Micronutrients and Thickened Feeds for Infant Reflux

Does your baby have acid reflux and has your pediatrician told you to try thickening your baby’s formula?

You are not alone. The European Society for Pediatric Gastroenterology Hepatology and Nutrition has published guidelines for the treatment of reflux and dietary management by thickening feedings is one of their first-line treatment interventions. So, it would not be surprising if your baby’s doctor recommended thickened feedings as a starting point.

The consensus is that thickening feeds are considered safe, especially in full-term babies, but the suggestion of more research is needed. Something that is not talked about is what kind of negative effect, if any, thickening feeds can have on infant nutrition status.

Some researchers have questioned if adding fiber to formula/human milk by thickening feeds can interfere with the absorption of micronutrients, specifically calcium, iron, and zinc.

As babies grow, the importance of getting adequate nutrition is crucial. So, let's take a look at what the research says.

A study done by Bosscher et al looked at thickening agents and compared their effects. Human milk was used as the reference standard.

They used a simulated digestion procedure using continuous-flow dialysis in vitro model. It consisted of two phases – gastric and intestinal. The study looked at how calcium, iron, and zinc absorption was affected by using thickened feedings.

What were the results?

It appears that human milk provides the optimal environment for the availability of calcium, iron, and zinc.

When using digestible carbohydrates (pregelatinized waxy rice starch) as a thickening agent in infant formula, there seemed to be no influence on the availability of calcium, iron, and zinc in comparison with infant formulas not thickened. However, they did find a few cases where thickening with pregelatinized waxy rice starch increased the availability of calcium, iron, and zinc. More studies are needed.

When Bosscher et al looked at thickening infant formula with indigestible carbohydrates (like gum-based thickeners – Simply Thick, Gel Mix), it seemed to reduce the availability of calcium, iron, and zinc.

Things to consider.

The word bioavailability is a large idea. It is best to determine bioavailability by in vivo tests; this study used in vitro. One can assume that the study used an in vitro technique as they are less time-consuming and labor-intensive and are more ethical than in vivo techniques.

How to compensate?

Some studies say if you thicken with a gum-based thickener and use formula, which has been shown to reduce the availability of calcium, iron, and zinc, you can compensate by increasing the number of essential elements in the infant food that you provide to your baby. Other studies say more research is needed to explore how to compensate for the losses.

Overall, the consensus is that short-term interventions with thickened feeds to help combat acid reflux should be okay. There is more research needed on the implications of long-term use.

1. _{Rosen, R., Vandenplas, Y., Singendonk, M., Cabana, M., DiLorenzo, C., Gottrand, F., Gupta, S., Langendam, M., Staiano, A., Thapar, N., Tipnis, N., & Tabbers, M. (2018). Pediatric Gastroesophageal Reflux Clinical Practice Guidelines: Joint Recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition. Journal of pediatric gastroenterology and nutrition, 66(3), 516–554.}
2. _{Bosscher, D., Van Caillie-Bertrand, M., & Deelstra, H. (2001). Effect of thickening agents, based on soluble dietary fiber, on the availability of calcium, iron, and zinc from infant formulas. Nutrition (Burbank, Los Angeles County, Calif.), 17(7-8), 614–618.} 
3. _{Bosscher, D., Van Caillie-Bertrand, M., Van Dyck, K., Robberecht, H., Van Cauwenbergh, R., & Deelstra, H. (2000). Thickening infant formula with digestible and indigestible carbohydrate: availability of calcium, iron, and zinc in vitro. Journal of pediatric gastroenterology and nutrition, 30(4), 373–378.}
4. _{Salvatore, S., Savino, F., Singendonk, M., Tabbers, M., Benninga, M. A., Staiano, A., & Vandenplas, Y. (2018). Thickened infant formula: What to know. Nutrition (Burbank, Los Angeles County, Calif.), 49, 51–56.}
5. _{Bosscher, D., Van Caillie-Bertrand, M., Van Cauwenbergh, R., & Deelstra, H. (2003). Availabilities of calcium, iron, and zinc from dairy infant formulas is affected by soluble dietary fibers and modified starch fractions. Nutrition (Burbank, Los Angeles County, Calif.), 19(7-8), 641–645.}