Beth Israel Deaconess Medical Center
While the protective connection between moderate alcohol
consumption and heart health has been well-studied, new research from Beth
Israel Deaconess Medical Center (BIDMC) and the Harvard T. H. Chan School of
Public Health suggests that the association is more complicated than is widely
accepted.
Researchers found that in the hour following even moderate consumption
of alcohol, the risk of heart and stroke doubled.
The findings were published today in the American Heart
Association's journal Circulation and presented at the American Heart
Association's Epidemiology and Prevention/Lifestyle and Cardiometabolic Health 2016
Scientific Sessions.
"This new study highlights the
fact that alcohol has complex physiological effects that result in both higher
and lower cardiovascular risk depending on the amount of alcohol consumed,
drinking frequency and what aspect of heart health is being measured."
Mostofsky and colleagues analyzed data from 23 studies involving
30,000 participants to better understand the risk of heart attacks and strokes
in the hours and days after drinking alcohol.
"We found that even moderate alcohol consumption -- one
drink a day for women and up to two drinks a day for men -- may raise a
person's risk of a heart attack or stroke approximately two-fold within the
hour following consumption compared to other times," Mostofsky said.
"After 24 hours, though, only heavy alcohol intake conferred a continued
heightened risk. In other words, heavy drinking increases risk both in the
short-term and the long-term, but drinking smaller amounts has different
effects in the subsequent hours than it does in the subsequent days and
weeks."
Immediately following alcohol intake, heart rate increases,
blood pressure rises and blood platelets become stickier.
This may increase the
risk of heart attack and stroke. But over time regularly drinking small amounts
of alcohol appears to lower cardiovascular risk by increasing levels of
high-density lipoprotein cholesterol (HDL), the so-called "good"
cholesterol, and by reducing the tendency to form blood clots.
"It's possible that the briefly higher cardiovascular risk
in the hours after drinking small amounts of alcohol may be outweighed by the
longer term health benefits of regular moderate drinking," said Mostofsky.
"However, heavy alcohol use was associated with higher heart attack and
stroke risks at all times studied. Six to nine drinks in a day nearly doubled
the risk, and 19 to 30 drinks weekly elevated the risk by up to six times
more."
According to the 2015 Dietary Guidelines for Americans published
by the U.S. Office of Disease Prevention and Health Promotion, heavy drinking
is typically described for men as consuming 15 or more drinks per week and more
than 8 drinks per week for women.
Moderate drinking is up to one drink per day
for women and up to two drinks per day for men. A drink is one 12-ounce beer,
four ounces of wine, one and a half ounces of 80-proof spirits or one ounce of
100-proof spirits.
"These results support the American Health Association
recommendation that says if you don't drink, don't start in hopes of helping
your heart health. There are plenty of other ways to do that," said Murray
Mittleman, MD, DrPH, Department of Medicine at BIDMC and a professor of
epidemiology at the Harvard T.H. Chan School of Public Health.
"If you do
drink, do so in moderation, and if you're on medications or have other health
concerns, talk with your doctor about whether even moderate drinking is
safe."
In addition to Mostofsky and Mittleman, co-authors include
Harpreet Chahal, BMSc, MD, MPH, Schulich School of Medicine & Dentistry,
Western University, London, ON, Canada; Eric Rimm, ScD, Brigham and Women's
Hospital; and Kenneth J. Mukamal, MD, MPH, BIDMC.
Dr. Mostofsky's research is supported by the National Institutes
of Health (grant L30-HL115623-02) and the Harvard Catalyst/The Harvard Clinical
and Translational Science Center (National Center for Research Resources and
the National Center for Advancing Translational Sciences, National Institutes
of Health Award KL2 TR001100).