# Nutrition and diets in primary sclerosing cholangitis
Nutrition plays an important role in primary sclerosing cholangitis (PSC). The disease affects how the body absorbs fats and certain nutrients, and research is increasingly focusing on the role of intestinal flora and bile acids in the disease process. Below is an overview of diets and eating patterns that are receiving attention in research and practice.
Fat-restricted diet
ResearchediPositive results in clinical studies, not yet standard treatment
In PSC, bile drainage can become impaired, leading to poor fat digestion. Fat-restricted diet (reduced unsaturated and saturated fats) can help reduce abdominal pain, diarrhea, and fatty stools. This pattern particularly limits animal fats and fried foods, while vegetable oils in small amounts can be better tolerated.
Research shows that many PSC patients benefit from adjustments in fat intake, especially when there are clear digestive problems. The mechanism is that less fat requires less bile production, which relieves the stressed bile ducts. However, no universal limit has been established; what works well varies per person.
Risk: prolonged strict fat restriction can lead to deficiency of fat-soluble vitamins (A, D, E, K) if not properly supplemented.
Vitamin D supplementation
ResearchediPositive results in clinical studies, not yet standard treatment
Recent research (2026) shows that vitamin D supplementation is associated with reduced risk of bile duct and liver cancer in PSC patients. Vitamin D plays a role in the inflammatory response and immune regulation, both impaired in PSC.
Many PSC patients have vitamin D deficiency, partly because it is a fat-soluble vitamin that is poorly absorbed in this disease, and partly because cholestasis (bile stasis) impairs vitamin D activation. Supplementation can thus both correct a deficiency and potentially provide protection.
Interaction: vitamins are better absorbed with fat-rich meals, but in PSC this is paradoxically difficult. A healthcare provider can determine whether supplementation via food or supplements is more appropriate.
Nutrition rich in macronutrients (proteins and carbohydrates)
ResearchediPositive results in clinical studies, not yet standard treatment
PSC is often accompanied by inflammatory bowel disease (IBD). Recent research (2026) points to sarcopenia (muscle loss) in children with PSC-IBD, especially a type where weight remains relatively normal but muscles weaken. This suggests that protein quality and intake deserve attention.
An eating pattern that contains sufficient high-quality protein (from fish, poultry, plant-based sources) and favors complex carbohydrates over refined sugars can help maintain muscle and bone mass better. This is especially important in chronic disease.
Risks: insufficient intake can accelerate deterioration of liver function and immunity; conversely, certain protein sources (red meat) can fuel inflammation.
Bile acid-aware nutrition
ExperimentaliOngoing in study setting, outcome still unknown
Recent research (2026) shows that dysbiosis (disrupted intestinal flora) in PSC-IBD leads to abnormal bile acid profiles, which in turn can promote colitis-related cancer and disease progression. This opens a new perspective: nutrition that supports healthier intestinal flora and bile acid metabolism.
Nutrition rich in fiber types (soluble fibers from oats, barley, apples; insoluble from vegetables) can promote the growth of certain bacteria that process bile acids better. This is still in the experimental phase, but the importance of the gut-liver axis in PSC is becoming increasingly clear.
Nutrition with fermentable carbohydrates (prebiotics) and fermented products (probiotics) is being studied as a way to counteract dysbiosis. However, this is not standard therapy and should be done under guidance.
Risk: certain fiber types can actually worsen abdominal symptoms if increased too quickly; individual tolerance varies widely.
Vitamin B6 monitoring
ResearchediPositive results in clinical studies, not yet standard treatment
A 2026 study shows that elevated blood vitamin B6 levels are predictive of worse outcomes in PSC, independent of geographic location. This suggests that B6 intake should not simply be increased and that certain B vitamins may metabolize differently in PSC.
This is not an argument for avoiding intake (B6 is essential), but rather for caution with excessive supplementation. Many multivitamins and energy drinks contain high doses of B6.
This requires individual adjustment; a doctor can determine whether and how much B6 supplementation is appropriate.
Mediterranean dietary pattern
ResearchediPositive results in clinical studies, not yet standard treatment
The Mediterranean dietary pattern (abundant olive oil, fish, vegetables, limited red meat, moderate dairy) is extensively studied in liver disease because of its beneficial effects on inflammation, gut flora, and bile acid metabolism. For PSC, no large randomized trials are available, but the logic is compelling: the pattern limits harmful fats, contains many antioxidants and dietary fibres, and supports a healthier microbiota.
This pattern combines well with fat restriction (through preference for plant-based oils in modest amounts) and attention to protein sources.
The risks are small; it is more of a supportive dietary pattern than a specific treatment.
Diet aimed at IBD control
ResearchediPositive results in clinical studies, not yet standard treatment
Because PSC and inflammatory bowel disease reinforce each other—both psychologically and biologically—dietary choices that help reduce IBD also have implications for PSC. A diet low in ultra-processed foods, limited in certain emulsifiers and artificial sweeteners, and rich in unprocessed ingredients, can reduce intestinal inflammation.
Research into nutritional interventions in IBD (including monodiectic treatment, elimination diet approaches) is also being investigated in PSC-IBD populations, although this remains largely experimental.
This requires individual assessment; what improves IBD can differ from person to person.
Fasting and intermittent fasting
ExperimentaliOngoing in study setting, outcome still unknown
Intermittent fasting and periodic fasting are being investigated as an anti-inflammatory strategy in liver disease. Theoretically, fasting can promote autophagy (self-digestion of damaged cells) and reduce inflammatory markers. However, no clinical evidence is available for PSC.
Given poor absorption and the risk of malnutrition in PSC, caution should be exercised. Without guidance, fasting can lead to serious deficiencies.
This is not routinely recommended without explicit supervision by a doctor and dietitian.
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**Dietary choices in PSC are always tailored.** The disease varies greatly from person to person in severity, relationship with IBD, absorption problems, and liver function. A specialized dietitian, preferably with experience in liver disease, can work together with your doctor to determine which adjustments are meaningful for your situation. Nutritional supplements, vitamins, and diets should always be coordinated with your doctor, as PSC medication and the disease itself have many interactions with diet.
_This information never replaces a doctor's judgment. Always discuss your situation with your own healthcare provider._