Breast Milk Information: Types, Content & Nutritional Benefits

Breast Milk – Types, Content, and Composition

Medically Reviewed By
Anindita Bhattacharya (Diabetologist/Nutritionist/Dietitian)
View more Diabetologist/Nutritionist/Dietitian Our Panel of Experts

Breast milk contains over 200 beneficial elements and more are being added to this list with each passing day. Breast milk is unique in that your body will automatically customise the milk you produce according to the needs of your baby. Thus, the breast milk produced if your baby is born full-term will be different from the milk produced if your baby is born prematurely. This is why there can be no substitute for breast milk. It is recommended that all babies be exclusively breastfed for up to six months, and breast milk continues to be a major part of your baby’s diet at least till he or she is a year old.

Why Is Breast Milk the Best Source of Food for Your Baby?

As a mother, you make breast milk specifically for your baby. Since breast milk contains just the right amount of nutrients and other elements essential for your child at each stage, it is considered the best source of food for babies. Breast milk is known to provide protection against infections and minimises the risk of certain health problems later in life, such as diabetes, obesity, and asthma. According to a study conducted in 16 countries by the WHO, breastfeeding can reduce the chances of a child becoming obese by up to 25%. Breast milk contains all elements necessary for your baby’s body to grow, develop, mature, and survive.

What Is Colostrum Milk?

The milk produced in the first few days after the birth of your baby is known as colostrum. Lasting for about five to seven days, colostrum is thick and sticky usually with a pale yellow colour. The high antibody content in colostrum makes it vital for the baby’s health and acts as the first vaccine of sorts. Though very concentrated, this milk is easily digested and is produced in small quantities just enough to satiate the requirements of your newborn.

What Is Colostrum Milk?

Other features of colostrum are:

  • It has a high content of protein, minerals, salt, Vitamin A, antibodies, and very little fat and sugar.
  • It acts as a laxative promoting the easy passage of meconium (baby’s first stool).
  • It prevents neonatal jaundice by encouraging the expulsion of bilirubin from the gut.

The earlier your baby starts feeding on colostrum, the better it is for both of you. The baby gets a nutritional head start, and your milk production gets off to a quick start as well.

What Is Transitional Milk?

This is considered the second stage of your breast milk production and can be seen about a week after delivery. Your breasts are likely to feel full and hard, while some pain and redness cannot be ruled out. Frequently feeding your baby will provide you relief, and this can last for a few days. In the following two weeks, you can expect to see an increase in the quantity of milk as well as changes in its composition. The amount of fat and sugar increases while immunoglobulin and protein levels in breast milk dip during this phase.

What Is Mature Milk?

It might look thin and watery, but mature milk contains all the nutrients that are required for your baby’s well-being. Its composition and consistency will keep on varying from feed to feed on a daily basis as well as from month to month. After the first few weeks, the number of white cells in breast milk will decrease while the level of the antibacterial enzyme, lysozyme, will increase. The amount of milk you produce will increase as the baby grows till your child moves on to solid food.

Which Nutrients Are Found in Breast Milk?

Quite a few of the nutrients found in breast milk, such as infection-fighting white cells cannot be manufactured outside of the human body. It is estimated that 100 ml of breast milk contains about 65 calories. Here is a brief break-up of the contents of breast milk:

  1. Proteins

Whey and casein are the two types of proteins found in breast milk and offer your child protection against infections. The balance between these two proteins with whey accounting for 60% and casein for 40%, allows for easy digestion of breast milk by the baby. Of the specific proteins found in breast milk, lactoferrin helps prevent the growth of harmful organisms like yeast and coliform, while Secretory IgA offers protection against E.Coli and allergies, and lysozyme has anti-inflammatory properties. An important amino acid called taurine is found in large amounts in breast milk. This is essential for the proper development of the baby’s brain and eyes.

  1. Fats or Lipids

The fats in breast milk are essential for baby’s brain development and absorption of fat-soluble vitamins. They are also a source of calories besides promoting the development of the brain and the nervous system. Making up only 4% of the breast milk, fats provide around 50% of the baby’s calorie intake. Fatty acids such as linoleic and linolenic help in the production of a substance called myelin that coats the nerves and helps in the transmission of messages through the nervous system.

