The invention concerns a use of C7 sugars and derivatives of formula (I), called avocado perseose, which have, inter alia, a protective activity to epidermal skin cells. These C7 sugars and derivatives are capable of maintaining the expression of markers of adult stem cells, in particular basal stem cells. Avocado perseose can also be used for preventing the deleterious effects of environmental damage. Avocado perseose has a beneficial effect on the conservation of the potential of epidermal stem cells and thus helps maintain skin homeostasis.