French men might eat more fat or do other things that increase heart disease. So, the men’s higher rate of heart disease compared to women doesn’t undermine the theory that red wine consumption helps reduce the rate of heart disease.

This points out that an increase in red wine consumption could lead to other health problems that might outweigh the benefit of lower heart disease. Thus, drinking more red wine might not make North Americans healthier.

The author never suggested every person in France has the kind of diet described. On average, the French have a low rate of heart disease, a diet high in fat, and a high quantity of red wine. Some people might have a different diet, but that doesn’t change the overall average.

The author never suggested drinking red wine is the best way to reduce heart disease. Pointing out that there’s a better way to reduce heart disease doesn’t undermine the position that drinking red wine can be one way to reduce heart disease.

The reason the author cites to France is that they, on average, have a diet high in fat. If other regions have lower rates of heart disease, it could be that they don’t eat as much fat, or do other things to reduce heart disease besides red wine.