Here is the study:
Cell Metabolism - Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population
Just a quick look over it and I see this: The study indicates that for those OVER 65 a low protein diet INCREASE cancer mortality and overall mortality... the opposite in what was reported in the age 50-65 population.
They also only used a single 24 hour dietary recall, rather than a longitudinal anysis... and participants self reported. They used this dietary recall from ONE 24 hours period as the standard for what that person ate every day.
I'm not scientist...and far from an expert at validating the legitimacy of a study, but not taking into consideration the types of foods each person ate to get their protein would make a significant impact. To just say protein is at fault is completely bogus. These people are not reporting where they got their proteins from. Is is fatty burger? Bacon? Fried chicken? I would highly doubt lean sources of protein combined with a diet of heart healthy fats and nutrient rich carb sources in moderation would yield such a result.
Yeah, bodybuilders may do some unhealthy things with their bodies, but one we do know is how to optimize is a diet. With the knowledge we have available from some of the incredible coaches on this board, we have the knowledge to design a diet that both optimizes performance and health...
EDIT: Hey, hopefully this makes people scared of meat, which would drive down demand and thus decrease the cost of meats! One could only hope...