Like claims for defamation or commercial disparagement, Lanham Act claims are viable only if they involve statements of fact, rather than opinion. But what happens if an advertising statement concerns an issue that is a matter of scientific debate? Does that make the statement an opinion, and therefore non-actionable? The answer, of course, is “it depends” — as illustrated by a recent Fifth Circuit case, and how it distinguished itself from a Second Circuit case with a different outcome.… More