What are the contraindications of phenylalanine?
- Pregnant women or people suffering from liver and kidney should not take phenylalanine supplements.
- Phenylalanine supplements, in any form, should NOT be taken for more than two or three consecutive weeks.
- This supplement can produce long-term nervous symptoms like headache and/or anxiety.
- Phenylalanine supplements may raise blood pressure by its stimulating production role of epinephrine and norepinephrine, so that is not recommended for people with hypertension, or people with a family history of hypertension.
- People with antidepressant medication and medication for hypertension should not take this amino acid supplement.
- In case of illness should avoid taking supplements of phenylalanine or other amino acid without medical supervision.
- Individuals with phenylketonuria should not take this amino acid, nor sources phenylalanine as aspartame, which may be present in products that normally do not contain phenylalanine (jams, biscuits, tabletop sweeteners,…). In this case, they are labeled with the notice or warning: “contains a source of phenylalanine”.
- A diet rich in foods that contain lots phenylalanine are not suitable for people with phenylketonuria. PKU is a disease caused by people who can not properly metabolize this amino acid, which causes damage to the body as growth deficit, lesions in the central nervous system, learning disabilities, greater predisposition to kidney stones. Dietary treatment in these patients is to control the intake of this amino acid.
- In the diet for lupus, it is recommended to reduce the intake of this amino acid.
- People with cancer should avoid this amino acid supplement without medical advice, especially if suffering melanoma (Phenylalanine is degraded into tyrosine, which in turn stimulates the synthesis of melanin and may affect skin cancer).
More information on amino acids.
This article was endorsed by Elisenda Carballido - Dietitian nutritionist. Postgraduate in Phytotherapy and master in Nutrition and Metabolism.