The Diet of Male Rats Affects the Risk of Breast Cancer in Female Offspring

breast cancer
Experiment performed at University of São Paulo's Food Research Center with 60 animals and explores a little-known influence of paternal diet on daughters' health (Photomicrograph showing apoptotic cells, indicated by arrows/Breast Cancer Research)

An animal model study performed by the University of São Paulo’s Food Research Center (FoRC-USP), one of the Research, Innovation and Dissemination Centers (RIDCs) supported by FAPESP, has found that paternal nutrition can induce breast cancer in female offspring. The results have recently been published in the journalBreast Cancer Research and publicized by the same university’s Center for Science Diffusion.

The experiment involved three groups of male rats. Two groups were fed a high-fat diet, based on animal fat (pork lard) in one case and hydrogenated vegetable fat (corn oil) in the other. The control group was fed a standard low-fat diet. Females raised on commercial feed were mated with the males. Next, FoRC’s researchers, working with colleagues from Thomas Ong’s laboratory in the Food & Experimental Nutrition Department of the University of São Paulo’s Pharmaceutical Science School (FCF-USP), induced breast cancer in 50-day-old female offspring and monitored development of the disease.

The incidence of breast cancer was found to be higher in the daughters of rats fed the diet rich in pork lard than in the daughters of rats in the other two groups. Moreover, tumors took longer to appear, were less numerous and grew less in the daughters of rats given the corn oil diet.

The researchers were surprised by the reduced risk of breast cancer for the offspring of male rats fed on corn oil because in humans a high-fat diet is usually considered a health hazard. “This shows that different kinds of fat have different effects. The key factor is the type of fatty acid involved. Animal fat is rich in saturated fatty acids, whereas corn oil is rich in polyunsaturated fatty acids of the n-6 series,” Ong said in an interview given to USP’s Center for Science Diffusion.

For Bernadette Franco, who heads FoRC, the study was innovative, and the discovery should be seen as “a significant contribution to knowledge of the relationship between diet and cancer prevention”. Previous research showed that maternal diet, especially fat intake, affects the risk of breast cancer in daughters. “Ong’s team have now drawn attention to paternal diet,” she stressed. “This study opens up opportunities for the investigation of new disease prevention strategies through diet, which is a top priority for our researchers at FoRC.”

The study, which analyzed the protein and microRNA expression profiles of the male rats’ sperm and their offspring’s mammary glands, was conducted in partnership with Georgetown Lombardi Comprehensive Cancer Center in Washington DC, USA. The changes identified in these molecules may explain the differences in the development of breast cancer in the three groups’ offspring.

The article entitled “Paternal programming of breast cancer risk in daughters in a rat model: opposing effects of animal- and plant-based high-fat diets”, authored by Thomas Prates Ong and others, was published in Breast Cancer Research and can be viewed at