Regular readers of my blog will have realised by now that I have a great interest in Omega 3 fatty acids. Research suggests that these essential fats play a role in the prevention of several diseases ranging from heart disease to cancer, stroke, diabetes, arthritis, asthma, osteoporosis, mood disorders (including depression), eye diseases and many more (including most conditions with a link to inflammation). A major voice for the importance of these fats is Artemis Simopoulos MD. Dr Simopoulos is president of The Centre for Genetics, Nutrition and Health and a member of the board of directors of the American Association for World Health. Since 1984 her research has been largely dedicated to the evolutionary aspects of diet, the omega-6:omega-3 ratio of the diet and the importance of omega-3 fatty acids for health.
In an interview (1) Dr Simopoulos said that one of the biggest food myths today is that you have to give up fat to lose weight and enjoy health. A statement I wholeheartedly agree with. Of course, not all fats are the same and today I want to discuss the virtues of omega 3 fatty acids. These can be found in fish, especially oily fish such as salmon, trout, mackerel and sardines, seafood, as well as flaxseeds, walnuts and green leafy vegetables. Meat and eggs in the UK do not contain large amounts of omega 3 fatty acids anymore since our farming methods have drastically changed over the years, this has contributed to the huge decline in our intakes of this vital fat. Grass reared animals will have better omega 3 fatty acid levels, but nowhere near as high as in the past when animals were less intensively reared.
Dr Simopoulous has written many research and review papers about the importance of omega 3 fatty acids, and I am going to use some information from a fairy recent one (2) to provide the basis for this post. She has also written many books including ‘The Omega Plan’.
It is thought that humans evolved on a diet that was very rich in essential omega-3 fatty acids, and a ratio of omega-6:omega-3 fatty acids of about 1:1 (or at most 2:1). Currently the western diet has an imbalanced ratio of about 15:1 !! This represents a huge shift and a relative ‘deficiency’ in omega-3 fats. The excessive amounts of omega-6 fats and the very high omega-6:omega-3 ratio today is thought to be a major contributor to many of the diseases listed above. A diet rich in omega-3 fatty acids and with a lower omega-6:omega-3 ratio is highly desirable for reducing the risk of many of the chronic diseases in the Western world. Low intakes of omega-3 fats and higher intakes of omega-6 fats can lead to an increase in inflammation in the body since omega-3 fats are used by the body to make potent anti-inflammatory chemicals whereas too much omega-6 can lead to the production of pro-inflammatory chemicals by the body.
Nutrition can affect our genes and hence have an influence on disease. Over the last 10,000 years our diet has drastically changed, especially over the last 150 years, to almost unrecognisable degrees in most people. However, genetically we have not changed much (our DNA is much the same). Our genes today are incredibly similar to those of our ancestors who lived around 40,000 years ago. Our diet now is so very different, particularly in the type of fats we eat, and in the antioxidant nutrient content of our foods (antioxidants are found abundantly in vegetables and fruits) and this is surely affecting our health.
The review paper(2) details the ways in which our diet differs from that of our pre-industrial ancestors:
1. We have an increase in energy intake and a decrease in energy expenditure
2. Our diets are richer in saturated fat, omega-6 fats and trans fats and lower in omega-3 fats
3. We do not eat as much complex carbohydrates and fibre
4. We eat a huge amount more cereal grains and a reduced amount of fruits and vegetables
5. We eat less protein, antioxidants and calcium
Omega-6 fatty acids are found abundantly in our diets – most seeds, nuts, vegetable fats (vegetable seed oils) are omega 6 rich. By contrast our diets are generally low in omega-3 fats: short chain omega-3 fats (alpha linolenic acid) are found in flaxseeds and walnuts (as well as chia and perilla seeds) and in their longer chain forms (EPA eicosapentaenoic acid and DHA docosahexaenoic acid) are found in oily fish. The long chain omega-3 fats seem particularly important for our health and are found in concentrated amounts in the human brain. The body can use the short chain omega-3 fats from the diet to form the longer-chain EPA and DHA forms but the process is far from efficient. EPA and DHA are used by the body to produce the biological chemicals which have potent anti-inflammatory effects. As a nutritionist I feel that it is essential we work toward increasing the intake of omega-3 and decreasing the intake of omega-6 fats in our diets in order to redress the omega-6:omega-3 balance (2).
If you feel that you do not eat oily fish regularly (you may be vegetarian or vegan or example), at least twice per week, then you may wish to consider taking an omega-3 fish oil supplement that provides around 250-300mg EPA and 250-350mg DHA per day. Choose supplements that also contain vitamin E or another antioxidant since these protect the oil from degradation. For vegans and vegetarian flaxseeds and walnuts represent good sources of the short chain omega-3 fatty acid – however, a flaxseed oil supplement that provides around 500-1000mg alpha-linolenic acid daily is worth considering. Again, choose a supplement that contains a protective antioxidant. There are now some vegan EPA and DHA supplements being produced from algae. They are obtainable from only a few sources and can be expensive but their popularity and availability are rising and they are worth considering.
Dr Simopoulos offers 7 general dietary guidelines(1):
1.Enrich your diet with omega-3 fatty acids with cold-water fish, flax and walnut oil
2.Use canola, olive and flax oils as your primary oils
3.Eat seven or more servings of fruits and vegetables each day
4.Eat more peas, beans and nuts
5.Eat less saturated fat
6.Avoid oils high in omega-6 fatty acids such as corn, safflower, peanut, soyabean, sunflower and cottonseed oils – avoid products made from these oils
7.Avoid trans-fatty acids (found in many processed foods. Trans fatty acids are used in the prepared food industry to prolong the shelf life of baked goods like biscuits).
In addition to this I would add that a healthy diet is one that contains minimal amounts of processed and refined foods. Think natural!
(1)http://www.1stvitality.co.uk/pdfs/Barleans_GB_dr_Simopoulos.pdf
(2)Simopoulos AP. 2008. The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular and other chronic diseases. Exp Biol Med (Maywood). 233:674-688
Written by Ani Kowal
Related posts:
- Omega 3 fatty acids protect the heart
- Can Omega 3 fatty acids in late pregnancy reduce the risk of asthma development in children?
- Omega 3 fatty acids from fish oil may be helpful for some menopausal symptoms
- Omega 3 fatty acids for life
- Long chain omega 3 fatty acids may be helpful in treating depression
Brilliant article Ani, as ever. Well researched and written. Thanks.
Thanks Robin!