So the big question is naturally – “What is the difference between breast milk and formula?” Firstly, although it is very easy for your body to make milk, making milk in a laboratory is not so easy and the addition of each nutrient needs to be very carefully measured and considered for absorption and potential toxicity. Additionally, certain components in breast milk simply cannot be duplicated in the lab, or are not stable for long term storage. So it is expected that these confounding factors will result in quite a couple of differences between breast milk and formula, each with their own biological consequences for your baby. Formula manufacturers are also constantly striving to improve their product and although they will probably never be able to match breast milk, it is a lifesaving product to have if you cannot produce milk or enough milk for your baby.

Having said that, breast milk is always better than formula, even if a mother can truly not produce enough milk, she can always breastfeed and supplement with formula.

Every drop of breast milk is liquid gold!

Let’s have a look at some of the differences between breast milk and formula I could dig up:


The main nutritional differences are due to the fact that breast milk is produced by a biological system, that varies from day to day and is influenced by temperature, a mothers diet and baby’s demand. It is impossible to create such a diverse and varied product in a sterile laboratory, and formula is thus lacking in many nutrients and bioactive components. Since achieving the same nutritional composition as breast milk is impossible, formula design aims at matching breastfeeding performance or the growth rate of breastfed infants. Let’s look at the main differences in nutrition in four main categories:


The predominantly small whey protein in breast milk is easily digestible and more completely absorbed vs. the predominantly large casein protein (usually derived from cow or goats milk) found in formula, which can result in digestive problems for your baby. In cases where formula causes digestive upsets, parents can usually switch to hypoallergenic products, which have smaller and easier to digest proteins although the cost of these formulae tends to be much higher.


Breast milk is very rich in Omega-3 fatty acids (needed for brain and vision development), cholesterol and lipase – the fat digesting enzyme. Formula is rich in Omega 3 fatty acids but a different variety than that of breast milk – and without added cholesterol and lipase, which makes the fats less digestible than those of breast milk. These differences can result in a slight neurological and visual deficits for formula fed compared to breastfed infants.


The main carbohydrate in milk is lactose – or milk sugar, which is a very important energy supply to your baby. Most formula brands contain enough lactose, as this can be derived from cow and goats milk. It is very rare for a baby to be lactose intolerant, so if a formula must be chosen, those containing lactose are better. One thing to keep in mind is that bottle fed babies can be easily overfed (due to the easy flow of milk from the teat vs. a breast), so watch out for the right cues from baby indicating that he or she is full.

Minerals and Vitamins

Vitamins and minerals such as iron, zinc and calcium in breast milk are easily digested and optimally absorbed by your baby, while the vitamins and minerals in formula are often difficult to absorb, and are thus less efficiently absorbed (as is the case with most normal vitamin and mineral supplements). Often, to compensate for lower absorption, formula companies can add more of these minerals and vitamins, but this can create digestive problems.

Health and well-being

Immune support

Immune support through breastfeeding is a very complex matter, as the mother’s milk contains living antibodies against bacteria and viruses that the baby will find in his immediate environment. These especially include antibodies specific to the mothers gut flora (which is the first bacteria a baby would be exposed to during natural birth), made by lymphocytes that migrate to the mothers breast tissue from the gut during pregnancy. Additionally, when a mother gets exposed to a bad bacteria or virus, she makes antibodies, which then gets included in the breast milk and thus the baby gets protection against diseases in her surroundings through nursing. So basically the immune support in breast milk is live and specific to each baby, which cannot possibly be recreated in formula milk. Formula manufacturers have included a number of immune supportive components in formula milk, such as pre- and probiotics (found in certain brands only), but cannot include live antibodies due to the long shelf life of formula milk. Plainly stated, formula milk can support your baby’s immune system, but cannot amplify it.

Allergies & Digestibility

Since human breast milk is biologically designed for your baby, it is optimally digested without any allergic reactions. The mother’s diet does, however, play an important role, where consumption of large amounts of certain foods, such as cow’s milk, can result in an allergic reaction in the baby. Cow’s milk, soy, gluten, nuts and eggs are probably the most common allergens that can be found in mothers milk, and if your baby is allergic to it, it could cause symptoms of fussiness, gassiness or in more serious cases a rash, digestive upsets and cold or flu-like symptoms.

It is generally advised that a breastfeeding mother should eat what she wants, and how much she wants unless she notices obvious allergic symptoms in her baby. This is naturally with the exception of alcohol, caffeine and drugs that can cause serious harm to a baby.

Long term health

Here I would just like to add in that there have been some studies that have shown a definite long term benefit to breastfeeding your baby.

Firstly, the benefits to your baby would include the following:

  • a Reduced chance of food allergies through adolescence (see more here and here)
  • Protection against diabetes, lymphoma, leukaemia and Hodgkin’s disease (see more here)
  • Protection against various childhood infections and obesity (see more here)
  • Possibly an increased performance in intelligence tests during childhood and adolescence (see here and here)
  • Support of normal jaw and facial development and decreased chance of orthodontic treatment later in life (see here)

Secondly, the benefits to mothers include:

  • Easier weight loss and faster return to pre-pregnancy weight (see more here and here)
  • A decreased risk of ovarian, breast and endometrial cancer (see more here and here)
  • No evidence of a decreased bone density or increased risk of osteoporosis due to breastfeeding (see here)

Physical Contact

I have added in this section because I believe the physical contact between mother and baby that is ensured through breastfeeding offers significant advantages to mothers and babies. This skin-to-skin contact has been shown to reduce crying in babies as well as promote better-regulated sucking and swallowing patterns. It also reduces stress in babies which n turn promotes better sleep. Long term studies have also suggested that kangaroo care (or lots of skin-to-skin contact) boosts baby’s mental development.

If a baby is bottle fed – the same connection can be made through always holding your baby when feeding him, even when he is bigger and able to hold the bottle himself. Naturally, even bottle fed babies can be kangaroo-cared – and should be!

Who is Helene Steenkamp:

Scientist, Writer, Scientific proofreader. I am a Namibian born South African citisen with a great love for nature and its intricacies. I write from home for my own website BioParentology which is focussed on parenting, pregnacy, birth, breastfeeding, health and exersise research. I completed my PhD in molecular phylogenetics at the University of Pretoria in 2011, and has since worked as a postdoctoral researcher in this field at the university as well as the National Zoological Gardens of South Africa. Through my work I have published several peer reviewed scientific articles with the use of phylogenetic tools, where I mostly specialised in bacterial and viral genetics. I have also co-supervised 5 MSc students in the field and have assisted them not only in data analyses but also in article structuring and scientific writing. To complement this I completed a course in proofreading and copy editing in 2012


For more interesting facts about breastmilk and breastfeeding visit the website:

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