Omega 3 & 6 - the all-important ratio
Essential fatty acids are vital for good health, but do you know your numbers?
We are all aware of the health problems that a high-fat diet can bring such as an increased risk of obesity, type 2 diabetes and heart disease. However, diets that are in favour of completely cutting out fat are not to be encouraged. Fat is necessary for many processes in the body including providing energy, absorbing vitamins and producing hormones.
What are omega-6 and omega-3?
Our body can synthesise most of the fats we need from the foods we eat, but 2 essential fatty acids, linoleic acid (omega-6) and alpha-linoleic acid (omega-3), cannot be produced by the body, we get these directly from our diet. Fats are required in every cell of our bodies and are vital for regulating blood pressure, strengthening our immune system and keeping our brains healthy. Whilst omega-6 can be found in most vegetable oils, poultry, leafy green vegetables and nuts; omega-3 is in a smaller number of foods such as oily fish, seeds and nuts.
What is the importance of the omega-6 to omega-3 ratio?
The ratio of omega-6 to omega-3 in our bodies is very important. Omega-6 fatty acids have a pro-inflammatory role while omega-3 fatty acids have an anti-inflammatory role. Although inflammation helps the immune system to fight infection, chronic inflammation in the body can lead to the development of disease, including heart disease, cancer and autoimmune diseases.
Ideally, our omega-6 to omega-3 ratio should be around 3:1. But there is increasing evidence that an even lower ratio of 2:1 or even 1:1 could be beneficial for our health. A low ratio of these fatty acids is necessary to reduce excess inflammation in the body. The modern day western diet is high in omega-6 as it’s packed full of vegetable oils, but is low in omega-3. Many of us have a ratio around 16:1 which is worryingly much higher than it should be.
How does our diet affect our levels of omega-6 and omega-3?
Because we obtain omega-3 and 6 from the foods we eat, different diets have an impact on the amount of these fatty acids we consume. There are 2 main types of omega-3 fatty acids: long chain, referred to as EPA and DHA and short chain also known as ALA. DHA is an important fatty acid for brain development whilst EPA helps to reduce cellular inflammation in the body.
Animal products which contain omega-3 are high in EPA and DHA, whereas plant-based foods contain ALA omega-3. Although our bodies can turn ALA omega-3 into EPA and DHA, we struggle to do this and only manage to convert a small proportion of the ALA we eat into the beneficial EPA/DHA. Because vegans and vegetarians do not eat fish, they obtain very little EPA and DHA from their diet. Algae oil is a popular supplement containing DHA suitable for vegetarians and vegans.
How can we improve our omega-6 to omega-3 ratio?
Increasing our intake of oily fish, flaxseeds and taking a supplement of cod liver oil are effective ways to increase omega-3 levels. Although too much omega-6 can cause excess inflammation, we must not forget that it is still an essential fatty acid, so it cannot be cut entirely from the diet. Some sources of omega-6 are better than others, such as sesame and avocado oils which contain lower levels of omega 6 compared to sunflower oil.