N-3, n-6 and n-9 dietary fatty acids modulate the growth parameters of murine salivary gland tumors induced by dimethylbenzanthracene

Variations in dietary fatty acid composition influence the biological behav iour of certain tumours. Diets enriched with oleic acid (18:1 n-9) seem to promote tumour progression on several lines due perhaps to the development of essential fatty acid deficiency (EFAD), whereas n-3 fatty acids have a p rotective effect. Since the role played by lipids on salivary gland tumorig enesis has not yet been studied, an experimental model is presented. BALB/c mice were fed on four different diets: control, corn oil, fish oil and ole in groups. Salivary gland adenocarcinomas were chemically induced by using 9,10-dimethyl-1,2-benzanthracene. Animals were sacrificed at the 20th post- injection week and several tumour parameters were analysed. Linoleic acid s howed no promoting activity. Tumour size was larger in the olein group than in fish oil fed mice, indicating that the oleic acid, linked to the induce d EFAD condition, has a protumorigenic activity whereas n-3 polyunsaturated fatty acids appear to exert a protective effect. (C) 1999 Harcourt Publish ers Ltd.