Omega-3 Fats & The Essential Fatty Acids
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Omega-3 fats & their benefits have had a lot of press recently, but what exactly are their benefits to your health & how can you get more of them in your diet?
The Omega-3 family of fats and their cousins the Omega-6 fats are known as Essential Fatty Acids (EFAs). This is because the human body lacks the required enzymes needed to produce them. It is the atomic structure of these EFAs that makes them so important, as the carbon atoms that form the molecule are joined by double-bonds. This makes the molecules more flexible, and the more double-bonds the more unsaturated the fatty acid is. Omega 3 & 6 fatty acids have more than one double-bond so are known as polyunsaturated fatty acids.
Let us delve deeper into body chemistry for a moment...
Our body produces enzymes that allow us to insert double-bonds into fatty acid molecules, but not before the seventh carbon in the molecule. This insertion process is known as desaturation and allows the fatty acid to perform different functions in the body. (incidentally, the Omega-3 fatty acid has its first double-bond at the third carbon, and the Omega-6 fatty acid has its first double-bond at the sixth carbon, which is how they get their respective names.) Plants also have the ability to insert double-bonds before the seventh carbon and so are also able to produce Omega-3 & Omega-6.
At the start of the Omega-3 chain is a molecule known as Alpha-Linolenic Acid, which is the building-block our bodies use to manufacture two other fatty acids, known as Eicosapentaenoic Acid (EPA for short) and Docosahexaenoic Acid (DHA for short). As long as you have a good supply of Alpha-Linolenic Acid your body can manufacture the other two. However if you are lacking nutrients that make up the enzymes that carry out this manufacturing process, OR your diet is significantly higher in Omega-6 compared to Omega-3 (both use the same enzymes, so can be considered to be competing with each other) then you may not produce enough EPA & DHA. That is the whole point - a healthy body requires sufficent EPA & DHA.
Thanks to the food chain, nature has the solution. Fish are also able to carry out the same processes to produce EPA & DHA. Small fish eat plankton and plants which contain Alpha-Linolenic Acid. These fish produce some EPA & DHA and the fish that in turn eat them carry on the process. So by eating oily fish that feed on smaller fish, you can get a ready made supply of EPA & DHA. Simple!
So how does the body use the different types of Omega-3 acids and what health benefits do they give you?
One of the major benefits of Omega-3 fatty acids is their anti-inflammatory properties. These have been shown to ease the symptoms of inflammatory illnesses such as Arthritis, Eczema and Asthma. The body converts EPA into a substance called Series-3 Prostaglandins (PGEs for short). It is these hormone-like substances that help to calm inflammation.
The Omega-6 fatty acids (known as Linolenic Acid) also have anti-inflammatory properties. Linolenic Acid is converted in to Gamma Linolenic Acid (GLA for short) which in turn is converted into Series-1 PGEs which have the same anti-inflammatory benefits as the Series-3 variety.
However GLA can also be converted into Arachidonic Acid. This fatty acid is essential for the proper functioning & growth of the brain, but it is also converted into Series-2 PGEs which are pro-inflammatory. Although the pro-inflammatory nature of the Series-2 PGEs is an essential part of our immune response, an excess can lead to an increase in inflammation & increase the severity of an inflammatory disease. Arachidonic Acid is found predominantly in animal products such as meat, dairy and eggs. One current line of thought in nutritional therapy is that a high consumption of animal products (as found in a typical western diet) may be one of the reasons for the increase in inflammatory diseases.
Omega-3 fats also help to thin the blood & reduce the blood levels of cholesterol. Thinning the blood using fish oils can be beneficial for people with high blood pressure or for those who suffer from arterial thickening due to diseases such as angina. To achieve the necessary levels of Omega-3 to thin the blood, a fish oil food supplement is recommended, however if someone is already prescribed blood thinning drugs (such as Warfarin) they should not start further supplementation without first consulting their doctor.
