An essential omega-3 fatty acid and a predominant structural component of the brain (roughly made up of 60% fat), Docosahexaenoic acid (DHA) is a vital nutrient, playing multi-functional roles for brain health and disease prevention.
The turnover of DHA in the brain is swift. Optimal DHA intake is crucial during pregnancy and also while breastfeeding, as it's vital for brain development in utero and infancy. DHA is also required for the maintenance of normal brain function in adults.
Increasing research suggests that DHA intake above standard nutritional requirements can decrease your risk of or modify the course of several brain diseases.
DHA is 'essential' as our bodies can't synthesise it, so we have to get it from food. The most abundant and absorbable form of DHA is oily fish like sardines, wild salmon and mackerel.
You need to eat two portions of fatty fish a week to provide your body with adequate amounts. You can also ensure you're getting enough by taking a daily fish oil supplement.
While research is ongoing regarding the effects of DHA consumption for several diseases and disorders, positive results have emerged for cognitive decline, Alzheimer's, learning ability, ADHD and depression. In this article, we'll aim to answer many of the most common questions surrounding DHA – and suggest ways to up your intake.
4 Ways in Which DHA Can Support Brain Health
1) May protect against cognitive decline and reduce Alzheimer’s risk
There are many benefits from supplementing with fish oils. If you don’t eat much oily fish, taking supplements might help to improve your cognition.
In 2013, a randomised controlled trial (RCT) demonstrated this by splitting 176 healthy adults with low DHA status into two groups.
One took fish oil supplements for six months, while the other took a placebo.
Memory notably improved in the DHA group versus placebo. Women showed the most significant improvements in episodic memory, and men exhibited the greatest advances in reaction times of working memory.
A trial published in 2017 showed positive effects from DHA supplementation on hippocampal volume and cognitive function in older adults with mild cognitive impairment.
240 elderly MCI patients took part in the Chinese study. They also had a loss of volume in the hippocampus (the brain area associated with memory).
One group supplemented 2g DHA per day for 12 months versus placebo. The DHA group showed significantly improved cognitive function and also had decreased loss of hippocampal volume.
Higher DHA intake appears to correlate with a reduced risk of Alzheimer’s disease. Some evidence suggests that higher DHA intake and increased DHA blood levels may decrease Alzheimer’s and dementia risk.
Some researchers suggest a promising strategy for Alzheimer’s prevention is to maintain a healthy nerve cell population in the brain with consistent DHA consumption, long term.
2) May aid depression
Many positive studies researching the link between fish oils and depression focus on both EPA and DHA, and a diet higher in oily fish may decrease depression symptoms.
While some studies show that a higher proportion of EPA to DHA has more beneficial effects on depression, DHA is still essential for good mental health and deficiency is associated with depression.
DHA may help mediate depression in women, and much research finds supplementation with both EPA and DHA is most effective for depressive symptoms.
One small study found a correlation between lower DHA consumption and depression.
DHA supplementation in healthy pregnant women may reduce the risk of postnatal depression.
3) May help to reduce the risk of ADHD and relieve symptoms
ADHD is one of the most commonly diagnosed neurodevelopmental disorders in schoolchildren in the UK.
Symptoms continue into adulthood, and ADHD often comes with other developmental conditions, including autism, dyslexia, and dyspraxia.
ADHD symptoms can fall into the categories of inattentiveness, hyperactivity and impulsiveness.
Some people may experience inattentiveness but not the other two, and this is known as ADD, which often goes undiagnosed as it can be less noticeable.
While research into supplementation with omega-3 fats EPA and DHA are inconsistent, enough positive studies warrant further investigation.
Omega-3 fats are essential for brain and nervous system function, and DHA deficiency in infancy could increase the risk of ADHD in early life.
Some research shows that supplementing with omega-3 fats, specifically DHA, may improve literacy and behaviour in children with ADHD.
A 2013 study showed improved spelling and literacy, hyperactivity and behaviour in children supplementing with high daily doses of either DHA or EPA.
In children with ADHD, DHA may improve word reading and oppositional behaviour. This change may be more pronounced in children with learning difficulties.
Supplementing with DHA may also improve spelling, attention, hyperactivity, restlessness and overall ADHD symptoms.
While several studies show that behaviour in children with ADHD significantly improves with EPA and DHA combined, some researchers think DHA is more important.
Brain mapping shows that a person with ADHD has a brain that functions differently. It appears that there may be a deficiency of the neurotransmitter noradrenaline, which controls dopamine production.
Dopamine is a feel-good neurotransmitter with many tasks, including our reward-centred behaviour.
Low noradrenaline and skewed dopamine levels can result in impaired brain function in four parts of the brain:
- The frontal cortex
- Limbic system
- Basal Ganglia
- Reticular activating system
These parts of the brain are associated with organisation, executive function, regulation of emotions and attention.
Deficiencies in these brain areas can result in impulsiveness, inattention, lack of organisation and more.
DHA supports dopamine and serotonin production, improving mood and sleep. It may also reduce hyperactivity.
4) DHA is essential for children’s brain health
Adequate DHA intake is vital during pregnancy and while breastfeeding as it’s essential for brain development both in the womb and in infancy.
DHA deficiency may also increase the risk of ADHD.
Research shows that children with higher blood levels of DHA and total omega-3 are more likely to pass a test to determine executive function (the ability to plan and organise, recall facts, multi-task, pay attention and switch focus).
Research suggests that babies born to mothers with increased blood levels of DHA had advanced attention spans well into their second year.
During their first six months, these infants were two months ahead of those born to mothers with lower DHA levels.
Researchers analysing the results of several trials concluded that omega-3 fats, particularly DHA, may improve brain function and mood in children.
Kids with low literacy ability and those with little DHA in their diet seem to benefit most from having increased omega-3s.
Deficient DHA could negatively impact learning and behaviour in healthy children. It appears that they might benefit from supplementing with DHA as it can improve brain activity, cognition and behaviour.
Poor sleep negatively affects cognitive function, focus, concentration and learning. It can considerably affect school performance and behaviour in children.
In 2014, researchers noted associations between lower blood DHA levels and increased sleep disturbance. They found that supplementing with DHA improved their sleep, it was less disturbed, and some children had an average of an extra 58 minutes of sleep per night.
DHA is considered by many to be a brain nutraceutical. It’s a primary structural component of the brain and is crucial for brain growth, development, and maintaining normal brain function in adults.
It may help to protect against cognitive decline, reduce Alzheimer’s risk and aid depression. DHA may also help to improve ADHD symptoms and increase brain activity and cognition in healthy children.
It can enhance brain function and mood in children with inadequate DHA in their diet and those with low literacy.
You can’t synthesise DHA and must get it from food by eating two portions of oily fish per week (sardines, mackerel, anchovies, wild salmon, herring etc.).
Sadly, many people are justifiably concerned about the toxicity in fish from heavy metals, pesticides and other contaminants and opt for a fish oil supplement instead.
UnoCardio X2 is an ultra-pure fish oil from WHC that’s third-party tested for purity, freshness and stability. Providing 420mg of DHA per dose, this high-strength supplement helps you meet your daily quota of essential fatty acids. It is currently ranked #3 (of 54) in Labdoor’s independent league table of fish oils. Each pack provides a two-month supply.
Written by Rebecca Rychlik, Nutritional Therapist and Homeopath. Follow Rebecca on Instagram, Facebook and Medium, @rebeccabitesback.
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DHA is ‘essential’ as our bodies can’t synthesise it, so we have to get it from food. #FishOil #Nutrition