UK bans ‘misleading’ vegan ad ‘linking cow’s milk to cancer’

An advertisement campaign initiated by a UK vegan group has been banned by UK authorities for falsely linking cow’s milk to cancer.

The campaign – launched by vegan group ‘Viva!‘ last September in Bristol, England – resulted in banners appearing on buses with messages claiming the following:

“Some dairy industry facts we bet you don’t know…Most cows are pregnant when milking. That’s why milk contains 35 hormones, including oestrogen…some of these are linked to cancer. Milk is for babies, so let Viva! wean you off the teat!”

According to the UK Advertising Standards Authority (ASA), two people lodged complaints against the adverts stating that the above claims were misleading as they implied that cow’s milk could cause cancer.

In attempting to defend its posters, Viva! said the claim referred to hormones that were naturally occurring in cow’s milk, which increased during pregnancy and were essential for calf development.

The claim did not refer to hormone treatments or artificial hormones, the ASA was told.

Image source: Viva! website

According to the UK authority, the group highlighted that the ad stated the hormones were “linked to” cancer, rather than that they “caused” cancer.

It said “linked to” was wording commonly used to express an association between two factors when there was a potential, or likely relationship; but not an absolute causative relationship.

The group suggested that consumers were used to seeing the phrase “linked to” as opposed to “causes” in that context.

In support of the claim, the group referred to a range of papers, which they believed demonstrated the presence of over 35 hormones in cow’s milk.


However, the complaints were upheld.

While the claim stated that some hormones in cow’s milk were “linked” to cancer rather than definitively stating that they caused cancer, the ASA considered that 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.

In a statement the ASA said: “The claim did not itself make clear whether it related to naturally occurring hormones and/or to artificial hormones”.

We considered that 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.

“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 ASA stated.

The authority ruled that 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.