Omega-6 and omega-3 fatty acids (FAs) both play an important role in health. Unfortunately, a lot of people have the perception that we need to take supplements of both groups of fatty acids. This is not strictly true.
What we tend to forget is that most people who follow a western diet that contains poly- and monounsaturated margarine, as well as cooking and salad oils, get an overdose of omega-6 FAs. If you use margarine and sunflower oil in your kitchen, then the chances are good that you're getting more than enough of the omega-6 fatty acids. In fact, you may be getting too much.
A complicated relationship
The problem with these essential fatty acids is that we not only have to make sure that we include them in our diets, but that the amounts we eat are balanced.
Researchers have discovered that the so-called omega-3 to omega-6 ratio should be about 1:5 for optimal health. This means that we must make sure that we eat 1g of omega-3 for every 5g of omega-6.
Seeing that the intake of omega-6 in western countries has increased dramatically with the introduction of margarine and salad and cooking oils, most of us get more than enough omega-6. The general intake of omega-3, which is mainly found in fish and fish oils, has however, decreased just as dramatically over the years so that we hardly ever achieve the ideal ratio of 1:5. In many diets, the ratio is 1:20, or even 1:40. It is, therefore, important to make sure that we eat more omega-3.
The reason why we need a 1:5 balance of omega-3 and omega-6 intake is that these essential fatty acids compete with each other in our bodies for enzymes. If you eat too much omega-6 and not enough omega-3, only omega-6 will be metabolised and your body won’t be able to use the omega-3 fatty acids. Such an imbalance can cause all kinds of diseases.
Omega-3 and health
If you eat sufficient omega-3 FAs, you will be protected against the following diseases and conditions:
- Heart disease - omega-3 FAs lower the risk of developing heart disease and can reduce the risk of dying from a heart attack by 30%.
- Blood clots - omega-3 FAs make blood less sticky and prevent blood clots.
- Hypertension - omega-3 FAs lower blood pressure.
- High blood fat levels - omega-3 FAs lower ‘bad’ cholesterol and triglyceride levels in the blood.
- Breast cancer - high omega-6 and low omega-3 FA levels may predispose women to develop breast cancer.
- Colon and bowel cancer - omega-3 FAs may prevent colon cancer.
- Rheumatoid arthritis - research results indicate that omega-3 FAs may help to prevent this crippling disease.
- Crohn’s disease - there is some indication that the omega-3 FAs may help to alleviate chronic inflammatory bowel disease.
In addition, omega-3 FAs are important for the normal development of the brain, nervous system and vision in infants before, and during the first year after birth. Omega-3 FA supplementation during pregnancy and even in breast-fed infants is advisable.
Although research into the role of omega-3 FAs in psychiatric conditions, such as depression and schizophrenia, is still in the early stages, some studies have shown promising results.
Sources of omega-3 fatty acids
More and more scientific evidence points to the fact that omega-3 FAs are important for human health and normal development. It is becoming increasingly clear a person who follows a western diet with a low fish content is exposed to omega-3 FA deficiency and an imbalance in the omega-3:omega-6 ratio.
The following foods and supplements are rich sources of omega-3 FAs:
- Fish - mackerel, herring, salmon, tuna, sardines, anchovies, trout and sturgeon
- Fish oils - cod liver oil, salmon oil, tuna fish oil
- Salmon oil capsules
- Plant sources - flaxseed, canola, walnut and soya oils
- Omega-3 enriched foods - eggs, milk, bread and margarine
If you suspect that you are not ingesting sufficient omega-3 FAs, make a plan to eat fish at least twice, if not three times a week. You can also switch to using flaxseed, canola or soya oils and start using enriched foods, such as omega-3 enriched eggs, milk, bread and margarine. If you are at risk of any of the above-mentioned diseases, regular intake of salmon oil supplements is advised.
Dr Ingrid van Heerden is a registered dietician and holds a doctoral degree in Nutrition and Biochemistry. She believes that "we are what we eat" and offers free nutrition and weight loss advice via her DietDoc service on Health24.com.