Role of fibre and fruit in the Mediterranean diet to protect against myocardial infarction: a case–control study in Spain

Objective To assess the association between a first acute myocardial infarction and the consumption of fibre and fruit.Design Hospital-based case-control study with incident cases. A validated semi-quantitative food frequency questionnaire (136 items) was used to assess food intake.Setting Three third-level university hospitals in Pamplona (Spain).Subjects Cases were subjects aged under 80, newly diagnosed with acute myocardial infarction. Each case patient (n=171) was matched to a control subject of the same gender and age (5 y bands) admitted to the same hospital.Results An inverse association was apparent for the three upper quintiles of fibre intake. After adjustment for non-dietary and dietary confounders, an inverse linear trend was clearly significant, showing the highest relative reduction of risk (86%) for the fifth quintile (OR=0.14, 95% confidence interval: 0.03-0.67). An inverse association was also apparent for fruit intake, but not for vegetables or legumes.Conclusions 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.