The object of the invention is the use of compounds comprising one or more free sulphhydryl and amino groups for preparing a composition for locally binding aldehydes in saliva during smoking. The preferred compounds are cysteine and its derivatives. Also claimed are methods for decreasing the risk of smoking related cancers by using a composition of aldehyde binding substance(s), and a composition comprising aldehyde binding substance(s), characterized in that the composition is attached to or combined with a tobacco product, filter or holder.