History of the PKU Diet
The first detection of PKU can be traced back to Professor Følling in Norway in 1934. The parents of two children that were not developing as they should, took urine samples to Følling, their physician, and large amounts of phenylalanine were discovered. It then became Følling’s mission to test the urine of children showing similar developmental issues across the country. Over 400 children were tested and high levels of phenylalanine were detected prevalently throughout several of the subjects.
In 1936, Lionel Penrose was the first to use ‘diet’ to treat PKU. However his initial diet of apples, sugar and not much else, caused malnutrition amongst his subjects as they were getting no protein or amino acid substitutes alongside this low protein diet.
Horst Bickel developed a treatment for Sheila Jones in 1951/2. Robert Guthrie developed newborn screening in the mid 1960s, and it was subsequently rolled out across the UK in 1969. Previously, a nappy test (urine test) was conducted on children from 1952-1969 in the UK as Følling originally had done in Norway in 1934. But it was not applied to newborns, was not very sensitive and was not done universally.
Both Bickel and Guthrie were born on the 28th June, hence why we now celebrate International PKU Awareness Day on this day each year.
The first child to be successfully treated in 1951, was unfortunately unable to maintain the diet at the time. However, it was the first time the low phe diet was deemed effective. The original diet consisted mainly of gluten-free wheat starch in water, orange juice, cabbage, turnips, butter, apples, cooked apples and banana. In 1963 the first PKU guidelines were released and registers began monitoring patient diet and uptake.
Over the years, the guidance on the ‘age’ for staying on diet has also changed. Diet only in childhood was seen as necessary in the 1960s, whereas today, ‘diet for life’ and ‘treatment for life’ are advised.
The age for staying on diet steadily increased as the IQ of PKU adults was consistently falling.
In 1960, the first manufactured protein substitutes were produced and the idea of ‘free foods’ was introduced. ‘Free foods’ are now called ‘exchange free’ foods, to avoid unrestrained eating within this food group. For example, sugary sweets might be a ‘free-food’, but if you ate them in excessive amounts, you could be susceptible to tooth decay, obesity and other health problems.
The NSPKU, consultants, dietitians, PKU researchers and companies, continue to push through studies to increase our knowledge of PKU and treatment.
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