Rows of Candy Dispensers

 If the last few months of writing about PKU has made anything clear, it is that treatment options have changed dramatically. Chances are good that medical knowledge will also continue to progress. What is possible for PKU patients (particularly those in the United States) has exceeded the expectations of prior decades.

One of the biggest changes has been the possibility that PKU patients can safely eat animal proteins, which for many of us was understood as completely off-limits. The trick for parents of children today is the reality that no one knows exactly how their child will respond to future treatment. Some people with PKU do not respond strongly to Kuvan. Some patients on Palynziq take a very long time to respond to treatment, or have side effects that cause them not to continue with the treatment option. This means parents should prepare their child for any possibility.

I have had a few parents of PKU children ask what I thought they should do to prepare their child for a future change like Palynziq. Here are my un-scientific thoughts.

  1. Manage expectations and focus on life-skills: Because you don’t know what treatment your child will respond to (or what better treatments may come available!), emphasize the importance of diet but with the hope that this may not be forever. Have discussions with your child about all the possibilities and what it all could mean. In the meantime, make social events about people rather than food. Focus on the positive skills the diet produces. Some of these include: attention to detail, planning skills, achieving goals, communication, self-advocacy, and empathy. Listen to my talk on the life lessons that come from living with PKU for more.
  2. Teach your child about all types of foods: It is natural to wonder whether teaching your child about foods they can’t eat will be difficult for them.  You know your child best, but keep in mind that nothing about the PKU diet is easy. Providing awareness and knowledge of how the rest of the world operates will give them insight, and help them be more prepared if and when they respond to a treatment that allows them to eat a normal diet. In my opinion, this also includes teaching your child how to prepare foods that are not on their diet. In reality, your child will become an adult and probably want to cook a meal for someone without PKU at some point. Although they may not be able to taste high-protein foods they prepare, it can give them a general comfort level in the kitchen. You may be surprised your child does not really want to try high-protein foods if they don’t feel like they are doing something wrong by preparing it. I remember having fun making meatballs in the kitchen with my mom as a child, and was not really interested in trying it.
  3. Include nutrition in daily phenylalanine goals: I understand this is very difficult to do, especially if your child has a very low tolerance. My phe tolerance never exceeded 350mg, or 7g of protein a day. Fruits and vegetables are natural additions to the PKU diet, so it is important to use them as a base as much as possible. For example, when serving low-protein pasta with spaghetti sauce, make sure to include some bell peppers and carrots in the dish. Add extra cucumbers, squash, tomatoes, and other low protein produce whenever and wherever possible. Add fresh herbs (check the phe) for micronutrients. I began to teach myself about nutrition in my thirties, and I was surprised at how much I did not know.  PKU makes people naturally conscious of food, and because of the very strict limits, it has been demonstrated to lead to disordered eating. Highlight the health and nutrition of food choices as much as possible over restrictions. Depending on your own household’s dietary choices, you may want to discuss the differences between nutrition in animal products versus formula. Most PKU people grow up with strong anti-animal food conditioning. If they transition to a normal diet later, this could be hard to break without preparation.
  4. Eat a wide variety of foods: Availability of food options will vary greatly depending on your geography. I have lived in primarily urban/suburban areas, which makes it easy to find produce that is ‘non-traditional.’ Eating foods on repeat for days does make the diet easier to manage. But a broader palate will likely make a transition to a higher protein diet easier. Some produce options I have appreciated include: kumquats, jicama, parsnips, yucca root, nopales (cactus), tomatillos, waterchestnuts, plantains, medjool dates, jackfruit, papaya, sauerkraut, turnips, beets, or artichoke. Always check the phe, but variety adds nutrition. Coconut and avocado are a little higher in phe but add necessary healthy fats which help with fullness. Also, I can’t verify the accuracy of this, but I was told by a neurobiologist that umami flavor is the “meat” flavor trigger in the brain. Umami seasoning can be purchased, and may help your child be more comfortable with meat flavors. This may or may not be helpful when your child is young and on a very strict diet, but may be useful as they get closer to an age where they need to transition to a different diet.

The biggest take-away is to be supportive of your child’s stage of treatment, with the awareness that they may have a dramatic treatment change in the future. This could provide hope or be a source of frustration as they have to wait, depending on the circumstances. Communication and open dialogue is key. Diet change is also a significant life event, and knowing this will make a big difference. Preparedness goes a long way, and the more we learn and share as a community, the greater our opportunities for success in the future!


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