Liquid gold: The benefits of breast milk
Posted on 25 June 2019
Breast milk is not just food for baby – it provides potent health-giving properties for mom, too.
Dr Jonathan Buckley, a paediatric nephrologist at Mediclinic Constantiaberg, offers a closer look at this natural wonderfood.
▶ How does your body adapt to produce milk when you’re pregnant?
The growth and development of your mammary (breast) tissue is controlled by the hormone prolactin. In preparation for the production of milk, prolactin levels increase markedly during pregnancy. However, milk is not yet secreted, because progesterone and oestrogen, the hormones of pregnancy, block this action of prolactin. After delivery, levels of progesterone and oestrogen fall rapidly, prolactin is no longer blocked, and your milk secretion begins.
▶ What are the different stages of milk production?
Breast milk has three different and distinct stages: colostrum (in the first two to three days after delivery), transitional milk (from day seven to 14) and mature milk (after two weeks).
▶ Why is colostrum so important?
Colostrum is a special milk that is produced in small amounts (about 40–50ml on the first day) but is all your baby normally needs at this time. Colostrum is rich in white cells and antibodies, especially IgA, and it contains a larger percentage of protein, minerals and fat-soluble vitamins (A, E and K) than later milk. Vitamin A is important for protection of the eyes and often makes the colostrum yellowish in colour. Vitamin E is an important anti-oxidant and Vitamin K plays a role in helping blood to clot. Colostrum also provides important immune protection to your baby when he or she is first exposed to the microorganisms in the environment. In addition, epidermal growth factor found in this special milk helps to prepare the lining of your baby’s gut to receive the nutrients of mature milk.
▶ How does your breast milk change, as your baby grows older?
Milk starts to be produced in larger amounts between two and four days after delivery, making your breasts feel full. On the third day, your baby is normally drinking about 300–400ml every 24 hours, and by the fifth day, up to 800ml. The content of this transitional milk includes high levels of fat, lactose, water-soluble vitamins and more calories than colostrum.
▶ And what constitutes
Mature milk contains all the nutrients your baby needs in the first six months of life, including fat, carbohydrates, proteins, vitamins, minerals and water. It is easily digested and efficiently used. There are two types of mature milk – foremilk and hindmilk – and both are necessary when breastfeeding to ensure your baby is receiving adequate nutrition to grow and develop properly. Foremilk is found during the beginning of the feeding and contains water, vitamins and protein. Hindmilk occurs after the initial release of milk. It contains higher levels of fat and is necessary for weight gain.
Mature breast milk also contains bioactive factors that augment your baby’s immature immune system, providing protection against infection, and other factors that help digestion and absorption of nutrients.
Breastfeeding benefits for mom
The hormone oxytocin is released when you breastfeed. This feel-good hormone not only helps you to bond with your baby and reduces feelings of stress and anxiety, it also stimulates postpartum uterine contractions. This helps your uterus return to its normal size. Breastfeeding has also been linked to reduced risks of breast and ovarian cancers and may reduce your risk of developing heart disease, osteoarthritis, obesity and hypertension.
Ingredients of mature breast milk include
Long-chain fatty acids which are crucial for your baby’s brain, retina and nervous system development.
Proteins help your baby grow and develop, activate her immune system and develop and protect neurons in her brain. Alpha-lactalbumin, the major protein in breast milk, has antibacterial properties and helps stimulate your baby’s immune system.
Lactoferrin, a protein that transports iron in the body, also has antifungal effects. Complex sugars (oligosaccharides) help your baby create a healthy gut and develop the immune system.
Enzymes are substances that act as catalysts in biochemical reactions. For example, lactose synthatase is important in the synthesis of lactose, while xanthine oxidase carries iron.
Hormones are organic molecules that help regulate physiological activities. Erythropoietin (Epo) is the primary hormone responsible for increasing red blood cells, others include growth-regulating hormones and hormones that regulate metabolism and body composition.
Antibodies (immunoglobulins), mainly secretory immunoglobulin A (sIgA), coats your baby’s intestinal lining and prevents bacteria from entering the cells.
White blood cells kill micro-organisms and protect your baby from infections.
Stem cells are distinguished from other cell types because they have the ability to self-renew and to develop into more differentiated cells. However, the importance and function of stem cells in breast milk is currently not fully understood.