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A Fishy Tale and a Drop of Oil

by David Taylor(more info)

listed in essential fatty acids, originally published in issue 78 - July 2002


It is evident that more people are becoming aware of the importance of our diet, the food we eat and its quality. We now know to eat more fresh fruit and vegetables, cut down on meat products, go for organic and take it easy with the booze. More and more people are also looking for that special supplement that will help ease a plethora of complaints ranging from arthritis to hypertension. As with the National Health Service, working to cure our ills, we are changing our diets and taking our supplements in order to effect some sort of intervention. We have become our own Individual Illness Service, waiting for an illness or disorder to come along, and then trying to find something to 'cure' it.

But what if we didn't have these problems in the first place. What if we could take some preventative steps, do something that would minimize the chance of our illnesses and disorders manifesting themselves in the first place? Where then do we start? And what should we do?

Essential Fatty Acids

Well, take fat, for instance. We are always being told to cut down on fat, but is that strictly true? The human brain for instance is over 50% fat and about a quarter of that fat is docosahexaenoic acid (DHA). DHA is an omega-3 essential fatty acid (EFA), a vitally important ingredient for building cell membranes and the formation of new tissue. You get very high concentrations of DHA in both the brain and the eyes. As the brain has its growth spurt in the third trimester of pregnancy and during early childhood, it makes sense that levels of pre- and postnatal supplies of DHA will affect the health outcome of our children. Indeed, DHA contributes to normal foetal and neonatal growth, including neurological development, learning and behaviour and health outcomes in adult life.[1]

We cannot make these fatty acids ourselves, EFAs need to be consumed as part of the diet. As a consequence, polyunsaturated fatty acid (PUFA) levels in both the developing foetus and the mother depend entirely on maternal diet. This is especially true for DHA.[1] DHA levels in the newborn baby positively affect birth weight, birth length and head circumference (good measures of healthy babies), but levels of linoleic acid in the mother's diet have been found to act negatively on head circumference. Indeed, a diet high in trans-unsaturated fatty acids seems to be associated with lower maternal and neonatal PUFA levels. So maybe eating foods high in DHA and getting rid of those awful processed fats during pregnancy may improve the health of newborn infants and keep mum healthy as well.[1]

Research Studies

The importance of taking DHA as a preventative measure can best be illustrated by taking a look at two recent studies. In the first of these, researchers at Bristol University have shown that the breast-fed children of mothers who ate oily fish during pregnancy have better visual development than children whose mothers did not eat oily fish or who did not breast-feed. The researchers concluded that for full-term infants, breast-feeding and a mother's DHA-rich diet are major factors in enhancing the visual development of children.[2]

The second study, carried out in Denmark, found that low consumption of fish was a strong risk factor for premature births and low birth weight.[3] This research was based on current knowledge that omega-3 PUFA in amounts above 2g a day can delay spontaneous delivery and prevent the recurrence of pre-term delivery. Researchers surveyed more than 8,000 women about how often they had eaten fish during pregnancy. Their findings indicate that pregnant women with a daily intake of less than 0.15g omega-3 PUFA or 15g fish were most at risk.3 What seems likely is that DHA suppresses the formation of chemicals called prostaglandins, which in turn cause the uterus to contract.

What Our Diets Should Include

What these two studies illustrate is that DHA in our diet, either through DHA-rich food or by supplements, acts to support both mother and child both during and after pregnancy, minimizing risks and increasing health outcomes. So what should we be including in our diets? DHA is at its highest concentrations in meat, fish and eggs, and especially in such fish as tuna, trout, mackerel, anchovies and herring. It is because of this that levels of omega-3 fatty acids are a lot lower in the diets of vegans and vegetarians. However, alpha-linolenic acid (LNA) is found in flaxseed (linseed), evening primrose, borage (starflower), nuts, and other plant sources, and our body is able to convert this to DHA. Indeed, vegan and vegetarian mothers who breast-feed their infants supply both alpha-linolenic acid and DHA. On a cautionary note, vegans and vegetarians should address the levels of linoleic acid in their diet as it inhibits the synthesis of DHA from alpha-linolenic acid. The Food and Agriculture Organization/World Health Organization suggests that the ratio of linoleic acid to alpha-linolenic acid is kept between 4:1 and 10:1.[4]

There are many factors that contribute towards maternal health. Indeed, of the estimated 13 million babies born prematurely across the world, the majority die shortly after birth and those that survive risk cerebral palsy, blindness, deafness and developmental disorders. However, we can take some simple preventative steps in order to minimize the risks. Including DHA in our diets may not only keep us healthy but may also be responsible for building healthy, illness-resistant babies.


1. Hornstra G. Essential fatty acids in mothers and their neonates. The American Journal of Clinical Nutrition. 71(S): 1262S-69S. 2000.
2. Williams C et al. Stereoacuity at age 3.5 y in children born full-term is associated with prenatal and postnatal dietary factors: a report from a population-based cohort study. The American Journal of Clinical Nutrition. 73(2): 316-22. 2001.
3. Olsen S and Secher NJ. Low consumption of seafood in early pregnancy as a risk factor for preterm delivery: prospective cohort study. British Medical Journal. 324: 447. 2002.
4. Sanders TAB. Essential fatty acid requirements of vegetarians in pregnancy, lactation, and infancy. The American Journal of Clinical Nutrition. 70(3): 555S-59S. 1999.


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About David Taylor

David Taylor is a psychologist with a background in psychopharmacology and development. From working with children he developed an interest in the effects of environmental factors, particularly the effects of nutrition, upon mental and physical health. He is co-director of Optimum Nutrition North East in Durham City, with his wife Sandra, a health psychologist. They take a holistic approach to health and wellbeing focussing upon nutrition, stress and lifestyle. For more information about Optimum Nutrition North East and the services and products available Tel: 0191 3849088; E:; W:

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