Learn About Ketogenic Diet and Cancer

The ketone diet or “keto diet” is currently being evaluated for its potential role in both the prevention and treatment of cancer. However, there are some questions to consider. Cancer is not a single disease, but a large group of diseases and the keto diet can be useful for one type (or molecular subtype) but harmful for another. The answer also depends on how risk (prevention), treatment (such as chemotherapy and radiation), survival, or how it affects the risk of recurrence. We will look at past studies, potential benefits, side effects, risks, and contraindications. Importantly, if you are living with cancer, it is essential to consult an oncologist before starting any diet of any kind.

Ketogenic Diet

A ketogenic diet (also known as a “keto diet”) is a diet that is high in fat and low in carbohydrates is “neutral” in protein, and has a slightly higher amount of protein than regular western diets. Specifically, the ketogenic diet consists of the following elements:

  • Fat: 55% to 60%
  • Protein: 30% to 35%
  • Carbohydrates: 5% to 10% (for those who consume a 2000 calorie daily meal, this is equivalent to 20 to 50 grams of carbohydrates)

This is in contrast to the 2015-2020 USDA Diet Guidelines, which recommends:

  • Fat: 20% to 35% (with emphasis on healthy fat)
  • Protein: 10% to 35%
  • Carbohydrates: 45% to 65%

The ketogenic diet limits carbohydrates very significantly, but unlike many low-carb diets, which consist of 20% to 30% carbohydrates.

Keto Adaptation

The goal of a ketogenic diet is to burn fat instead of sugar (glucose) as a body energy source. When your carbohydrate intake drops significantly, your body switches to burning fat. This is the process of producing ketone bodies (keto-adaptation). (This nutritional ketosis is different from diabetic ketoacidosis, a dangerous condition that many people are familiar with).

Keto Diet and Illness

Ketogenic has been shown to lead to weight loss, at least in the short term. It has also been shown to help reduce the number of seizures of drug-resistant epilepsy and has been studied for its potential role in conditions ranging from Parkinson’s disease to autism.

Effect On Cancer Cells

There are several ways ketogenic can benefit at least some cancers.

The first is essentially cancer cells that are “starved.” Many years ago, Otto Warburg was awarded the 1931 Nobel Prize in Physiology or Medicine for the idea that sugar gives cancer (the Warburg effect). This makes sugar a devil in many areas as a cause of cancer growth, and in fact, PET scans rely on the fact that many types of cancer cells consume sugar to identify tumors. I will. However, the theory behind the ketogenic diet with cancer, rather than just being cells that are sugar bullies before normal cells develop, is to exploit the dependence of cancer on glucose. Thing.

Cancer cells differ from normal cells in many ways, including their ability to adapt to changes in the environment. From laboratory studies, it appears that at least some cancer cells have difficulty using ketones as an energy source (either because of down-regulation of the enzymes required to use ketones or because of keto-adaptation and Mitochondrial dysfunction is less likely to go through a process called a theory, because the induction of ketosis benefits normal cells and allows them to more easily adapt to metabolize ketones.

In other words, the ketogenic diet, in theory, can play a role in cancer because it affects lowering insulin levels. Studies show that both insulin and insulin-like growth factors can stimulate cancer growth.

In order for cancer to grow, it is necessary to develop new blood vessels that support the tumor, a process called angiogenesis. In a mouse model of glioma, a ketogenic diet was found to reduce angiogenesis.

Finally, it is believed that ketone bodies may actually have direct toxicity to cancer. One study examined the effects of ketone body supplementation on both laboratory-grown cancer cells and mice with metastatic cancer. In the lab, ketone supplements have been found to reduce both the health and growth of cancer cells. In mice with metastatic cancer, ketone supplementation was associated with increased survival (50% to 68% longer depending on the particular ketone body used).

Preventable Mechanism

A ketogenic diet may also theoretically work in a way that can reduce the risk of at least some cancers.

Cancer begins when a series of mutations occurs in normal cells. A genetic predisposition may exist, but most mutations are acquired overtime via oxidative stress. Free radicals are unstable molecules produced by carcinogens and normal metabolic processes in the body. The theory behind eating an antioxidant-rich diet is that antioxidants act to “neutralize” free radicals by donating electrons. Second, oxidative stress is a phrase that refers to the imbalance of free radicals and antioxidants, so that more free radicals are than antioxidants.

Ketones reduce the production of free radicals and at the same time increase the body’s antioxidant capacity. Free radicals are associated with the causes of mutations that can lead to cancer, but they are also important for people living with cancer. Cancer constantly changes and develops new mutations. In fact, it is these new mutations that provide resistance to previously effective chemotherapy and targeted therapies. Nonetheless, limiting the fruits and vegetables that can occur on a ketogenic diet can counteract this effect, as explained below, but the true effect is unknown at this time.

Another study has shown that the ketone body B-hydroxybutyrate suppresses oxidative stress.

Potential Benefits In Cancer Prevention Or Treatment

Research into the effects of the ketogenic diet on both prevention and treatment of cancer is just beginning. Since human studies to date have been relatively few, we will also look at the mechanisms by which ketosis is involved in cancer and the previous animal and laboratory studies.

Preclinical Researches (laboratory and animal)

Human cancer cells grown in the lab or in animal research do not necessarily explain what happens in humans (we share the example below), but they do play a potential role in cancer. I’m clear.

Overall, animal studies suggest that a ketogenic diet may have anti-cancer effects for most cancers. In a 2017 study review, 72% of studies showed an antitumor effect of a ketogenic diet on cancer in animals. No precancerous effects (tumor exacerbation with a ketogenic diet) were found in this review.

