Children and Omega-3 Fatty Acids

Dr Morten Bryhn explains the benefits of Omega 3 for children.

The brain and DHA

The brain has the greatest density of fat of any organ in the body. In the unborn child, fatty acids are incorporated into brain cells and the retina of the eye during the last three months of pregnancy and the process continues during the first year after birth. The most important fatty acids for the brain and retina are the polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) an omega-3 fatty acid, and arachidonic acid (ARA). DHA accumulation in the foetal brain mainly comes from the mother´s consumption of fish. Concentrations of DHA in brain tissues increase three to fivefold during the last 3 months of pregnancy and by as much again during the first 3 months of life. The accumulation of DHA in the brain continues for at least the first 2 years of postnatal life.

Brain development and fatty acids

The importance of a healthy diet during pregnancy is documented by the observation that mothers of low-birth-weight infants consumed far less polyunsaturated fatty acids than did mothers of infants with normal birth weights⁽¹⁾. Furthermore, mothers of low-birth-weight children had significantly lower levels of DHA and ARA in their red blood cells. The nutritional situation of pregnant women declines especially with respect to polyunsaturated fatty acid content⁽²⁾. The diet of pregnant women should therefore contain sufficient polyunsaturated fatty acids not only to cover their own requirements, but also that of their unborn babies. This regimen should continue after delivery since the content of DHA in mothers’ milk is directly related to the diet or dietary supplementation taken⁽³⁾. Most women choose to give birth to children during a fairly short period of their lives. Serial births lead to a depletion of DHA in women, continuously reducing the availability of this important fatty acid for the youngest children⁽¹⁾.

Development of vision and intelligence

DHA is highly enriched in the retina of the eye. This marine fatty acid is a structural component of the tissue responsible for the conversion of light energy into electrical impulses. Visual acuity in babies born at term who were given an infant formula fortified with DHA was significantly better than in those given a standard formula⁽⁵⁾. Even though visual acuity will improve as a function of the child growing up and gaining access to fatty acids by its own dietary efforts, a situation with sub-optimal vision at birth may affect basic problem solving and other early signs of intellectual development. Even though an unborn child is given priority ahead of its mother when given access to a supply of essential polyunsaturated fatty acids, an inferior diet on the mother’s part may reduce the chances of normal intelligence development in her child. It has been demonstrated that access to essential polyunsaturated fatty acids early in life is important for intellectual development during the first years, and that it can also have an impact on IQ, school abilities and academic performance up to the age of 18⁽⁶⁾.

Omega-3 fatty acids and hyperactivity

Attention deficit-hyperactivity disorder (ADHD) is characterised by the inability to sustain attention, to modulate activity level or to moderate impulsive actions. Two clinical studies using omega-3 fatty acids have paved the way for better understanding, treatment and prevention of this disabling disease by the use of food supplements containing essential polyunsaturated fatty acids.

The prevalence of ADHD is estimated at about 7% of all children, with boys more often affected than girls⁽⁷⁾. It is a chronic condition with symptoms that last a lifetime. In fact more than 50% of the inmates in UK prisons have been given this diagnosis, a fact that underlines the social consequences of the disease. The ADHD child may have normal learning abilities but the ADHD symptoms block his or her normal acquisition of skills and social adaptation. Alienation and poor ability to adapt to a social lifestyle are very often the long-term effects that these children have to live with.

Genetic factors play an important role⁽⁸⁾, but environmental conditions may also be important. Western-style diet has been blamed for the increasing prevalence of the disease. As regards fat intake, no differences have been recorded in the intake of polyunsaturated fatty acids between ADHD children and normal age-matched controls⁽⁹⁾. However, there are different types of polyunsaturated fatty acids, with different effects on mental behaviour. Violent behaviour, for example, has been attributed to a high intake of linoleic omega-6 fatty acid from plant oils⁽¹⁰⁾. Marine omega-3 fatty acids, on the other hand, have been shown to have the opposite effect⁽¹¹⁾.

With these observations in mind, Richardson and co-workers in Oxford have performed two controlled studies in ADHD children, one in Belfast⁽¹²⁾ the other in the Durham region of the UK⁽¹³⁾. Forty-one and 117 children respectively, were given either treatment with polyunsaturated fatty acids, mainly omega-3 fatty acids or placebo for a period of 12 weeks.

Group differences in change scores all favoured the active treatment compared with placebo. Treatment appeared to reduce ADHD-related symptoms even though no effects were recorded on motor skills. These findings are very interesting, bringing hope to the parents of ADHD children. The question arises as to whether just one of the polyunsaturated fatty acids used in the studies was responsible for the effects, or whether they should be taken in combination. In a study from the US on ADHD children, only one of the marine omega-3 fatty acids, DHA was used alone⁽¹⁴⁾. Interestingly no clinical benefits could be recorded in this study. This indicates that EPA, which was the main constituent of the PUFA combination used in the British studies, was responsible for the positive outcome. “The current balance of evidence raises the possibility that EPA may be the important component in reducing ADHD symptoms⁽¹²⁾.”

Children should increase their intake of marine omega-3 fatty acids by eating more fatty fish like salmon, trout, mackerel, tuna, sardines, and anchovies. A marine omega-3 food supplement for children is an option for children who do not like fish or who do not get enough in their diet. For normal development of intellectual capacity, vision and skills, a combination of the omega-3 fatty acids should be taken. However, for children with diagnosed ADHD, omega-3 containing sufficient amounts of EPA concentrate should be tried in combination with behavioural therapy and reduction of sugar intake. The dose of EPA in the Durham study was 600 mg daily. In teenagers and adults the dose should probably be doubled.

REFERENCES

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Article issued: 25 October 2005

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Article by
Dr Morten Bryhn
Dr Morten Bryhn is a medical doctor specialising in Cardiology and Internal Medicine with a PhD in Cardiology. He has published a number of scientific articles and given many lectures in the field of therapeutic use of Omega 3 fatty acids.