Can Keto Diet help for Cancer and Why?

Why Keto Diet is suggested to help for Cancer

The keto diet produces a metabolic shift in the body known by the name of “ketosis”, during which the body stops producing glucose and starts producing ketones instead.

These ketones can be used as an alternative source of energy and nutrition for the body cells. However, it is suggested that putting the body in a state of ketosis can play a major role in stopping the development and growth of the cancer cells, and even kill them.

There are several theories explaining why the keto diet helps in treating cancer. Though, it is mostly suggested that cancer cells can only survive on glucose because they are unable to metabolize ketones to use it as a fuel for growth and development.

That’s why by restricting carbs, cancerous cells end up starving and eventually die. However, more research is still required to understand exactly what happens within this process and why the keto diet can kill cancer cells or stop their development. 

In this regard, it is important to understand that the keto diet effectiveness might vary depending on the type of cancer. In some cases, it was found that glucose restriction was able to shrink the cancer tumor and eliminate cancerous cells. Nevertheless, in other cases, the keto diet was only able to stop cancer development. This is believed to depend on the type of cancer and its vulnerability to glucose restriction. 

A recent preclinical study done in 2019 by the University of Texas at Dallas showed that a keto diet has anti-cancer effects. "Both the ketogenic diet and the pharmacological restriction of blood glucose by themselves inhibited the further growth of squamous cell carcinoma tumors in mice with lung cancer," said Dr. Jung-Whan "Jay" Kim, corresponding author of the multinational study and an assistant professor of biological sciences at UT Dallas.

Furthermore, many animal studies support these claims and have shown a decrease in tumor growth while on the ketogenic diet. For instance, a study that observed brain tumors in mice showed a 65 % size reduction by following a ketogenic diet as compared to no reduction in size while on a regular diet.

How Keto Diet works for Cancer

When carbohydrates are consumed by an individual, they are metabolized in the body and converted into glucose. Glucose being the main source of energy and nutrition used to feed the body and the brain cells.

However, the keto diet is a regimen that requires consuming 70 to 80 percent of fat, 10 to 20 percent of protein, and around 5 percent of carbohydrates only (less than 50 grams per day). Hence, by following this diet that is very low in carbohydrate, the body gets depleted from its carbohydrate reserves in few days, and the liver is not able to produce enough glucose anymore.  

Subsequently, this will deprive the body from its main source of energy: glucose. 

Faced by this situation, the body is forced to start looking for an alternative source of energy to survive. With the absence of carbohydrates, fat is the only substitute available. Accordingly, the body starts burning fat for energy instead of carbs. 

This metabolic shift produced in the body is known by the name of “ketosis”, in which the liver starts producing ketones from fat instead of glucose from carbohydrates because carbs are not available anymore.

Ketones are a great source of energy and nutrition for the normal body cells. However, it has been observed that cancer cells lack a specific enzyme that helps them metabolize ketones. Accordingly, since they are unable to utilize them for energy and nutrition, cancer cells will starve and eventually die or to the least, won’t be able to develop anymore.  

However, consuming excess protein beyond a certain amount greater than 20% of daily caloric needs, could make excess proteins go through a metabolic pathway in the body to provide additional glucose, hence feeding cancer cells.

It’s a delicate formula to follow and calculate macronutrients accordingly in order to stop the body from producing glucose and shut down the main energy source for cancer.

Keto Diet Guidelines for Cancer

A standard ketogenic diet suggests consuming approximately 80% of fat, 15 % of protein and around 5% of carbohydrates (less than 25 grams per day).

However, for cancer patients, the diet should be much more strict and proportions should reach 90% of fat, 8% of proteins, and only 2% of carbohydrates (less than 10 grams per day compared to a standard keto diet at 5% of carbohydrates). 

It is very important to properly administer and restrict the keto diet amounts to achieve growth inhibitory effects. Some researches have shown that when the diet was administered ad libitum or in unrestricted amounts, the results were not the same.

These ranges can vary depending on each cancer patient and the type of cancer. That’s why, it’s very important to always consult a medical health professional before altering any diet plan.

The goal of this food regimen is to force the body move into a state of ketosis. There is not one standard ketogenic diet for cancer, rather it is a ratio of carbohydrates, protein and fat that should be applied. 

The diet plan of the ketogenic diet is to consume high fat foods such as healthy oils, meats, fish, high fat-dairy, some nuts and non-starchy vegetables while completely avoiding sugar, high carbohydrate foods, and most fruits and low-fat products.

