What is brain health
The brain is the most significant and complex organ of the human body. Increasingly, we are becoming aware that certain nutrients may help to safeguard brain health, which refers to the ability to concentrate, remember, learn, play and maintain a clear and active mind.
- It is now recognised that a healthy brain is needed to live a fuller and longer life.
- Brain health supports human thoughts, planned actions and emotional connections.
- Maintaining brain health across the course of a lifetime can help to optimise levels of independence.
- Preserving brain health is also important in the mission to curtail heavy healthcare and economic costs that poor brain health can bring.
- Over time, poor brain health can manifest in several different ways but characteristically as cognitive impairment or dementia.
- A host of underlying cellular and molecular changes within the brain including oxidative damage, mitochondrial impairment and alterations in glucose-energy metabolism and nerve inflammation have been claimed to contribute to cognitive decline and brain ageing.
What are omega fatty acids?
Omega-3 and omega-6 fatty acids are important components of cell membranes and are precursors to many other substances in the body, such as those involved with regulating blood pressure and inflammatory responses.
Alpha-linoleic acid (ALA, omega-3) and linoleic acid (LA, omega-6) are essential fatty acids that are not produced in adequate amounts by humans. For these reasons they need to be consumed from dietary or supplement sources. Once ingested ALA and LA produce other fatty acids:
- ALA yields eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) omega-3 fatty acids.
- Docosapentaenoic acid (DPA) is the intermediate fatty acid between EPA and DHA.
- LA yields the omega-6 fatty acids gamma-linoleic acid (GLA) and arachidonic acid (ARA).
EPA and DHA produce anti-inflammatory signalling molecules whilst ARA generates signalling molecules that can exacerbate inflammation, which shows that whilst we need some omega-6 fatty acids for health, Western diets provide an overabundance of these which can displace omega-3 fatty acids. Subsequently, proportionally higher amounts of omega-3 fatty acids are needed to protect aspects of health, including brain health.
Role of omega-3 fatty acid supplements in brain health
It is known that omega-3 fatty acids from dietary sources are under consumed. The mean intake of EPA and DHA are only consumed as recommended in 26% of 17 European countries. It is known that omega-3 supplementation generally correlates with improvements in blood biomarkers.
- DHA is a nutrient abundant in neuronal membranes. Quantitatively, DHA is the most important omega-3 fatty acid in the brain though there is now a growing body of evidence that others including EPA and DPA also possess neuroprotective properties most likely having both independent and shared effects.
- Certain nutrients may help to normalise or even attenuate some of the changes that occur with brain ageing. Research amongst patients with Alzheimer’s disease shows that brain nutrient status parallels circulatory status, indicating that the brain depends on certain nutrients from the circulation.
- >1 g/day docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) significantly improved episodic memory in older adults with a history of mild memory complaints.
- Omega fatty acid supplementation could help to reinforce habitual intake by raising blood levels. Certain subgroups such as those with lower baseline blood fatty acids levels, who are breastfeeding infants or who have neuropsychiatric conditions such as ADHD, ASD or depression, also appear to benefit more strongly from omega use.
- Omega fatty acids were found to improve ADHD symptoms and fatty acid profiles. Amongst main stream school children, 3-months of Omega 3/6 treatment improved reading ability, with children with attention problems again showing particular benefits.
- Blood levels of EPA, DHA and total omega-3 fatty acids were significantly reduced amongst individuals with dementia. In addition, EPA was reduced amongst those with pre-dementia compared with healthy elderly controls.
- Omega fatty acids can protect against neurodegeneration in older adults, and bearing in mind the scale of ageing populations and rising healthcare costs linked to poor brain health, omega supplementation could be a useful strategy for helping to augment dietary intakes and support brain health across the lifespan.
Thus, omega-3 supplementation appears to be effective at improving EPA and DHA status. This in turn may have a role in maintaining and augmenting brain health, particularly amongst those with low baseline levels of fatty acids, with increased demands such as lactating mothers or those with diagnosed neuropsychiatric conditions. Certainly, given that the ageing population, mental health conditions, and cognitive decline are currently showing no signs of subsiding, it makes good sense to ensure that omega fatty acid levels are optimal across the lifespan be it through dietary or supplement sources.
References:
Derbyshire EJ (2018) Brain Health across the Lifespan: A Systematic Review on the Role of Omega-3 Fatty Acid Supplements. Nutrients 10(8), 1094.
