W. Doyle

n-6 and n-3 fatty acids during early human development.

Abstract. The food intakes of pregnant women were analysed from two contrasting socio‐economic areas in London. There were significant differences in mean calorie and EFA intakes. Analysis of maternal and cord blood essential fatty acids (EFAs) in relation to birth weight, placental weight and head circumference were consistent with the dietary data. To assess the EFA tissue status of the low birth weight babies, the umbilical arteries from 14 separate babies of different birth weights were studied. Surprisingly high levels of the Mead acid (20:3 n‐9) were found, with the highest appearing in the artery from the baby with the lowest birth weight. This data may not necessarily imply an EFA deficiency, but at the least it probably indicates a remarkable thirst for long chain n‐6 and n‐3 fatty acids for fetal brain development.

The Association between Maternal Diet and Birth Dimensions

Nutrient intakes of 513 women during one week towards the end of the first trimester of pregnancy were recorded and analysed. Correlations between maternal nutrient intake and birthweight, newborn head circumference and newborn length were significant for many nutrients. These associations were found to be greatest for the babies below median weight. Maternal intake of the B vitamins notably thiamin and niacin, and minerals, notably magnesium and iron, were significantly correlated with birthweight, head circumference and length. Vitamin-mineral supplementation of the mothers during the last two trimesters of pregnancy had no significant effect on birth dimensions. It is concluded that the principal associations of maternal diet and birth dimensions probably had their origin during ovulatory maturation and early embryonic development.

Nutrition and neurodevelopmental disorders.

Since the 1960s the structural requirements for the growth, development and function of the brain have become better understood due to the recognition of the prodigious energy needs for brain development and its structural requirements for lipids. The most vulnerable period of neural development is during embryonic and fetal growth. There is now both retrospective and prospective evidence that maternal nutrition prior to conception is most important to pregnancy outcome. Our studies on maternal nutrition in pregnancy again illustrate the relationship of maternal nutrition to birthweight and head circumference. In a study of 513 pregnancies we found that nutrient intakes in mothers of low birthweight babies were well below those of mothers whose babies were in the 3.5–4.5 Kg range at which morbidity is at its lowest. Nutrient intakes tracked with birthweight, independent of smoking and alcohol up to, but not above 3,270 g. The closest correlations were obtained with the diet of the mother at or about the time of conception rather than later in the pregnancy. Our studies also reveal that premature and intrauterine growth retarded babies were born with deficits of the types of essential fatty acids (arachidonic AA, docosahexaenoic DHA acids) known to be required for brain development. Deficits of brain DHA have been found experimentally to impair visual and cognitive development and also to cause haemorrhage, not unlike peri-ventricular haemorrhage in low birthweight babies, the above evidence is suggestive of a route to test the prevention and treatement of these types of membrane related disorders.

The Association of Maternal Social Class with Maternal Diet and the Dimensions of Babies in a Population of London Women

Records of the diets of 513 London mothers towards the end of the first trimester of pregnancy have been reported previously to show the maternal nutritional intakes associated with birthweight in the optimum range, which may be assumed to approximate to basic maternal needs for reproduction. The diets associated with low birthweight and small head size were also recorded and were found to be inferior. The present paper shows social class gradients for baby size and 35 essential dietary components, providing an indication of which basic maternal nutritional needs were not always met. There was no social class gradient for intake of total energy, or the energy carriers carbohydrate and fat. There were, however, statistically highly significant social class gradients for intake of protein, seven minerals and six B-vitamins, all of which were also highly significantly correlated with birthweight. Maternal intake of these 14 components of diet fell progressively as birthweight fell, but only for the mothers of smaller babies below 3270g, the median for the study. Further increase of maternal intakes of any nutrient by mothers whose babies were above median did not apparently further increase birthweight. The social and medical problem presented by maternal nutrition is that of a minority of women who enter pregnancy with qualitatively inadequate nutritional status. This minority is found in all social classes but increases from social class I to V, and further still among single mothers. The women comprising this minority eat foods not meeting basic maternal needs for a range of nutrients characteristic of whole grains, vegetables and fruit and dairy produce, which may partly be explained by their high cost.

