Improved general health status in an unselected infant population following an allergen-reduced dietary intervention programme: the ZUFF-STUDY-PROGRAMME. Part II: infant growth and health status to age 6 months. ZUg-FrauenFeld

AIM OF THE STUDY

An allergen-reduced dietary intervention programme with strict dietary requirements was implemented over the first four months of life in an unselected population-based infant cohort and compared to a non-intervention cohort (the ZUFF study). Recommendations for the dietary programme in the intervention cohort were extended, but not strictly implemented, until the end of month six. The intervention was based on breastfeeding, a moderate whey hydrolysate formula (pHF), and delayed introduction of weaning foods with a high allergenicity. This study was a prospective, controlled, and unblinded study, the first to assess the effects of an allergen-reduced, pHF-based early nutritional programme in a broad unselected infant population. Because overall healthy development of the infant is a major objective of any nutritional programme, the study evaluated the effects of the dietary intervention on infant growth and general health status rather than specific allergic manifestations. Part I of this paper gave results for nutritional behaviour only, and Part II gives results for growth and general health status during the intervention period through the sixth month of life.

METHODS

Assignment of study infants was to demographically comparable intervention (Z) or control (FF) cohorts according to place of birth. In the intervention cohort (Z=564), the recommended dietary regimen was breastfeeding and--if exclusive breastfeeding was not possible--supplementation with a moderately hydrolysed, allergen-reduced infant formula (pHF). Weaning foods were delayed until four months of age or later in case of weaning foods with high allergenicity. In the control cohort (FF=566), there was no specific intervention. Imbalances between cohorts in confounding (adjuvant) factors that could influence health-related outcomes were integrated as covariates into the logistic regression of the main analyses. Growth parameters included weight, length, head circumference, BMI, and Z scores (SDS). General health status was assessed by clinically significant findings in gastrointestinal, respiratory, or skin symptoms.

RESULTS

Growth at 6 weeks and at 3 and 6 months was similar for Z and FF. Significantly fewer Z than FF infants had clinically noteworthy health findings at 3 months (Z=27% versus FF=37%, odds ratio=0.63, CI=0.48-0.82) and 6 months (Z=33% versus FF=49%, odds ratio=0.51, CI= 0.40-0.66). This corresponds to a 30 % reduction in overall health concerns at 6 months for the intervention cohort. At 3 and 6 months, differences between cohorts in most measures of general health status were strongly influenced by a lower incidence of skin symptoms in the Z cohort. Within FF, there were fewer exclusively breastfed (eBF) infants with health problems at 3 months compared with those who were partially (pBF) or non-breastfed (nBF) (eBF=31%, pBF=40%, nBF=39%, p< 0.05). In contrast, in the Z intervention cohort, the number of infants with health concerns was similar for exclusively breastfed infants and for those in whom mother's milk was supplemented or replaced by pHF (eBF=29%, pBF=25%, nBF=26%, ns). In a subanalysis of overall health findings in infants without a family risk of allergies, there were again significantly fewer Z than FF infants with any health or any skin problem.

CONCLUSION

An allergen-reduced dietary recommendation that includes a moderate whey hydrolysate infant formula (pHF) has no negative effects on growth parameters up to 6 months of life in an infant population unselected for atopic risk. The dietary intervention produced improvements in general health status when compared with a control cohort that received infant formula with unhydrolysed proteins (IF), and high allergenic weaning foods at an earlier age. The difference between cohorts was principally due to fewer adverse skin findings. (ABSTRACT TRUNCATED)

Improved general health status in an unselected infant population following an allergen reduced dietary intervention programme. The ZUFF-study-programme. Part I: Study design and 6-month nutritional behaviour

