There are also red, yellow, and green lights for the diet of phenylketonuria

Phenylketonuria (PKU) is an autosomal recessive genetic disease. Due to the lack or dysfunction of phenylalanine hydroxylase (PAH) in the patient's body, phenylalanine (Phe) cannot be normally metabolized into tyrosine (Tyr), causing phenylalanine and its metabolites to accumulate in the blood and tissues. If not treated in time, it can lead to intellectual disability, nervous system damage and other problems in patients.

Neonatal screening data show that the average incidence of hyperphenylalaninemia (HPA) in the Chinese population is about 1/11,000. In general, phenylalanine hydroxylase deficiency is divided into:

Mild HPA: 120-360umol/L

Moderate PKU: 360-1200 umol/L

Classic PKU: ≥1200 umol/L

Both mild PKU and classic PKU require a low-phenylalanine diet to manage the condition.

So what should we pay attention to in our daily diet?

1. Eat properly using the traffic light diet

1. "Red light" foods: These foods have a high phenylalanine content and are generally high-protein animal foods and soy products, which should be avoided, such as meat, fish, eggs, milk, beans, nuts, and foods with added gelatin and aspartame.

2. "Yellow Light" Foods: Most cereal foods, such as rice, wheat, quinoa, oats, corn, etc., as well as milk, bread and other foods, need to be limited in consumption (their protein contains high levels of phenylalanine) and should be avoided in large quantities. Potatoes, vermicelli, starch, low-protein rice/noodles, etc. can be used to replace some cereals as staple foods.

3. “Green light” foods: most vegetables, fruits (except dried figs), corn flour, potato flour, tapioca flour, kudzu powder, pure sugars, oils and fats, and common condiments (soy sauce should be limited to less than 2 tablespoons per day). For infants or children with low dietary intake, special medical foods without phenylalanine can be selected to ensure nutritional intake while controlling phenylalanine intake.

2. Pay attention to supplementing vitamins and minerals

Due to the large number of dietary restrictions, children may not take in enough vitamins and minerals. Therefore, we should combine the clinical biochemical test report with the child's condition and follow the doctor's advice to determine whether supplements are needed.

3. Learn about food labels

Parents and children should learn how to read food labels to understand whether the food contains foods rich in phenylalanine, which will help them better manage their diet.

4. Develop a personalized diet plan

Each patient has a different tolerance, so a personalized diet plan needs to be developed in the clinical nutrition department based on the individual's phenylalanine tolerance and nutritional needs.

5. Monitoring phenylalanine levels

Regularly test the phenylalanine level in your child's blood and adjust the diet plan based on the test results.

Parents, please note that dietary management for children with phenylketonuria is a lifelong task. Through strict dietary control and appropriate treatment, most patients can grow and develop normally.

References:

[1] Gu Xuefan. Clinical genetic metabolic diseases[M]. Beijing: People's Medical Publishing House, 2015.

[2] Neonatal Screening Group of the Birth Defect Prevention and Control Committee of the Chinese Association of Preventive Medicine, et al. "Consensus on Dietary Treatment and Nutritional Management of Phenylalanine Hydroxylase Deficiency." Chinese Journal of Pediatrics 57.6(2019):5.

[3] Feng Zhichun, Wang Yan, Yang Rulai. Theory and practice of prevention of genetic metabolic diseases[M]. Beijing: People's Medical Publishing House, 2023.

[4] The picture is from the Internet.

Author: Sheng Jinye, Niu Yang, Feng Yi

Instructors: Cai Wei, Tang Qingya

Department of Clinical Nutrition, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine

Project source: Shanghai Health Science Popularization Youth Talent Project (JKKPYC-2022-06)