What are macros

It is very common to encounter the word “macros” while reading about the ketogenic diet. This term is short for macronutrients that include carbohydrates, fat and protein. These three substances provide our body with energy (calories) when we eat. 

Accordingly, if you wish to follow a ketogenic diet and make sure to maintain the “state of ketosis”, it is imperative for you to understand what are these macronutrients, and what you should do to balance them properly. 

Below is a brief explanation about each macronutrient and its main functions:

Carbohydrates:

Carbohydrates are made up of sugar and starches, and they are the body’s first source of energy. However, it is possible to survive on minimal quantities since fat and protein become the sources of energy when carbohydrates are not available. 
It is important to count net carbs as the total carbohydrate intake. Net carbs or impact carbs are common terms used in the ketogenic diet. It is the amount of carbs directly absorbed by the body that will contribute to calories, while indigestible (unabsorbed) carbohydrates that we know as dietary fiber, are subtracted from this amount.  In other words, the amount of net carbs is the total amount of carbohydrates minus the dietary fiber.

1 g of carbohydrates = 4 calories

Protein: 

Proteins have many important functions in the body since they play different roles as antibodies, enzymes and hormones. They are needed for immunity, growth, tissue repair and to preserve lean body mass.

Amino acids are what makes proteins and they are known to be the building blocks of proteins. There are twenty amino acids, nine out of them are considered to be the essential ones. These are not produced by the body, instead they come from the food we eat. 

Any deficiency in proteins intake may lead to several health conditions. That’s why the ketogenic diet requires to consume enough protein in order to preserve lean body mass. 

The general requirements are 0.8 grams per kilogram of body weight to preserve muscle mass and 0.8-1.2 grams per kilogram of body weight in order to gain muscle mass. It is important to note 0.8 g/kg is the minimal requirement to maintain good health.

1g of protein = 4 calories

Fat:

Fats provide energy for the body and support cells growth. They help the body absorb fat-soluble vitamins (vitamin A, D, E, K) and nutrients. They also help protect the organs and keep the body warm.

Fats are made up of fatty acids and glycerol. There are two essential fatty acids called linoleic acid and linolenic acid (omega 3 and 6) that the body cannot produce. Accordingly, these should come from the food we eat. 

Consuming fats is also known to influence satiety as it gives a feeling of being full for longer.

1 g of fat = 9 calories

Keto Diet for Cancer: Foods List

The various food types incorporated in the keto diet are high in good fat and very low in carbohydrates. Maintaining the proper proportions is critical to maintain the state of ketosis. Proportions should be done as per the macro calculation provided in the diet structure section.

Below is a list of the various food types for Keto diet: 

- Healthy fats: incorporate healthy high fat foods daily such as some oils (coconut, olive), avocadoes, nuts (macadamia, walnuts, almonds, pecans), and seeds (sunflower, pumpkin, sesame, flax). 

- Meat: it is suggested to consume grass-fed beef instead of grain-fed, and free-range poultry because they contain higher amounts of omega-3. Pork, bacon and organ meats can be consumed in moderation.

However, it is important to avoid eating too much meat in order to maintain the protein restrictions. It is also important to note that processed meats like sausages and cold cuts contain added carbohydrates. You should avoid them. 

- Dairy: some dairy products are allowed such as butter, high fat cheese, and high fat yogurt, because of their low lactose content. Low fat dairy products should not be consumed as they tend to be higher in carbohydrates.

- Fish: it is suggested to consume fatty fish like salmon, wild-caught fish being the best option. Avoid breaded fish because it contains carbohydrates. 

- Non-starchy vegetables: non-starchy vegetables (low carb) include leafy greens (kale, Swiss chard, spinach, lettuce), cauliflower, broccoli, Brussels sprouts, asparagus, bell peppers, onions, garlic, mushrooms, cucumber and celery. Mostly, all vegetables that grow above the ground are lower in carbohydrates, and hence can be consumed.

- Fruits: fruits that are low in net carbs such as berries are allowed. 

- Nuts: nuts can be consumed in moderation as a snack. Avoid cashews and peanuts since they are high in carbohydrates.

- Dark chocolate: 90% dark chocolate and cocoa powder are allowed. Only higher than 70% dark chocolate can be consumed. For example, one ounce (28 grams) of unsweetened chocolate (100% cocoa) has 3 grams of net carbs.

