Breast cancer is the second most widespread type of cancer among women in the United States, according to the American Cancer Society (ACS), who estimate that there will be around 40,610 deaths attributed to this type of cancer in 2017.
The known causes of lifestyle-related breast cancer have so far included alcohol consumption, lack of physical exercise, obesity, choice of contraceptives, hormone therapy, and breast-feeding. The new research may add an imbalanced diet during pregnancy to this list.
A new study carried out by the Georgetown Lombardi Comprehensive Cancer Center in Washington, D.C., suggests that eating foods that are high in fat during pregnancy may affect the risk of developing breast cancer in female offspring across generations.
Senior study author Leena Hilakivi-Clarke, Ph.D., a professor of oncology at Georgetown Lombardi, and colleagues recently reported their findings in the journal Breast Cancer Research.
Testing a high-fat diet in mice
To study the intergenerational impact of diet, the mice specimens were mated in two different phases. In the first phase of the experiment, the pregnant female mice were randomly divided into one of two groups after mating.
The females in the first group were fed a diet with a normal fat intake, with 16 percent of its calories taken from fat, while those in the second group were fed a high-fat diet.
The high-fat diet took just over 41 percent of its calories from fat. Around 39 percent of these calories came from corn oil, while roughly 2 percent of the calories came from soybean oil.
Since the gestation period in mice is around 19 to 21 days, the controlled feeding of the second group started on day 10 of their pregnancy, which roughly corresponds to the second trimester of pregnancy in humans, a point at which the ovaries of the female fetus begin to develop.
The offspring and further generations that resulted from this phase of the experiment were placed on a normal diet.