Diet & Nutrition

Importance of nutrition in porphyria

Porphyrias are due to deficiencies in enzymes in the chemical pathway that makes heme from porphyrins and other precursor substances. This pathway of enzymes is called the heme biosynthetic pathway. Enzyme deficiencies in the porphyrias are usually inherited. However, the enzyme deficiencies alone do not produce disease. Additional factors determine whether or not there will be disease manifestations. Diet is one of the additional factors that influences the manifestations of certain types of porphyria.

The so-called acute porphyrias, which are acute intermittent porphyria, hereditary coproporphyria, variegate porphyria and ALAD porphyria are characterized by acute attacks of abdominal pain and other symptoms. Attacks of these diseases can be brought on by restricting intakes of carbohydrate and energy. (Energy is measured in calories or kilocalories.) Conversely, providing a normal or increased intake of carbohydrate and energy is part of the prevention and treatment of attacks of porphyria. Therefore, attention to diet is particularly important in these diseases.

The acute porphyrias are affected by diet, because the chemical pathway in the liver that makes heme from porphyrins and other precursor substances is very sensitive to intakes of carbohydrate and energy. In the acute porphyrias porphyrin precursors (8-aminolevulinic acid and porphobilinogen) and porphyrins are produced in excess amounts by the liver. Porphyrin precusors are in excess especially during acute attacks of porphyria.