A Swiss population-based assessment of dietary habits before and after the March 1996 'mad cow disease' crisis

Objective: To assess differences in dietary habits in the general population of Geneva, Switzerland, after the 1995 (BSE) crisis. Design: Repeated population-based survey during 1993, 1994, 1995 and 1996. Setting: The Bus Sante 2000 epidemiological observatory of Geneva, Switzerland. Subjects: A representative sample of 1190 men and 1154 women. Main outcome measure: Dietary habits assessed by a semi-quantitative food frequency questionnaire. Results: The proportion of women who reported not having eaten beef was 7.7% in 1993-1995 and went up to 14.6% in 1996 (age-adjusted difference + 6.4%, 95% CI + 2.4 to + 10.4). Among men, the proportion of non-beef-eaters remained constant (5%). There was a sharp increase of women who did not eat liver (+ 14.7%, + 9.1 to + 20.3) but less so in men (++ 5.1%, - 0.7 to + 10.8). Among women who ate meat, the amount of beef intake decreased by 120 g/month (95% CI - 208 to - 36). While chicken intake increased (+ 44 g/month, - 2 to 88), overall intake of meat (including poultry but not fish) declined by 204 g/month (or 2.7 kg per year). In men the decrease in beef intake was not statistically significant (- 48 g/month, - 172 to 80), but consumption of chicken increased (++ 56 g/month, + 8 to + 104). Fish intake was stable in both genders. The reduction in intake of animal protein (- 3.5 g/day) in women and of retinol intake in both sexes (women - 77 μg/day; men - 56 μg/day) was statistically significant. Conclusions: The BSE crisis coincided with spontaneous differences in food habits, especially in women, that may have nutritional consequences at the population level.