Suppression of growth by dietary fish oil of human breast carcinomas maintained in three different strains of immune-deficient mice.

It has been reported that high levels of dietary fish (menhaden) oil, compared with corn oil, suppress the growth of MDA-MB231 and MCF-7 human breast carcinomas maintained in female athymic nude (T lymphocyte-deficient) mice. The purpose of this study was to determine whether dietary fish (menhaden) oil, compared with corn oil, can also suppress the growth of these carcinomas when maintained in female beige-XID-athymic nude (T lymphocyte- and NK/LAK cell-deficient) mice and in female severe combined immune-deficient (SCID) mice (total lack of functional T and B lymphocytes). Results clearly show that dietary fish (menhaden) oil can significantly (p < 0.05) suppress the growth of these carcinomas in the beige-XID-athymic nude mouse and the SCID mouse. Such results provide evidence that the growth suppression of MDA-MB231 and MCF-7 human breast carcinomas, induced by dietary fish oil, is not mediated by immune system mechanisms involving T lymphocytes, B lymphocytes, and/or NK/LAK cells.