Breastfeeding offers mothers more than bonding, it can also reduce breast cancer risk

Breastfeeding has long been promoted for its benefits to infants, but research shows it may also protect mothers, including lowering their lifetime risk of breast cancer.

A large pooled analysis of 47 studies across 30 countries found that breast cancer risk decreases by 4.3% for every 12 months of breastfeeding, cumulative over a woman's lifetime, not just per child, according to the National Library of Medicine.

"When you're breastfeeding, you often don't ovulate, and that means your body isn't producing as much estrogen and progesterone," said Elaine Hart, MD, FACOG, an obstetrician/gynecologist at Loma Linda University Health and a fellow of the Academy of Breastfeeding Medicine. "Since breast cancer is frequently hormonally driven, that reduction lowers the risk."

The protective effect is strongest with longer durations of breastfeeding. Hart says that while exclusive breastfeeding offers the greatest benefit, any amount contributes.

"There are studies showing that even partial breastfeeding offers advantages. But breastfeeding at least every four hours during the day and six at night, whether directly or by pumping, extends that period of not ovulating, which strengthens the protective effect."

Breast cancer is the most commonly diagnosed cancer among women in the United States, according to the American Cancer Society. One in eight women will face a diagnosis in their lifetime. While breastfeeding does not eliminate the risk, population studies consistently show a meaningful decrease.

The advantages of breastfeeding extend well beyond cancer prevention. Research links it to lower risks of ovarian cancer and obesity for mothers, while babies gain protection from infections, allergies, and obesity later in life.

For mothers, the American Institute for Cancer Research (AICR) reports that lactation increases energy expenditure, burning about 500 extra calories a day. Longer breastfeeding duration is also associated with a lower risk of obesity, diabetes, and cardiovascular disease.

For children, the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) finds that breastfed babies are less likely to become overweight or obese later in childhood.

Experts believe several factors play a role:

• Babies regulate their own milk intake better than bottle-fed infants
• Breast milk composition naturally changes with the infant's needs, promoting healthy growth
• Hormonal and metabolic programming during infancy may influence long-term weight control

Still, Hart says that breastfeeding is not always easy initially. "I tell new moms, you're giving your baby a gift that lasts a lifetime, and you're protecting your own health, too," she said. "But it requires perseverance, support, and education."

For women considering about breastfeeding, Hart offers a straightforward recommendation: "Decide that you are going to succeed. Especially with your first baby. Even one year can make a meaningful difference for your health, and your baby's."