Dietary patterns and the risk of acute myocardial infarction in 52 countries: results of the INTERHEART study.

Description

The INTERHEART study had already reported that the consumption of fruits and vegetables was an independent modifiable risk factor for myocardial infarction (MI). This post-hoc analysis from the INTERHEART study examined the association of three different dietary patterns and MI. Using factor analysis, the three patterns identified were 1- Oriental (high intake of tofu and soy and other sauces), 2- Western (high in fried foods, salty snacks, eggs and meat), and 3- prudent (high in fruits and vegetables). An inverse relationship between the prudent pattern and MI was observed: a high intake of fruits and vegetables was cardioprotective. A U-shaped association between the Western pattern and MI was demonstrated while there was no relationship between the Oriental pattern and MI. Moreover, a dietary risk score was computed from meat, salty snacks, fried foods, fruits, green leafy vegetables, cooked vegetables, and other raw vegetables (the higher score indicated the poorer diet). There was a linear positive relationship between the dietary risk score and MI. Finally, an unhealthy dietary pattern, as assessed by the dietary risk score, accounted for 30% of the population-attributable risk. Frank B. Hu wrote an editorial on the INTERHEART subanalysis and recognized that the study by Iqbal et al. was the first large study to quantify eating patterns in all geographic regions of the world and involving different cultures. As a retrospective case-control trial, however, Hu mentioned that a recall bias may have occurred. For instance, because of an incident MI event or intermediate conditions, a patient may have changed his/her diet or may not have reported the exact dietary habits. Moreover, the food-frequency questionnaire had been simplified to shorten interview time and lack of detailed information on foods also made it difficult to appropriately characterize dietary patterns. Hu concluded that encouraging individual behavioural changes alone is unlikely to fight globalization’s powerful effect on food patterns.