Essential fatty acids are those fats that you can only get through diet because your body cannot make them. The two essential fatty acids are alpha-linolenic acid, an omega-3 fat and linoleic acid, an omega-6 fat.
Enzymes in your body convert alpha-linolenic acid into longer chain omega-3 fats known as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These fats are crucial for your health and wellbeing.
What omega-3 fats do
Every human cell has a protective, permeable membrane. These membranes hold water, vital nutrients and electrolytes. They regulate what goes in and out of the cell, and are how cells can communicate with each other.
Omega-3 fats, EPA and DHA, are vital components of the cell membranes in the nervous system, brain and the retina. You need EPA for concentration and vision, while DHA is critical for brain development, especially in fetuses and young children.
Omega-3 fats (mainly EPA) are also transformed into compounds known as series 3 prostaglandins. These prostaglandins have a range of beneficial anti-inflammatory effects. For example, they can thin the blood, break down blood clots, improve blood flow and lower the risk of heart disease.
Where to get omega-3
Vegetable oils (rapeseed and flaxseed), flaxseeds, chia seeds, sunflower seeds, walnuts, green leafy vegetables and soy products are good sources of alpha-linolenic acid. Your body needs to convert them into the crucial, longer-chain EPA and DHA omega-3 fats. However, this conversion process may not be efficient as research suggests that only approximately 2-10% of alpha-linolenic acid is converted into EPA or DHA.
Oily fish including herring, mackerel, halibut, trout, kipper and salmon contain preformed EPA and DHA and are thus better sources of omega-3 fats than plants. Oily fish tend to accumulate their omega-3 fats in their flesh so you can absorb more EPA and DHA from them. White fish such as cod, haddock, plaice, and mullet also contain omega-3, but it is more concentrated in their livers. If you avoid fish for ethical or religious reasons, algal oils are an alternative source.
Signs that you may be omega-3 deficient
- Cracked nails
- Dry hair and skin
- Dry mucous membranes
- Frequent infections
- High blood pressure
- Low immunity
- Poor coordination
- Poor memory
Please note that these symptoms are not exclusive to an omega-3 deficiency. They may also be caused by other health conditions or nutritional deficiencies.
The daily recommended intake
There is no specific recommended daily dose for omega-3 in the UK. However, the guidelines suggest that we should aim to eat two portions of fish (at least one oily) each week. In the US and Canada, the daily recommendation for alpha-linolenic acid is
- 1-3 years: 0.7g
- 4-8 years: 0.9g
- 9-13 years: 1.2g males, 1.0g females
- 14-18 years: 1.6g males, 1.1g females, 1.4g pregnant females, 1.3g nursing females
- 19+ years: 1.6g males, 1.1g females, 1.4g pregnant females, 1.3g nursing females