Research: Pregnancy, childbirth and breastfeeding may reduce the chance of breast cancer

Mother’s milk Provides the baby with all its nutritional needs – water, sugar, proteins and fats, in a composition that changes depending on the needs of the baby, its age and even the time of day. The milk also contains vitamins and minerals, as well as antibodies that help the baby’s immune system protect him from diseases in the beginning of his life. There is no doubt that breastfeeding is very good for the baby, for many reasons.

dictation Originally published on the Davidson Institute for Science Education website

A new study found Now that breastfeeding is beneficial not only for the baby’s health but also for the mother’s. The study found that pregnancy, childbirth and breastfeeding are associated with the accumulation of T cells in the breasts. These are white blood cells of the immune system that specialize, among other things, in protecting against cancerous tumors, and therefore may reduce the risk of developing breast cancer.

Already during pregnancy, the breasts of the future mother undergo changes that will allow them to produce milk that will nourish the baby in the first months of his life. As part of these changes accumulate in the breast tissue Cytotoxic T cells (toxic) whose main function is to kill cells infected with viruses and damaged cells that may develop into a malignant tumor. Thus they may protect the mother from cancer, unless the cancer cells develop faster than their rate of destruction, and then a tumor develops. Some of the cells even remain in the breast for a long time and exist there Immune memory.

In the study, breast tissues of women who underwent breast reduction or preventive mastectomy were examined. Some of the subjects had given birth in the past and breastfed for at least six months, and the rest had never given birth. The researchers found that the T cells that specialize in eliminating cancer cells were preserved in the mothers’ breasts even more than thirty years after their last birth.

The researchers also tested the phenomenon in mice, and found that only in those of them that went through a complete cycle of breastfeeding, which ended with the withdrawal of the mammary glands after the pups were weaned, a significant increase in the amount of T cells in the area of ​​the mammary glands was recorded. On the other hand, in mice that did not give birth, or that stopped nursing unnaturally after the pups were removed from them, no similar increase was observed. Accordingly, cancerous tumors in the nipple area of ​​the lactating mice developed more slowly than those of the mice in the other groups.

To examine whether there is a connection between breastfeeding and the reduction of the risk of developing cancerous tumors, the researchers examined about a thousand women who suffered from aggressive (triple negative) breast cancer. All the women in the study had previously given birth. The amount of T cells in the tumor was higher in women who breastfed, and tended to increase the longer they breastfed. Also, their tumors were more permeable to the cytotoxic T cells compared to women who did not breastfeed, a feature that was associated with higher chances of recovery.

Breastfeeding is indeed beneficial, but not all women who give birth can or want to breastfeed. One of the limitations of the study is that it focused on only one type of breast cancer, and it is not yet clear if a similar phenomenon is also seen in other types. In addition, there are many factors involved in pregnancy and breastfeeding – for example, the duration of breastfeeding, the number of births of the mother and more. This makes it difficult to draw firm conclusions, because it is difficult to determine what the decisive factor is and to separate the effects of breastfeeding from the effects of childbirth.

There may also be differences in the behavior of immune system cells and cancer cells depending on the ethnicity of the women. Factors that are not directly related to the tumor cells themselves, but to the wider environment of the body and the breasts, may change the way the immune system reacts to cancer and its development. It is known, for example, that changes in the composition The population of bacteria (the microbiome) Living naturally in the mammary glands may affect the immune response. Diet may also affect the development of cancerous tumors and their degree of aggressiveness.

Despite the reservations, the new findings may open the door to the development of immunotherapy drugs News against cancer, which will mobilize the body’s immune system to destroy malignant tumors. The researchers also emphasize the need to develop personalized methods for cancer prevention and treatment, which take into account the patient’s pregnancy and breastfeeding history. They also point out that in future studies in the field of immunotherapy, it will be important to take into account data on the pregnancies and breastfeeding of the participants. If we manage to understand exactly what the T cells that settle in the breast tissue do and what molecules they recognize, it will be possible to create drugs and vaccines that mimic their action, thereby preventing the development of breast cancer and perhaps also treating existing tumors.