UW-Madison study reveals new options for peopl...( MADISON For people with the genetic...)

MADISON For people with the genetic condition known as phenylketonuria (PKU), diet is a constant struggle. They can eat virtually no protein, and instead get their daily dose of this key macronutrient by drinking a bitter-tasting formula of amino acids. Yet drink it they must; deviating from this strict dietary regimen puts them at risk of developing permanent neurological damage.

In the near future, fortunately, a better option may become available.

In April, a team of University of Wisconsin-Madison researchers will publish the second of two key papers showing that a unique protein derived from whey known as glycomacropeptide, or GMP is safe for people with PKU to eat. GMP is the first known natural protein that is safe for this group, and these findings are poised to revolutionize the PKU diet. Already, Cambrooke Foods, a Massachusetts company that specializes in the manufacture of medical foods, is in the process of developing GMP-fortified snack foods for commercial sale.

"It's so important to individuals on the PKU diet to have new options, to have their diet liberalized. It's a quality-of-life issue," says Denise Ney, a professor of nutritional sciences who led the two studies. "Adolescents have an especially difficult time [staying on the diet], but it's so critical that they do."

People with PKU are born without the enzyme responsible for breaking down phenylalanine, one of the 20 major amino acids that form the proteins we eat in everyday foods. While small amounts of phenylalanine are essential for PKU patients, excess amounts stay in their bodies indefinitely and interfere with brain function. Those who go off-diet often suffer from concentration problems and depression. Some even sustain permanent brain damage. The GMP protein isolated from whey, on the other hand, is the only known dietary protein that contains only trace amounts of phenylalanine; absolutely pure GMP, in fact, is completely phenylalanine
'/>"/>