Abstracts

Infants with phenylketonuria (PKU), an inability to metabolize the amino acid phenylanaline (phe), have traditionally been fed artificially with formulas containing little or no phe.

This interesting Norwegian study of 74 PKU infants shows that PKU infants can be breastfed in combination with phe-free formula and achieve weight, length and head circumference within the normal range of Norwegian growth charts.

Breastfeeding rates in Norway show that 98-99 per cent of mothers initiate breastfeeding and that around three months 90 per cent are continuing to breastfeed, and longer term breastfeeding is increasing dramatically. By the time infants are diagnosed with PKU they are already being breastfed. Since the benefits of breastfeeding are of particular importance to children with PKU, this study tested various combinations of breastfeeding and phe-free formula depending on the infant's s-phe levels.

When the s-phe levels are below 1200µmoles/l the feed starts with the phe-free supplement followed by breastfeeding without restriction. For children with s-phe greater than 1200µmoles/l there is a daily and gradual decline in the amount of phe-free supplement and breastmilk is increased naturally. After hospital discharge, the child's blood levels and growth are regularly monitored.

Solid food is introduced between 4 and 6 months of age and is consumed after the phe-free supplement and breastfeeding in order to maximize the intake of human milk.

A group of scientists from the US Harvard School of Public Health and the Wagenining Centre for Food Sciences in the Netherlands review the literature on the relationship between the consumption of trans fatty acids, saturated fats and the risk of coronary heart disease.

They conclude that both metabolic and epidemiological studies indicate an adverse effect of trans fatty acids on the risk of coronary heart disease. In addition they conclude that on a "per gram basis the adverse effect of trans fatty acids appear to be stronger than that of saturated fatty acids."

In both Canada and the US, heavily hydrogenated margarines still retain a large share of margarines consumed and represent a large share of the trans fatty acids consumed. High consumption of commercially prepared foods such as baked goods, and fried fast foods (donuts and French fries) also contributes to large consumption of trans fatty acids in North America. Currently trans fatty acids are not labelled in Canada or in the US, thus there is little or no incentive for food manufacturers to reduce levels. Some high trans fatty acid foods may even be promoted as "no cholesterol", implying health benefits. The US Food and Drug Administration has recently announced plans to include trans fatty content on food labels. How this is to be done is still in question. Some suggestions are to combine the trans fatty acid content with the saturated fat content. But this does not take into account that trans fatty acids present a higher risk for heart disease. Moreover as fast foods need not be labelled, an overall reduction of trans fatty acids in the food system is required if a reduction of risk for coronary heart disease is to achieved.

Editor's note: both labeling and reduction of trans fatty acids have important implications for pregnant and lactating women in addition to risk for heart disease. Consumption of hydrogenated fats -- trans fatty acids _ reduces intakes of essential long chain fatty acids needed for neural and retinal tissue development. The role of essential fatty acids AA (arachadonic acid) and DHA is well known in providing the developing infant both pre- and post-natally and the young child with the building blocks for brain, cognitive and visual development. (See INFACT Canada Newsletter Summer 1998 _ http://www.infactcanada.ca)

Full and informative labeling as well as reduced levels of trans fatty acids in our food system are necessary measures to improve public health. In the meantime, chuck the donuts and the French fries and read labels to avoid foods with hydrogenated fats.

Low birth weight occurs in about 17 per cent of infants born worldwide; most of these are in developing countries and are born full term. Development of low birth weight infants is frequently associated with lower developmental levels, more frequent infectious diseases, and increased under-nutrition. All these are intensified by poor social circumstances.

Breastfeeding is known to have a protective effect in the incidence of infectious disease and produce higher cognitive development. This study examines how the prevalence of breastfeeding _ intensity and longitudinal prevalence -- affect both LBW and HBW infants born in poor regions of northwest Brazil.

Two parallel cohorts of 131 LBW and 131 HBW with a gestational age > 37 weeks were suitably matched and tested at 6 months and 12 months using the Bayley Scales of Infant Development. Mothers filled out questionnaires on socioeconomic data; morbidity rates including hospitalizations were assessed by trained field workers making home visits; breastfeeding frequency was recorded at every home visit for the previous 24 hours. Complementary feeding was mainly cereals, some beans and small amounts of meat in soups from about the fifth month on.

Poor socioeconomic conditions had a stronger detrimental effect on LBW. After controlling for socio-economic factors, diarrhea in the first 6 months was strongly associated with mental development at 6 and 12 months and motor development at 6 months in LBW infants but not in HBW infants.

Frequency of breastfeeding over the first 4 weeks was significantly associated with mental and motor development at 6 months in both the LBW and the HBW group. The association remained after adjustment for socio-economic variables and diarrhea morbidity but was no longer apparent at 12 months of age.

This study is unique in that it documents the relationship between daily breastfeeding frequency data and shows a close response relationship between the number of breastfeeds and infant development. Additionally it reaffirms the important protective effect of breastfeeding in poor economic circumstances.