Aging and impairment of innate immunity.

As we age, it is common for certain phenotypic changes to arise within the population. A number of observations have led scientists to believe that these changes result from an accumulation of cellular defects over time. With enough cell damage, tissue function is compromised and the risk for disease escalates. More importantly, when these defects arise in cells of the innate immune system, the body can no longer defend itself against a variety of pathologies. The main culprit for cellular damage seen with age is thought to be reactive oxygen and nitrogen species produced from endogenous metabolic pathways. To determine how an individual will age, it is thus important to consider all of the factors involved in both the production of and the response to oxidative stress. These factors include genetics, lifestyle, environment, and gender. Understanding the mechanisms of aging can allow us to develop strategies for overcoming the negative aspects of this process and ultimately to help individuals age more gracefully.