It is an illness that affects many elderly people: cognitive decline. It is characterized by the loss of Memoryspeech or difficulty recognizing loved ones. This is one of the main causes of loss of autonomy. It is therefore essential to discover habits that can delay it.
Previous research has already highlighted several habits that help protect the brain. These include:physical activityan active lifestyle or even regular consumption ofolive oil or fish, particularly as part of a Mediterranean diet.
More recently, researchers from the School of Public Health in the United States have been interested in where people live and its impact on cognitive decline. They have noticed that living in a neighborhood with green spaces can significantly reduce the level of cognitive decline, particularly in “mid-life,” around the age of 50. Their results are published in the journal Environmental Health Perspectives.
Living in a green neighborhood could reduce cognitive decline
To reach these conclusions, the researchers based their findings on a study on the health of nurses conducted in the United States in 1976. The participants provided certain information, including their lifestyle and address. These specialists analyzed the presence of green spaces in the neighborhoods where the volunteers lived. The study panel consisted of 16,962 nurses aged at least 70.
Then, the researchers calculated the cognitive decline participants using five sets of tests carried out four times between 1995 and 2001. In addition, the specialists knew which participants carried the APOE-ɛ4 gene, “a variant of the APOE gene that is a major risk factor for Alzheimer’s disease”. The authors of the study explain that in the methodology they took into account certain factors such as age, level of education and mental health history, in particular the Depression.
Researchers call for greening cities
While the researchers found that all participants showed cognitive decline over time, they noted that “Exposure to greenery in midlife was associated with slower annual rates of cognitive decline”. More precisely, “Higher average exposure to greenery in midlife was linked to higher levels of cognitive function as well as slower cognitive decline,” note the authors.
The beneficial effects of contact with greenery were also visible in people at risk of Alzheimer’s disease, “APOE-ɛ4 carriers exposed to more greenery had cognitive decline three times slower than people without the gene,” experts note.
In contrast, people living in urban, densely populated areas had more pronounced cognitive decline. “Importantly, this association was stronger for participants living in low socioeconomic status and high population density neighborhoods.”the researchers note.
“The results highlight the importance of prioritizing the preservation and creation of green spaces, particularly in low socioeconomic status neighborhoods, to promote cognitive health in later life.”concluded in the press release Marcia Pescador Jimenez, assistant professor of epidemiology and co-author of the study.
Sources :
- Living in Greener Neighborhoods during Midlife May Slow Cognitive Decline – School of Public Health (communiqué) 17/07/2024
- Midlife Residential Greenness and Late-Life Cognitive Decline among Nurses’ Health Study Participants – Environmental Health Perspectives (juillet 2024)
