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 1996 (BSE) crisis.
Design: Repeated population-based survey during 1993, 1994, 1995 and 1996.
Setting: The Bus Santé 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 (+2 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 (+2 56g/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 micrograms/day; men -56 micrograms/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.