Climate change tied to over half million stroke deaths globally, study finds

Climate change could be linked to more than half a million deaths from stroke across the globe, a new study suggests.

Over the last three decades, researchers found that non-optimal temperatures across the globe were increasingly linked to death and disability due to stroke.

Majority of these strokes were due to lower than optimal temperatures, according to the first-of-its-kind study, published in the journal Neurology on Wednesday.

Scientists suspect higher blood pressure may be caused by blood vessels constricting with low pressures, contributing to stroke risk.

Researchers also found an increase in strokes tied to higher than optimal temperatures.

Such higher temperatures may cause dehydration, which could affect cholesterol levels and result in slower blood flow – factors that may also lead to stroke.

The study, however, shows only an association and does not prove that climate change causes stroke.

“Our study found that these changing temperatures may increase the burden of stroke worldwide, especially in older populations and areas with more health care disparities,” study co-author Quan Cheng from the Xiangya Hospital Central South University in China said.

In the study, researchers looked at 30 years of health records for more than 200 countries and territories.

They assessed the number of stroke deaths across different regions, countries and territories, and the burden of stroke-related disability due to non-optimal temperatures.

In 2019, more than 521,000 stroke deaths were linked to non-optimal temperatures.

Compared to high temperatures, the study found that more than 474,000 of the total deaths were linked to lower-than-optimal temperatures.

“This is the first study to assess the global stroke burden attributed to nonoptimal temperature. The dramatic increase in the burden due to high temperature requires special attention,” scientists wrote.

Researchers also found that central Asia had the highest death rate for stroke linked to non-optimal temperatures at 18 deaths per 100,000.

“More research is needed to determine the impact of temperature change on stroke and to target solutions to address health inequalities,” Dr Cheng said.

“Future research should aim to reduce this threat by finding effective health policies that address potential causes of climate change, such as the burning of fossil fuels, deforestation and industrial processes,” she added.