Nutritional Advice for Persons with Porphyria
Herbert L. Bonkovsky, MD
Wake Forest Baptist Medical Center in Winston-Salem, North Carolina
Professor of Gastroenterology
Jessy Philip, RD, PhD
Carolinas Health Care System, Charlotte, NC
Department of Medicine, Univ of CT Health Center and Univ of NC School of Medicine
Overview: Good nutrition is important for all of us, including those with porphyria. For the most part, persons with porphyria should follow the sensible and usual dietary advice of the Centers for Disease Control, the US Department of Agriculture, and other responsible and reputable governmental agencies.
Because over-nutrition and obesity are such a great problem in the USA and other western countries, it is important that patients with porphyria do their best to avoid becoming obese or gaining weight beyond their ideal body weights. The acute porphyrias [Acute Intermittent Porphyria, Hereditary Coproporphyria, Variegate Porphyria, and ALAD deficiency porphyria] may be made worse by prolonged fasting or severe ['crash'] dieting, because, in these forms of porphyria, glucose and other carbohydrates help to repress the activity of hepatic ALA synthase 1, the first enzyme of the heme synthetic pathway. In these forms of porphyria, uncontrolled up-regulation of ALA synthase 1 in the liver is a necessary component of the metabolic abnormalities that may give rise to acute attacks.
General Advice: There is no special or particular diet required or recommended for persons with porphyria. Rather, the principles of good and sensible nutrition apply. These principles call for a varied and balanced diet, particularly with avoidance of over-nutrition. Consumption of too many calories, in excess of daily needs for calorie and energy consumption, has emerged as one of the greatest public and personal health problems of Americans. The growing problem of obesity is present in much of the world, not just in North America.
Figure 1 shows current general dietary recommendations for Americans, as developed by the Department of Health and Human Services and the Centers for Disease Control. http://health.gov/dietaryguidelines/2010.asp Such advice should be followed by persons with porphyria, as well as those without. The keys are adherence to a varied and balanced diet with balanced, moderate consumption of carbohydrates, protein, and fats. To reduce the risks of cardiovascular diseases, such as atherosclerosis or heart attacks, the fats should include little or no trans-fats and preferably include a substantial proportion as unsaturated fatty acids [such as olive oil, safflower oil], rather than saturated fatty acids [such as animal fat]. The protein may be in the form of animal or vegetable protein. The carbohydrates should preferably not include large amounts of refined sugars or high fructose corn syrup, although oral or intravenous carbohydrate in the form of dextrose may be prescribed for therapy of acute attacks of porphyria. However, day in and day out, even persons with one of the acute porphyrias should not be consuming large amounts of dextrose (sugar) or fructose.
Nutritional Advice for Persons with Acute Porphyria. The acute or inducible porphyrias include Acute Intermittent Porphyria (AIP), Hereditary Coproporphyria (HCP), Variegate Porphyria (VP), and porphyria due to severe deficiency of ALA dehydratase (ALADP). Most persons that have one of these forms of porphyria, all of which are due to inherited deficiencies in one of the enzymes of heme biosynthesis, have no symptoms or signs of porphyria most of the time. They may, however, occasionally develop acute attacks, usually characterized by severe bouts of abdominal pain with increases in blood pressure and pulse rate and with severe constipation. Sometimes, the pain may be in the chest, back or extremities instead of, or in addition to, the abdomen [belly]. Such attacks are characterized by a marked up-regulation of an enzyme in the liver called delta-aminolevulinic acid synthase 1 (ALAS1). This up-regulation leads to a marked over production and urinary over-excretion of delta-aminolevulinic acid (ALA) and porphobilinogen (PBG), which are the biochemical hallmarks of acute porphyric attacks.
The treatment of such acute attacks is focused on decreasing the up-regulation of hepatic ALAS1. This is done by the administration of sugar [dextrose] and by the administration of heme, which must be given intravenously. During acute attacks, patients often have nausea and vomiting, as well as disturbances of normal gastrointestinal function, so that it is necessary for the dextrose to be administered intravenously, as well. If the attacks are less severe, however, patients may be able to take in dextrose orally, such as by adding sugar to orange juice, by sucking on hard candies, etc. During such acute attacks, the usual therapeutic recommendations by experienced physicians are for the daily intake of dextrose or other metabolizable carbohydrates to be approximately 300 grams per day.
