Did you know that inflammation, however benign it sounds as a complaint, actually underlies all chronic diseases? Scientists are increasingly fascinated about its role in the body. Dr Ann Walker tells us how to avoid the risks...

The most important piece of dietary advice I give to my patients to improve their well-being is to increase their intake of omega 3 essential fatty acids (EFAs). A healthy balance of EFAs is fundamental for reducing the body’s inflammatory tendency - the underlying factor in all chronic disease. Indeed, the number of positive clinical studies published on omega 3 EFA supplements outstrip all those on other dietary supplements put together. Public awareness of these benefits is increasing and accounts for the growing popularity of fish oil supplements.

There are two families of EFAs which must be provided by diet: omega 6 EFAs (found in seed oils; sunflower and corn) and omega 3 EFAs (in fish oils and some vegetable oils). While the ideal intake ratio of omega 6:omega 3 EFAs is thought to be about 4:1, modern diets can reach a ratio of 25:1 due to excessive intakes of the 6 and a low diet of oily fish.

If the EFAs present in the cell membranes are predominantly omega 6, they can invoke a response that is excessive and cause inflammation. However, if the cell membranes contain a healthy balance of EFAs, the inflammatory response is dampened down, as the chemical messengers derived from omega 3 EFAs moderate those derived from omega 6.

Why is this important? Because inflammation underlies all chronic diseases, including cancer, heart disease, diabetes, autoimmune conditions and inflammatory conditions of skin, lungs and bowel. Hence a high omega 6:omega 3 intake ratio will exacerbate these conditions.

Two omega 3 EFAs are essential nutrients and they are not interchangeable: DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), both found in oily fish.

DHA contributes to the structure of cell membranes that are laid down in infancy and is especially important for the development of brain, nervous tissue and the photosensitive cells of the retina. In adulthood, DHA is required for the maintenance of cell health in general, particularly brain cells. Studies have shown that low levels of DHA increase the risk of Alzheimer′s disease and depression. EPA helps protect the health of the heart and arteries: it reduces risk of atherosclerosis and has a relaxing action on blood vessels, reducing blood pressure.

Food or supplements?

Useful amounts of ‘active’ omega 3 EFAs (DHA and EPA) are only provided in the diet by oily fish. If eaten at the usual recommended intake of two portions a week, this would provide an average of about 500mg of DHA plus EPA per day. Unfortunately, even this may not be enough to counter the proinflammatory effects of modern diets. Hence, the Food Standards Agency has just increased its weekly maximum recommendations for oily fish consumption to four portions for most people. Two portions are advised for pregnant women to take into account the small risk of pollutants from sea fish causing foetal damage.

Supplements can be an acceptable alternative for people who don’t like fish and a costeffective way of getting a regular supply of ‘active’ omega 3 EFAs. Dietary supplements are manufactured from fish liver oil (usually cod) and from the flesh of oily fish (fish oil). An important difference between cod liver oil and omega 3 fish oil supplements is that fish oil contains less vitamin A and can be taken during pregnancy, when intakes of this vitamin should be kept low to avoid risk of birth defects.

What to look for on the label

The omega 3 content of fish oils varies considerably. Most people don’t realize that when a product is labelled as ‘high in omega 3’, only 60% of the product, at best, consists of the ‘active’ forms. However, all good-quality products are labelled with their DHA plus EPA contents, so you can use this information to calculate how much you need. A healthy person should aim for a daily intake of 1,000mg of DHA plus EPA per day although clinical studies suggest that people with inflammatory conditions need more - up to 2,000mg DHA plus EPA per day.

My recommendations

It is important to remember that nutrition is a network and that changing one thing can affect another, particularly when increasing intake of any highly unsaturated fatty acids such as omega 3 EFAs. So, a diet needs to contain adequate levels of antioxidants (eg. by eating plenty of fruit and vegetables) alongside omega 3 supplementation to avoid oxidation (rancidity) in the body. Also, to achieve a healthy EFA balance, I recommend cutting down on seed-oil intake. Replace cooking oils such as sunflower with olive oil. Olive oil contains mostly monounsaturated fatty acids, which do not contribute to EFA balance. Similarly, fat spreads based on sunflower oil should be replaced with olive-oil-based margarines or butter.

Never buy cheap fish oils or those from non-reputable manufacturers, as these can contain excessive levels of marine pollutants. Reputable manufacturers obtain fish from cleaner seas and reduce pollutants further by distilling the oil.

I have seen many vegetarians or vegans in my clinic suffering from inflammatory conditions, such as eczema. Although they won’t take fish oil, they have responded well to supplementing with algal DHA. I recommend flaxseed oil (10 to 15ml a day or several large capsules) together with capsules of algal DHA, to give between 300-600mg per day.

Given time, even the worst inflammatory conditions such as chronic sinusitis will usually be resolved by achieving a healthy EFA balance. But remember, exchanging cell-membrane fatty acids takes time and so patience is required, as anti-inflammatory effects may not be noticed for three months or longer.

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