Omega-3 fatty acids are a well-known nutrient, found in various cold-water fish (such as tuna, mackerel and sardines), nuts and leafy vegetables. It is often said how they are ‘good for your brain’, but is this true? How exactly do they improve cognitive health and wellbeing? A study published on 5th October provides insight into the impact on the brain areas and neurotransmitters involved in memory, learning and mood.
New evidence, published in the medical journal of the American Academy of Neurology, suggests that eating more omega-3 fatty acids increases the size of certain brain areas, leading to better cognitive function (including memory) when aged 40-50 years. .
In this recent experiment, the average age of participants was 46, including some volunteers with the gene, APOE4, that is linked to a higher chance of developing Alzheimer’s disease. Researchers looked at the link between a range of Omega-3 fatty acid concentrations in red blood cells with MRI scans involving cognitive markers of brain aging.
There were different categories within the 2,183 people tested, those with little Omega-3 fatty acids in their system compared to those with much higher levels. Interestingly, it was found that a higher level of Omega-3 fatty acids corresponded to a larger hippocampal volume in the brain. The hippocampus, in the temporal lobe, is responsible for functions such as memory and learning.
Specifically, the hippocampus helps us to recall certain types of important information, namely declarative relationships and spatial memory. This involves instances such as learning lines for a play, or certain everyday routes to travel to a destination. Damage to this area of the brain can result in numerous psychological disorders, such as amnesia (memory loss) and Alzheimer’s disease (the specific degenerative brain disease that causes dementia).
Results showed that consuming more Omega-3 fatty acids boosts abstract reasoning, and the ability to understand complex concepts with the help of logical reasoning. It is thought that this could link to the levels of intelligence as well as the speed of informational processing. However, critiques of this study say that more tests need to be conducted with a younger group of participants, to see the cognitive changes over time.
Omega-3 fatty acids contain various micronutrients that “enhance and protect the brain” (study coauthor, Debora Melo van Lent), such as EPA and DHA. Further details as to how these micronutrients protect the brain is open for debate. Current scientific theories include the need for fatty acids in the neuronal membranes; when these are replaced with other types of fatty acid, it can make the neuron (nerve cell) unstable. Strengthening the neuronal cell membranes can improve connectivity and communication between neurons, which may increase the rate of signaling and mental processing throughout the entire brain. These micronutrients are said to increase serotonin production, leading to a happier mood, reduced stress and less impulsive behaviour. The anti-inflammatory nature of EPA and DHA is thought to link to mental health conditions as well as neurodegenerative disorders.
This anti-inflammatory property of Omega-3 fatty acids has been a part of previous research, namely for certain mental health conditions such as depression. These molecules can easily diffuse through the neuronal membranes, to potentially interfere with mood-related neurotransmitters (such as dopamine and serotonin), and cause more to be transmitted. This may enhance overall feelings of happiness and mental wellbeing. Omega-3 oil pills are often prescribed in combination with serotonin reuptake inhibitors to combat the symptoms of depression.
This poignant study seems to have revealed the neuroscientific benefits of incorporating Omega-3 fatty acids into your diet, even if the specific details as to why are open to debate and further psychological research. It is clear that there are mental and physical health benefits, as well as reducing the chance of developing Alzheimer’s disease through protecting the hippocampus.
Featured image by Robina Weermeijer on Unsplash