Unrestricted consumption of fruits and vegetables in phenylketonuria: no major impact on metabolic control.
OBJECTIVE
The treatment of phenylketonuria (PKU) requires consistent restriction of protein intake from natural sources. Therefore, protein from all foods has to be accounted for, even the small amounts in fruits and vegetables. We studied whether free consumption of fruits and vegetables containing less than 75 mg phenylalanine (phe) per 100 g affects metabolic control in children with PKU.


METHODS
Fourteen children (2-10 years) were included in a cross-over study, with a two-week period of conventional treatment (accounting for protein from fruits and vegetables) and a two-week period with free fruit and vegetable consumption. The instruction to follow liberal fruit and vegetable consumption in the first or second study period was randomized. Detailed daily dietary records were obtained throughout the study. Phe and nutrient content was calculated. Dried-blood phe concentration was monitored daily.


RESULTS
Although total phe intake increased by an average of 58 mg per day (P=0.037) during the 2 weeks of free fruit and vegetable consumption, dried-blood phe concentrations were unchanged. Total intake of fruits and vegetables did not increase, but patients instead used the higher phe tolerance to consume more of other foods, which were calculated and accounted for.


CONCLUSIONS
Free consumption of fruits and vegetables does not impair metabolic control in PKU patients over a 2-week period.
University Hospital for Children and Adolescents, Department for Inborn Metabolic Diseases, University of Leipzig, Leipzig, Germany.
C
C
Rohde
U
U
Mütze
J F W
JF
Weigel
U
U
Ceglarek
J
J
Thiery
W
W
Kiess
S
S
Beblo
D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D015930:Diet Records; D018753:Diet, Protein-Restricted; D004044:Dietary Proteins / Q000009:adverse effects* / Q000097:blood; D002149:Energy Intake; D005638:Fruit / Q000737:chemistry*; D006801:Humans; D010649:Phenylalanine / Q000008:administration & dosage / Q000097:blood*; D010661:Phenylketonurias / Q000097:blood / Q000178:diet therapy*; D014675:Vegetables / Q000737:chemistry*
D004044:Dietary Proteins; D010649:Phenylalanine