Just as the human body ages and changes appearance over the years, so too will a roof. Due to the severity of the roof environment, even a one-year-old roof may look different from a roof that was just installed. While cracks or blistering may first be noticed at close range (as from a ladder when cleaning the gutters), please be mindful that these normal weathering characteristics may not be visible when the roof is viewed from the front lawn or driveway. And if the problem is not severe and the shingles are still providing the protection intended, then it is not a cause for alarm.
A roof is an important investment, since it literally protects the whole house from the elements. However, there are no magical creams or ointments to prevent a roof from aging.