Uluc,

Of course you are correct that correlation does not imply causation.  
I was not trying to imply that vegetarians are healthier than non- 
vegetarians because they don't eat meat. Rather, I was trying to say  
(but perhaps I didn't do a good job at it) that it is possible to eat  
healthy diet which includes animal products and also one which does  
not include animal products. I do not have data on hand to back this  
up right now, but I do feel that vegetarians generally pay more  
attention to what they eat than most non-vegetarians, and therefore  
end up eating healthier. There are of course many additional factors  
that contribute to health, and it is also difficult to measure	
healthiness. I don't have any personal stake in it, but I will once  
again plug "Becoming Vegan". In this book there are several studies  
which find lower rates of certain diseases in vegetarians than in non- 
vegetarians. A complicating factor though, is that some of the	
comparisons are between completely different populations, e.g.	
Asians, who have traditionally consumed few dairy products, and  
Western Europeans. As you say, there are many confounding factors  
which could be at play.

Rob
On May 23, 2007, at 11:57 AM, Uluc Saranli wrote:

>
>> ... However, one must also keep in mind that comparisons between  
>> vegetarians and meat-eaters should be made comparing average  
>> health of vegetarians to average health of meat-eaters, and many  
>> such studies show vegetarians to be healthier overall than omnivores.
>
> I want to point out that this argument is on logically shaky	
> grounds since correlation does not imply causation (http:// 
> en.wikipedia.org/wiki/Correlation_does_not_imply_causation). There  
> may be numerous other reasons behind the better health of  
> vegetarians not directly related to their diet such as their	
> overall lifestyles, etc. Such comparisons rarely yield conclusive  
> information about the actual causal relation between two phenomena.
>
> - Uluc
>
>