Maternal Dietary Canola Oil Suppresses Growth of Mammary Carcinogenesis in Female Rat Offspring

Abstract

As suggested by rodent studies and studies using human breast cancer cells, dietary canola oil is linked with lower breast cancer risk. Here, we investigated the effect of maternal (pregnancy plus lactation) dietary canola oil on the susceptibility of female Sprague-Dawley rat offspring to mammary carcinogenesis. Although the control diet had 10% soybean oil, the treatment diet was formulated to contain 10% canola oil as a fat source. N-nitroso-N-methylurea was injected to induce mammary cancer in offspring. The offspring of canola-fed dams showed significantly decreased tumor multiplicity (1.0 ± 0.3 vs. 1.9 ± 0.3, respectively; P = 0.04) and tumor volume (1232.5 ± 771.0 mm³ vs. 6,302.5 ± 1,747.4 mm³, respectively; P = 0.01), along with increased survival rate (87% vs. 47%, respectively; P = 0.01). In addition, the mRNA expression of development-related gamma-glutamyltransferase 1 was significantly higher in the lactating mammary tissues of the canola group dams and mammary tumor tissues of the offspring [2.5 ± 0.6 vs. 0.5 ± 0.2, respectively (P = 0.01) and 0.98 ± 0.03 vs. 0.56 ± 0.15, respectively (P = 0.05)]. These results suggest a potential anticancer effect of maternal dietary canola oil and may be useful in devising prenatal nutritional strategies to reduce breast cancer risk in humans.

ACKNOWLEDGMENT

This work was funded by the USDA-NIFA and Northern Canola Growers Association. Lawrence Mabasa, Kyongshin Cho, Mark W. Walters, Sajin Bae, and Chung S. Park designed the project; Lawrence Mabasa, Kyongshin Cho, and Sajin Bae conducted the research; Lawrence Mabasa analyzed the data; Lawrence Mabasa, Kyongshin Cho, Mark W. Walters, Sajin Bae, and Chung S. Park wrote the article; and Lawrence Mabasa had primary responsibility for the final content. All authors read and approved the final manuscript. We thank Dr. W. Slanger for his statistical advice.