Nutraceuticals as Supportive Therapeutic Agents in Diabetes and Pancreatic Ductal Adenocarcinoma: A Systematic Review

Simple Summary Pancreatic ductal adenocarcinoma is one of the most lethal diseases, with an exceptionally poor prognosis. The successful clinical management of strongly related diabetes could significantly contribute to more efficient control of cancer development and progression. In this regard, various natural products have been explored. This review evaluates the therapeutic potential of four natural products (Curcumin-Curcuma longa L.; Thymoquinone-Nigella sativa L.; Genistein-Glycine max L.; Ginkgo biloba L.) and one nutritional intervention, in the form of a low-carbohydrate ketogenic diet in pancreatic cancer and diabetic patients, and discusses their possible integration in supportive cancer management. Although the results have shown their effectiveness in the treatment of diabetes, the therapeutic response and survival time were not significantly improved in pancreatic cancer patients, despite improvements in several biological parameters. Nevertheless, based on published data, the studied natural products and nutritional intervention can potentially become promising therapeutic approaches for pancreatic cancer risk reduction through early intervention at the onset of diabetic complications. The correlation between pancreatic ductal adenocarcinoma (PDAC) and diabetes-related mechanisms support the hypothesis that early therapeutic strategies targeting diabetes can contribute to PDAC risk reduction and treatment improvement. A systematic review was conducted, using PubMed, Embase and Cochrane Library databases, to evaluate the current evidence from clinical studies qualitatively examining the efficacy of four natural products: Curcumin-Curcuma longa L.; Thymoquinone-Nigella sativa L.; Genistein-Glycine max L.; Ginkgo biloba L.; and a low-carbohydrate ketogenic diet in type 2 diabetes (T2D) and PDAC treatment. A total of 28 clinical studies were included, showing strong evidence of inter-study heterogeneity. Used as a monotherapy or in combination with chemo-radiotherapy, the studied substances did not significantly improve the treatment response of PDAC patients. However, pronounced therapeutic efficacy was confirmed in T2D. The natural products and low-carbohydrate ketogenic diet, combined with the standard drugs, have the potential to improve T2D treatment and thus potentially reduce the risk of cancer development and improve multiple biological parameters in PDAC patients.