Khaberni - A new study revealed that using a home air purifier equipped with a HEPA filter for just one month can improve some brain functions in adults aged over 40.
HEPA air purifiers, an acronym for "High Efficiency Particulate Air," are used to remove fine particles suspended in the air inside homes. These particles, often resulting from car exhaust and traffic pollution, are associated with an increased risk of respiratory and cardiovascular diseases, as well as neurological diseases such as Alzheimer's and Parkinson's.
Although environmental health experts increasingly recommend using these devices to reduce exposure to air pollution, studies that directly investigated their impact on cognitive abilities are still limited, especially among people living near highways and areas with heavy traffic.
The study relied on analyzing data from 119 individuals aged between 30 and 74 years, living in Somerville, Massachusetts, a city known for its high levels of air pollution due to its proximity to Highway 93 and Route 28, which are major congested roads.
The researchers randomly divided the participants into two groups; the first group used a real air purifier equipped with a HEPA filter for a month, then used a placebo device for another month—a device similar in shape and performance but without an air-purifying filter, with a rest period between the two phases. The second group used the devices in the reverse order.
After each phase, the participants underwent tests to measure several cognitive functions, such as visual memory, motor speed, executive functions, and mental flexibility—skills associated with concentration, thought organization, responsiveness, and decision-making.
The results showed that participants aged 40 and over, about 42% of the study sample, were able to perform the mental flexibility and executive function tests 12% faster after using the air purifier equipped with a HEPA filter, compared to using the placebo device.
The researchers confirmed that this improvement remained consistent even after accounting for other factors that might affect the results, such as how much time participants spent indoors or the level of stress they felt during testing.
Although the improvement rate seems limited, the researchers clarified that it roughly equals the cognitive benefits derived from increasing daily physical activity, pointing out that prevention from cognitive decline—even if slight—is very important in the long term, as any minor decline in mental performance could be associated with an increased risk of serious health problems, and even an increased death risk.
The researchers highlight that individuals living near highways or main roads are exposed to higher levels of air pollution, and they have higher rates of diseases associated with it.
There are still unanswered questions, including whether the benefits could be greater for older adults, as the number of participants over sixty in the study was very limited, and whether using air purifiers for longer periods might lead to better and more sustainable results.
The researchers are also seeking to understand how these devices affect the brain, as previous studies suggest that fine particles could negatively affect the "white matter" in the brain, which is responsible for transmitting nerve signals and maintaining communication between different brain areas.
The research team plans to continue studying this relationship to find out whether reducing fine particles inside homes can actually protect the brain and help reduce cognitive decline associated with air pollution.
