Japanese women are generally not at high risk for
heart attacks — unless they live with in-laws, according to a new study.
Married Japanese women who live with both their husbands and a set of
parents — in Japan, that almost always means the husband’s parents,
according to the researchers — were three times more likely to suffer a
heart attack than those living just with their husbands.
Having children at home also was associated with an increased risk of
heart attacks among Japanese women, but not by as much, the study found.
When women lived with both parents and children, the risk of heart
attacks doubled rather than tripled.
The heart attack risk was slightly higher among women living with both
spouses and children, the study found.
The study was conducted by researchers at the Harvard School of Public
Health and was published in this week’s issue of the journal Heart.
“We tend, in the West, to view family relations and social support as
being protective of health,” said Dr. Ichiro Kawachi, an epidemiologist
at the school and one of the study’s authors. “This is the first
epidemiological study to show that these traditional living arrangements
in Japan are rather harmful for women.”
He added, “If you’re balancing a spouse and children, it’s also a
problem.”
Remarkably, however, the living arrangements do not affect men’s health.
“One of the overwhelming things that stands out is that it doesn’t
matter for Japanese men what the living arrangements are,” Dr. Kawachi
said. “They’re immune from the stresses in the home.” Young Japanese
women are “voting with their feet” by postponing marriage and having
fewer children, he added.
The researchers followed 91,000 Japanese men and women
living in different household arrangements for more than 10 years. The
participants ranged in age from 40 to 69 and had not been diagnosed at the
start of the study with any serious illnesses, including heart disease,
stroke or cancer.
By the end of the study, 671 participants had been diagnosed with coronary
artery disease, 339 had died of heart disease, and 6,255 had died of other
causes.
Women who lived with their spouses and parents, usually in-laws, were less
likely to smoke or drink heavily, but were three times more likely to have
had a heart attack, the researchers found.
They were not more likely to die of a heart attack than the women who lived
alone with their spouses. Dr. Kawachi speculated that once the women fall
ill, they begin to receive the support they need, in which case “having
parents around is probably helpful.”
The results were adjusted to control for age, smoking and other factors.
“This is yet another study that shows a link between stress and increased
rates of cardiovascular disease, although we don’t have the definitive study
that proves it,” said Dr. Nieca Goldberg, a cardiologist specializing in
women and author of the book “The Women’s Healthy Heart Program.”
An earlier study from Sweden found that marital stress increased the risk of
heart disease for women, she noted. But emotional stress may be a marker for
other risk factors and not necessarily a risk in itself, Dr. Goldberg added.
Dr. Kawachi said that the risk for heart attacks may not be quite as high
among Japanese women who live with both parents and children, compared to
those living just with parents, because parents may be helping with child
care and other responsibilities, offsetting other stresses.
