Global warming impacts on lactating mammalian milk: A systematic review

Climate change represents a significant loss of billions of dollars for the livestock sector, prompting researchers to investigate how global warming and heat stress impact dairy cow productivity. However, research on the effects of climate change on human health remains a knowledge gap. This systematic review aims to highlight the main findings of the impacts of global warming on the nutritional value of mammalian milk. We systematically reviewed seven databases from October 2024 to April 2025, excluding papers related to seasonal climate effects. Twenty-one eligible studies were selected in our literature review, revealing several contradictory research outcomes. Among 14 studies about the direct impact of climate change on milk protein content, about 86 % reported a reduction in protein concentration. Similarly, among 13 studies on milk fat content, approximately 62 % indicated a reduction in fat concentration. Such a finding suggests a trend but also indicates that further studies are necessary. No paper discussing the effects of climate change on the nutritional quality of human milk was found. Therefore, we emphasize the need for studies on this topic, given the rapid pace of climate change and the vulnerability of particular human groups, including women and newborns in developing countries.