The Advertising Standards Authority (ASA) has told a vegan pressure group to stop its adverts which implied that drinking cow’s milk could cause cancer.
The ASA's ruling stems from vegan campaign group Viva! advert, regarding the claim “Most cows are pregnant when milking. That’s why milk contains 35 hormones, including oestrogen…some of these are linked to cancer.”
Two complainants contacted the advert regulator and challenged it, asking whether the implied claim was misleading and could be substantiated.
Viva!, whose advert appeared on the sides of buses in Bristol during 7 and 8 September 2017, defended the claim and said it is "backed with scientific evidence".
The group said the advert says "linked to" and is not the same as "causes". It says other organisations, such as the WHO, use the word "linked to" when talking about cancer and in text aimed at the general public.
But ASA said consumers would nonetheless interpret it to mean that because of the hormones that were present in cow’s milk, drinking cow’s milk could increase a person’s risk of developing cancer.
The regulator said the claim did not itself make clear whether it related to naturally occurring hormones or to artificial hormones.
'Misleading'
ASA said consumers were likely to understand from the context of the ad as a whole, which focused on calves and pregnant cows, that the claim related to the naturally occurring hormones that were present in cow’s milk.
It said in a statement: "We considered that such a claim must be substantiated by robust evidence that demonstrated a link between the naturally occurring hormones in cow’s milk with incidences of cancer in human populations.
"We therefore concluded the claim “milk contains 35 hormones, including oestrogen … some of these are linked to cancer”, as it would be understood by consumers to mean that due to the presence of hormones, drinking cow’s milk could increase a person’s risk of developing cancer, had not been substantiated and was therefore misleading.
"The ad must not appear again in the form complained about. We told Viva! not to make claims which stated or implied that due to the presence of hormones, drinking cow’s milk could increase a person’s risk of developing cancer."
