Lactose-free and soya formula: when is it recommended

May 30, 2022 Manuel Fernández

What specialist infant formulas are there? Lactose-free and soya formulas are some of them, and today we are going to talk about them.

Because there are many occasions when babies do not tolerate ordinary infant formulas well, and that is why manufacturers offer different special infant formulas to respond to your baby's needs.

It is a stage that raises many doubts, which is why, if you are having difficulties finding an infant formula for your baby, our midwives have prepared the following post especially for you: special infant formulas, lactose-free and soya-based.

When is infant formula indicated?

There is no doubt that breastfeeding is the best food for your baby during the first six months exclusively, and as a complement up to the age of 2. This type of nutrition for your baby provides the best metabolic input, reduces allergic sensitisation and increases your baby's immunity. It protects them against infections, reduces the risk of sudden infant death and offers some protection against chronic diseases.

However, there are many circumstances that require the use of infant formula, whether out of necessity or out of maternal choice. Situations that make it necessary to look for other feeding alternatives in order to complement or replace breastfeeding, and in these cases adapted formulas should be used, as their composition is regulated by various international bodies.

When should you use ordinary formula or special formula?

Adapted infant formula, also simply called infant formula, is designed to feed your baby with a bottle. It is made from cow's milk and is intended for the healthy baby born at term or for the large premature baby (with a birth weight above 2,500 grams), and it is generally well accepted by infants.

But there is a percentage of between 2.5 and 5% who, during their first year of life, suffer from a cow's milk protein allergy. And it is here, with these babies, that we are going to use special infant formulas. They are babies who present dietary intolerances or allergies, gastrointestinal problems that cause them alterations in absorption or problems of another nature, or congenital metabolic errors. That is why the use of special formulas must be reserved for babies who present a disorder that prevents the use of conventional formula.

What do special infant formulas contain?

Special infant formulas are designed on the basis of the regulations and recommendations of the Nutrition Committee of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ES-PGHAN) and of the American Academy of Pediatrics (AAP). They are adapted formula milks in which the composition of macronutrients has been modified. Basically, however, the modification affects the carbohydrates or the proteins.

Is it necessary to prescribe special infant formula?

With regard to special infant formulas, the recommendation that science gives us is that they can be considered both a food and a medicine and that, therefore, it would be necessary, on the one hand, for the paediatrician to indicate them with their prescription and, on the other, for the pharmacist, who, thanks to their proximity to the public, can monitor the diet of the infant fed with these formulas in many different respects.

We have deeply internalised that it is the paediatrician who guides us throughout the whole process, but we should also know that it is recommended that the pharmacist be able to guide and advise the parents and carers of babies on the composition and appropriate use of these adapted formulas, the preparation of the bottle and the storage conditions of the product.

Types of special infant formula

Below you will find the different types of special infant formula currently available on the market. We will also describe the most commonly accepted indications for you:

Lactose-free formulas.
Soya protein formulas.
Protein hydrolysate formulas: hypoallergenic and hypoantigenic.
Elemental or monomeric formulas.
Anti-constipation formulas.
Anti-colic formulas.
Anti-reflux or anti-regurgitation formulas.
Day/night nutritional formulas.
Formulas for premature infants.
Formulas for the dietary treatment of congenital metabolic errors.

Lactose-free infant formula

Lactose is the main carbohydrate in milk and requires the enzymatic activity of lactase to give rise to two products: glucose and galactose. In this type of lactose-free infant formula for babies, the lactose has been partially or totally replaced by another carbohydrate that does not cause problems with absorption.

Dextrinomaltose or glucose polymers can be used, while the rest of the composition remains the same as that of adapted milks. In addition, dextrinomaltose and glucose polymers provide low osmolarity, achieving good digestibility and absorption.

When is the use of lactose-free special infant formula indicated?

This type of lactose-free special infant formula is indicated exclusively for babies and young children who present lactose intolerance due to malabsorption. The most frequent cause of this lactose intolerance in babies is the secondary kind following an infectious gastroenteritis, and in older children it is usually a primary, late-onset lactase deficiency.

