A recent study published in Nutritional Neuroscience has found that greater adherence to the Mediterranean diet is linked to a reduced risk of cognitive decline among elderly individuals. Conducted over a three-year period, the research highlights that this association is particularly significant for women aged 65 and older. The findings add to the growing body of evidence suggesting that diet can play a crucial role in maintaining cognitive health.
The Mediterranean diet is characterized by high consumption of fruits, vegetables, whole grains, legumes, nuts, and olive oil, moderate intake of fish and poultry, and low intake of dairy products, red meat, and sweets. This diet is known for its rich antioxidant content, which helps combat oxidative stress—a harmful process that can lead to brain aging and neurodegenerative diseases such as Alzheimer’s.
The researchers conducted this study to investigate whether the Mediterranean diet could help prevent cognitive decline in elderly people. With the global rise in dementia and no effective medications to prevent or treat it, exploring modifiable lifestyle factors like diet is crucial.
Previous studies have shown mixed results on the impact of the Mediterranean diet on cognitive health, with some suggesting significant benefits while others found no effect. This study aimed to provide more definitive answers by focusing on a rural Chinese population, a group that has not been extensively studied in this context.
The study was conducted in Gansu Province, China, from January 2019 to March 2022. The researchers used a multi-stage stratified sampling technique to select participants from various administrative divisions, including prefectures, counties, townships, and villages. Participants had to be over 60 years old, live in a village for more than a year, and be cognitively normal at the beginning of the study. They excluded individuals with a history of stroke, severe psychiatric disorders, or major organ dysfunction.
At the start, 3241 individuals were assessed, but only 2313 who met all criteria were included in the study. After three years, 1648 participants completed the follow-up assessments. The study involved face-to-face interviews to gather information on participants’ demographics, lifestyle, medical history, and psychological factors.
Cognitive function was measured using the Mini-Mental State Examination, a widely used test that assesses various cognitive abilities including memory, attention, and language skills. Adherence to the Mediterranean diet was evaluated using the Mediterranean Diet Adherence Screener, which asks about dietary habits related to key components of the diet.
Over the three-year follow-up, 23.8% of participants experienced cognitive decline. The study found that those with higher adherence to the Mediterranean diet had a lower risk of cognitive decline. Specifically, 20.6% of participants with low adherence to the diet experienced cognitive decline, compared to 20.4% of those with high adherence. This difference, while small, was statistically significant.
Further analysis showed that the protective effect of the Mediterranean diet was particularly pronounced in women aged 65 and older. In this group, higher adherence to the diet was associated with a significantly lower risk of cognitive decline.
The study also examined which components of the Mediterranean diet were most strongly linked to cognitive health. It found that higher consumption of beans, fish, and cooked vegetables with tomato-based sauces were particularly protective against cognitive decline. These foods are rich in antioxidants and anti-inflammatory substances, which may help protect the brain from damage.
However, the study also has some limitations. The researchers only measured diet adherence at the beginning of the study and did not account for changes over time. Additionally, the study focused on a rural Chinese population, which may limit the generalizability of the findings to other groups. Future research should include longer follow-up periods and multiple measurements of diet adherence to better understand how dietary habits impact cognitive health over time.
The study, “Mediterranean diet related to 3-year incidence of cognitive decline: results from a cohort study in Chinese rural elders,” was authored by Yuping Feng, Jiancheng Wang, Rong Zhang, Yunhua Wang, Jing Wang, Hongyan Meng, Hu Cheng, and Juxia Zhang.
