Global warming is likely to increase illnesses caused by undernutrition, due to heat exposure, say Monash University researchers.
While it’s known global warming will indirectly result in more undernourished people through threatened crop production and increased food insecurity, the world-first study analysed the link between heat exposure and increased undernourishment illness.
The researchers, led by Yuming Guo, Associate Professor of Environmental Epidemiology and Biostatistics in the School of Public Health and Preventive Medicine, analysed daily hospitalisation data covering almost 80 per cent of Brazil between 2000 and 2015. In particular, they studied the link between daily mean temperatures and hospitalisation for undernourishment according to the International Classification of Diseases.
The results showed for every 1°C increase in daily mean temperature during the hot season, there was a 2.5 per cent increase in the number of hospitalisations for undernutrition.
“The association between increased heat and hospitalisation for undernutrition was greatest for individuals aged over 80, and those five to 19 years,” the researchers said.
“We estimated that 15.6 per cent of undernutrition hospitalisations could be attributed to heat exposure during the study period.”
The study states increased heat may cause illness through undernourishment in a number of ways:
- Reduced appetite.
- Increased alcohol consumption.
- Reduced motivation or ability to shop and cook.
- Exacerbation of any undernutrition.
- Worsening already impaired digestion and absorption by increasing gastrointestinal morbidity.
- Impaired thermoregulation.
The study, published this week in PLOS Medicine, highlights the growing problem of undernutrition as a result of global warming.
“Climate change is one of the biggest threats to the reduction of hunger and undernutrition, especially in low and middle-income countries,” the report said. “It has been estimated that climate change will reduce global food availability by 3.2 per cent and thus cause about 30,000 underweight-related deaths by 2050.
“However, this may actually underestimate the real effect of climate change on future undernutrition-related morbidity and mortality, because it overlooks the direct and short-term effects of temperature rise.
“It is plausible to speculate that climate changes could not only increase the rate of undernutrition in the most affected areas of the globe, but at the same time impair individuals’ capacity to adapt to projected rises in temperature.”
The report says global strategies addressing the syndemic of climate change and undernutrition should not only focus on food systems, but also on the prevention of heat exposure.