The Remarkable Benefits of Breast Milk

Oct 1, 2025

Breast milk is the ideal food for babies in the first six months, providing everything a baby needs for optimal growth and development*. Breast milk changes over time to meet the needs of your growing baby and its unique composition is tailored to support digestion, strengthen the immune system, and promote healthy cognitive and physical development.

Why Is Breast Milk Beneficial?

Breastfeeding offers a range of benefits for both baby and mother. In addition to being a natural source of nourishment, it helps establish a strong foundation for long-term health.

  • Gentle Proteins: Breast milk contains the right balance and quality of proteins to support baby’s needs. These proteins are easy to digest and support baby’s rapid growth and development.
  • Immune system support: Antibodies in breast milk help protect against infections, reducing the risk of common childhood illnesses like ear infections, diarrhea, and respiratory issues.1
  • Short and long-term health benefits: Studies suggest that breastfeeding may protect babies from gastrointestinal and ear infections, and it potentially lowers the likelihood of developing allergies, asthma, obesity, and type 2 diabetes later in life.2

Key Components of Breast Milk

The composition of breast milk is dynamic, adapting to meet a baby’s nutritional needs. It includes:

  • Proteins, fats, and carbohydrates: These macronutrients provide energy, aid in brain development, and support bone growth.
  • Vitamins and minerals: Essential nutrients like calcium, iron, and zinc contribute to strong immunity and proper development.
  • Human Milk Oligosaccharides (HMOs): These unique carbohydrates are only found in breast milk and have been shown to nourish beneficial gut bacteria and support baby’s developing immune system.3

How Breast Milk Changes Over Time

Breast milk is not a static food—it evolves as a baby grows, ensuring they receive the necessary nutrients at every stage.

  • Colostrum: Produced in the first few days after birth, this thick, nutrient-dense milk is packed with antibodies that provide immune protection.
  • Transitional milk: As a mother’s milk supply increases, this phase delivers higher amounts of fat and lactose to support energy levels and brain growth.
  • Mature milk: By the second or third week postpartum, mature milk has developed and provides the right mix of nutrients each time baby feeds.*

* All breastfed and partially breastfed infants in Canada should receive a daily vitamin D supplement of 10ug (400 IU). 

References:

1. Government of Canada, 2023. Breastfeeding your baby. Accessed February 2025. URL: https://www.canada.ca/en/public-health/services/child-infant-health/breastfeeding-infant-nutrition.html 
2. World Health Organization, 2017. Continued breastfeeding for healthy growth and development of children. Accessed February 2025. URL: https://www.who.int/tools/elena/bbc/continued-breastfeeding#:~:text=Breastfeeding%20has%20also%20been%20shown,)%20(2%2D
3. Bode L, et al. Glycobiology. 2012;22(2):1147-1162.