A Practitioner

Key Ingredient of Mediterranean Diet Could Be Fibre

NEW YORK (Reuters Health) - People who follow the so-called Mediterranean diet tend to live long lives and have lower than average rates of heart disease--but what are the diet's magic ingredients? Large quantities of antioxidant-rich wine? Preferences for fish full of protective omega-3 fatty acids?

Or, as a group of Spanish researchers propose, lots and lots of fibre.

M. A. Martinez-Gonzalez of the University of Navarre in Pamplona, Spain and colleagues surveyed the diets of a group of Spanish residents and found that people who ate the most fibre were 86% less likely than those who ate the least fibre to suffer a non-fatal heart attack.

Furthermore, the study authors note, this link between high fibre and low risk of heart attack existed independently of other dietary factors that can influence cardiovascular health.

"Our data suggest that a substantial part of the postulated benefits of the Mediterranean diet on coronary risk might be attributed to a high intake of fibre and fruit," Martinez-Gonzalez and colleagues write.

Scientists were first alerted to the possible significance of the diet--rich in vegetables, fruit, grains, wine, olive oil, beans and fish--when they began to notice lower rates of heart disease in Mediterranean populations. In these areas, geographic and agricultural factors have fostered the adoption of diets relatively high in fibre and fatty acids, and low in artery-clogging saturated fats.

Despite the apparent benefits of the diet, the authors of the current report write that relatively few studies of the relationship between nutrition and heart disease have focused on residents of Mediterranean countries.

In response, the researchers conducted nutritional surveys of 171 residents of a local hospital who had suffered their first, non-fatal heart attack, and compared their diets with those of people who had not had a heart attack.

Reporting in the latest issue of the European Journal of Clinical Nutrition, the investigators found that people who ate the most fibre were 86% less likely to have a heart attack than people who reported eating the least fibre. Eating fruit also appeared to cut the risk of heart attack, although the researchers found no relationship between heart attack and vegetable or legume intake.

Many past studies have linked high fibre consumption to a lower-than-average risk of heart disease, Martinez-Gonzalez's team notes.

In the current study, people who ate a lot of fruit appeared to be no better off than those who ate average amounts--at least 250 grams, or around two servings, per day--suggesting that some type of "threshold" exists regarding the benefits of eating fruit, the report indicates.

In addition to adding fibre, fruits may improve health by taking the place of less healthy treats. "The pattern of eating almost exclusively fruit as the dessert after the main meals may explain the high consumption observed in Spain and may have some interesting benefits, such as replacing alternative foods rich in saturated fat," such as ice cream, cakes and cookies, the authors point out.

SOURCE: European Journal of Clinical Nutrition 2002;56:715-722.