It is also important for persons with one of the acute porphyrias to avoid drugs or other factors that are known to be able to trigger acute attacks. Chief among these are estrogen and especially progesterone. Thus, some menstruating women unfortunately experience monthly symptoms during the middle of their menstrual cycles, around the time of ovulation, when their endogenous production of progesterone is at a peak. Such women may benefit from drugs such as gonadotropin-releasing hormone antagonists [leuprolide] or low doses of oral contraceptives, which interrupt their normal monthly hormonal cycles. Some benefit from receiving prophylactic infusions of Panhematin on a monthly basis, typically administered shortly before the time of the month when they ovulate [mid-menstrual cycle].
A number of drugs and chemicals are capable of up-regulating hepatic ALAS1 and are thus best avoided by persons with acute porphyria. Such drugs include barbiturates, such as phenobarbital, hydantoins such as phenytoin and carbamazepine, sulfonamides such as sulfamethoxazole or sulfisoxazole [and many others]. Another factor that is capable of triggering acute porphyric attacks is excess intake of alcoholic beverages. Thus, persons with acute porphyria should avoid any binge drinking. Good general advice is that men should drink alcohol either not at all or not more than two drinksl per day and women should drink not all or not more than one drink of alcohol per day.
Any acute stress such as an acute illness or severe emotional or psychological stress or exhaustion may also trigger acute porphyric attacks. Therefore, patients with acute porphyria should receive vaccinations to protect them from preventable acute infections, including annual flu shots, Pneumovax [a vaccination that protects against development of pneumonias], vaccinations to protect against diphtheria pertussis and tetanus, with booster shots for tetanus at least every ten years, vaccinations to protect against hepatitis A or hepatitis B infection, and for those who have had chicken pox, the vaccination to protect against development of shingles (Zostrix).
There is no convincing clinical or scientific evidence that any particular foods (with the exception of alcoholic beverages, as described above) are capable of triggering or worsening acute porphyric attacks. There are, however, some foods that have been shown to contain chemical substances that, in large amounts, can up-regulate hepatic ALA synthase 1. Such foods include charcoal-broiled meats, cabbage, and Brussels sprouts. The amounts of such foods that would need to be eaten in order to produce induction of hepatic ALA synthase 1 have not been carefully studied, but are probably far above the amounts that would be eaten as part of reasonable, well balanced diets. None of these foods needs to be avoided completely by persons with acute porphyria, unless they have true allergies to them, which are very uncommon. Moderation in all things is the best course of action. The Appendix lists suggested meal plans for persons with acute porphyria who are of normal weight and with normal daily needs for energy [~30-35 Kcal/kg BW/d].
Dieting in Acute Porphyria. It is important that persons with acute porphyria avoid crash diets with extreme decreases in daily carbohydrate and caloric intakes. However, it is also important that they avoid obesity. If they already are obese, they should gradually lose weight. This should be done with a formal diet plan and under the supervision of an experienced physician and nutritionist.
Sulfur Containing Amino Acids and Essential Amino Acids. Our normal diets contain proteins. In fact, regular and adequate intake of protein is essential to normal growth and health. Proteins are found in both vegetable and animal sources of foods. The building blocks of proteins are called amino acids. Some of these amino acids, such as methionine and cysteine, contain sulfur. Such amino acids are not the same thing as "sulfa drugs". They are not contraindicated for patients with acute porphyria. In fact, methionine is one of the nine essential amino acids: if adequate amounts of these nine amino acids [histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine] are not consumed regularly, deficiencies will develop that can lead to malnutrition and disease. The reason is that humans are unable to make these amino acids and must take them in regularly, in order to achieve and maintain adequate levels to permit their bodies to make the hundreds of thousands of proteins that are essential for good health.
Porphyria Cutanea Tarda [PCT]. The major risk factors for the development of Porphyria Cutanea Tarda are excess alcohol intake, cigarette smoking, increased iron, certain chronic viral infections, especially hepatitis C virus and human immunodeficiency virus, and estrogens. About 20 to 25% of persons with Porphyria Cutanea Tarda (PCT) also have a genetic predisposition in the form of a inherited partial deficiency of an enzyme called uroporphyrinogen decarboxylase. However, such a deficiency in itself is not sufficient to produce symptomatic PCT; other factors are also needed.
