Causes of ICP: environment
Environmental factors are thought to play a role in the development of the condition because ICP is more common in the winter months in some countries. There has been very little research conducted into the possible reasons for this variation, and at present it can’t be fully explained. Some theories include that the cause of ICP could be linked to:
- sunlight and vitamin D levels, as research studies have shown that supplementation with vitamin D can improve cholestasis in animals
- diet, as people often have a tendency to eat fattier foods in the winter
- low levels of the element selenium. More research needs to be done to investigate this.
We are asked about diet all the time. To date there is no research that suggests a particular food type to avoid or to eat more of. It makes sense to avoid, or cut down on, saturated fats such as cakes, crisps and chocolate, so healthy eating is probably the best advice we can give you. Your liver will certainly appreciate it! You may see diets advocating eating certain coloured foods or drinking lots of warm water with lemon. There isn’t any evidence that following these recommendations will harm you (although it is possible to drink too much water, believe it or not), but please still take any medications that you have been prescribed by your doctor. There is research to show that drugs like ursodeoxycholic acid can help some women, but no research to show that following specific diets will help or cure ICP. We very much hope that this will change in time. When and if research does uncover a diet that can really help we will be the first to let you know. You may be interested in the Metabolic Profile Study currently being conducted at Imperial College London, which is investigating aspects of diet related to ICP.
Some women are diagnosed with ICP following a course of penicillin-based antibiotics. Although the exact nature of the link between infection, antibiotics and ICP is not clear, research has identified a common genetic change in both women with ICP and women with drug- (antibiotic-) induced cholestasis. Whilst this does not mean that the antibiotics cause ICP, they may increase the woman’s chances of developing the condition. This is another of the small genetic changes that we refer to.
Reyes H et al. Selenium, zinc and copper plasma levels in intrahepatic cholestasis of pregnancy, in normal pregnancies and in healthy individuals, in Chile. J Hepatol 2000; 32: 542–549
Wikström Shemer, Marschall HU. Decreased 1,25-dihydroxy vitamin D levels in women with intrahepatic cholestasis of pregnancy. Acta Obstet Gynecol Scand 2010; 89: 1420–3.