I subscribe to many email newsletters. One of the best is that of the Life Extension Foundation (LEF.org). The LEF maintains a huge health database. It is particularly strong in nutrition and functional medicine. The March 2014 issue has an article entitled “Getting Back to Basics… How Low-cost Zinc Helps Combat Deadly Immunosenescence” by Heath Ramsey. Immunosenescence is a decline in immune function associated with advancing age. It places older individuals at increased risk for a range of almost every serious disease, from infections to cancer. The article references a study in which animals with normal zinc levels had 28% fewer experimentally induced tumors when they were given a modest zinc supplement.
Zinc supplementation in the elderly has been shown to: restore normal function of the killer cells that go after virally- infected and cancerous cells; boost the the stress response of white blood cells from older adults, providing an immune system anti-aging mechanism; boost the immune response to vaccines; and improve cellular immunity and increase survival rates in older mice. I find all of this particularly amazing in that when I was studying physiology some 40 plus years ago, the role of zinc in the body was unknown.
Estimates are that 35-45% of people over age 60 are deficient in zinc. It is not unlikely that the same is true of older dogs. This is another example of a very inexpensive nutritional supplement providing huge benefits.