this sort of puts it all together--it is not a simple problem

[Lani]

of just omega3s and 6s or phytoestrogens or not...

So don't stress out if you just have to have that ice cream. The time when it might have made a big difference MAY be long past--it may not--we are not really sure, so...
and this was done in her2+mice

Reprod Toxicol. 2006 Dec 10; [Epub ahead of print]
Modulation of mammary tumor development in Tg.NK (MMTV/c-neu) mice by dietary fatty acids and life stage-specific exposure to phytoestrogens.

Luijten M,
Verhoef A,
Dormans JA,
Beems RB,
Cremers HW,
Nagelkerke NJ,
Adlercreutz H,
Penalvo JL,
Piersma AH.
Laboratory of Toxicology, Pathology, and Genetics, National Institute of Public Health and the Environment, Bilthoven, The Netherlands.
Breast cancer is a major public health problem among women worldwide. Phytoestrogens and dietary fat composition are being investigated to elucidate the role of nutrition in breast cancer risk. Both epidemiological and rodent studies suggest that the chemopreventive effect of phytoestrogens depends on timing of exposure. We investigated spontaneous mammary tumor development in female heterozygous MMTV/c-neu (Tg.NK) mice upon isoflavone exposure on background diets rich in either n-6 or n-3 polyunsaturated fatty acids (PUFAs). Three different exposure protocols were used, either from conception to weaning, or from weaning onwards, or lifelong. Mice fed diets high in n-3 PUFAs developed mammary tumors 15 weeks later than mice fed n-6 PUFA diets. In the latter mice, isoflavone exposure from weaning onwards resulted in a significant decrease in tumor incidence and a delay in tumor onset. Therefore, the effects of phytoestrogen exposure on tumor formation appear to depend on the composition of the background diet and on the timing of exposure within the life cycle.
PMID: 17229545 [PubMed - as supplied by publisher]