Can the Ketogenic Diet Support Cancer Treatment?
Where the science is at.
Nutrition plays a huge role in health — and for people living with cancer, it can make a real difference in how the body copes with treatment and recovery.
In recent years, researchers have been taking a closer look at the ketogenic diet (KD) as a possible supportive therapy for cancer [1].
The idea is simple but powerful: by changing how the body produces energy, the ketogenic diet may help make life harder for cancer cells — while giving healthy cells what they need to function.
What Is the Ketogenic Diet?
The ketogenic diet is a high-fat, low-carbohydrate eating plan that encourages the body to switch from burning glucose (sugar) to burning fat for energy.
When carbs are restricted, the liver produces ketones, an alternative fuel source. Healthy cells can use these ketones efficiently — but many cancer cells cannot [1,2].
Cancer cells rely heavily on glucose to grow. So by reducing glucose and insulin levels, the ketogenic diet may effectively “starve” some cancers of their main energy source.
Studies show this can slow tumour growth, increase oxidative stress in cancer cells, and may improve survival and quality of life [1–6].
How the Ketogenic Diet May Help Fight Cancer
Scientists are learning that the benefits of the ketogenic diet go well beyond reducing blood sugar. Research has shown it can influence multiple biological pathways linked to cancer growth and treatment response:
Lower glucose and insulin levels reduce signals that promote tumour growth [1–6].
Increased oxidative stress makes cancer cells more vulnerable to damage [1,2,7].
Improved mitochondrial function helps normal cells work more efficiently [7].
Reduced inflammation, which plays a major role in tumour development and spread [1,7].
Inflammation is now recognized as a driver of many cancers. The KD has been shown to lower pro-inflammatory molecules like TNF-α, IL-1β, and IFN-γ, which could help make other cancer treatments more effective [1].
Why the Ketogenic Diet Looks Promising for Brain Cancer
Some of the strongest research so far has come from studies on gliomas and glioblastoma multiforme (GBM) — aggressive brain tumours that depend almost entirely on glucose for energy.
Because glioma cells can’t use ketones efficiently, a ketogenic diet may cut off their main fuel source, creating an “energy crisis” inside the tumour [12].
This disruption can trigger oxidative stress, slow tumour cell growth, and even lead to cancer cell death. Several studies suggest that KD may work as a helpful add-on therapy for brain tumour patients, potentially improving both survival and quality of life [12].
Obesity, Diet, and Cancer Risk
Unhealthy diets and obesity have become some of the leading preventable causes of cancer.
Obesity not only raises the risk of developing cancers such as breast, liver, pancreatic, and uterine cancers — it’s also linked to poorer outcomes and higher mortality after diagnosis [8].
This link is driven by a combination of chronic inflammation, hormonal changes, insulin resistance, and altered cell signalling in fatty tissue.
Because the ketogenic diet can reduce insulin resistance and inflammation while supporting weight loss, it’s being studied as a tool for reducing obesity-related cancer risks and improving long-term survival [8].
Combining the Ketogenic Diet with Conventional Treatments
The ketogenic diet isn’t meant to replace standard treatments — but research suggests it can make them work better together.
In clinical studies, KD has been shown to be safe and well-tolerated when combined with chemotherapy [9].
It may improve quality of life, reduce fatigue, and limit chemotherapy side effects [9,13].
A 2023 study at Osaka University Hospital found that patients who continued the ketogenic diet for more than 12 months had significantly longer survival times [10].
In pancreatic cancer research, the ketogenic diet enhanced the effects of chemotherapy drugs such as gemcitabine, nab-paclitaxel, and cisplatin, slowing tumour growth and improving survival [14].
This combination effect appears to come from changes in metabolism — reduced tumour glucose, altered energy pathways, and an increase in oxidative stress that makes cancer cells more sensitive to treatment [14].
Other Cancers Under Study
Research into the ketogenic diet has expanded well beyond brain and pancreatic cancers.
