In recent years, scientists have uncovered the potential of diet-based strategies as an effective way to starve cancer cells and improve treatment outcomes, bringing new hope in the fight against cancer.
The ketogenic diet (KD) — a low-carb, high-fat regimen with a long history of therapeutic use — has garnered significant attention. Research suggests that this diet may slow cancer progression by placing metabolic stress on cancer cells, potentially weakening their ability to grow and spread, and making them more susceptible to anti-cancer drugs.
Carbohydrates have long been a staple in our diet, serving as the body’s primary source of energy. When we reduce carb intake, the body begins breaking down fat for energy, leading to a state called ketosis. In this state, fats are converted into ketone bodies, which circulate in the bloodstream. Normal cells can take up these ketone bodies as an alternative to glucose to produce energy (ATP) and maintain cellular functions. However, cancer cells are much less efficient at utilizing ketones, which could hinder their growth.
Ketosis can be achieved by fasting or by selective nutrition as in ketogenic diet. A diet can help you achieve ketosis without the negative effects of fasting, such as malnutrition and fatigue. This makes the ketogenic diet a cost-effective, accessible, and safe therapeutic option that can be used as a preventive or supportive treatment. However, it is crucial to follow this diet under medical supervision to ensure safety and effectiveness.
How Ketogenic Diet Works Against Cancer
The power of diet-based therapies lies in understanding and targeting the unique metabolism of cancer cells. Cancer cells have an incredibly high metabolic demand to support their growth, proliferation, and survival. Most cancer cells depend on a process called the “Warburg effect,” where they use up large amounts of glucose and ferment it into lactate, even in the presence of oxygen. This heavy dependence on glucose is a hallmark of cancer, which makes the ketogenic diet a promising therapeutic approach.
The ketogenic diet comprises high fat, moderate protein, and very low carbohydrates. The diet maintains a normal calorie intake while significantly lowering glucose levels and depriving cancer cells of their preferred energy source. This also reduces levels of Insulin-like Growth Factor 1 (IGF-1), a factor known to promote cancer growth. Meanwhile, healthy cells adapt by using ketone bodies for energy—something cancer cells are not able to do quite effectively.
What’s even more compelling is that ketosis not only disrupts cancer’s energy supply but also boosts the immune system’s ability to target and destroy cancer cells. Additionally, the ketogenic diet was shown to reduce angiogenesis—the process by which tumors create new blood vessels to support their growth. These findings highlight the potential of the ketogenic diet, especially as a complementary therapy. When paired with other treatment modalities, it holds the promise of enhancing overall therapeutic outcomes, offering doctors and patients a new approach in their fight against cancer.
Encouraging Research Data
Recent experiments offer promising insights into the ketogenic diet and its benefits in cancer treatment. Animal studies have shown encouraging results, particularly in reducing tumor growth and improving the response to immunotherapies.
A study published in Frontiers in 2024 by Dr. Pierre Bigot and team from Angers University France, demonstrated that when renal tumor cells isolated from 18 patients were exposed to ketone bodies, a significant reduction in cancer cell growth and viability was seen, paired with increased mitochondrial metabolism.
“Ketogenic diet (KD) significantly reduced renal tumor cell growth proliferation. We finally observed that a change in intratumoral immunity was associated with PD-L1 overexpression on the surface of tumor cells induced by KD.” the team stated.
They further emphasized, “This dual effect of KD may be used as an adjuvant therapy in synergy with current first line immunotherapies in the management of patients with metastatic renal cancer.”
Additionally, the isolated tumor cells were transplanted in mice to induce cancer. When the mice were fed a ketogenic diet, their tumors shrank, and they responded better to anti-PDL-1 antibody treatments.
The benefits of keto diet are not limited to one type of cancer. Research has shown positive effects in colorectal, brain, and breast cancers. However, clinical studies in this context have been very limited to date. Early trials reveal a critical nuance: the ketogenic diet alone isn’t sufficient for treating cancer. Instead, its potential lies in being used alongside conventional treatments such as immunotherapy, chemotherapy, radiotherapy, PI3K inhibitors, and antiangiogenic treatments.
A recent Keto-CARE (NCT03535701) trial explored the feasibility of achieving ketosis in women with stage IV metastatic breast cancer, proving that ketosis is indeed achievable. In the next phases they will be enrolling women with metastatic breast cancer to evaluate the effect of 6-month ketogenic diet on chemotherapy outcomes. The team will also track immune biomarkers as well as other biologic and behavioral measures.
Who Should Consider the Ketogenic Diet?
While the ketogenic diet shows promise in cancer treatment, it’s not for everyone and should always be done under medical supervision. Gradually reducing carbs is advised, making the transition smoother. Consulting a nutritionist and an oncologist is crucial before beginning the keto diet to set clear expectations, get useful resources (like meal plans and cookbooks), and ensure it aligns with your treatment goals.
It typically takes about two weeks to enter ketosis, during which time it’s important to keep daily carb intake below 50 grams (excluding fiber). However, sticking to this low-carb regimen can be challenging for some. Additionally, a ketogenic diet isn’t suitable for everyone—people with conditions like fatty acid transport disorders, porphyria, and certain metabolic diseases should avoid it. Individuals with heart disease, osteoporosis, or kidney issues, as well as pregnant women, should also be cautious.
Short-term side effects may include fatigue, dizziness, nausea, or constipation, but these usually subside as the body adjusts. Long-term risks like liver problems, kidney stones, and vitamin deficiencies can occur, so experts recommend multivitamin and mineral supplementation like calcium and vitamin D, and drinking plenty of fluids. For cancer patients, intermittent use of the ketogenic diet during chemotherapy or immunotherapy may enhance treatment outcomes.
In conclusion, while promising, there are still uncertainties about the ketogenic diet’s long-term effects and overall efficacy. Animal studies show potential, but more clinical research is needed to understand its impact on specific tumor types and how it can enhance treatments like immunotherapy, chemotherapy, or radiotherapy. Researchers are also exploring alternatives to strict keto diets, such as supplementing with ketone bodies. As studies progress, the ketogenic diet could become a very practical, easy-to-implement yet valuable strategy in targeting cancer progression and improving patient outcomes.
