Aging is associated with several changes in brain structure and a gradual decline in cognitive abilities. This decline typically begins in early adulthood, affecting various cognitive functions such as processing speed, memory encoding, working memory, and reasoning skills. In contrast, skills like vocabulary and general knowledge, usually remain stable or even improve until after the age of 60.
Fortunately, the progression of cognitive decline can be significantly influenced by lifestyle choices. Factors like physical activity, social engagement, and dietary habits play pivotal roles in maintaining cognitive health. A recent study has shown that incorporating omega-3 fatty acids into the diet, for instance, is linked to better cognitive functioning, reduced loss of neurons, and improvements in other brain-related measures.
For this study, the research subjects were selected from the Seventh-Day Adventist community, known for their generally healthy lifestyle. Characteristics typical of this group include an active lifestyle, a nutritious diet, and abstaining from smoking and alcohol consumption.
Scientists assessed the levels of omega-3 fatty acids in the participants’ red blood cells, particularly focusing on EPA and DHA. They used this information to calculate the omega-3 index, a measure combining EPA and DHA, intended to reflect the omega-3 content in red blood cells. The investigation included conducting MRI scans and cognitive tests to explore the relationship between these omega-3 levels, brain volume, and cognitive performance.
In their analysis, the researchers identified varied connections between omega-3 fatty acids, cognitive functions, and the size and thickness of different brain regions. They found that both EPA and the overall omega-3 index showed positive associations with delayed memory and processing speed test scores. However, these fatty acids did not demonstrate a significant link with working memory or executive functions.
Contrary to their initial hypotheses, which anticipated a strong link between omega-3 fatty acids and hippocampal volume — crucial for learning and memory — the researchers did not find any significant correlation in this area. Intriguingly, instead of the hippocampus, EPA and the omega-3 index were correlated with the volume of the entorhinal cortex, a region integral to learning and memory that connects with the hippocampus.
Additionally, the study showed that EPA, DHA, and the omega-3 index correlated with an increased volume of total white matter in the brain. Aligning with previous findings, this relationship suggests a possible link between diets rich in omega-3 and both the microstructure of white matter and cognitive functions.
Reflecting the inherent limitations of association studies, the researchers suggest that further, more comprehensive research is needed to explore the connection between omega-3 fatty acids and cognitive abilities. This future research should involve diverse neuroimaging techniques and include a broader and more prolonged observation of participants to deepen the understanding of these relationships.
To view the original scientific study click below:
Omega-3 Fatty Acids, Cognition, and Brain Volume in Older Adults