A theory on popular media: the more popular it is, the less the information it provides bears any semblance to accuracy, truth, or scientific fact. As the audience size grows - meaning that any given topic is going to be far outside the specialty knowledge of nearly all of the audience members - any urge to accuracy is completely subsumed by the need for do and say things that will keep that audience's fleeting attention. I think this principle is fairly well illustrated by Oprah and company's present examination of calorie restriction and some related topics in medical research in the context of enhanced human longevity.

There's a style to this sort of thing, in which the presenters construct a framework for their article or show that ostensibly bears some semblance to the underlying reality under discussion, but within which a majority of the "facts" provided are simply wrong, chosen for their ability to grasp attention rather than any scientific backing they may have.

Hence for a discussion of longevity, wild and unsupported claims are fair game. At the present time, the scientific consensus is that human practice of calorie restriction will not greatly enhance maximum longevity, but does greatly improve health and greatly reduce risk of age-related disease. That isn't as exciting, however, as earlier speculation on attaining 120 year or more life spans, so the more exciting "fact" is what gets aired:

Dr. Oz says calorie restriction is the number one way doctors say we can extend longevity. "The data that we have in rodents and some larger animals now indicate you can probably extend your life expectancy by up to 50 percent potentially from doing this," he says.

Freedom of speech bears just as much of an implied caveat emptor for the listener as any other freedom. Expect people to lie to you (by omission, laziness, or more direct motives) when it serves their own self-interest more than telling you the truth - which is the case for almost all popular media serving large audiences.