Infants need breast milk for proper nutrition. A mother’s milk has an almost nature-perfected mixture of fat, vitamins and protein, which is 99 percent of the nutrition a baby needs for growth. Also, breast milk has antibodies, which are helpful for a baby’s immune system to ward off viruses and bacteria. Surprisingly, breastfeeding may have an additional benefit for mommy, as it burns extra glucose to decrease pregnancy weight quicker. A baby sucking on the tit releases the hormone oxytocin, which leads the uterus to change to its pre-pregnancy shape and may lower uterine bleeding after a child is born. Breastfeeding can decrease chance of bone loss, ovarian cancer, and breast cancer.

Women with breast cancer who breastfed their babies are significantly less at risk of the disease recurring or killing them, a study has found in the Journal of the National Cancer Institute.

Researchers analyzed the data of 1,636 women with breast cancer who completed a questionnaire about breastfeeding.

The researchers found that breastfeeding had a strong protective effect, especially in relation to particular types of tumor including the most common hormone-sensitive strain. Remarkably, the protection was strongest for women who had a history of breastfeeding for six months or longer.

Lead researcher Marilyn Kwan, from US health care provider Kaiser Permanente, said: “This is the first study we’re aware of that examined the role of breastfeeding history in cancer recurrence, and by tumor subtype. Women who breastfeed are more likely to get the Luminal A subtype of breast cancer, which is less aggressive, and breastfeeding may set up a molecular environment that makes the tumor more responsive to anti-estrogen therapy.”

“Breastfeeding may increase the maturation of ductal cells in the breast, making them less susceptible to carcinogens or facilitate the excretion of carcinogens, and lead to slower growing tumors.” said Co-author Bette Caan.

These tumors are less likely to spread to other parts of the body than other types and are treatable with hormonal drugs such as tamoxifen and aromatase inhibitors.

Overall, a history of breastfeeding reduced the chances of cancer returning after treatment by 30 percent, while the risk of dying was lowered by 28 percent. The reduction in cancer risk comes in proportion to the cumulative lifetime duration of breastfeeding. That is, the more months or years a mother breastfeeds, the lower her risk of breast cancer.