Tauroursodeoxycholic acid, commonly known as TUDCA, has garnered increasing attention in scientific discussions, particularly concerning its potential relevance to cancer. This overview aims to provide a clear understanding of TUDCA, its biological functions, and the current scientific perspectives on its relationship with cancer.
What is TUDCA?
Tauroursodeoxycholic acid is a naturally occurring bile acid found in small quantities within the human body. It forms in the digestive system when bile salts are metabolized into ursodeoxycholic acid (UDCA) by bacteria in the large intestine. UDCA then conjugates with taurine to create TUDCA. This compound is a water-soluble bile acid, distinguishing it from many other typically lipid-soluble bile acids.
TUDCA’s biological function involves aiding in the digestion and absorption of fats and fat-soluble vitamins, such as vitamins A, D, E, and K. It also protects liver cells from damage caused by more hydrophobic bile acids that can become toxic if they accumulate.
The Proposed Link Between TUDCA and Cancer
Researchers are investigating TUDCA’s potential connection to cancer due to its observed effects on cellular processes, particularly its role in reducing endoplasmic reticulum (ER) stress. The ER is a cellular “protein-folding factory” that synthesizes and correctly folds proteins. When cells experience rapid growth or nutrient deprivation, this factory can become overwhelmed, leading to misfolded proteins and ER stress.
Chronic ER stress can activate cellular pathways that allow cancer cells to survive and proliferate. TUDCA is recognized as a “chemical chaperone,” meaning it helps proteins fold correctly, alleviating cellular stress and restoring ER function. By mitigating ER stress, TUDCA is theorized to make cancer cells more susceptible to death or to slow their growth. Additionally, TUDCA exhibits anti-inflammatory properties, as inflammation can contribute to cancer development and progression.
Review of Scientific Research
Scientific investigation into TUDCA and cancer is primarily divided into preclinical research and human clinical trials. Preclinical research, including studies in cell cultures (in vitro) and animal models (in vivo), has shown promising anti-cancer effects. For instance, TUDCA has inhibited the proliferation and invasion of breast cancer cells by reducing matrix metalloproteinases (MMPs), enzymes involved in cancer metastasis. It has also slowed tumor growth or induced cell death in lab settings for specific cancers, including brain, colon, and liver cancers.
In animal models, TUDCA has attenuated the development of colitis-associated colon cancer and reduced liver cancer incidence by preventing ER stress-induced apoptosis and inflammation. However, some studies on hepatocellular carcinoma models in mice indicated TUDCA did not alter the growth of established tumors, suggesting its potential might be more in prevention than treating existing tumors. While these preclinical findings are encouraging and suggest TUDCA could be a chemopreventive agent, it is important to recognize that results from lab and animal studies do not guarantee the same effects in humans. Human clinical trial data for TUDCA as a standalone cancer treatment are currently lacking, meaning its direct application in human cancer therapy is not yet established.
Safety and Clinical Perspective
TUDCA is readily available as a dietary supplement and is not approved by the U.S. Food and Drug Administration (FDA) as a drug for cancer treatment. Its established medical use as a prescription drug is for specific cholestatic liver diseases, such as primary biliary cholangitis. When taken within recommended dosages for its approved uses, TUDCA is generally considered safe and well-tolerated.
Known side effects observed in studies are typically mild and often involve gastrointestinal issues, such as diarrhea, nausea, bloating, or constipation, especially at higher doses exceeding 1500 mg daily. These symptoms usually diminish as the body adjusts or with dose adjustments.
Given the limited research on TUDCA supplementation during pregnancy and nursing, it is advisable for individuals in these groups to avoid it unless specifically recommended by a healthcare provider.
Patients undergoing cancer treatment should avoid using TUDCA or any other supplement as a substitute for standard, proven cancer therapies. Supplements can have unknown effects or potentially interfere with the effectiveness of prescribed treatments, including chemotherapy and immunotherapy. Consulting with an oncologist or medical team is always recommended before incorporating any new supplement into a cancer care regimen.