This innovative dietary approach to cancer involves a ketogenic diet and calorie restriction to improve longevity and quality of life in dogs and cats (and humans!).
Cancer is one of the leading causes of death in dogs and cats. Animal parents fear this disease more than any other, not only because of the reduced quality of life it brings, but also because we often fail to successfully treat it. Combine this with endless hospital visits and horrendous costs, and it’s no wonder people dread a diagnosis of cancer in their dogs and cats. In this article, we’ll focus on a dietary approach involving ketosis and calorie restriction, and how it’s helping treat cancer in companion animals.
Why is cancer still so hard to treat?
It seems counterintuitive, that cancer – into which more research dollars have been poured than any other disease — should lag so far behind other health problems in its response to treatment. We see improved longevity and quality of life in dogs and cats with other common problems, such as diabetes, or cardiac and renal disease, so what’s missing when we treat cancer?
It turns out we do not understand the true nature of cancer. To successfully deal with any disease, we must first actually understand it.
Over the last decade, integrative human and veterinary practitioners have increasingly turned to the work of 20th century German scientist and Nobel Laureate, Otto Warburg, for his groundbreaking studies on cancer. Warburg discovered that cancer cells have a different type of metabolism from normal cells; they produce their energy by fermentation, a process that “burns” sugar only. In contrast, normal healthy cells use a process that’s 18 times more efficient, and which burns not only sugar, but also fats and proteins. Warburg showed that because of this difference in metabolism, cancer cells have an “Achille’s heel”: we can starve them by removing all starch and sugar from the patient’s diet and replacing them with fat. In short, he had discovered cancer’s Holy Grail. Even though we have known about this since around the time of WWII, however, Warburg’s work has been ignored in favor of theories that rely only on drugs to treat cancer.
The ketogenic diet
Over the last several decades, an American geneticist and biochemist named Thomas Seyfried has verified and expanded on Warburg’s work. He has shown that a high fat and carbohydrate-restricted diet, combined with calorie restriction, will not only starve cancer cells — controlling their rampant growth — but do so with dramatically increased longevity and quality of life for the patient.
This high fat, calorie- and carbohydrate-restricted diet is called a “ketogenic” diet. It forces the body to produce “ketones”, tiny, water-soluble, energy-rich molecules. These ketones are produced by the liver from fatty acids (a process called ketogenesis), and there are three of them: acetoacetate, beta-hydroxybutyrate and acetone.
Mammalian bodies were forced to evolve ketones hundreds of millions of years ago. Their role (together with fatty acids) was to ensure survival. Back then, ketones and fatty acids replaced glucose under the very common conditions of starvation and/or extreme exercise, or when carbohydrates were unavailable. All these situations produce a metabolic state called ketosis, in which fatty acids and ketones become the principal sources of energy, largely replacing glucose. Importantly, ketones take over from glucose in providing the brain with its energy supply. Today, we mostly use a ketogenic diet combined with fasting to induce ketosis.
A ketogenic diet requires lots of fat, not too much protein, and virtually no soluble carbohydrates (fiber is fine!). Fats usually form more than 80% of the diet, with protein levels of between 5% and 20%. Starch/sugar levels are generally kept below 5%. Note that proteins are limited because excess protein will be converted unwanted sugar.
“Keto” diet with calorie restriction = more cancer survivors
Cancerous tissue cannot cope with ketosis. It is unable to use fat or ketones for energy; cancer cells can only use sugar. This means anything that forces the body to enter ketosis (fasting, exercise, ketogenic diet) may be used to starve cancer. In ketosis, after three to seven days, blood sugar levels drop while ketone levels rise, as they and the fatty acids take over sugar’s role in energy production.
The increasing use of ketogenesis combined with calorie restriction (by integrative practitioners), is producing a growing number of animal and human cancer survivors who are enjoying excellent quality of life despite original prognoses of “hopeless”. The critical difference between these cancer survivors and a matching population of (now deceased) cancer victims was, and is, their diets. The cancer survivors enjoy a diet lacking in sugar, high in fat, and somewhat restricted in calories and protein. Although many still have cancer, it’s being successfully managed, just like any other degenerative disease process.
Feeding a ketogenic diet
For decades, my approach to managing cancer has involved a program of fresh, whole and raw foods based on evolutionary principles. While this program has always produced excellent results, the introduction, over the last eight years or so, of the ketogenic and calorie-restricted version of this program has produced results that far outstrip previous outcomes in longevity and quality of life.
See Table 1 for an example of a ketogenic diet suitable for both dogs and cats. Here are some notes about this recipe:
- All ingredients are finely ground (retaining some texture — not a paste!), mixed thoroughly, then divided into meal-sized portions and frozen.
- Fat and meat (protein) sources can include beef, lamb, pork, chicken, duck, turkey, etc. Add extra fat when using leaner cuts. Coconut oil, olive oil, and salmon or krill oil (for Omega-3s) are all suitable.
- Ground bone should be derived from young animals/poultry; this ensures it is (relatively) soft, toxin-free, and rich in cartilage.
- Ground offal should include (at least) liver, heart and kidney, with liver predominating.
- Cartilage is added because it inhibits the growth of cancer by preventing it from developing a blood supply.
- Vegetable pulp/juice is included because so many of the “phytonutrients” found in vegetables are “anti-cancer”. Vegetable material is best pulped using a juicer. The pulp is the fiber portion of the diet, important for gut and kidney health. Because the juice contains sugar, it may prevent the animal from entering ketosis; in this case, use less juice and/or use fermented raw vegetables (kimchi/sauerkraut).
- The additional ingredients (see Table 2) fill the nutritional gaps in this diet, substituting for the nutrients found in a wide range of foods a dog or cat would eat in the wild.
Transitioning to a ketogenic diet
Transitioning to this diet must be a gradual process in order to prevent digestive upsets. The sudden introduction of a high fat diet may also trigger pancreatitis, although the use of fresh raw fats has largely overcome this problem.
During the transition period, it is important to begin measuring and recording ketones and blood sugar. Blood testing is ideal for this, but can be difficult for the “at home” dog or cat. Collecting urine is simpler; once urinary ketones are present, blood sugar is assumed to be low. If ketones are not detected, gradually increase the fat content (which also decreases the protein), until ketones are detected. The aim is to achieve and maintain ketones at the highest possible level, with blood sugar as low as possible, while maintaining an optimal body weight. Now we are starving the cancer and feeding the dog or cat, an idea way to proceed!
Although this is still an emerging area of veterinary (and medical) science, we have amassed ample evidence to support the use of a ketogenic diet and calorie restriction in the majority of canine and feline cancer patients, no matter what other treatments they are receiving. As a bonus, we also know that a state of ketosis is highly protective against much of the damage caused by radiation and chemotherapy!