The present invention relates to a phytocomplex or natural concentrate rich in polyphenolic compounds such as hydroxytyrosol and 3,4-DHPA- EDA, derived from the waters from the pressing of olives for oil and/or olive pomace as residues of the olive milling process, for use in the reduction/attenuation of the symptoms and/or side effects associated with/caused by diabetes and/or the pathological conditions associated therewith.