Major Ager: Declining Defenses
Its Effect: Run-down Immune System

When we hear the word infection, we usually think of green mucus oozing from our nostrils. When it comes to aging, however, we're concerned not only with the acute infections like colds and the flu. We're also concerned with the chronic infections—the behind-the-scenes inflammatory response in your body that ages your entire system. In fact, much of the aging process is a side effect of defense mechanisms that our body has designed. An overworked and tired immune system causes chronic inflammation in your body, which increases the risk of mutations that can lead to cancer.