The main dietary advice for persons with Porphyria Cutanea Tarda is to avoid all alcohol in any form. In addition, adherence to a low iron diet with avoidance of any medicinal iron and with ingestion of limited amounts of liver or red meat, is recommended, at least until remission of active PCT has been achieved. Remission is achieved by the removal of iron, usually by therapeutic phlebotomy, which is the removal of one unit of blood every week or two. This is continued until an iron reduced state has been achieved. Patients with active PCT typically require the removal of eight to twelve pints of blood, although this number is variable. The progress of iron removal is best followed with serial measurements of serum ferritin. The ideal serum ferritin is 50 to 100 ng per ml. Typically, removal of one pint of blood will lead to a decrease in serum ferritin of about 30 ng per ml. An alternative for the treatment of PCT, especially without acquired or inherited iron overload [hemochromatosis] is the use of low dose-antimalarial drugs, such as chloroquine or hydroxy-chloroquine.
Erythropoietic Protoporphyria [EPP]. In EPP there is excess production of protoporphyrin by developing red blood cells in the bone marrow. This is due usually to an inherited deficiency in an enzyme called ferrochelatase or heme synthase, the final enzyme in the heme synthetic pathway. A less common form of EPP is caused by an increase in activity of the erythroid form of ALA synthase [ALAS2], the first enzyme of the heme synthetic pathway.
Many persons with EPP have a mild degree of anemia with measures of iron that suggest iron deficiency. Some such persons appear to benefit from iron administration, although often, despite taking medicinal iron, they continue to have low levels of serum iron, increases in iron binding capacity, and low levels of serum ferritin, suggesting that they are not absorbing the iron in a normal way. For unknown reasons, a few persons with EPP and evidence of iron deficiency have seemed to worsen with iron administration. Therefore, use of medicinal iron supplements in EPP should be undertaken carefully and with careful monitoring by an experienced physician.
There also have been a few reports that intake of glucose has led to an improvement in EPP. In addition, the use of intravenous heme [which contains iron] has been found to help improve liver damage in persons with EPP.
For the most part, there is no particular special diet recommended for patients with EPP. A varied well balanced diet with avoidance of excess calories and with assurance of adequate intakes of iron and other minerals and vitamins is recommended.
Rare Cutaneous forms of Porphyria. Congenital Erythropoietic Porphyria. CEP is a rare genetic disorder characterized by deficient activity of an enzyme called uroporphyrinogen 3 synthase (also sometimes called uroporphyrinogen co-synthase). It is characterized by severe over-production of uroporphyrin 1, which is manifest at birth and in the neonatal period. There is no particular diet that is indicated or recommended for persons with CEP. The same thing may be said of the rare form of cutaneous porphyria called hepato erythropoietic porphyria, which presents in the new born period, as does CEP, but which is due to severe deficiency of uroporphyrinogen decarboxylase (homozygous or compound heterozygous deficiency).
Advice about Vitamins and Minerals: For most Americans who are consuming mixed, well-balanced diets, there is no need for routine use of vitamin or mineral supplements. Persons who consume few dairy products [milk, yogurt, cheese, etc] and older persons, especially women, and those with little exposure to sunlight are prone to develop deficiencies of vitamin D and to have inadequate intake of calcium. Thus, they should have their serum levels of 25-hydroxy vitamin D checked and should seek advice of a well-trained physician or nutritionist regarding supplements of vitamin D and calcium. There is potential harm from the excessive intake of vitamin D or calcium, or of excessive intakes of other fat-soluble vitamins [vitamins A and E]. Thus, moderation in intake is best. There is little harm, but also little likelihood of benefit, in the intake of water-soluble vitamins [vitamins B and C]. Iron may trigger or worsen Porphyria Cutanea Tarda, and it may also increase levels of hepatic ALA synthase 1. Thus, it should not be taken in medicinal form unless there is evidence of iron deficiency. There is little reason for anyone with porphyria [or most without porphyria] to take in supplemental copper, zinc, selenium, chromium, silver, gold, or other metals.
Advice about Herbal Remedies and Dietary Supplements. Herbal remedies and dietary supplements (HDS) have become popular in the USA and in many other parts of the world. In fact, there is widespread irrational enthusiasm for taking such supplements. We recommend against their use because the composition and purity of them are uncertain. They are unregulated by the US Food and Drug Administration, and they have not been shown to be safe and effective. Many of them probably contain chemicals that are capable of up-regulating hepatic ALAS1 and thus of triggering or exacerbating acute porphyria. In addition, they often are adulterated with potentially toxic substances, such as heavy metals.