The number and types of claims being made for the role and action of various nutrients to the development, health and well-being of humans, has prompted groups such as ESPGHAN to introduce to modern Nutrition a similar approach to that which is applied to claims in the field of Medicine: “Evidence-based Medicine”. Evidence-based Medicine is the integration of best research evidence with clinical expertise and patient values.
The application of the principles of “Evidence-based Medicine” to modern nutrition requires that, wherever and whenever practicable, clinical studies in humans should be the basis of substantiation for claims of clinical benefit and improved or enhanced developmental parameters. This is particularly so in relation to claims made for infant formulas.
It is recognized that ethics consideration prevents the conducting of studies with human subjects of the actions of some nutrients, their biochemical impact, and the clinical outcome of their withholding or supplementation. For this reason, the studies of some nutrients have been confined to studies in species of mammals other than humans. Examples would include Taurine, Choline, Sialic Acid, etc.
The essential fatty acids represent an area of nutrient research which lends itself to Evidence-based Nutrition. The past two decades have been a period of intense clinical studies into their effect on infant neurodevelopment. Whilst such studies can demonstrate essentiality of these nutrients in infant development, and indicate dose-relationship, it must also be recognized that their incorporation into various infant formulas does not necessarily translate into equivalence.
Various brands of infant formula can differ in nutrient profile, and particularly in the overall fatty acid profile. For this reason, only clinical studies based on that particular formulation can be considered as a basis for clinical benefit claims.
That some infant formula manufacturers elect to incorporate into their infant formulas levels of LCPUFAs significantly lower that those recommended by FAO/WHO for term infant formulas — and therefore lower than the levels of LCPUFAs used in clinical studies showing significant enhancement of neurodevelopment — point up very clearly why claims for a particular branded formula should be supported by clinical studies carried out using that particular branded formula .
More recent appreciation of the extremely low rate of metabolic conversion of dietary omega-3 “precursor” a-linolenic acid to DHA within the body has pointed up the fact that “preformed” DHA is itself an essential nutrient for appropriate infant development. Numerous clinical studies in both breast-fed infants and formula-fed infants now confirm the neurodevelopmental functional outcome benefits of adequacy of dietary LCPUFA throughout the period of infancy.
Whereas healthcare professionals are now being deluged by claims that specific “cocktails” of nutrients (e.g. nucleotides + vitamins + antioxidants + prebiotics) enhance an infant's immune-competency, we have yet to see any clinical evidence that these “cocktails” provide any beneficial outcome at all. On nthe other hand, a recent observational study carried out in a large number of pediatric clinics in Spain, has demonstrated a statistically significant reduction in the incidence of upper respiratory illness at several time points throughout infancy, when formula has LCPUFAs in line with FAO/WHO recommended levels.
Mammalian studies on the influence of perinatal choline adequacy on memory performance throughout later life, and the more recent appreciation of breast milk choline at levels higher than previously thought, have resulted in revised Adequate Intake (AI) recommendations for dietary choline intake in infancy — a result of “Evidence-based Nutrition”.
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