PURPOSE: To determine the effects of average alcohol consumption and changes in alcohol intake on the insulin resistance syndrome parameters in a 3-year follow-up study. METHODS: Longitudinal study of 1856 and 1529 alcohol drinking men and women in the French DESIR study (Data from an Epidemiological Study on the Insulin Resistance syndrome), aged 30 to 64 years. RESULTS: In men, fasting glucose, body mass index, waist circumference, systolic blood pressure, and HDL-cholesterol were positively associated with average alcohol consumption while there was no association with insulin or triglycerides concentrations. A change in alcohol intake was positively associated with HDL-cholesterol concentration and systolic blood pressure at follow-up. These effects of alcohol could not be attributed specifically to the intake of wine. In women, while the alcohol HDL-cholesterol relation was similar to that found in the men, the only significant effect of average alcohol intake was an increase in systolic blood pressure, with a spurious decrease in blood pressure related to a 3-year increase in alcohol intake. CONCLUSIONS: Alcohol only provided a beneficial effect on HDL-cholesterol. The beneficial effect seen by other authors of moderate alcohol drinking on diabetes and cardiovascular risk may be due to effects on parameters other than those included in the current definitions of the insulin resistance syndrome.