Federal regulators on Monday sued the maker of a popular pomegranate fruit drink, POM Wonderful LLC, in a widening effort by the government to clamp down on food ads that tout specific health benefits.

The Federal Trade Commission's suit alleges that Pom's advertisements for POM Wonderful 100% Pomegranate Juice and its POMx supplements contain "false and unsubstantiated claims" about treating or preventing heart disease, prostate cancer and erectile dysfunction.

One...