  1. Vitamins

The vitamin content of breast milk will depend on your vitamin intake as a mother. So, make sure your diet includes food that is rich in vitamins A, D, E, K, C, niacin, riboflavin, and pantothenic acid. Vitamins are what makes for healthy bones, skin, and eyes. They are also useful in preventing diseases like scurvy and rickets. In order to make sure you are not deficient in any of these vitamins, your doctor might suggest that you continue taking prenatal vitamins while breastfeeding. This is to make sure that the baby receives all the essential nutrients and to replenish the nutrients lost during childbirth in the mother’s body.

  1. Carbohydrates

Lactose makes up around 40% of all the calories in breast milk and is the primary carbohydrate in human milk. It plays an important role in ridding the stomach of unhealthy bacteria and encouraging absorption of calcium, phosphorus, and magnesium.

  1. Hormones

Hormones in breast milk include prolactin, relaxin, endorphins, cortisol, leptin, oestrogen, progesterone, as well as thyroid hormones and growth factors. These are necessary to control metabolism, stress levels, pain, and blood pressure, among other things.

  1. Enzymes

It is estimated that breast milk contains about 40 different enzymes. Some of these are helpful in breaking down fats to assist with digestion, while others boost immunity against germs and ailments. Lipase is an enzyme present in breast milk that helps break down fat so that babies can digest it easily.

  1. Minerals

Minerals aid in the development of strong bones, while increasing the efficiency of red blood cells and ensuring proper nerve and muscle functions. Iron, zinc, calcium, sodium, magnesium, selenium, and chloride are some minerals found in breast milk.


Composition of Key Nutrients Found in Breast Milk

The composition of breast milk keeps varying depending on various factors such as the age of the child, the mother’s health, and the mother’s diet, to name a few. Water makes up around 90% of breast milk, and this is essential to keep the baby hydrated, control body temperature, provide lubrication for the joints, and protect organs.

Also, the composition of a mother’s milk differs throughout the day as well as during a feed. For instance, the foremilk or first milk expressed during a feed is intended to be thirst-quenching. The milk that comes later, known as the hindmilk is rich and full of creamy good fats for your baby. Here is a tabulation of the composition of some nutrients found in breast milk:

Nutrient Mean Value in Breast Milk (100 ml)
Protein 1.3 g
Fat 4.2 g
Carbohydrate 7 g
Sodium 15 mg
Calcium 35 mg
Phosphorus 15 mg
Iron 76 mcg
Vitamin A 60 mcg
Vitamin C 3.8 mg
Vitamin D 0.01 mcg
Magnesium 3.5 mg


Other Vital Components of Breast Milk

There are quite a few other substances that are a part of breast milk, and these are essential to your baby’s continued well-being. They are:

  • Human Milk Oligosaccharides (HMOs)– A type of dietary fibre, these promote the growth of healthy bacteria in your baby’s stomach to help in digestion and regular bowel movements.
  • Human Milk Microbiota– Breastmilk contains various types of bacteria. Some of these are found in the milk of all mothers, while others will be unique to you depending on your diet, immunity, environment, and lifestyle. When passed on to the baby, it will help them develop their own individual intestinal microbiota, which will then be useful in fighting off infections.
  • Antibodies Also known as immunoglobulins, this helps boost the baby’s immune system. Colostrum, also known as the first breast milk, is especially packed with anti-bodies.

Quite a few growth factors are also found in human milk, which is beneficial to the gut, the nervous system, blood, and the hormones that control metabolism. There are also plenty of other ingredients in breast milk that have not been identified yet.

Eating a healthy, nutritious diet when you’re pregnant and during the breastfeeding years will be beneficial to your health as well as that of your child. Ensure that your diet is a balanced one comprising of whole grains, legumes, fruits, vegetables, lean protein such as chicken, dairy products with low-fat content, and plenty of water.

If you are having problems getting your baby to latch on, then you can seek the help of a lactation consultant. Most women who are having difficulties grasping the technique of breastfeeding find that expert guidance is extremely useful. You can also consult your gynaecologist if you have other concerns or reach out to a paediatrician to get a better understanding of your child’s health.

Disclaimer: This information is just a guide and not a substitute for medical advice from a qualified professional.

Also Read: Engorged breasts – Things you need to know

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