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.
back to the top »