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 The protective effects of moderate drinking were not universal
across Asia. And it’s not clear whether all types of alcohol offer
the same benefits - both papers urge further exploration of that and
other questions. But both also find increased risk of harm when
drinking goes from moderate to heavy.
“There is now solid evidence that alcohol, when consumed on a
regular basis and at low volumes (up to one drink for women and two
drinks for men daily), confers protection against cardiovascular
disease, whereas regular amounts of more than four to five drinks
daily and heavy episodic drinking have (the) opposite effects,”
write Drs. Stefan Kiechl and Johann Willeit, neurologists at
Innsbruck Medical University in Austria, in an editorial in the
journal Circulation.
One of the new studies looked at drinking and risk of experiencing
abdominal aortic aneurysm (AAA), a “ballooning” of the main blood
vessel from the heart that delivers blood to the trunk and lower
body.
The condition kills about 11,000 Americans each year and contributes
to the death of 17,000 more, according to the Centers for Disease
Control and Prevention. Men, especially those over age 60, are most
likely to have AAA. Smoking and high blood pressure can increase the
risk, and if the aneurysm ruptures, it can be life threatening.
Heart attack, which affects about 1.5 million people in the U.S.
each year, is subject to many of the same risk factors and also can
be life threatening.
For the heart attack study, researchers used data from 52 countries
to compare 12,000 cases of first heart attacks with 15,500 similar
people who did not have a heart attack. Trained staff administered
alcohol use questionnaires to heart attack victims and the
comparison group.
Compared to not drinking at all, current alcohol use was linked to a
13 percent lower risk of heart attack, on average, in almost all
regions, with the exception of South Asian countries including
India, Sri Lanka, Pakistan and Bangladesh.
In other regions, the protective association went away when alcohol
consumption increased beyond four drinks per week.
Having six or more drinks in the past 24 hours was associated with a
40 percent increased risk of heart attack, especially for people
over age 65.
“There have been several postulated mechanisms by which low levels
of alcohol use could protect against heart attack and by which heavy
alcohol use could increase the risk of heart attack,” said lead
author Dr. Darryl P. Leong of the Population Health Research
Institute at McMaster University and Hamilton Health Sciences in
Canada.
It could also be true that people who drink a low to moderate amount
of alcohol do other things differently that might affect their risk
of these problems, Leong told Reuters Health by email.
These findings suggest caution before “recommending: low to moderate
alcohol use,” Leong said, “given that alcohol may not be protective
for all people and is also implicated as a cause of some cancers and
injury.
“There is little doubt that heavy drinking should be avoided,” he
said. “We do not know at an individual level if there is a ‘safe’
threshold of alcohol use; this will need further study.”
For the AAA study, researchers combined two Swedish data sets with a
total of 70,000 men and women over age 45 who were followed from
1998 to 2011.
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Their alcohol consumption was reported in food frequency
questionnaires, and the incidence of AAA was cross-referenced with
Swedish Health Registries. Over the 14-year period, 1020 men and 194
women were diagnosed with AAA.
Drinking four to six glasses of alcohol per week was associated with
a 20 percent lower risk of AAA for men and a 44 percent lower risk
for women, compared to drinking less than one or two glasses per
week.
The risk kept decreasing up to the point of consuming 10 glasses per
week for men and five for women. Among specific alcohols, beer and
wine in particular were associated with lower risk.
However, for people who did not have cardiovascular diseases,
moderate drinking was not tied to any change in AAA risk.
“Generally speaking, the development of AAA and heart attack is a
slow process that is thought to begin with an inflammatory damage of
the vessel walls,” said lead author Dr. Otto Stackelberg. “This
damage can, for example, be caused by infections, cigarette smoke,
high blood pressure, or other circulating components in your blood,
like fatty acids or sugar.”
“The alcoholic component itself (ethanol) has previously been found
to alter levels of fatty acids in the blood, while antioxidants
found in fermented beverages like wine and beer have been connected
to other favorable effects (e.g. decrease inflammation in the vessel
walls),” said Stackelberg, of the Institute of Environmental
Medicine at the Karolinska Institutet in Stockholm, in an email.
Although moderate alcohol use has been associated with many
cardiovascular diseases, this is the first time a study has
specifically identified an association with AAA, he told Reuters
Health. It may be that the association is due to a third factor or
behavior he and his team did not account for, he said.
“I would not advise anyone to start to drink alcohol if they have
not been drinking before based on these findings,” Stackelberg said.
“However, a low to moderate consumption does not seem to be harmful
for most individuals so I would neither discourage those who like to
take a glass of wine to dinner.”
“The American Heart Association recommends no more than two daily
glasses of alcohol for men, and no more than one daily glass for
women,” he noted.
SOURCE: http://bit.ly/1iNg3Ou and http://bit.ly/1rd5XsC Circulation,
online June 13, 2014 and http://bit.ly/V2Kmpm Circulation, online
June 25, 2014.
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