The negative effects of red meat on human health and of livestock production on the natural environment are being over-emphasised in the move towards plant-based diets, say researchers at the University of the Free State and the Agricultural Research Council.
The higher absorption and use of nutrients from livestock foods, which “stimulates mental and cognitive development” more than vegetarian or grain-based diets, is being ignored, they wrote in the latest issue of the South African Journal of Science.
A “balanced message” should be conveyed to the broader scientific community and to the public on the role of livestock in meeting global nutritional needs and contributing to global warming, the authors argue.
“The percentage quoted for developed countries indicates the greenhouse gas contribution from livestock is less than 6%, while that for developing countries is 40% to 50%. However, the reason for this relatively low contribution from developed countries is because of very high contributions from other sectors.”
The authors estimate that livestock is responsible for only 4% of the world’s greenhouse gas emissions through methane production.
In sub-Saharan Africa ruminants are important in human diets, with foods from animal sources essential to support early childhood and cognitive development.
“Many rural households depend on ruminants and these animals are central to the livelihoods and well-being of these communities,” they write. “Millions of children in developed countries already suffer from impaired cognitive development from poor nutrition due to the insufficient consumption of livestock source foods.”
But a recent report by the EAT-Lancet Commission focuses on a diet of vegetables, fruits, whole grain, legumes, nuts and unsaturated oils, some seafood and poultry and little to no red meat, processed meat, added sugar, refined grains and starchy vegetables.
The World Wide Fund for Nature (WWF), which last week launched its plant-based diet, building on the work of EAT-Lancet, says plant-based diets can globally cut food-based greenhouse gas emissions by 30%, wildlife losses by up to 46%, agricultural land-use to about 40% and premature deaths by 20%.
But, says Tatjana von Bormann of WWF South Africa, the push away from a meat-based diet has potentially “under-recognised” effects, particularly on small-scale livestock producers and land use.