Nutrition Implications in Neuroendocrine Tumors and Carcinoid Syndrome

Working in clinical practice, gastrointestinal-related symptoms are a common occurrence. 

Among the variety of diseases and disorders, I see, many tend to mimic symptoms of irritable bowel syndrome (IBS). I currently practice in the oncology world and see this A LOT- both treatment and disease are leading to gut-related symptoms like bloating, gas, diarrhea, constipation, etc. and it can be difficult to manage especially in those who may already have been diagnosed with IBS.

Gastrointestinal neuroendocrine tumors (GI-NETs) are unique and rare tumors that can secrete or produce various types of amines and peptides (ex. Insulin, gastrin, vasoactive intestinal peptide, glucagon, and somatostatin). In many diagnosed with GI-NETs, especially those with advanced tumors, it is common to have carcinoid syndrome (CS). People experiencing CS also potentially develop issues with malnutrition and vitamin and mineral deficiencies (fat-soluble vitamins and nicotinic acid deficiency).

Symptoms of Carcinoid Syndrome (CS) Include:

• Diarrhea
• Flushing
• Abdominal cramping
• Low blood pressure
• Fast heart rate
• Bronchoconstriction (narrowing of the airway)

To help manage these symptoms of carcinoid syndrome it is generally recommended to limit amine-rich foods such as vasoactive amines (i.e histamine) as these can trigger the body to go into a carcinoid syndrome crisis leading to the above symptoms. Additionally, if diarrhea is present, it is recommended to limit insoluble fiber intake to better manage the frequency of bowel movements. Food You Love is a great resource to have on hand, as it provides recipes and meal plans to help you find foods to eat without feeling overwhelmed.

Examples of High Amine Foods Include:

• Aged cheeses
• Alcohol
• Smoked, salted, pickled fish/meats (herring, salami, sausage, corned beef, bologna, pepperoni)
• Any spoiled protein foods
• Yeast extracts and brewers yeast, hydrolyzed proteins
• Broad beans, sauerkraut, shrimp paste, soybean products, miso products, soy sauce, tofu

Examples of Moderate Amine Foods Include:

• Caffeine-containing foods (coffee, tea, soda)
• Chocolate
• Nuts (peanuts coconuts, brazil nuts)
• Tomatoes, bananas, raspberries, avocados

In addition to diet management to reduce symptoms associated with this type of tumor, the treatment can sometimes cause issues as well. Somatostatin analogues like octreotide and lanreotide, have been linked to exocrine pancreatic insufficiency, which can cause bloating, gas, diarrhea, and steatorrhea (fatty stools). Therefore pancreatic enzyme replacement therapy is crucial to allow normal nutrient absorption to prevent further malnutrition and vitamin/mineral deficiencies. Supplementation with fat-soluble vitamins is also often recommended due to potential deficiencies. Chemotherapy treatments that are also sometimes prescribed to treat GI-NETs also produce an abundance of gastrointestinal side effects that also affect nutrient absorption.

To help keep your gut strong, amino-acid supplementation is often recommended to help rebuild and strengthen your gut. Amino acids like L- Aspartic Acid, L-Valine, L- Serine, L- Threonine, and L-Tyrosine have been shown in research to help heal the damaged intestinal villi as well as prevent the breakdown of the gut barrier, which can lead to leaky gut. Enterade is a wonderful product that I recommend for anyone going through cancer treatment. It provides these amino acids and can also rehydrate you if suffering from vomiting and diarrhea.

As always, if you are diagnosed with a GI-NET please talk with your provider about seeing a registered dietitian. We are able to make solid, evidence-based recommendations to help you feel better and stay nourished.

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