is it correct?

I think that this is one of those very vague and misleading statements which needs a lot more clarification. Oven cookery can be done at many temperatures and possibly whatever truth is behind this statement refers to roasting at high temperatures. When food is roasted to give a browned outside or top to the dish, the browning can produce carcinogens if the food is cooked too much. On the other hand, the browned outside of roasted meat also adds flavour, so it is important not to overcook food. The same thing happens, of course, on a flame grill or barbecue and too much burning or browning is not a good thing. Cooking a dish, such as a casserole, in a slow oven is a very healthy way of cooking because the food is thoroughly cooked and not overheated. Slow cooking like this, especially in acid sauces (like adobo or tomato recipes) tends to break down the fibres of meat and make it more digestible.

three years later for goodness sake do not believe everythin yhou read on the net. no oven cooked food is not bad for your health if its healthy food to start with .cooking in the oven does not make it unhealthy what a crock of s.h.i.t that is. where do you get these cockamamie ideas as that really a vague and stupid statement to begin with.