Newswise — Global warming may increase undernutrition through the effects of heat exposure on people, according to a new study published this week in PLOS Medicine by Yuming Guo of Monash University, Australia, and colleagues.

It has been well documented that global warming will indirectly result in more undernourished people through threatening crop production in the long term. In the new study, researchers analyzed daily hospitalization data that covers nearly 80% of the population of Brazil, spanning the years 2000 through 2015. They studied the link between daily mean temperatures and hospitalization for undernutrition.  

For every 1°C increase in daily mean temperature during the hot season, there was a 2.5% increase in undernutrition hospitalization (OR=1.025, 95% CI 1.020–1.030, p<0.001). People under age 19 years or over age 80 years with undernutrition were the most vulnerable to heat exposure. Overall, heat exposure was estimated to be responsible for 15.6% (95% CI 9.0–21.4) of undernutrition hospitalization during the study period. That fraction increased from 14.1% to 17.5% over the study period, during which time the mean temperature increased by 1.1°C.

“The possible pathways of this direct impact of heat might include reducing undernourished people’s food intake, impairing their digestion and absorption function, and causing fluid and electrolyte disturbances,” the authors say. “Global strategies addressing the syndemic of climate change and undernutrition should not only focus on food supply but also the prevention of heat exposure especially among the young and elderly people.”

Funding:

RX was supported by China Scholarship Council [grant number 201806010405] (https://www.csc.edu.cn/chuguo/s/1267). QZ was supported by a Monash Graduate Scholarship and Monash International Postgraduate Research Scholarship (https://www.monash.edu/graduate-research). SL was supported by the Early Career Fellowship of the Australian National Health and Medical Research Council [grant number APP1109193] (https://www.nhmrc.gov.au/). YG was supported by the Career Development Fellowship of the Australian National Health and Medical Research Council [grant number APP1107107 & APP1163693] (https://www.nhmrc.gov.au/). The funding bodies did not play any role in the study design, data collection, data analyses, results interpretation and writing of this manuscript.

Competing Interests:

I have read the journal's policy and the authors of this manuscript have the following competing interests: YG is a member of the Editorial Board of PLOS Medicine. MA holds investigator-initiated grants from Pfizer and Boehringer-Ingelheim for unrelated research and an unrelated consultancy from Sanofi. The other authors declare no actual or potential competing financial interests.

Citation:

Xu R, Zhao Q, Coelho MSZS, Saldiva PHN, Abramson MJ, Li S, et al. (2019) The association between heat exposure and hospitalization for undernutrition in Brazil during 2000−2015: A nationwide case-crossover study. PLoS Med 16(10): e1002950. https://doi.org/10.1371/journal.pmed.1002950