Fatty acids, nutrients during pregnancy can reduce risk of breast cancer in female offspring

US Department of Defense Congressionally Directed Medical Research ProgramsAug 4 2011

Era of Hope conference to feature compelling research examining benefits to daughters During pregnancy, women are counseled to refrain from consuming certain types of foods, beverages and medications in order to avoid jeopardizing the health and development of the fetus. In fact, the American Pregnancy Association has a list of a dozen items they recommend expectant mothers omit from their diets. However, there are some additions, such as folic acid, that, when taken before and/or during pregnancy, can actually reduce the risk of birth defects and other disorders. Research presented today at the Era of Hope conference, a scientific meeting hosted by the Department of Defense Breast Cancer Research Program (BCRP), reveals findings suggesting that if an expectant mother increases her consumption of foods high in certain fatty acids or nutrients during her pregnancy, she can potentially reduce the risk of breast cancer in her female offspring.

The research delves into breast cancer risk reductions attributed to the fetus when the mother, while pregnant, increases omega 3 fatty acids within her diet or consumes dietary methyl nutrients (methionine, choline, folate and vitamin B12). Some findings hypothesize that these diet augmentations may even prevent breast cancer from ever developing in the offspring.

"This is exciting and intriguing research," said Captain Melissa Kaime, M.D., Director of the Congressionally Directed Medical Research Programs (CDMRP), under which the BCRP is managed. "To be able to reduce the risk and possibly prevent this devastating disease before birth is an incredible notion; the BCRP is proud to support research with such potential."

Maternal dietary alterations, including increasing the consumption of omega 3 fatty acids, may reduce the risk of breast cancer to the fetus by causing epigenetic changes in utero and later through nursing. These changes may alter gene expression permanently, a change referred to as imprinting. Researchers at Marshall University conducted a study to investigate whether having a diet rich in omega 3s while pregnant would result in changes to fetal mammary gland gene expression, thereby reducing the chance that female offspring would later develop breast cancer.

In this study, there was a reduced incidence of mammary gland cancer observed for the offspring of mice that, while pregnant and nursing, consumed a diet containing canola oil, rich in omega 3, compared with the offspring of mice that, while pregnant and nursing, consumed a diet containing corn oil rich in omega 6 fatty acids. Reviewing the gene expression profiles of both groups showed that many genes related to cancer development differed between the two groups. Significant differences in the patterns of two important epigenetic markers were also observed.

"Pregnant women should be mindful of what they consume since their diet may incite epigenetic changes that could impact the development of their offspring, not just in utero but also for time to come," said Dr. Philippe Georgel, Marshall University. "Additional research continues, as we seek to elucidate the effect of diet on breast cancer-specific gene expression."

Links are being drawn to complete mammary gland development of the mother during pregnancy and reduction in breast cancer risk in her daughters. Supplementing the mother's diet with lipotropic nutrients (methionine, choline, folate and vitamin B12) is thought to increase methyl metabolism which stimulates the full development of the mammary gland, thereby inducing an epigenetic imprint in the mammary gland of the fetus and decreasing its breast cancer risk. Investigators at North Dakota State University are researching this link with the overall objective of determining the extent to which supplementing diets with methyl nutrients during pregnancy reduces the offspring's overall breast cancer susceptibility.

The study looked at 45 pregnant rats and randomized them into two groups: one to receive a control and the other to be fed a methyl-supplemented diet. Once the pups were born, they were separated into three additional groups depending on the feeding regime of their mother. When the female pups reached a specific age, they were exposed to a chemical that induced breast cancer and researchers charted when the first tumor appeared and measured all tumor sizes and volumes. Results demonstrated that the offspring from the methyl-supplemented diet group showed a decrease in tumor incidence and growth when compared to the control group. Also, they had fewer tumors and fewer tumors that multiplied.

"The conclusions of this study suggest that we may be able to prevent the development of breast cancer in daughters of women at risk for breast cancer by supplementing the mother's diet during pregnancy," said Dr. Chung Park, North Dakota State University. "We look forward to exploring this study further to strengthen the implications of these initial findings."