Already in antiquity people had identified causes of aging: the body ages because it loses a lot of water. Avicenna, who lived a thousand years ago and who was a scientist and physician, wrote the first treatise about the rapid aging of a person, who doesn’t drink enough water. Avicenna made a simple conclusion after watching ripe and juicy melon during few days: in the bright sun the melon became shriveled and dry, so old age is dryness. Modern scientists said the same, but using other words: old age is when the cells lose water. Women feel it particularly acute: dehydration of the skin is the main reason for the appearance of wrinkles.