An average 138 g of fried food was consumed daily, including 14 g of oil used for frying. About 7% of the total amount of food consumed was fried. Fried food consumption ranged from 0-817 g/day for men and 0-657 g/day for women. Sixty two per cent of participants used olive oil for frying and the rest used sunflower oil or other vegetable oils.
Participants with a higher fried food intake were younger, of a higher level of education, more often smokers, and less often sedentary at work (table 1). Moreover, they had a lower prevalence of diabetes mellitus and hyperlipidaemia, a higher energy and ethanol intake, and a lower consumption of non-fried vegetables, fruit, dried fruit and nuts, milk products, and non-fried fish (table 2). They also had a lower frequency of diagnosed hypertension. Among women, the frequency of menopausal status decreased with the consumption of fried food (table 2).
Table 1 Consumption of fried foods, sociodemographic variables, and lifestyles of study participants at baseline, by quarters of fried food consumption. Values are means unless stated otherwise
Table 2 Morbidity, menopausal status, use of hormone treatment, consumption of non-fried food, and potential mediators of study association among study participants at baseline, by quarters of fried food consumption. Values are means unless stated otherwise (more ...)
During a median follow-up of 11 years, 606 definite coronary heart disease events occurred (466 myocardial infarctions and 140 anginas requiring revascularisation). There were also 712 definite, possible, or probable coronary heart disease events and 1135 deaths from all causes.
For definite coronary heart disease events, no association with fried food consumption was observed in analyses adjusting for energy intake, age, sex, and centre (table 3, model 1). The hazard ratio of coronary heart disease for the highest versus the lowest quarter of fried food consumption was 0.94 (95% confidence interval 0.72 to 1.23; P for trend 0.52). Similar results were obtained after additional adjustment for the main confounders (table 3, model 2): 1.11 (0.84 to 1.46; P for trend 0.60). Finally, no association was observed between fried food and incident coronary heart disease after adjusting for possible mediators such as body mass index, waist circumference, and hypertension (table 3, model 3). Compared with the first (lowest) quarter of fried food consumption, the multivariate hazard ratios of coronary heart disease were 1.15 (0.91 to 1.45) in the second quarter, 1.07 (0.83 to 1.38) in the third quarter, and 1.08 (0.82 to 1.43) in the fourth quarter (P for trend 0.74). Lastly, after full adjustment, a 100 g increase in the consumption of fried food did not show an association with risk of coronary heart disease (hazard ratio 1.00, 0.90 to 1.11). The results were similar after censoring the first two years of follow-up and after excluding those who reported a change in their diet during the previous year. The results did not vary between those who used olive oil for frying and those who used sunflower oil or other vegetable oils (P for interaction 0.22), or between the sexes (P for interaction 0.19).
Table 3 Association between fried food consumption and incidence of definite coronary heart disease and all cause mortality during 11 years of follow-up in Spanish cohort of European Prospective Investigation into Cancer and Nutrition
Similar results were also obtained in the combined analysis of definite, possible, and probable coronary heart disease events. Compared with the first (lowest) quarter of fried food consumption, the multivariate hazard ratio of coronary heart disease in the fully adjusted model (model 3) was 1.08 (0.88 to 1.34) for the second quarter, 1.06 (0.84 to 1.33) for the third quarter, and 1.04 (0.81 to 1.34) for the fourth quarter (P for trend 0.83).
Fried food consumption also failed to be associated with all cause mortality. Compared with the lowest quarter of fried food consumption, those in the highest quarter had a hazard ratio of 0.93 (0.77 to 1.14; P for trend 0.98). Moreover, no association was observed between a 100 g increase in intake of fried food and total mortality (1.00, 0.92 to 1.08; table 3, model 3).
Of the total amount of fried food consumed, 24% (34 g/day) was fish, 22% (31 g/day) meat, 21% (30 g/day) potatoes, and 11% (15 g/day) eggs. No association was observed between each of these fried food groups and incident coronary heart disease (table 4). Comparing the highest and lowest quarters, the multivariate hazard ratio for the fully adjusted model was 1.13 (0.89 to 1.44; P for trend 0.26) for fried fish, 1.09 (0.82 to 1.43; P for trend 0.32) for fried meat, 0.90 (0.70 to 1.15; P for trend 0.45) for fried potatoes, and 0.87 (0.68 to 1.13; P for trend 0.30) for fried eggs. These fried foods also failed to show an association with all cause mortality (table 4).
Table 4 Association between consumption of main types of fried food and incidence of definite coronary heart disease and all cause mortality during 11 years of follow-up in Spanish cohort of European Prospective Investigation into Cancer and Nutrition (more ...)