To Reduce Cancer Risk, Plant-Based Diets May Beat Keto

Plant Based Whole Food Keto Diet

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Key Takeaways

  • Cancer is one of the leading causes of death worldwide, but knowing which dietary pattern can reduce the risk of developing cancer remains a challenge.
  • In a recent study, researchers reviewed available data focusing on the plant-based whole food diet and the ketogenic diet. They looked at how both diets relate to cancer risk and outcomes for cancer survivors.
  • The data supports the whole food plant-based diet more than the ketogenic diet. However, there are some potential benefits of going keto, so combining both diets may have unique benefits for certain people looking to lower their cancer risk.

While cancer is caused by many factors, diet, in particular, has a profound effect on a person’s risk.

Among the many diets recommended for cancer prevention and treatment, two tend to get the most attention: the ketogenic (keto) diet and a whole food plant-based diet.

In a recent review published in JAMA Oncology, researchers compared the two popular diets to see which one had more evidence supporting its potential to lower cancer risk and improve the health of cancer survivors.

The winner: Plant-based.

Keto Diet
  • High in fat

  • Moderate in protein

  • Low in carbohydrates

Plant-Based Diet
  • Low in fat

  • Moderate-to-high in carbohydrates

Study author Urvi Shah, MD, a hematologic oncologist at Memorial Sloan Kettering Cancer Center, told Verywell the review was challenging because of the volume of studies dedicated to keto diets for cancer compared to whole food plant-based diets. But using the clinical trial data they had, researchers determined a plant-based diet can better negate several risk factors for cancer, including excess fat, inflammation, insulin resistance, and elevated levels of insulin-like growth factor 1 (a protein known to promote cancer development).

Plus, because plant-based foods are also rich in phytochemicals (plant chemicals) such as flavonoids, they offer cancer-fighting antioxidant and anti-inflammatory effects, Shah said.

Plant-Based vs. Keto: What’s the Difference?

A whole food plant-based diet is focused on nutrient-dense plant-based foods, like nuts, fruits, vegetables, and beans. It’s low in fat with a moderate-to-high intake of carbohydrates. People who follow this diet also limit their intake of processed foods, oils, and animal products.

A keto diet, on the other hand, focuses more on the macronutrients consumed than specific food choices. Overall, a keto diet is high in fat, moderate in protein, and low in carbohydrates.

The study authors defined a ketogenic diet as one that is rich in animal proteins with some starchy vegetables.

Is There Any Benefit to Choosing Keto?

If the evidence favors a whole plant-based diet, are there any benefits to going keto? According to Laura Dority, MS, RD, LD, a registered dietitian who specializes in the ketogenic diet, the first thing to understand is that not all keto diets are created equal. In fact, some can rely heavily on plants.

Dority said that the phrase “ketogenic diet” is more of an umbrella term for different aspects of fat intake. One person’s keto diet may be heavy in animal-based saturated fat. But another person’s keto diet may emphasize plant-based fats, such as olive oil and avocado.

Both diets can provide the correct quantities of macronutrients to achieve ketosis—the desired effect of using fat for energy.

“There is no rule that says a ketogenic diet has to include animal products,” Dority said. “The human body can achieve ketosis with plant foods only when they are well-chosen.”

If you want to follow a keto diet that offers some of the benefits of a whole food plant-based diet, focus on incorporating:

  • non-starchy vegetables
  • avocados
  • fatty fish
  • extra virgin olive oil
  • macadamia nuts

Dority added that a keto diet may offer unique physiological benefits to people with cancer—specifically, through what’s known as the Warburg effect.

“Most cancer cells need large amounts of glucose for survival,” she said. “So, the theory of reducing carbohydrates (glucose) to help combat cancer has now flowed from a treatment approach into using this diet as a prevention tool.”

At the end of the day, Shah reminds people not to overcomplicate their dietary choices.

“When in doubt, remember that if a food is derived from plants and not processed, it is most likely going to have beneficial effects on one’s overall health, risk of obesity, diabetes, and risk of cancer,” said Shah. “Therefore, it is best to prioritize these foods, which include legumes, seeds, nuts, whole grains, fruits, and vegetables, and make this the bulk of your meals.”

What This Means For You

Both a ketogenic diet and a whole foods plant-based diet may offer health benefits in the oncology world, but marrying the two dietary patterns to create a lower-carb/higher fat plant-based whole food eating pattern could be the “sweet spot” for people trying to lower their cancer risk or support their health after having cancer.

That said, if the approach is too restrictive, emphasizing nutrient-dense foods and limiting refined sweets and carbohydrates is a healthful step.

2 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Key TJ, Bradbury KE, Perez-Cornago A, Sinha R, Tsilidis KK, Tsugane S. Diet, nutrition, and cancer risk: what do we know and what is the way forward? BMJ. 2020;368:m511. doi:10.1136/bmj.m511

  2. Shah UA, Iyengar NM. Plant-based and ketogenic diets as diverging paths to address cancer: a review. JAMA Oncol. Published online July 7, 2022. doi:10.1001/jamaoncol.2022.1769