Cancer is not only a genetic or inflammatory disease, it is also a metabolic disease. A keto diet can starve cancer cells by targeting the metabolic hallmarks of this dreaded disease.
Q: We hear a lot about keto diets and their health benefits these days. What exactly is a ketogenic diet and is there anything it can do for a dog or cat with cancer?
A: Cancer is affecting an increasing number of dogs and cats. There are a multitude of cancer drugs, herbs, and remedies available, but an increasingly common strategy is to fight cancer with diet, especially a ketogenic (“keto”) diet.
Cancer has long been considered a genetic disease, but it is also an inflammatory and metabolic disease. Diet has profound effects on inflammation and metabolism. The ketogenic diet targets the metabolic aspect of cancer proliferation.
The goal of a ketogenic diet is to limit carbohydrates and promote the production of ketones, small molecules made in the liver by the breakdown of fat. This fat can come from food or stored body fat. The resulting metabolic state is called ketosis. (It’s not the same as ketoacidosis, a dangerous disease that can develop in diabetic pets.)
Cancer as a metabolic disease
In a normal metabolism, cells burn glucose (sugar) to produce energy. A ketogenic diet “trains” normal cells to use ketones instead of glucose by severely limiting dietary carbohydrates. And since protein can also be used by the body to make glucose, through a process called gluconeogenesis (“creation of new glucose”), protein is also moderately restricted.
Normal cells can switch from glucose to ketones. Even the brain – the body’s largest consumer of glucose – can adapt to using ketones for much of its energy needs. But cancer cells cannot. They depend on glucose fermentation for the energy they need to grow and spread. Their abnormal metabolism prevents them from using ketones like normal cells can. Cancer cells produce energy inefficiently, so they need a huge amount of glucose to function. The keto diet reduces glucose availability, so Cancer is hungry, but still provides plenty of fuel for healthy cells to keep going.
The effects of carbohydrates on the body
Giving carbohydrates to your dog or cat has several effects on his body. First and foremost, it stimulates the pancreas to release insulin, the hormone primarily responsible for glucose metabolism. It allows glucose from the blood to move into the cells; and it promotes the storage of body fat from excess glucose. But high blood levels of insulin and glucose contribute to the development and growth of cancer.
When insulin pushes this excess glucose into body fat, the fat doesn’t stay there. It is metabolically active, sending cellular messengers that promote inflammation. Remember that cancer is also an inflammatory disease. Carbohydrates pave the way for the development of cancer. The keto diet, however, promotes the burning of body fat for fuel while preserving muscle mass, and it reduces overall inflammation.
What keto is not
Contrary to popular opinion, keto is not a typical high-protein or raw-meat diet. It is a high fat, moderate protein and low carbohydrate diet. This is a common error that you will see in magazines and all over the internet. It is committed by people who don’t understand the science and equate keto with an Atkins-like low carb diet.
A typical nutrient ratio is around 15% to 30% protein, 70% to 75% fat, and 5% to 10% carbs. Compare that to a typical commercial dry dog food, which is around 20-30% protein, 10-20% fat, and 30-65% carbs; or a similar dry cat food, which is approximately 30% to 45% protein, 10% to 20% fat, and 30% to 50% carbohydrate (see table below). Canned, freeze-dried, dehydrated and frozen diets tend to contain more protein and fat, but depending on the product, they can still contain 15-50% carbohydrates. (You can estimate the carb content of a pet food by looking at the guaranteed analysis on the label. Subtract protein, fat, fiber and moisture from 100; the rest is digestible carbs .)
keto science
Ketogenic diets have been used and studied for decades, primarily to control epilepsy. Their use for cancer is relatively new. However, studies have offered tantalizing evidence of their benefits. In the 1990s, researchers at Colorado State University discovered that canine lymphoma was vulnerable to a low carbohydrate diet. Other research has shown the same effect for many other types of cancer in humans and animals, with rare exceptions.
One study found that a ketogenic diet stabilized advanced cancer in just four weeks; some patients even experienced partial remission. Other studies have shown that even aggressive metastatic tumors respond to keto, improving survival. Human studies have shown that keto diets improve survival time and, perhaps more importantly, quality of life for cancer patients.
how to go keto
Currently, no commercial dog food fits the ketogenic paradigm perfectly. Even the few “keto” recipes for pets are unbalanced, deficient, or inaccurate. A general rule of thumb is to use a fat to protein ratio of 1.5:2:1, with up to 15% of the diet consisting of cooked or pureed non-starchy vegetables, such as kale, broccoli and green beans. , to provide a variety of anti-inflammatory trace minerals, fiber and antioxidants. Supplements, including calcium, are not optional.
Be sure to work closely with a veterinary oncologist and/or holistic practitioner when implementing keto for your dog or cat. Luckily, fat tastes good, and most pets will appreciate the change.
Precautions when using a ketogenic diet
- Gastrointestinal signs (vomiting, diarrhea, constipation) may occur when starting a ketogenic diet, but usually dissipate as the body adapts to it.
- The ketogenic diet can be problematic for some cancer patients because it tends to cause weight loss. Cachexia (emaciation) is a serious problem for these animals. Increasing healthy dietary fats can help offset any potential weight loss. The best options are omega-3s like EPA and DHA — which themselves have cancer-fighting effects — and oils like flaxseed, olive, and avocado. Medium chain triglyceride (MCT) oil with low lauric acid content (as opposed to regular coconut oil) is easy to digest and quickly increases blood ketones; a nice double shot.
- Dogs (and cats) that have been eating low-quality dry kibble most of their lives may be at risk for pancreatitis if they switch to a high-fat diet too quickly. It takes a few weeks for the cells to fully adapt to the fat. Unfortunately, time is something that many cancer patients don’t have; but any movement in the keto way will help. Cooked-in fats are particularly dangerous, as are pro-inflammatory omega-6s like corn, sunflower, and safflower oils.
- The ketogenic diet is often used in children with severe epilepsy; about one in ten develop calcium oxalate bladder stones. It has not been studied or documented in dogs or cats, but drinking plenty of water generally protects against crystals and bladder stones.
A ketogenic diet can be helpful in preventing and treating cancer, and the benefits of this dietary approach to overall health, energy, and weight maintenance are definitely worth pursuing.
