The present invention relates to a composition comprising a combination of one or more dietary carotenoids or their cis-trans isomers, preferably at least lycopene, with vitamins E and C, or with derivatives of vitamins E and C, for use in the prevention of damage of human cells, especially lymphoid cells, by ionising radiation. Particularly, the composition of the invention efficiently protects human cells against gamma radiation doses up to 5000 Gray (Gy). The composition of the invention is especially useful to be administered to patients undergoing radiation therapy in cancer treatment, to people living in the vicinity of a nuclear power station, after a nuclear based accident and/or improper use of nuclear material and to flight staff on aeroplanes and spacecraft.
