Most of the time, as a breastfeeding advocate, I'm on the defensive, making the case for the benefits of breastfeeding. But I think it's time to frame the conversation a different way. Breastfeeding is the natural way of things; it doesn't need defending. Female bodies are uniquely and biologically suited to produce proper nourishment for their babies. So, rather than talk about what breastfeeding can do, I'll talk about what baby formula, or, artificial breast milk, can't do, the disadvantages of baby formula.

According to the World Health Organisation, a mother feeding her baby directly at the breast is obviously the first choice, as it helps develop neuronal connections in the baby's brain and muscles in the baby's jaw and face, as well as strengthen the baby's immunity by allowing germs to pass back and forth with the mother.

The second-best choice, according to the WHO, is still the mother's own milk—hand-expressed or pumped and fed to the baby via spoon, cup or tube. It requires a little additional effort, but it's worth it, as it's still better than the third-best option on the WHO's list: screened donor milk, usually from a milk bank.

Only if that, too, is unavailable, should women use baby formula—the fourth-best solution. Why? Because the disadvantages of baby formula are many.

The disadvantages of baby formula

Baby formula can't respond to your baby's changing dietary needs.

Most formula milk for babies is cow's milk modified with other ingredients. It is a fixed, static combination of substances that does not respond to the needs of the baby.

On the other hand, breast milk changes constantly—from morning to evening, from day to day. It can be affected by a mother's diet, but more importantly, it is affected by the baby's needs. Immediately after birth, the mother produces a type of breast milk called colostrum, which is low in fat and carbohydrates and high in protein and antibodies—precisely the nutrient balance that the baby needs in its early days.

The benefits of breast milk include the fact that it is easily digested by the baby's immature system, allowing him or her to pass a first stool (an important milestone) and it contains live cells that offer protection against infection and allergies. After colostrum phases out, research has found that the lipid or fat and cell composition of breast milk changes each time milk is drained by the baby, suggesting that breast milk respond to a baby's needs.

Similarly, the mother of a premature or low-birth weight baby produces milk that exactly suits the requirement of her own baby, and it is different from the milk produced by the mother of a full term baby: Breast milk of mothers of pre-term babies contains higher levels of total nitrogen, protein nitrogen, sodium, chloride, magnesium and iron, as well as different compositions of fatty acids, to help complete premies' development.

Baby formula has shown no correlation to increased intelligence.

Studies show that babies who are not breastfed score lower on intelligence tests compared to breastfed babies. Breast milk contains all nutrients needed by the baby's brain to reach its maximum potential, while artificial breast milk fulfills only the baby's caloric requirement.

Additionally, breastfeeding facilitates bonding, which has also been shown to correlate with increased intelligence. While parents, of course, can bond with their child outside of feeding, breastfeeding creates regular opportunities for skin-to-skin contact and undivided attention, while ensuring the baby's needs are met—three key components for a child to feel loved and secure.

Baby formula does not have immunity-boosting qualities.

We may live in cleaner environments than we used to, but there are still plenty of reasons to be concerned about your child's immunity. Baby formula, while it contains basic nourishment, doesn't have the properties or allow the germ-sharing that strengthen immunity.

On the other hand, there is a growing body of evidence that proves the benefits of breastfeeding include decreased incidence of meningitis, respiratory and gastrointestinal infections, and conditions like asthma and allergies among babies. This is particularly important for families in India's polluted metros to note. With Delhi as the world's most polluted city, the air of our other metros not much better, and the incidence of asthma on the rise across the country, breast milk can help shield your child in a way artificial breast milk cannot. It's also an important consideration for parents of premature babies, whose organ systems – including the immune system – may be underdeveloped at birth.

Baby formula can't promote of the positive, long-term health effects breast milk does.

The incidence of later-life or non-communicable conditions – including diabetes, obesity and childhood cancers – is lower among breastfed babies. Breastfeeding even correlates with a lower risk of SIDS (Sudden Infant Death Syndrome), whereas artificial breast milk does not have any correlation to better long-term health.

But the disadvantages of baby formula are not all on the baby's side. Women who feed their children formula miss the health benefits of breastfeeding, too: A lower risk of heart disease, type 2 diabetes, breast cancer, and more.

But wait a minute—haven't we all heard the argument: "My babies were fed formula and they are perfectly OK!" I am glad they are. But is baby formula best nourishment you can offer your child? Absolutely not—not even third-best.

Every year formulas are being improved with newer ingredients in a quest to get them closer to breast milk. But without live cells, antibodies, and hundreds of yet unknown nutritive and protective factors, they are nowhere close yet.