The Advertising Standards Authority has upheld two complaints against Britain’s biggest organic food certifier, the Soil Association, after it said that organic farming produces healthy food and is more humane to animals.

The complaint was about a leaflet for donations to the Soil Association, which said, “Does your food leave a bad taste? Demonstrate good taste – support the Soil Association.”

The complainant objected to a statement that “organic farming produces healthy food,” because he believed there was no guarantee, whatever the farming method used, that the food would be healthy, the authority said.

The authority considered that the Soil Association had not shown that organically-produced food conveyed noticeable health benefits over and above the same food when conventionally produced or that a diet of organic food could guarantee no harmful effects. It asked the Soil Association to amend the claim.

The authority also upheld a complaint about a claim that organic farming was more humane to animals. The authority considered that the advertisers had not substantiated the claim that organic farming methods were more humane to animals than industrial farming techniques. The authority concluded that the advertisers had not justified the claim and asked them to delete it until they could substantiate it.