When your dog develops cancer and will need the proper medicine, diet and supplements can play a key role in preventing and treating the disease.
No one wants to hear the “C” word from their veterinarian. Unfortunately, canine cancer is an increasingly common health issue, and just as the causes are complex, so are the choices of medicine and treatment options. The good news is that diet and supplements have a significant part to play in the battle against this disease.
What diet can do
The importance of diet in treating and preventing cancer is long established. Some veterinarians claim to treat cancer by dietary manipulation alone, focusing on the elimination of toxins and providing potentially deficient nutrients to support the immune system and liver.
Growing evidence supports the basic principle in cancer nutrition of minimizing simple sugars and complex carbohydrates, and favoring protein and unsaturated fats as the main energy sources. This is based on studies of the metabolic requirements of cancer versus host cells. Cancer cells use protein for energy and will utilize certain amino acids, such as arginine, at the expense of the host.
Fats provide more calories per gram than protein and carbohydrates, an advantage to very sick animals able to ingest only small amounts of food. Most animals find fats more palatable. The biochemical response to food deprivation (even 24 hours of anorexia) leads to substantial dependence on fat-derived fuels.
As cancer progresses, alterations in normal patient metabolism occur; often these changes are irreversible without treatment and adequate nutritional support. Diet in cancer patients can be extremely challenging when the animal is inappetant, able to swallow only small amounts of food, or is vomiting. Cachexic patients need high energy in the form of fat, and even carbohydrates may have to be reintroduced at this stage, even though they give the tumor an energy supply.
Ideally, I prefer animals to be taken off refined commercial diets and put on raw whole food. If you opt to home-prepare the food, you need good instructions on how to create the right diet for your dog, and must be willing to spend the time putting it together every day, using fresh, high quality ingredients. Some excellent companies produce well-formulated raw food diets that are complete and take the hard work out of it if you have limited time.
Dogs that have been used to commercial diets all their lives and are now very ill with cancer have to be transitioned carefully (it may not even be possible or advisable some cases). I do not use diets high in bone for these animals. Those with cachexia may not be able to handle raw food diets. At this stage, cooking the food, feeding it warm and not cold, and using high energy convalescence products is required.
The home-formulated raw diet I use is essentially based on 2:1 meat/meaty bone to vegetable/fruit with an emphasis on human grade organic food. I also pay attention to the full spectrum of colors in fruits and vegetables to give the animal a good mineral/vitamin spread. If vitamin/mineral supplements are used, they must be bio-available and ideally sourced from whole plants. Additions to the basic diet include eggs, cottage cheese (especially if the liver is showing measurable signs of stress), spirulina, wheat grass, alfalfa juice and barley greens.
Reducing the acid load is helped by vegetables, fruits and the additions mentioned above combined with the elimination of refined carbohydrates, grains, sugars and dairy foods. Evidence indicates cancer progresses more in an acid environment. The addition of digestive enzymes may be useful, especially in animals that have been fed refined diets for years.
Supplements for cancer
Many supplements, in addition to Omega 3 fatty acids and l-arginine, are commonly used with basic cancer nutritional therapy. If your dog is undergoing chemotherapy and radiotherapy, note that some supplements can radically alter the availability and toxicity of these potent treatments. Here are some common supplements that have a growing evidence base for efficacy and safety in animals, and that I consider for my cancer patients:
Antioxidants include vitamins A, C, E, beta carotene and lutein. Chronic oxidative stress with the formation of reactive oxygen species, especially when antioxidant capacity is inadequate, has been hypothesized to contribute to DNA damage, malignant transformation, and eventual tumor development in numerous species.
The main message I would give about antioxidants is that they are of most use in prevention. They are often contraindicated in active cancer treatment, particularly cases undergoing treatments that rely on pro-oxidant cell death.
Mushrooms are increasingly shown to contain different classes of biologically active compounds with strong immunemodulating and anticancer properties. One extensively used in both traditional herbalism and modern clinical practice is Coriolus versicolor, also known as Yun-Zhi. The chemical composition of the mushroom is very complex. Among its various bioactive components, polysaccharopeptides (PSP) and protein-bound polysaccharides (PSK) have the strongest biological activity.
• PSP and PSK can inhibit the proliferation of leukemia, lymphoma, hepatoma, breast, lung and prostate tumor cell lines. Their antimetastatic activity has also been demonstrated.
• PSP contributes to tumor eradication by stimulating both humoral and cell-mediated immune responses.
• PSP and PSK increase the synthesis of interferon (IFN)-c and interleukin (IL)-2.
• They enhance T-cell proliferation.
• They stimulate macrophage-derived nitric oxide production and counteraction of the immuno-suppression induced by cytotoxic drugs.
Other mushrooms of interest are Cordyceps sinensis, Ganoderma lucidum and Grifola frondosa. Each has a specific array of immunemodulatory effects and needs to be carefully selected and understood, especially when lympho-proliferative diseases are present or when chemotherapy is used.
Curcumin is an extract from turmeric (Curcuma longa). It can be extremely useful in many canine cancers. It has been shown to have the following effects:
• Anti-proliferative effects in cancer cell lines
• Induces apoptosis
• Anti-angiogenic factors
• Impedes tumor growth and metastases
• Helps control matrix metalloproteinase activity
• Pro-oxidant in high dose
It is generally well tolerated, though it has mild blood-thinning properties so should not be given in cases of haemorrhagic tumors or immediately post surgery. It can be poorly absorbed so the quality of the product with regard to its percentage of curcuminoids is essential. Curcumin can selectively enhance the cytotoxicity of chemotherapy agents, and may reduce negative side effects.
Artemisinin is the active extract from the herb sweet wormwood (Artemisia annua). It has been shown to have the following properties in relation to cancer:
• Increased apoptosis
• Selective cytotoxicity against cancer cells due to their higher iron content when compared to normal cells
Artemisinin should not be used with high antioxidant supplements that act to buffer and protect against free radicals, because its cytotoxicity depends on the production of free radicals produced as a result of its interaction with iron in the cancer cell. It should not be given during or after radiotherapy for up to two months. Radiotherapy causes the release of iron into local tissue, which could potentially lead to increased local cell damage.
Remember that an integrative veterinarian needs to assess your individual dog’s cancer case to determine his nutritional and supplement requirements.