Nutritional status of schoolchildren in an inner city area.

Data were collected on the seven day weighed food intakes of 65 schoolchildren, aged 12-13 years, living in an inner city, socially deprived area in east London. Blood samples were collected during the week and analysed for cholesterol, serum ferritin, vitamins A, E, B-12, beta carotene, and folic acid. Boys generally fared better than girls with almost a quarter of the girls having intakes of calcium, magnesium, iron, zinc, vitamin A, and riboflavin less than the lower reference nutrient intake, an amount which, by definition, is enough for only the few people in a group who have low needs. Although the mean energy intake was close to the estimated average requirement for both boys and girls, 74% did not meet the recommended intake for fibre and a high proportion of children consumed more than 11% of their energy from saturated fat (85%) and added sugar (88%). Thirty seven per cent of the children ate no fresh fruit during the week they kept a diary and only 19% had vegetables (fresh or frozen), other than potatoes, on a daily basis. Their main sources of energy were chips, bread, and confectionery. No association was found between fat intakes and plasma cholesterol concentrations. Girls had significantly lower blood concentrations of folic acid, ferritin, and beta carotene. The findings of this study confirm the anxieties often expressed that many schoolchildren, particularly in less affluent areas, are eating diets which are unhealthy according to government recommendations.

Nutrition of women in anticipation of pregnancy.

A causal connection between maternal nutrient intake and birth outcome is not universally accepted. In this paper further empirical support is provided, particularly in relation to the impact of maternal nutrition around the time of conception or very early in pregnancy. It is argued that the hypothesis that maternal nutrition has no connection with birthweight is very easily refuted. It is suggested that there should be a new category of recommended dietary allowances; “women in anticipation of pregnancy”. The diet of 513 pregnant London women were recorded for 7 days during the first trimester of their pregnancy. Birthweight and nutrient intakes were found to be significantly correlated but only over the lower half of the birthweight range. The optimum birthweight range with the lowest perinatal and infant mortalities is 3,500–4,500 g and it is suggested that the nutrient intake of the 165 women who had babies in this optimum weight range provide tentative values for nutrient intake recommendations in anticipation of pregnancy, but are not claimed to be representative. The need for adjustments of recommendations for the individual, for example for a low body mass index, is discussed. A body mass index of 24 kg/m2 is recommended based on the median of the 165 women.

The nutritional status of women in the first trimester of pregnancy attending an inner-city antenatal department in the UK

We have previously found high rates of poor iron and folate status in women who had delivered a low birthweight baby (LBW) in an ethnically diverse inner-city area of the UK. However, little was known of the nutritional status in the local general obstetric population. We therefore investigated biochemical measures of nutritional status in the first trimester of the first pregnancy. Routine blood samples collected at the antenatal booking clinic were analysed for haemoglobin (Hb), serum ferritin, red cell folate (RCF) (n=100) and erythrocyte transketolase activation coefficient (ETKAC) for thiamin status (n=90). We found 9% of women in our sample had a low Hb level, 10% had a low serum ferritin and only one had a low RCF. This is a substantially lower number of women with biochemical deficiencies than we found previously in women three months after delivering a LBW baby. However, 34% had low thiamin status. Thiamin status was negatively correlated with gestational age at birth (r=-0.407, p<0.001). Differences in nutritional status were observed between ethnic and socio-economic groups. Hb levels differed between ethnic (p=0.001) and socio-economic groups (p=0.02), with Africans and women in manual occupations/unwaged having the lowest Hb levels. RCF levels also differed between groups (p<0.001) with Caucasians and those in non-manual occupations having highest levels. ETKAC also differed between ethnic groups (p=0.008) with Africans having the highest level indicating a poorer status. The study highlights the need to improve nutrition particularly in ethnic minorities and low income groups who are most at risk of adverse birth outcomes such as LBW.

