As a cancer dietitian, I often encounter people seeking various dietary approaches to support cancer prevention, treatment, or overall health. One of the more extreme and controversial diets making waves in the health and wellness world is the carnivore diet, which involves eating only animal products—primarily meat, fish, and eggs—and excludes all plant-based foods. While its proponents claim benefits like weight loss, reduced inflammation, and improved energy, it’s important to evaluate the science behind it, particularly in the context of cancer care.
What Is the Carnivore Diet?
The carnivore diet is essentially a zero-carb, high-fat, and high-protein diet. Followers eat only animal-based foods, completely eliminating vegetables, fruits, grains, legumes, and all processed foods. It’s the opposite of plant-based eating and is akin to an extreme version of the ketogenic (keto) diet, with one key difference: it doesn’t allow any plant-based fats or oils, even those typically considered healthy.
Can the Carnivore Diet Help with Cancer Prevention?
While some proponents suggest that cutting out carbohydrates can “starve” cancer cells (since some cancer cells rely on glucose), the evidence supporting the carnivore diet for cancer prevention or treatment is limited and mostly anecdotal.
Most cancer research supports a diet rich in plant-based foods—like fruits, vegetables, whole grains, and legumes—which provide fiber, antioxidants, and phytochemicals that play a key role in reducing cancer risk. These nutrients help fight inflammation and oxidative stress, both of which are linked to cancer development. By eliminating all plant foods, the carnivore diet removes these protective compounds, which could potentially increase the risk of cancer in the long term.
Potential Benefits and Risks for Cancer Patients
Pros:
- Simplicity: For people who have difficulty digesting fiber or have food sensitivities during cancer treatment, the carnivore diet’s simplicity could be appealing.
- High Nutrient Density: Animal products provide essential nutrients like protein, B vitamins, iron, zinc, and healthy fats, which are crucial for maintaining muscle mass and energy during cancer treatment.
Cons:
- Lack of Fiber and Phytochemicals: One of the most significant concerns with the carnivore diet is the absence of dietary fiber, which is vital for gut health and may reduce the risk of colon cancer. Fiber also supports the body’s immune system and helps eliminate toxins.
- Long-Term Health Risks: A diet high in red and processed meats has been linked to an increased risk of several cancers, particularly colorectal cancer. Excessive consumption of saturated fats from animal sources may also raise the risk of heart disease.
- Gut Microbiome Disruption: A diet devoid of plant-based foods can negatively impact the gut microbiome, which affects immune function and cancer prevention. A diverse and healthy microbiome is often supported by fiber-rich plant foods.
Is There a Place for the Carnivore Diet in Cancer Care?
Cancer treatment is a physically and emotionally challenging journey. Maintaining a balanced, enjoyable diet can be a source of comfort and nourishment during this time. The carnivore diet’s restrictive approach can increase stress around food choices and may lead to disordered eating patterns. This is particularly concerning for those who already struggle with food aversions, appetite changes, or nausea during treatment.
The primary focus for survivors should be on nourishing the body with a balanced diet that promotes healing. While short-term dietary changes like reducing carbs or dramatically increasing protein may have specific benefits for some individuals, the long-term elimination of plant foods raises concerns.
Conclusion
The carnivore diet is an extreme and restrictive dietary approach that lacks scientific evidence for its use in cancer prevention or treatment. While it may provide short-term benefits for some people, its long-term impact on cancer risk is concerning. In contrast, a balanced, whole-food-based diet has benefits no matter where you are in your journey. These foods provide the protective nutrients and fiber needed to support cancer prevention and overall well-being.
OK – so you know that processed meats and excess red meat are carcinogenic but you still have so many questions. That is why I created my Processed Meats Guide- tailored for cancer survivors and anyone looking to reduce their risk. It translates the research into practical applications and answers all your burning questions about processed meats. You can feel confident knowing you are reducing your cancer risk by eliminating/reducing this group 1 carcinogen!
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References
- World Cancer Research Fund, American Institute for Cancer Research. Continuous Update Project Expert Report 2018. Diet, nutrition, physical activity, and colorectal cancer.
- Song, M., Garrett, W. S., & Chan, A. T. (2015). Nutrients, foods, and colorectal cancer prevention. JAMA Oncology, 1(1), 20-28.
- David, L. A., Maurice, C. F., Carmody, R. N., et al. (2014). Diet rapidly and reproducibly alters the human gut microbiome. Nature, 505(7484), 559-563.
- Sonnenburg, J. L., & Bäckhed, F. (2016). Diet-microbiota interactions as moderators of human metabolism. Nature, 535(7610), 56-64.
- Farvid, M. S., Stern, M. C., Norat, T., et al. (2016). Consumption of red and processed meat and breast cancer incidence: A systematic review and meta-analysis of prospective studies. International Journal of Cancer, 138(11), 2433-2445.
This blog is not intended as medical nutrition therapy, medical advice, or diagnosis and should in no way replace consultation or recommendation from your medical professional.
