision, delayed devel-
opment, specific facial characteristics, trouble with muscles and joints, heart
abnormality, and mental retardation. Problems can be long-lasting and even
permanent. Prenatal exposure to alcohol can delay motor skill development
in children, cause difficulties in maintaining balance, and limit growth in