- Drinks: water is the best choice in order to stay hydrated since it has no carbohydrates. Unsweetened coffee and tea can also be consumed. It is critical not to add any sugar. For example, 1 teaspoon of sugar is equivalent to 4 grams of carbohydrates. Hence, this will make it so difficult to remain within the recommended carbohydrates amount if you add any sugar.

Keto Diet for Cancer: Recommendations to Follow

- Always check food labels: some hidden carbs may be present in spices, vegetables, and drinks. Always read food labels carefully before you buy any product.

- Always stay hydrated: make sure you always drink enough water to stay hydrated. Carbohydrates retain water in the body, so a low-carb diet can lead to dehydration and constipation.

- Consume enough salt, electrolytes, and magnesium: minerals can be lost along with water while following a keto diet. It is important to consume enough salt and take electrolytes or magnesium if necessary.

- Restrict your calories consumption: always restrict your diet within the allowed daily calories requirements. Do not exceed the recommended calories, otherwise this will result in weight gain.

Keto Diet for Cancer: What you should Avoid

- Limit grains and starches: avoid wheat-based products like rice, pasta and cereals since they are high carbohydrate sources.

- Limit sugary foods: avoid soda, beverages and juices with added sugars, smoothies, cake, and candies.

- Limit fruits: avoid fruits that are not considered low net carbs and all fruit juices because they are high carbohydrate sources.

- Limit beans and legumes: avoid eating beans, lentils and peanuts because they have high carbohydrate content.

- Limit root vegetables: avoid potatoes, sweet potatoes, carrots and parsnips because they are high in carbohydrates.

- Limit high lactose dairy: while dairy can be high in fat, most are also high in lactose sugar. Be aware of the amounts of carbohydrates present in the dairy products consumed. Avoid highly processed dairy such as ice cream because they are higher in sugar content. 

- Avoid low fat or diet products: pay attention to low fat products because they are usually high in carbohydrates.

- Limit unhealthy fats: while a high fat diet is recommended, avoid consuming too much bad fat found in processed vegetable oils and mayonnaise.

- Limit alcohol: avoid full carbohydrates wine, beers, and cocktails with added sugars.

- Avoid processed food: processed foods should be avoided even if they are low in carbohydrates. They are composed of bad fats and increase the risk of several diseases.

- Be aware of sweeteners and sugar: sugar is naturally present in fruits and dairy, and hence these should be consumed in limited amounts. Watch out for sweeteners as well, and go instead for keto-friendly sweeteners or Stevia.  

- Avoid eating farmed fish: While eating fish is great for keto but you should avoid eating farmed fish because of the fewer benefits they might have and the chemical additives they might contain. 

Additional Keto Diet benefits:

The ketogenic diet includes many benefits besides its suggested ability to reduce cancer. For instance, the diet is known for its ability to treat epilepsy, reduce weight, control blood sugar, increase mental performance, increase energy, reduce blood pressure, and reduce cholesterol. The diet can also help in Alzheimer’s disease, type 2 diabetes, and solving acne problems.

Below is a list of the keto diet various benefits:

- Weight loss: the diet is quite effective for reducing weight as it increases the amount of fat burned in the body which contributes to weight loss. Plus, the diet triggers satiety much quicker. Hence, fewer calories are consumed, resulting in additional weight loss.

- Epilepsy: the diet reduces significantly seizures in epileptic patients, especially children. Studies have shown that a keto diet can reduce epilepsy, 50% among adults, and 90% among children.

- Improve physical performance: the body has large amounts of fat stores that are not used effectively. However, when the body starts burning fat efficiently for energy instead of carbs, it can benefit from large fat fuel reserves available. 
Hence, a long-lasting energy burning process. Accordingly, this diet can sustain improved energy and physical performance. 

- Heart disease: the diet can protect against heart diseases by reducing the risks factors associated with heart diseases such as overweight, triglycerides, hypertension, and blood sugar levels. The diet can also increase the good cholesterol (HDL) in the body and lower the bad cholesterol level (LDL). This would balance the cholesterol ratio in the body and help further in reducing the risks of heart disease.

- Triglycerides: the diet reduces drastically the triglyceride levels found in the blood. High levels of triglycerides are associated with heart disease.

- Cholesterol: the diet increases the level of good cholesterol called HDL and reduces bad cholesterol. High levels of HDL cholesterol lower the risk of heart diseases, because it helps in balancing the cholesterol ratio. 

