No, standard scientific procedure is to include controls for that kind of thing. So you don't compare young health nuts with the general population; you compare young health nuts who happen to be vegetarian with young health nuts who eat some red meat.
From a systematic review published in the American Journal of Clinical Nutrition in 2009 (Am J Clin Nutr May 2009 vol. 89 no. 5 1607S-1612S):
"There is convincing evidence that vegetarians have lower rates of coronary heart disease, largely explained by low LDL cholesterol, probable lower rates of hypertension and diabetes mellitus, and lower prevalence of obesity. Overall, their cancer rates appear to be moderately lower than others living in the same communities, and life expectancy appears to be greater. However, results for specific cancers are much less convincing and require more study. There is evidence that risk of colorectal cancer is lower in vegetarians and in those who eat less meat; however, results from British vegetarians presently disagree, and this needs explanation. It is probable that using the label “vegetarian” as a dietary category is too broad and that our understanding will be served well by dividing vegetarians into more descriptive subtypes. Although vegetarian diets are healthful and are associated with lower risk of several chronic diseases, different types of vegetarians may not experience the same effects on health."
From the published Position of the American Dietetic Association on vegetarian diets (Journal of the American Dietetic Association [2009, 109(7):1266-1282])
"It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. [....] Vegetarians also appear to have lower low-density lipoprotein cholesterol levels, lower blood pressure, and lower rates of hypertension and type 2 diabetes than nonvegetarians. Furthermore, vegetarians tend to have a lower body mass index and lower overall cancer rates."
Is this all screaming that meat is bad for you? Not at all. The point is that the argument has merit, if not proven. So, as I originally stated, for some people it is problematic.
My searches didn't yield more recent publications discrediting the studies up until 2009, but if you are aware of them by all means I am curious.