Other preclinical studies have shown that different types of cancer or molecular subtypes may respond differently to a ketogenic diet. For example, most cancer cells responded (the diet had an anticancer effect), but for some cancers (kidney cancer and BRAF-positive melanoma), the diet had a precancer effect. It looked like I had it. The fact that BRAF V600E-positive melanoma in a mouse model showed significant growth on a ketogenic diet implicates a different effect of a ketogenic diet on various cancer types as well as on certain molecular changes that promote tumor growth. Raises the concern that it may give.

Overall, it is important whether the ketogenic diet affects the metabolism of cancer cells. A 2019 study found that a ketogenic diet had a significant inhibitory effect on cells, which appeared to only exceed the cell’s energy supply. However, it is unclear what the mechanism is.

Most of the human studies on the ketogenic diet for cancer patients are small and currently focus primarily on safety.

The strongest evidence was found for glioblastoma, the most common and aggressive type of brain cancer. There is also good evidence of the potential benefits of a ketogenic diet in several other cancers including lung, prostate, colon, and pancreatic cancers.

Animal experiments are useful, but human situations can be different. For example, a mouse model of BRAF-positive melanoma showed significant growth on a ketogenic diet, but in a small study with only a few patients with BRAF-mutant melanoma, one could benefit from a ketogenic diet. Looked.

Recent studies of the effects of a ketogenic diet on women with ovarian or uterine cancer have focused primarily on safety, but have been encouraging in other ways. It has been found that a diet does not adversely affect women’s quality of life and has the potential to improve physical health, functioning, reducing fatigue, and reducing food cravings.

Side effects, Risks, Contraindications

All approaches to cancer require that the potential benefits be weighed against the potential risks, and it is important to consider side effects, potential risks, and situations in which the diet should not be used (contraindications).

Side Effects

When you start a ketogenic diet, you commonly experience a condition called “keto flu.” This includes fatigue, nausea, vomiting, poor exercise tolerance, constipation, and other gastrointestinal side effects.


These side effects, and the metabolic effects of a ketogenic diet, can pose several risks, including:

  • Dehydration
  • Kidney stone
  • Gout
  • Serious hypoglycemia that causes problems such as syncope

It’s also important to know that a ketogenic diet can cause false-positive alcohol breath tests.

Long-term side effects include low protein levels in the blood (hypoproteinemia), fatty liver, and deficiencies of vitamins and minerals. 1 Since diets are difficult to maintain and research is relatively new, all possible long-term effects are unknown.

Potential risks associated with cancer

Although little research has been done, there are some potential risks to consider among cancer patients before using a diet.

Food ingredients and potential deficiencies

Due to the rigors and requirements of a ketogenic diet, it can be difficult to get all the important nutrients needed for a healthy diet. In addition, increased fat can potentially be a problem. For example, a low-fat diet is associated with a lower risk of recurrence, depending on the type of breast cancer. On the other hand, a ketogenic diet may help some people lose weight. Obesity is associated with an increased risk of breast cancer recurrence.

It is also important to note that if you are dealing with cancer, or if you have an inherited disorder of fat metabolism, your body may not function as the body of a person who does not have cancer. Healthy cells can also have problems so that cancer cells cannot metabolize proteins and fats.

An important concern is limiting foods such as fruits. There are many studies that have found that people who eat many fruits and vegetables are at a low risk of cancer.

The lack of vitamin D has been raised as a concern because dairy products are restricted on some ketogenic diets. However, because some cancers are associated with lower vitamin D levels and worse outcomes, everyone with cancer determines their vitamin D levels, and oncologists at lower levels (or within the lower limits of the normal range).


The ketogenic diet limits fruits and legumes and can also reduce fiber intake. Fiber can be thought of as a “prebiotic” or food that nourishes the intestinal bacteria (microbiome). A variety of intestinal microbiomes are associated with greater efficacy for people with cancer treated by immunotherapy. Probiotics seemed ineffective, but the high fiber diet did. Fiber also helps maintain bowel function. Current USDA guidelines recommend a daily intake of 23-33 grams of fiber.

Cancer Fatigue

Cancer-related fatigue (cancer fatigue) can be exacerbated early by a ketogenic diet, and many have considered it to be one of the more troublesome side effects of cancer treatment.

Cancer Cachexia

Although praised as a way to lose weight, weight loss can be harmful to people with cancer. Cancer cachexia, a syndrome consisting of unintended weight loss and muscle wasting, is believed to be the direct cause of 20% of cancer deaths.


Avoid a ketogenic diet if you are pregnant, wish to become pregnant, or breastfeeding. Also, use with caution in people with diabetes and only under the careful supervision of a physician. There are some medical conditions in which ketogenic should never be used (contraindications). Some of these are:

  • Liver failure
  • Pancreatitis
  • Certain inherited syndromes such as primary carnitine deficiency, carnitine palmitoyltransferase deficiency, carnitine translocase deficiency, pyruvate kinase deficiency, porphyria, and other disorders of fat metabolism.

Diet and Cancer

We know that what we eat is important. Just as high-octane gasoline can help improve a car’s performance, given the right fuel, your body will work most efficiently. Studies on dietary details are just beginning. A diet high in fruits and vegetables and low in processed meat is associated with a reduced risk of many cancers, but little is known about how certain elements of our diet affect existing cancers. It is not done. Fortunately, many clinical trials designed to answer these questions are currently underway and some answers have been found. For example, intermittent fasting (long nighttime fasting) is associated with a lower risk of breast cancer recurrence.