As if helping fight inflammatory diseases & helping keep the blood thin was not sufficent, the Omega-3 fats also help keep your skin healthy. They do this by forming part of the phospholipid membranes around your cells which keeps them flexible & water tight. This allows the cells to hold on to water and not become dehydrated. Imagine how a balloon looks when partially deflated - the outside of the balloon becomes wrinkly! That is exactly what happens to skin cells when they become dehydrated. Not drinking enough water can cause this to happen but so can not getting the right amounts of EFAs in your diet.
Phospholipids also hold cholesterol in the membrane of the cell. Because they are extremely flexible molecules they hold in the more rigid cholesterol to balance their fluidity. If your diet is low in EFAs the body uses rigid, saturated fats to build membranes & cholesterol is therefore not absorbed. Instead the cholesterol is released into the blood stream & can cause an increase in blood cholesterol levels, which is linked to an increase in blood pressure and heart disease.
What are the signs of an Omega-3 & 6 deficiency?
Below is a list of symptoms that can be caused by a deficiency of EFAs. It is important to note that these symptoms often have more than one cause, so if you suffer from any of them it may not be due to a deficiency of EFAs. For example eczema can be caused by allergies, a poor digestive system or a weak immune system.
- Dry skin
- Eczema
- Dandruff
- Inflammatory diseases such as arthritis
- Poor memory
So how can you get more Omega-3 & 6 in your diet?
Nuts & seeds are an excellent source of both Omega-3 & 6 EFAs, and they also provide other beneficial nutrients such as zinc, calcium and magnesium. The best sources of Omega 6 are Pumpkin seeds, Sunflower seeds & Sesame seeds, and also Walnuts. Flax seeds (sometimes called linseed) and sunflower seeds are good sources of Omega-3 and eating a combination of the above will ensure a good supply of both.
In his book The Optimum Nutrition Bible, nutritionist Patrick Holford recommends eating a handful of mixed seeds each day by adding them to cereals, salads or soups. He recommends that half the seeds should be flax due to their Omega-3 content. He also recommends grinding them up to ensure you digest them properly as the hulls can be particularly difficult to break down. This can easily be done using a Pestle & Mortar but is not always going to be practical, so if you cannot grind them up make sure you chew them thoroughly (although this is easier said than done when eating sesame seeds!)
Eating nuts and seeds will provide you with good amounts of Alpha-linolenic and Linoleic acid and with the high consumption of animal products in the modern diet people are rarely short of the other Omega-6 acids.
But, if you want to get a ready-made source of EPA & DHA in your diet then oily fish is by far the best source.
Current guidelines recommend eating 3 portions of oily fish a week. The fish with the highest amounts of EPA & DHA are carnivorous fish such as Salmon, Herring, Mackerel and Tuna. If you cannot get fresh fish then tins of Salmon, Herring and Mackerel are fine, although tinned Tuna contains no EFAs as the oil is removed in the canning process. Personally I like tinned fish as they are easy to add to salads or sandwiches. Supermarkets also stock eggs that are rich in Omega-3, the chickens that lay the eggs are fed Omega-3 rich seeds which they pass on to their eggs. Recently you may have also noticed that other food products such as breakfast cereals and bread have had Omega-3 added to them.
The other way to increase your intake of EPA & DHA is to take a fish oil supplement. The levels of nutrients in supplements are usually much higher than nutrients found in food, which is why therapists use them to correct any deficiencies. For example most high quality Vitamin-C supplements provide 1 gram, which is the equivalent to eating 22 oranges!
It is always advisable to follow published guidelines (printed by law on the side of the supplement container) for the amount to take unless you have been advised differently by a qualified health practitioner. Certain supplements can also react with prescription drugs so if you are on any medication you should always consult your doctor before starting a supplement programme.
- Author: Stuart Cornock
- Source: Patrick Holford 'The Optimum Nutrition Bible'
- Source: Udo Erasmus 'Fats that Heal, Fats that Kill'
