A ounce of prevention is worth a pound of cure is nothing more than a non-prescriptive statement. There is also another proverb "A danger foreseen is half avoided". The problem is that we often do not know what danger awaits us. Prevention of premature ageing of skin includes good nutrition, balanced diet, avoidance of exposure to ultraviolet and tobacco, or consumption of alcohol. These conditions are necessary but not sufficient because no matter how hard we try damage is hard to avoid.