BACKGROUND

The best nutritional option for newborn infants is mother's milk. However, some newborn babies may not be exclusively breastfed during the first months of life, potentially leading to reduced overall health status and the early onset of allergic diseases in some infants. Considerable research has been devoted to the development and assessment of infant nutrition programmes, particularly to the prevention of allergies in high-risk infants. However, equal numbers of infants with and without an elevated familial risk of allergies will eventually develop allergic diseases. Therefore, optimizing nutritional programmes for the early infant population as a whole is an important--but as yet insufficiently studied--area of investigation. Moreover, although safe and effective nutrition must primarily support healthy development of the infant, few studies have evaluated the overall health benefits of nutritional interventions, but have focussed on specific allergic manifestations. In animal models, an allergen-reduced moderate whey hydrolysate formula (pHF, Nestlé Beba HA) induces the development of oral tolerance towards cow's milk proteins, without inducing sensitization. In infants with a high risk for allergies, pHF formulae reduce the early onset of allergic disease during the first 5 years of life by approximately 50% compared with a dietary regimen of unaltered proteins. At present, very little is known about the overall health benefits of such a dietary intervention on the unselected infant population as a whole.

AIM OF THE STUDY

The aim of our prospective, controlled study was to investigate the overall health benefits of an allergen-reduced nutritional programme in a newborn infant population unselected for atopic risk factors. The population in our study was as comparable as possible to the general population of healthy newborn infants. Our study included exclusive breastfeeding, use of a moderate whey hydrolysate formula (pHF, Nestlé Beba HA) if infant formula was needed, and delayed introduction of low-allergenic weaning foods. The study included assessments of compliance with the dietary programme, and evaluated nutritional habits, growth, and overall health status for 24 months. The health evaluation included allergic manifestations but did--by porpose--not define or evaluate them specifically. Part I of this paper gives results for nutritional habits during the first 6 months of life, Part II gives results for growth and general health status for the same time period, Part III will present feeding habits during the second half of the first year of life, and Part IV will present results to 24 months of age. The complete study report is published as a supplement to this journal.

METHODS

Nutritional assignment was to demographically comparable intervention (Z) or control (FF) cohorts according to the infant's place of birth. In the intervention cohort (Z, n = 564), the recommended dietary regimen was breastfeeding and/or the pHF formula, with no weaning food before 4 months of age. In the control cohort (FF, n = 566), there was no intervention. Longitudinal diet groups, defined for 4 months, excluding dropouts and noncompliants, were exclusive breastfeeding (eBF, Z, n = 201, FF, n = 162), partial breastfeeding (pBF, Z, n = 222, FF, n = 311), or non-breastfeeding (nBF, Z, n = 43, FF, n = 62). Imbalances between groups and cohorts in confounding factors that could influence health-related symptoms were integrated as covariates into the main analyses using logistic regression. Nutritional surveillance was carried out using continuous prospective monitoring.

RESULTS

The overall rate of breastfeeding, irrespective of partial or exclusive breastfeeding or the additional use of weaning foods, was similar in both cohorts at 4 and 6 months. However, from ages 3 to 6 months, significantly more Z than FF infants were exclusively breastfed (p < 0.05), and weaning foods were introduced at a significantly later age in Z t

Role of hydrolyzed formulas in nutritional allergy prevention in infants

BACKGROUND

In recent years, more and more discussions have arisen with regard to the role of (partially) hydrolyzed formulas as standard feedings for infants with a high risk to have allergy.

METHODS

This review is based on an extensive overview of the literature dealing with the subjects of allergy prevention and hydrolyzed formulas.

RESULTS

Although breast-feeding should receive absolute priority in the nutrition of infants, the existence of artificial milk formulas as an addition to or replacement of breast milk is a necessity. In high-risk infants with a family history of allergy, we might consider a hypoallergenic formula instead of the classical start formulas to reduce the risk of allergy. From a nutritional point of view, these formulas should only be hydrolyzed as much as necessary. On the other hand, for the treatment of food allergies, the peptides of the semi-elementary infant formulas should be as short as possible. This can, however, have an impact on the nutritional value of the formula. Therefore, a difference is made between partial and complete hydrolysates.

CONCLUSION

While a firm recommendation is not yet possible, physicians might consider partial hydrolysate formulas in high-risk infants if parents can afford the higher-cost option.