The International Agency for Research on Cancer (IARC) categorized processed meat as carcinogenic to humans. The associations are mainly drawn from epidemiological studies in populations that have a Western diet characterized by high intake of energy-dense and processed foods. Furthermore, the cause-and-effect relationships and the key carcinogenic drivers have yet to be documented. In recent years, an increasing number of plant-based meat alternatives have become more common on the market. These products undergo a similar or higher degree of processing than traditional processed meat products. The long-term health effects of these products have not yet been evaluated, as these products have only been available on the market for a limited time. In its third expert report, the World Cancer Research Fund (WCRF) states that it seems increasingly unlikely for specific foods, nutrients, or other components of foods to be important singular factors in terms of cancer prevention or causation. Rather, it may be our overall diet that is important for health.
The main goal of the CRC-3p project is to evaluate the association between diet and colorectal cancer (CRC) and increase the mechanistic understanding to ensure healthy, safe, and sustainable protein-rich food for the Norwegian population. CRC-3p will investigate the carcinogenic potential of proteins of both animal and vegetable origin, uncover the importance of processing degree and determine the role our dietary patterns play in colorectal cancer development. To generate new knowledge on the “diet-CRC” relationship, the CRC-3p project will study CRC-development in a sensitive mouse model, examine data from established Norwegian prospective epidemiological studies and collect new data from a CRC screening study to investigate the CRC risk associated with intake of processed proteins (meat and plant-based), in a healthy or unhealthy diet.
During 2024, the project held a kickoff meeting, and a workshop for the industry and researchers to discuss the design of the feed for the mouse studies, more specifically which protein sources and processing method - and degree - should be included in the first experiment. NMBU employed a PhD student, from August, who will focus on the mouse experiments, both planning, execution, analyses and data processing.
In 2025, we designed and started the first mouse trial. We made four different mouse feeds containing 50% commercial mouse feed, and 50% pork with varying degrees of processing, from the addition of only salt in group 1 to a mixture of additives corresponding to ultra-processing in group 4. The trial will be completed at the start of 2026 with subsequent analyses. We have also initiated a pilot to establish a method for fecal transfer of intestinal flora in the sensitive mouse model we are using. We have a research track student and a master's student associated with the experimental work together with the PhD student. In addition to experiments, the PhD student also takes courses and establishes a method for inflammatory biomarkers in colonic tissue. UiO has employed a PhD student from March 2025 who is in the process of PhD courses and the start of data analyses. Ethical approval from REK has been received and the necessary approvals from SIKT and NOWAC for access to data are being processed. The PhD student is now working on planning the analysis work and pre-registration of protocols at the same time as the course.
The project has weekly meetings with the team working with the mouse trials, monthly meetings in each work package, and work package leaders meet once every two months to ensure a good communication flow. Newsletters from the project manager are sent out twice a year. We have had a digital annual meeting for 2024 in January, and will have a physical annual meeting for 2025 at NMBU in November. An information meeting has also been held with the steering group. All the partners contribute with popular science publications, both in the online debate, websites and internal professional magazines, as well as meetings and conferences, when the opportunity arises.
The CRC-3p-project is a ground-breaking multi-disciplinary project that will use state-of-the art tools to generate new knowledge on the link between diet and colorectal cancer (CRC). The CRC-3p-project is designed to trace the carcinogenic potential of red meat and plant-based meat alternatives to reveal the significance of the protein source and the degree of processing (unprocessed, processed, ultra-processed) on CRC development. Additionally, CRC-3p seeks to elucidate how dietary patterns may influence the carcinogenic potential of the different processed foods. Essentially, CRC-3p aims to increase the mechanistic insight into diet and CRC to secure healthy, safe and sustainable protein-rich food for the Norwegian population.
