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Mediterranean-Style Diet
Improves Heart Function,
New Twin Study Shows
A study of twins shows that even with genes that put
them at higher risk of cardiovascular disease, eating
a Mediterranean-style diet can improve heart function,
according to research reported in Circulation:
"Cardiovascular Quality and Outcomes", an American
Heart Association journal.
Using data from the Emory Twins Heart Study, researchers
found that men eating a Mediterranean-style diet had greater
heart rate variability (HRV) than those eating a Western-type
diet. Heart rate variability refers to variation in the time interval
between heart beats during everyday life, reduced HRV is a risk
factor for coronary artery disease and sudden death.
“This means that the autonomic system controlling someone’s
heart rate works better in people who eat a diet similar to a
Mediterranean diet,” reported the researchers from the
departments of nutrition and epidemiology at Indiana University
in Bloomington.
Eating a Mediterranean-style diet, one characterized by low
saturated fats and high in fish, fruits, vegetables, legumes, nuts,
olive oil, cereals and moderate alcohol consumption, reduces a
person’s heart disease risk. But until now, the way the diet helps
reduce the risk of coronary disease remains unknown.
The research team analyzed dietary data obtained from a food
frequency questionnaire and cardiac data results from 276 identical
and fraternal male twins.They scored each participant on how
closely his food intake correlated with the Mediterranean diet;
the higher the score, the greater the similarity to a Mediterranean-
style diet.
To measure HRV, participants had their heart’s electrical activity
continuously measured and recorded with a Holter Monitor, a
portable, battery operated electrocardiogram device.
Using twins allowed team members to assess the influence of the
diet on HRV while controlling for genetic and other familial influence.
The Study’s Key Findings:
1. Measurements of HRV showed that the higher a person’s diet
score, the more variable the heart beat-to-beat time interval --
10 percent to 58 percent (depending on the HRV measure
considered) for men in the top Mediterranean diet score quarter
compared to those in the lowest quarter; this equates to a 9 percent
to 14 percent reduction in heart-related death.
2. Genetic influence on HRV frequency ranged from 20 percent --
95 percent, depending on the HRV measure considered.
Source:
American Heart Association.
Journal Reference:
“Mediterranean Dietary Pattern Is Associated With Improved
Cardiac Autonomic Function Among Middle-Aged Men:
A Twin Study. Circulation: Cardiovascular Quality and Outcomes”
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