Cow’s milk … blamed for autism. Shutterstock
The animal rights charity PETA recently made a link between autism and drinking cow’s milk. The article on its website discussed research that linked a dairy-free diet with a reduction in symptoms of autism in children. The charity cited two particular research projects which suggest a link between drinking cow’s milk and autism. It was originally released a few years ago, but has recently been relaunched on social media causing much discussion.
The research that underpins PETA’s claim is based on two small-scale studies. One was a “blind” study of 20 children, half of whom were given a diet free from gluten and casein – a protein found in mammalian milk – and half who had an unchanged diet. The children were observed for a year and the study concluded that the development of the children in the experimental group was significantly better than the control.
The second study similarly concluded that there may be a link between allergies, such as to cow’s milk, and autism. But both studies are based on very small numbers of children and while they suggest a potential link they do not conclude that an allergy to cow’s milk or gluten causes autism.
There is a long tradition of linking particular behaviours, diets, or public health measures to the development of autism. The most reported, and controversial, link was between the MMR vaccine and development of autism. In 1998, a research paper was published that suggested that the “triple” vaccine against MMR (measles, mumps and rubella) can cause autism in some children.
This has been discredited and widely disproved in medical science research. But the impact of this style of reporting scientific research continues.