Heart health tip in a nutshell

CHICAGO — Here's a health tip in a nutshell: Eating a handful of nuts a day for a year — along with a Mediterranean diet rich in fruit, vegetables and fish — may help undo a collection of risk factors for heart disease.

Spanish researchers found that adding nuts worked better than boosting the olive oil in a typical Mediterranean diet. Both regimens cut the heart risks known as metabolic syndrome in more people than a low-fat diet did.

"What's most surprising is they found substantial metabolic benefits in the absence of calorie reduction or weight loss," said Dr. JoAnn Manson, chief of preventive medicine at Harvard's Brigham and Women's Hospital.

In the study, appearing Monday in the Archives of Internal Medicine, the people who improved most were told to eat about three whole walnuts, seven or eight whole hazelnuts and seven or eight whole almonds. They didn't lose weight, on average, but more of them succeeded in reducing belly fat and improving their cholesterol and blood pressure.

Manson, who wasn't involved in the study, cautioned that adding nuts to a Western diet — one packed with too many calories and junk food — could lead to weight gain and more health risks. "But using nuts to replace a snack of chips or crackers is a very favorable change to make in your diet," Manson said.

The American Heart Association says 50 million Americans have metabolic syndrome, a combination of health risks, such as high blood pressure and abdominal obesity. Finding a way to reverse it with a diet people find easy and satisfying would mean huge health improvements for many Americans, Manson said.

Nuts help people feel full while also increasing the body's ability to burn fat, said lead author Dr. Jordi Salas-Salvado of the University of Rovira i Virgili in Reus, Spain.

"Nuts could have an effect on metabolic syndrome by multiple mechanisms," Salas-Salvado said in an e-mail. Nuts are rich in anti-inflammatory substances, such as fiber, and antioxidants, such as vitamin E. They are high in unsaturated fat, a healthier fat known to lower blood triglycerides and increase good cholesterol.

More than 1,200 Spaniards, ranging in age from 55 to 80, were randomly assigned to follow one of three diets. They were followed for a year. The participants had no prior history of heart disease, but some had risk factors including Type 2 diabetes, high blood pressure and abdominal obesity.

At the start, 751 people had metabolic syndrome, about 61 percent, distributed evenly among the three groups.