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Taste preferences of young children with phenylketonuria (PKU) Evans S, Daly A, Chahal S, MacDonald J, MacDonald A Dietetic Department Birmingham Children’s Hospital, Steelhouse Lane, Birmingham
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The primary treatment of phenylketonuria (PKU) is a restrictive lowphenylalanine diet with a limited range of natural foods allowed. Within the confines of the dietary restriction, it is important to encourage a wide range of flavour preferences to maximize food choice. Basic taste perceptions of bitterness and sweetness are largely innate and evident at birth (1). The early introduction of bitter-tast- the confines of their dietary restricing phenylalanine (phe)-free L-amino tion (7). However, it is unknown if acid supplements from diagnosis (<14 ‘flavour imprinting’ occurs due to the days of age), may be an important in- early introduction of L-amino acids fluence on food preferences in PKU. and, if so, how long this effect may There is a sensitive learning pe- last. The aim of this controlled proriod in the first few months of life, spective study was to determine the during which unpalatable flavours flavour preferences of children with can be rendered palatable (2). Hydro- PKU and to compare these with a lysed formulas designed for cows’ group of healthy age matched control milk protein intolchildren. erance contain free There is a sensitive learning METHODS amino acids, diperiod in the first few Thirty-five children and tripeptides and with PKU aged have similar bitter flavour notes (e.g. months of life, during which four to 13 years of age following a low sulphur volatiles) to vegetables like unpalatable flavours can be phenylalanine diet providing ≤10g/ broccoli (3). There rendered palatable. day of natural prois considerable evitein, were comdence to demonpared with 35 age/ strate that children gender-matched given these formulas during infancy are more likely to controls on a normal diet. Children prefer broccoli and other bitter and tasted 10 blinded puree foods (apsour-tasting foods than children who ple, banana, strawberry, low protein received sweeter milk-based formula custard, broccoli, cauliflower, carand the effects of this on flavour pref- rot, sweet potato, lemon, coffee) in erences can continue for several years random order and rated them using after the initial exposure (4-6). So it a seven-point pictorial hedonic scale might be expected that introduction (8) (super yummy to super yucky) of L-amino acid supplements in PKU and then ranked them in preferential order. Caregivers completed a neomay have a similar impact. Parental likes and dislikes and phobia questionnaire to measure their food neophobia may also affect chil- child’s variety-seeking tendency with dren’s food choices. There is evidence respect to food (9). Caregivers also that young children with PKU eat a completed a food frequency questionlimited range of foods even within naire indicating the number of times/
NHDmag.com March 2015 - Issue 102
