One person complained that the ad, which urged members of the public to opt for vegetarianism, could cause people to worry unnecessarily about how they might contract the disease.
Peta said the ad served to highlight the role livestock production played in the incubation, development and transmission of infectious diseases, including E.Coli, mad cow disease, MRSA and swine flu.
The charity felt consumers would understand, from government information and media coverage, that swine flu, like MRSA, was more commonly passed from human to human.
The ASA noted the diseases listed in the ad, two of which were known to originate from eating meat and two which were not.
The watchdog considered that readers of the ad could conclude that they could contract swine flu as a direct result of eating meat and concluded the ad was likely to mislead and cause undue distress to some readers.
The ad must not appear again in its current format.