Women face higher risk of cognitive decline from polluting cooking fuels: IISc brain scan study

Women exposed to household air pollution from cooking fuels may be at a higher risk of cognitive impairment than men, a study by the Indian Institute of Science (IISc) in Bengaluru has found.

The study, published in The Lancet Regional Health Southeast Asia journal, analysed MRI brain scans of ageing adults in the rural town of Srinivaspura in Karnataka, revealing that women might be at a higher risk of experiencing adverse effects in the brain.

A team, which also included researchers from the University of Chicago, US, explained that burning solid fuels for cooking, especially in poorly ventilated spaces, can release air pollutants, such as oxides of carbon, nitrogen, sulphur and heavy metals, along with suspended particulate matter.

The pollutants have been shown to affect the brain through varied mechanisms, primary ones being inflammation and oxidative stress, they said.

The researchers analysed more than 4,100 adults aged 45 and above, who are participants of the ongoing Centre for Brain Research-Srinivaspura Aging, Neuro Senescence, and COGnition (CBR-SANSCOG) study at IISc. MRI brain scans were taken for around a thousand of these participants.

Cognitive impairment, they explained, affects memory, reasoning, and speech. It may precede conditions like dementia and Alzheimer’s disease — in which the affected person faces trouble performing daily routine activities.

The study’s authors wrote, “Polluting cooking technology users may be at a higher risk for cognitive impairment. Rural females, who tend to be more exposed than males, could have greater vulnerability to (household air pollution’s) adverse effects on the brain.”

Given the increasing burden of dementia — an ageing-related disorder — in India, the findings have significant implications for public health, providing insights on how household air pollution can influence dementia risk, the team said.

“Policies promoting clean cooking fuel (or) technology adoption are imperative,” they wrote.

They added that the findings support those from previous studies which showed a lowered cognition and ability to process visual information in space among people using polluting cooking technology.

Further, upon analysing the MRI brain scans of women, the team found lower volumes of hippocampus — a brain region critical for memory and known to be significantly impacted in Alzheimer’s disease.

Overall, the study broadens the understanding of how pollution-causing cooking fuel is related with poor cognition, the authors said.

“Community-centred interventions to improve health literacy and clean cooking fuel adoption among rural Indians, could help reduce the substantial morbidities associated with polluting cooking fuel use, and reduce dementia risk,” they said.

The study is the only one to employ brain scanning techniques in a rural population to examine how household air pollution can adversely impact the brain structurally, the authors said.