Maternal malnutrition in the UK and low birthweight.

Most people would associate under-nutrition with third world countries but there are also serious problems in some parts of developed countries, not so much under-nutrition, but malnutrition. London can be described as a prosperous, cultured sophisticated city with a national health service that many envy. But further down the river, not far from Tower Bridge, is Hackney and another facet of London. In Hackney 10% of live births weigh less than 2.5kg. It is a multiracial inner city area of east London with one of the highest scores of overall deprivation in the UK. The level of dependence on income support is three times the national average and the level of unemployment is as high at 40% in some wards. In fact its not just Hackney, but the United Kingdom as a whole has a high incidence of low birth weight compared to other European countries. At 7% the UK has an incidence of low birth weight similar to Romania and Albania according to the WHO figures (WHO, 1992). Furthermore, the incidence of low birth weight in this country has not changed, and may even have increased, since the early 50s. The definition of low birth weight changed in 1982 from 2.5kg and under, to less than 2.5kg. So in those terms the incidence has actually increased. This paper describes studies undertaken over the last 20 years on diet and its relationship to low birth weight. The first study in 1978 compared the diets of mothers in Hackney with a more affluent part of London, Hampstead (Doyle et al., 1982; Crawford et al., 1986). The results of this study showed that Hackney mothers had significantly lower intakes of all vitamins and minerals than the Hampstead mothers, but energy intakes in the two groups were similar. This suggests that they were eating a similar amount of food but the choice of food was different between the two areas. The mean birth weight in the Hackney mothers was 300 g (over 10 ozs) lower than in Hampstead which is a considerable difference. In Hackney, 50% of the babies weighed less than 3 kg which some paediatricians believe should be the official demarcation point for low birth weight, since that is the level at which both mortality and morbidity begin to climb.

Food Intakes of Children, the DHSS, and the Prevention of Heart Disease

The DHSS recently reported on school childrens food intakes (1). Although the type of fat eaten is clearly an important issue, the DHSS study did not analyse the fat intake for its saturated and essential fatty acid content. We have explored the intakes of the children for fibre, sugar and saturated fats as well as additional vitamins and trace elements, not reported by the DHSS. The data from the DHSS survey was presented as a summary of the main food types eaten. They aggregated some food groups e.g. meat and meat products, fish and fish products, cakes and biscuits. While this approach might make little difference to protein intakes, it may be expected to make a difference to fat and essential fatty acid intakes. We have re-analyzed the childrens food intakes keeping within the confines of the food groups reported. We had to rely on certain assumptions about the nature of an ‘average’ diet; we therefore explored the possibility that our assumption of an average diet was incorrect and examined a worse and a better situation to define how much the nutrient intake varied. The result of the analyses illustrate an important principle in the context of the present concern for food and health. The only way in which we could satisfy NACNE and COMA recommendations for fat, saturated fat, fibre and sugar, without a radical change in eating habits, was by simply replacing half the ‘junk’ foods by an isocaloric amount of fresh fruit and vegetables. In addition there was a marked improvement in the intakes of beta-carotene, vitamin C, B6 and folic acid. These improvements in diet are of particular importance to children as it is well known that the period most vulnerable to nutritional distortions is during growth and development. No matter which way we looked at the data it is clear that not only are the school childrens diets unsatisfactory from the view point of prevention of cardiovascular disease in later life but they also leave much to be desired from the view point of the wide range of nutrients known to be important for general health, growth and development. If this is true for the mean values obtained, it will be even more true for the ‘high risk groups’.

Maternal Nutrition in Pregnancy: the Special Role of Dietary Fats and Socio-Economic Interactions

Maternal food intakes were assessed for one week in each trimester of pregnancy in 100 mothers from two socio-economically contrasting areas of London. There were significant differences in energy, fat and protein intakes as well as in many of the micro nutrients. There was also a significant difference in the mean birthweights with 11.8 per cent of the birthweights below 2500g and 50 per cent at or below 3000g in the lower socioeconomic group.