The immune system is one of the most important mechanisms for fighting disease and preserving health. Everything dogs and cats experience can affect their body’s energy balance or immune system. The three areas that are most important in protecting and bolstering the immune system are diet and nutrition, exercise, and stress reduction. Healthy dietary nutrition is perhaps the most vital component of a strong immune system, because this system relies on multiple nutrients to function properly. Nutritional deficiencies or excessive intake of particular nutrients may suppress the immune system and increase the risk for disease. Vitamins, minerals, antioxidants must be taken in a balanced way, as unbalanced supplementation can cause or exacerbate deficiencies. It’s not enough for food supplements to be simply ingested; they must be of a high enough quality for them to be absorbed properly to reach the tissues. The National Research Council (NRC) nutrient requirements for animals can be defined as nutrient levels adequate to permit the maintenance of normal health and productivity. Failure to provide a diet that fulfills the minimal requirements established by the NRC for any nutrient will ultimately immune-compromise the animal and render it more susceptible to infectious disease.
While wholesome nutrition is the key to maintaining a healthy immune system and resistance to disease, it is important to point out that poor nutritional intake can result from poor food choices or poor food quality. Nutritional deficiencies or imbalances, as well as exposures to various chemicals, drugs and toxins present a continual immunological challenge which can suppress immune function, especially in those animals genetically susceptible to immune dysfunction. Nutrigenomics is a fast-moving field of research that combines molecular biology, genetics and nutrition to regulate gene expression through specific nutrients. Nutrients have been shown to affect gene expression through transcription factors, which are biochemical entities that bind to DNA and either promote or inhibit transcription of genes. By understanding the roles of specific nutrients and how they might cause diseases (i.e. molecular dietary signatures), Veterinarians could recommend specific foods for an individual pet based on their genetic makeup. While there is hope that nutrigenomics will ultimately enable such personalised dietary advice, it is a science still in its infancy.
While it is difficult to enhance a normal functioning immune system, there are things that you can do to protect and strengthen the immune system of your pet during periods of illness or in the face of chronic disease. There are two major changes you can make in your pet’s diet to help their immune system. First, you can enrich their diet with antioxidants and second, you can make sure they are getting enough nutrients and micronutrients. Antioxidants are vitamins and minerals, found in foods and also available as supplements, that removes harmful oxidants from the bloodstream. Oxidants, also known as free radicals, are among the toxic byproducts produced when food is turned into energy. They are also byproducts of cigarette smoke, pollution, sunlight exposure, and many other environmental factors. Free radicals are capable of damaging DNA and suppressing the body’s immune system. Free radicals also play an important role in the development of many diseases. Nearly all types of cancers have been related to diets that are poor in antioxidants. Moreover, research suggests a strong correlation between most cancers and a high volume of free radicals that have not been neutralized by antioxidants. Thus, diets low in antioxidants increase the risk of developing cancer and, conversely, diets high in antioxidants may be substantially protective. Heart disease is also brought about, in part, by free radicals. Certain diseases of the central nervous system and some forms of kidney, gastrointestinal, and skin disease also involve free radicals. These diseases or conditions cannot be prevented simply by taking antioxidants. You can, however, ensure that you are doing everything possible to lessen their effects.
Marginal nutrient deficiencies in the diet can also weaken the immune system. Marginal deficiency is a state of gradual vitamin loss that can lead to a general lack of well being and impairment of certain biochemical reactions. Marginal deficiencies of micronutrients do not cause obvious symptoms of disease, but they can affect the body’s ability to resist disease and infection. They might also slow your pet’s recovery from surgery.
In summary, maintaining a good nutritional status and adequate micronutrient stores in the body is essential for mounting an effective immune response to opportunistic infections. With sound eating habits and proper nutritional planning, and by reducing exposure to environmental factors that promote the production of free radicals you can further ensure that you are doing everything possible to lessen the effect of free radicals on your pet’s overall general health and well-being.