How long should I use lactose-free milk for my baby?

Having to use this type of milk does not mean that it will be necessary for life. The recommendation is to keep using these lactose-free special formulas on a temporary basis, for between 2 and 3 weeks. This is because the lactase deficiency is usually temporary, and lactase is important for calcium absorption in the intestine, which means that it will be relevant for building bone mass and forming acidophilic flora in the colon.

Therefore, with regard to calcium, this type of lactose-free formula contains the amount of calcium recommended by the European Commission, which is 50-55 mg/100 ml. We should also bear in mind that if there were a need to give the baby or child a lactose-free formula for a prolonged period, an additional intake of calcium in the diet is recommended.

Another aspect to bear in mind is that, in cases of galactosaemia (the inability to use the simple sugar galactose), the use of lactose-free infant formula is not recommended, since they contain traces of lactose, and a formula free of disaccharides that contains fructose as an oligosaccharide is required. That is why it is important that the indication is given by a paediatrician.

And to finish with lactose-free milks, one of the best-known indications is the treatment of acute diarrhoea and its complications. ESPGHAN has currently reviewed the treatment of acute diarrhoea and recommends four hours of oral rehydration and early refeeding of the child in European countries.

Soya protein formulas

Soya protein special formula milks are first-stage and follow-on formulas in which the protein component replacing milk proteins is the protein isolated from soya flour. These formulas contain dextrinomaltose, glucose polymers and/or sucrose as carbohydrates and are free of lactose, since they are plant-based formulas, and they may also contain starch.

The importance of this protein lies in the fact that soya protein is nutritionally inferior to that of cow's milk, although its calorie content is similar to that of cow's milk formulas. It is deficient in methionine, lysine, proline and carnitine. And its digestibility is lower, providing a lower bioavailability of minerals (calcium, zinc, magnesium, iron and copper).

This means that these soya protein special formula milks are supplemented with methionine, carnitine and taurine, to bring them up to the levels in breast milk, and with calcium and phosphorus in amounts similar to those of adapted formulas. In addition, the calcium and phosphorus supplement is justified by the high concentration of phytates contained in soya, which can inhibit their absorption, which is why the calcium/phosphorus ratio must be between 1.2 and 2.

In any case, no undesirable effects have been described with the formulas on the market. They have a higher protein content than those made from cow's milk (2.25 g/100 kcal compared with 1.8 g/100 kcal). The lipids are of vegetable origin (oils such as soya, corn or coconut oil), since milk fat may contain traces of cow's milk proteins. Some preparations contain MCT oil (medium-chain triglycerides).

When should you use soya protein special infant formula?

It must be borne in mind that this type of soya protein special infant formula has a high concentration of manganese, aluminium and phytoestrogens, whose possible long-term impact is unknown. Its use is recommended in the following situations:

The need for a lactose-free diet: proven lactose intolerance (primary or secondary) and galactosaemia.
Feeding of infants in vegetarian families who cannot be breastfed and whose parents wish to avoid formulas derived from animal proteins.
Children with cow's milk protein allergy (mediated by IgE immunoglobulins) who are not sensitised to soya protein. These formulas should not be used in infants under 6 months with digestive symptoms.

Soya protein special infant formula is not indicated for:

Neither the enteropathy that is sensitive to cow's milk protein, nor allergy or hypersensitivity that is not mediated by IgE immunoglobulins, as in these cases there may also be allergy to soya protein.
The prevention of atopic diseases in high-risk children.
The prevention and management of infant colic, regurgitation or episodes of prolonged crying.
Children under 6 months with regard to allergy to cow's milk proteins.

Conclusion on special infant formulas

As we always tell you, every case is unique and, obviously, in this post you will have found a great deal of information about special milks that will help you to better understand why your paediatrician has prescribed one or another. It is a stage that, when we come up against these difficulties, is sometimes hard to get through, but with good help from the professionals around you, you will manage to get on top of the situation; what's more, it is a stage that passes, lots of encouragement, and if there is anything you need, we are here. (Information published in the magazine Farmacia profesional, “fórmulas lácteas especiales”, Vol. 23)