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PKU dieting with unrestricted fruits and vegetables?

April 2, 2015

A very interesting article came out last year [1]. The paper reports on an experiment where PKU patient were allowed to eat unrestricted amounts of fruits and vegetables. More specifically, all fruits and vegetables with less than 0.75mg Phe per gram were counted as “Phe free”. Surprisingly, the blood Phe levels of the patients were “consistently good” despite the additional Phe consumed. The daily Phe tolerance of the patients thus appeared to increase by an average of 83mg per day, which is a 25% increase.

Here is the title and abstract of the paper. You can click here to read the full version.

Simplifying the diet for patients with phenylketonuria (PKU): unrestricted consumption of fruit and vegetables” By Carmen Rohde, Alena Gerlinde Thiele, Ulrike Mütze, Wieland Kiess, Skadi Beblo, Leipzig


Over a period of three years, the phenylalanine content in fruit and vegetables was not taken into account in the daily phenylalanine balance for patients with phenylketonuria, a congenital metabolic disorder. In spite of a significantly higher intake of phenylalanine, no worsening of metabolic control could be detected.

Can you imagine not having to count fruits and veggies? Now, that would make the diet so much easier to manage!


[1] Rohde C, Thiele AG, Mütze U, Kiess W, Beblo S (2014) Simplifying the diet for patients with phenylketonuria (PKU): unrestricted consumption of fruit and vegetables. Ernahrungs Umschau 61(12): 178–180

From → PKU

  1. Could you clarify a bit more how significant not counting fruits and veggies would be (for those of use without PKU knowledge)? Do they contribute much towards Phe intake normally?

    • To answer your question Dennis: Fruits and veggies contain very little Phe, in general. Because of that, they are a staple of the PKU diet. So for somebody without PKU, fruits and veggies are not at all a significant source of Phe. But people with PKU get about 25% of their Phe intake from fruits and veggies (excluding the “high” veggies such as corn and peas).

      • Wow, that 25% of one’s Phe intake could come from fruits and vegetables alone is pretty startling.

        Is it difficult as a parent to try and follow the findings of this study? To go ahead and ignore that Phe and risk causing problems? (When I tried to arrange a blind test with my gluten intake, my wife refused to be the one to randomly add the gluten because she didn’t want to be the instigator of the side-effects)

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