Omega-3 biomarkers


The amount of omega-3 we have in our cells, in particular EPA and DHA, is vital to human health.

Whilst their benefits are most commonly associated with heart, brain and eye health, as well as the healthy development of the foetus during pregnancy and breastfeeding, omega-3s contribute to almost all biological processes. Omega-3 biomarkers (explained below) are useful clinical tools to identify whether our current fatty acid balance in the body is optimal – or suboptimal – and whether changes need to be made to the diet to improve our long term health.

As a quick refresher, having optimal omega-3 levels in our cells is essential for:

  • a healthy immune system
  • reducing risk of diseases, allergies and autoimmunity
  • optimal brain function for mood, memory and cognitive processing
  • reducing risk of mental illness such as depression and dementia
  • a healthy cardiovascular system
  • healthy cell cycle and genetics so we can grow, adapt and improve, whilst reducing the risk of unwanted excess cell growth or mutation

What is a biomarker?

A biomarker is a biological marker that generally refers to a measurable indicator of a certain biological state or condition. Most of the time we use biomarkers to gain information about the risk, presence or severity of an illness or condition.

There are three established omega-3 biomarkers and combining them gives us a very comprehensive overview of our current omega-3 related health status and provides valuable information about the structure, function and health of our cells and long-term disease risk.

The omega-6 to 3 ratio

This ratio helps us to understand the balance between these two important polyunsaturated fat families and is a very well established marker of general health and long term risk for disease. This ratio should be between 3 and 4 to 1, as too much omega-6 reduces the ability of our cells to function properly, making all biological functions less effective. For example, excessive omega-6 may mean that our cells are less able to replicate correctly, influencing growth and repair and risk of increased cell mutations. It may also affect the normal regulation of our heartbeat and reduce blood vessel flexibility, leading to arrhythmia and blood pressure issues. Excessive omega-6 levels also adversely affect our immune system and make us more prone to chronic illness and issues such as autoimmunity. A high omega-6 to omega-3 ratio is also associated with poor cell to cell communication in the brain, inhibiting the transmission of messages effectively through our nerve fibres and leading to issues with coordination, balance, focus, attention and even mood and sleep.

Typically, most people eating a Western diet rich in vegetable oils and grains will have a high omega-6 to omega-3 ratio, but the opposite is also not good for health. If omega-6 relative to omega-3 is too low, we may need to increase our omega-6 relative to our omega-3. The correct balance between these families of fats is vital for cells to function optimally, whilst many other processes such as inflammation and immune function in the body are also reliant on the ratio of these fats. Over time, if this ratio is imbalanced in favour of omega-6, disease risk also increases.

The AA to EPA ratio

This ratio is a more refined version of the omega-6 to 3 ratio and specifically tells us about inflammation in the body. Chemical messengers that cause an inflammatory response – triggered by injury, infection, stress or illness – are primarily produced from the omega-6 fatty acid arachidonic acid (AA). Similar chemicals are also produced by the omega-3 fatty acid EPA, but these are anti-inflammatory. The balance between AA and EPA in the body determines how inflamed we become following a trigger and how easily the body can prevent inflammation carrying on unnecessarily. Too much AA relative to EPA often means we have lots of inflammation occurring that isn’t needed and this can lead to significantly increased risk for inflammatory diseases such as heart disease, depression, ADHD, cancer and arthritis. An AA to EPA ratio of between 1.5 and 3 to 1 is a sign that inflammatory response is in the healthy range.

The omega-3 index

This well established biomarker refers to the total amount of omega-3 EPA plus DHA as a percentage of all fats that make up our red blood cell membranes. The sum of these two fats gives us a really good indication of whether we have enough omega-3 in our cells for their structure to be healthy. A healthy cell structure is vitally important for making sure cells can communicate and nutrients can pass into the cell, whilst allowing waste products, which naturally accumulate, to pass out. An omega-3 index of greater than 8% is associated with the lowest risk of cardiovascular illness and optimal health and wellbeing. The researchers who developed and validated the omega-3 index as a biomarker also developed an equation to identify a person’s daily omega-3 needs simply by using their body weight in combination with the omega-3 index, enabling a precise calculation of how much omega-3 an individual needs to bring their omega-3 index into healthy ranges within six months.

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