Studies show encouraging results in several other types, including breast, lung, gastric, and colorectal cancers, where patients have reported improved energy levels and quality of life [5,15].
There’s even early evidence that both fasting and ketogenic diets can reduce drug toxicity during chemotherapy and make treatments easier to tolerate [13].
In some cases, the ketogenic approach has been successfully used in children with astrocytomas and in adults with lung cancer that has spread to the brain [11].
What About Side Effects?
Most people tolerate the ketogenic diet well, especially under professional guidance.
Common early side effects — such as digestive discomfort, fatigue, or low blood sugar — usually settle after the body adapts.
When properly managed, the KD is considered safe, cost-effective, and sustainable for many patients [15].
The Importance of Professional Support
If you’re thinking about trying the ketogenic diet during cancer treatment, it’s vital to have the support of a qualified dietitian or nutritionist.
They can help you adjust gradually, make sure you’re getting enough nutrients, and ensure the diet fits safely alongside your medical treatment plan [7].
Every patient’s needs are different, and close supervision helps prevent complications while maximizing potential benefits.
The Bottom Line
The ketogenic diet is not a cure for cancer — but growing evidence shows it could become a valuable complementary therapy.
By reducing glucose and insulin, calming inflammation, and making cancer cells more vulnerable to treatment, the ketogenic diet may help improve both quality of life and treatment outcomes for many people living with cancer.
As research continues, scientists are increasingly viewing the ketogenic diet not as a trend, but as a promising metabolic approach that could help reshape how we think about cancer care.
References
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Talib WH, Al-Dalaeen A, Mahmod AI. Ketogenic Diet in Cancer Management. Curr Opin Clin Nutr Metab Care. 2023;26(4):369-376.
Liu S, Zhang X, Wang W, et al. Metabolic Reprogramming and Therapeutic Resistance in Primary and Metastatic Breast Cancer. Mol Cancer. 2024;23(1):261.
Weber DD, Aminzadeh-Gohari S, Tulipan J, Catalano L, Feichtinger RG, Kofler B. Ketogenic Diet in the Treatment of Cancer – Where Do We Stand? Mol Metab. 2020;33:102-121.
Urzì AG et al. Ketogenic Diet and Breast Cancer: Recent Findings and Therapeutic Approaches. Nutrients. 2023;15(20):4357.
Küçük AN, Çiftçi S. The Role of Intermittent Fasting and the Ketogenic Diet in Cancer Disease: Can They Replace the Mediterranean Diet? Eur J Cancer Prev. 2023;32(6):533-543.
Mundi MS et al. Ketogenic Diet and Cancer: Fad or Fabulous? JPEN J Parenter Enteral Nutr. 2021;45:S26–S32.
Barrea L et al. Could Ketogenic Diet “Starve” Cancer? Emerging Evidence. Crit Rev Food Sci Nutr. 2020;62(7):1800–1821.
Hagihara K et al. Promising Effect of a New Ketogenic Diet Regimen in Patients with Advanced Cancer. Nutrients. 2020;12(5):1473.
Egashira R et al. Long-Term Effects of a Ketogenic Diet for Cancer. Nutrients. 2023;15(10):2334.
Evangeliou AE et al. Restricted Ketogenic Diet Therapy for Primary Lung Cancer With Metastasis to the Brain: A Case Report. Cureus. 2022;14(8):e27603.
Ji C et al. A Ketogenic Diet Attenuates Proliferation and Stemness of Glioma Stem-Like Cells. Int J Oncol. 2020;56(2):606-617.
Plotti F et al. Diet and Chemotherapy: The Effects of Fasting and Ketogenic Diet on Cancer Treatment. Chemotherapy. 2020;65(3-4):77-84.
Yang L et al. Ketogenic Diet and Chemotherapy Combine to Disrupt Pancreatic Cancer Metabolism and Growth. Med. 2022;3(2):119-136.
Liu S et al. Metabolic Reprogramming and Therapeutic Resistance in Primary and Metastatic Breast Cancer. Mol Cancer. 2024;23(1):261.