What are Omega-3 fats?
Omega-3 fatty acids (also known as n-3 PUFAs) are a group of healthy fats which we need for many different roles in our body.
There are THREE types of omega-3 fats:
ALA - Alpha-linolenic acid DHA - Docosahexaenoic acid
EPA - Eicosapentaenoic acid
ALA - alpha-linolenic acid
ALA is called an ‘essential fat’ as it cannot be made in the body so must be consumed in our diet. Dietary sources of ALA are from plant sources such as green leafy vegetables vegetable oils (rapeseed and linseed) and nuts (pecans, walnuts and hazelnut).
DHA - docosahexaenoic acid and EPA - eicosapentaenoic acid
These fats can be made in the body from ALA but this is made in smaller amounts and more slowly, some studies have suggested only 2-10% of ALA is converted in the body. EPA and DHA are produced by water plants like algae thus fish is a rich source. These sources of omega-3 are thought to have the biggest health benefits.
Special mention about Omega-6 fats
Omega-6 fats or linoleic acid is another essential fat. It is found in a wide range of foods such as cereal products, meat and meat products, fats spreads vegetable oils (and foods cooked in these). As omega-6 is found in so many different products your diet is likely to be providing adequate amounts or in some cases too much, of this type fat.
What are the health benefits of omega 3?
ALA is needed for keeping your eyes healthy and also involved in nerve and cell development. EPA and DHA are needed during pregnancy and breastfeeding for healthy baby development.
Diets which contain Omega-3 are linked with health benefits such as helping to reduce blood pressure ,reduce the tendency for blood to clot, help to regulate the heart beat and reduce blood cholesterol levels (particular triglycerides). Some studies have also shown omega-3 can help maintain memory and prevent and treat depression. Fish which contains omega-3 also provides other health benefits such as being good sources of Vitamins A and D.
To get the most benefits from these essential fats we should be consuming more omega-3 food sources compared to omega-6 foods.
What is the connection with fish and omega?
As fish eat water plants like algae fish and particularly oily fish, is a rich source of DHA and EPA. We should have to have 1 portion (about 140g) a week, which will meet your omega-3 needs.
Types of oily fish are (fresh or tinned):
Salmon
Pilchards
Mackerel
Sardines
Trout
Herring
There are smaller amounts of omega-3 in white fish too such as cod, haddock, plaice, pollack, coley, dover sole, dab, flounder, red mullet and gurnard.
Plant-based sources of Omega 3
What if you don’t like fish or follow a vegan or vegetarian diet? How to you meet your omega-3 needs? Try to include the foods below which are sources of ALA fats:
Nuts: walnuts
Seeds: pumpkin seeds, flaxseeds, chia seed (can be added to cereal and yoghurt)
Vegetable oils- rapeseed, flaxseed and linseed
Soya foods and soya products- soya beans, milk, tofu
Green leafy vegetables or sea vegetables like algae, seaweed
Omega-3 fortified eggs (if eaten)
Fortified foods such as margarine, yoghurts and milk
Do I need supplements?
Supplements are not needed if you are including omega-3 food sources in your diet but if you are choosing a supplement then it is useful to consider the following:
Choose omega-3 from fish oils rather than fish liver oil supplements as these contain higher amounts of omega-3
Fish liver oils are also high in vitamin A so do not take with other Vitamin A supplements
Don’t exceed the amounts that you would have obtained from food so up to 450-500mg EPA and DHA a day
If you are vegetarian or vegan try supplements made from marine oils made from algae derived DHA (read more about plant-based diet here)
Omega 3 and cancer?
The ESPEN (European Society for Clinical Nutrition and Metabolism) pools together evidence from various studies to produce guidance and recommendations. They reported that there is weak evidence that showed a benefit of omega-3 or fish oil supplement in cancer. They also suggested this weak benefit may only be in individuals with advanced cancer who are undergoing chemotherapy and are risk weight loss. So, what does this mean? There is only weak evidence in this specific group, therefore it is unlikely that omega-3 supplements will benefit most cancer patients other than the usual health benefits. If you want to find out more on how this applies to you, contact me to discuss further.
Take home message
Omega-3 has many health benefits so useful to include in your diet. If you are happy to include fish in your diet it is a good way of getting your omega-3 requirements but if you avoid fish do try to include non-fish sources of omega-3 fats throughout your day. If you need advice on how to add omega-3 sources into your diet book now
Key References:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262608/
https://www.bda.uk.com/resource/omega-3.html