Twin insight into Mediterranean heart booster

Friday June 18th, 2010

Men facing a genetic risk of heart disease can help themselves by eating a healthy "Mediterranean" diet, researchers have reported.

Men eating a diet high in fish, fruits, vegetables, legumes, nuts, olive oil, cereals and moderate alcohol consumption have better heart health than those eating a Western diet high in fat, according to Dr Jun Dai, assistant professor of nutrition and epidemiology at Indiana University in Bloomington, USA.

Researchers measured heart rate variability, HRV, the variation in the time interval between heart beats during everyday life. Reduced HRV is a risk factor for coronary artery disease and sudden death.

Dr Dai and her colleagues used data from the Emory Twins Heart Study for the research, published in American Heart Association journal Circulation: Cardiovascular Quality and Outcomes.

They analysed 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 the 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.

“This means that the autonomic system controlling someone’s heart rate works better in people who eat a diet similar to a Mediterranean diet,” said Dr Dai.

Among the study’s key findings include:

• Measurements of HRV that showed that the higher a person’s diet score, the more variable the heart beat-to-beat time interval — 10 per cent to 58 per cent for men in the top Mediterranean diet score quarter compared to those in the lowest quarter; this equates to a 9 per cent to 14 per cent reduction in heart-related death.
• Genetic influence on HRV frequency ranged from 20 per cent – 95 per cent, depending on the HRV measure considered.

The study cannot be generalised to women or other ethnic groups because 94 per cent of participants were non-Hispanic white males, added Dr Dai.

Co-authors are Rachel Lampert, M.D.; Peter W. Wilson, M.D.; Jack Goldberg, Ph.D.; Thomas R. Ziegler, M.D. and Viola Vaccarino, M.D., Ph.D., principal investigator of the Emory Twins Heart Study.

Circulation June 2010

Tags: Diet & Food | Europe | Heart Health | Men’s Health | North America

Printer friendly page