- Blood pressure: the diet may also decrease blood pressure levels. Hypertension is associated with many diseases such as heart disease and kidney failure.

- Diabetes: the diet is beneficial for diabetes because it reduces carbohydrate intake and control levels of glucose in the blood. 

- Alzheimer’s disease: the diet can reduce symptoms and slow down the progression of the disease. This is mainly due to the ketones that can be used as an alternative source of energy and nutrition for the brain.

Other conditions: following a keto diet has also shown to have beneficial effects for other conditions such as Parkinson’s disease, acne, and polycystic ovary syndrome (PCOS). However, more research and findings are needed in order to support these statements further.

Keto Diet for Cancer: precautions

Before you start your keto diet, it is important to take some precautions in case you are taking some medication or if you have any medical condition. Always consult with a health expert especially if you have any of the following conditions or you are taking any medication.

- Blood-pressure: a combination of blood pressure medication and a low carb diet is risky because there’s a possibility of decreased blood pressure from the diet. Low blood pressure may occur within the first days and sometimes might take months to happen. If low blow pressure occurs, it is important to contact a doctor.

- Diabetes: the keto diet will reduce blood sugar levels due to the reduced carbohydrate intake. If you are taking any diabetes medication such as insulin to reduce blood sugar levels as well, it is important to discuss this with your doctor before starting the diet to avoid any possible complications.

- Pregnancy / breast feeding: it is not advised to restrict any food groups if you are pregnant or breast feeding. A balanced diet is highly required for developing babies. Since the keto diet eliminates completely some food groups, this can be risky for them. Always make sure to discuss this with a specialized nutritionist before starting any diet to make sure you avoid any sort of nutrient deficiencies. 

- Nutritional deficiencies: it is important to watch out for any possible nutritional deficiencies since the keto diet does not include all food groups. Other reasons that may lead to deficiencies are fewer calories that are consumed because they are subtracted from the TEE in order to promote weight loss or because less food is consumed due to increased satiety. Always make sure to follow up with a nutrition expert before starting this diet.

Keto Diet for Cancer: side effects

The ketogenic diet is mainly safe, however there are some side effects that need to be taken into consideration:

- Keto flu: the keto flu is a series of symptoms such as fatigue, headache, nausea and cramps that are experienced by some people following the keto diet. These symptoms are quite common especially at the beginning of the diet. However, this problem will be resolved in few days by the time the body starts adapting to lower carbohydrate intake and starts burning fat properly. To avoid these symptoms, it is recommended to reduce carbohydrates gradually out of the diet so that the body gets used to this gradually.

- Cramps:  leg cramps are common with the keto diet. It’s an indication of mineral deficiency, mainly magnesium. This is because carbohydrates retain water in the body. Hence, less carbs mean less water retention, resulting in fewer electrolytes as well. It is important to stay hydrated and consume enough salt as this helps retain magnesium in the body. 

- Constipation:  the main cause behind constipation is dehydration, due to less water retention from the reduced carbohydrates intake. It is important to drink enough water while making sure the vegetables consumed contain some fiber.

- Heart palpitations:  during the transition period, the heart may beat faster and harder. This is quite common especially because of dehydration and lack of salt. Accordingly, you should always make sure to have enough water and salt. This should usually solve this problem. However, if this situation continues, you should immediately seek medical assistance.

- Fatigue: at the initial stages of ketosis while the body is shifting to using fat for energy instead of carbohydrates, people would feel tired. Their physical performance might be affected as well. However, this should be resolved once the body adapts to the new process and starts burning fat properly to produce the required energy. 

- Ketoacidosis: this happens when the buildup of ketones results in higher levels of acids in the blood (byproduct of burning ketones). Ketoacidosis can affect the livers, kidneys, and the brain.

Ketoacidosis can occur for people following a low carbohydrates diet, though it is very rare. However, this can be a more common problem for people that suffer from diabetes. Accordingly, if you have diabetes, it is important to contact your doctor before starting the keto diet. 

- Hypoglycemia: this is when glucose levels become very low in the blood. Accordingly, people might experience blurred vision, headaches, and confusion. This might become dangerous if left untreated as it can cause seizures. In some cases, it can even be fatal. Hypoglycemia happens mainly because our bodies are not used to run on ketones from fat instead of glucose from carbohydrates, this might lead in some cases to hypoglycemia.