INTRODUCTION
Colorectal cancer (CRC), the third most common cancer worldwide1, develops in the tissues of the colon or rectum. The colon absorbs water and nutrients from foods, while converting leftover waste products into feces. The fecal matter is then stored in the rectum until elimination occurs2. The primary treatment for CRC is the removal of tumors via surgery. Other treatments include radiation therapy, chemotherapy, immunotherapy, and targeted therapy. These treatments can be combined to produce better outcomes. Examples include radiation or chemotherapy before surgery to reduce tumor size or chemotherapy post-surgery to kill leftover cancer cells1,3. Cancer treatments can have adverse effects on physiological and psychological measures. During treatment, feelings of isolation, fear, and sadness are common. Extreme fatigue, digestive issues, neuropathy, increased risk of infections, and cachexia are physiological side effects seen during treatment4-6.
As of 2026, CRC is now the leading cause of cancer related deaths in Americans under the age of 50 y. The rise in early onset CRC has become more prevent and has caused researcher, clinicians and patients/care-givers to attempt to identify other factors that might help with cancer prevention, treatment outcomes, and preventing recurrence This includes dietary and nutritional interventions.
Scientists have examined nutrition as a treatment intervention for cancer patients. Nutrition interventions are of interest due to cancer’s association with a dysregulated metabolism and negative effects on the gut microbiome. Concepts like these have sparked research studies in the oncology community. Researchers have studied nutrition interventions such that limit carbohydrates, limit calories, and/or limit raw foods, but evidence is limited8-9
Influence of Nutritional Interventions on Colorectal Cancer Prevention, Treatment Outcomes, & Recurrence
1Muscle Physiology Laboratory, Department of Kinesiology, San Francisco State University, San Francisco, CA
2Strengthening Treatments with Research Integrating Diet and Exercise (STRIDE) Cancer Foundation, Santa Rosa, CA
Cesar A. Carrera Jr.1,2, Charles Masters1,2, Gio Nino Dela Cuesta1,2, Kenny Tang1,2, Brushawn Johnson1,2 , & James R. Bagley1,2
RECURRENCE
CANCER PREVENTION
DURING TREATMENT
While nutritional interventions have sparked attention, they remain under examined. Most of the oncology research focuses on the more prevalent cancer types, like breast and lung cancer. Due to the challenges of complex research design and the limited availability of cancer patients for trials, studies often analyze mixed cancer populations. Currently, there is sparse research exploring the effects of during treatment nutritional interventions on colorectal cancer outcomes, for example.
Utilizing PubMed, Google Scholar, and the SFSU Library
databases, we identified 52 research articles, reviews,
meta-analyses, and position stands on CRC and diet/nutrition.
DISCUSSION
Nutritional oncology is a developing field in clinical research, with most studies examining mixed cancer populations. Specific nutritional interventions are being investigated for more conclusive outcomes, especially in specific cancer populations like CRC. Current research, regarding fatigue, cancer control, physical function, QOL, incidence and recurrence, suggest that nutritional interventions can improve these outcomes. They also highlight the relationship between nutrition and the occurrence of gastrointestinal cancers like CRC.
Findings from this review support well-balanced, mediterranean, and immune enhancing diets in creating better outcomes in CRC patients and in preventing incidence and recurrence of CRC. These interventions share the focus of including a variety of nutrient rich foods, instead of restricting foods such as in low-carbohydrate, neutropenic, or fasting interventions. Multidisciplinary treatments showed to be an effective tool, most likely due to its focus on individualized patient care. Currently, there is insufficient evidence to recommend or not recommend restrictive or uniform nutrient rich diets. Rather, a “healthy” well-balanced diet seems to be the most beneficial for lowering risks of developing CRC, as well as CRC recurrence after treatment, and in mitigating adverse effects during treatment, while helping to control the cancer.
Table 1. Adapted from Papamichael et al., (2026)
The purpose of this perspective review is to explore the current literature examining the effects of nutritional interventions in CRC patients, specifically for the prevention and recurrence of CRC as well as interventions administered during treatment.
The aim of this review is to bring awareness to the gap in oncology research and treatment interventions, while contributing to the foundation of a clinical nutrition prescription framework.
REFERENCES
Recommended components and intakes of a well-balanced diet: