Moms - Your Baby Bottle May Be Losing Vitamin C
Study: Air Traveling Through Milk in Bottles Likely Causing Degradation of Nutrient
St. Louis, MO (PRWEB) September 9, 2008
A first-of-its-kind study has revealed important new information for moms to consider when they select a baby bottle for their child. Depending on the bottle type, there may be minimal amounts of Vitamin C left in the milk after a 20-minute bottle feeding.
The study measured the level of Vitamin C loss during simulated 20-minute long baby bottle feedings. The results suggest that the amount of air within a baby bottle, bottle design, and the impact on vitamin C levels warrant closer examination. Recommendations for moms are listed at the end of this news release.
The bottle feeding study, "Comparative Analysis of Nutrients in Baby Milk Using Varied Milk Delivery Systems," was recently published in the International Breastfeeding Journal (http://www. internationalbreastfeedingjournal. com/). The study was conducted by a group of researchers at the University of Nevada-Reno, led by Dr. Jimi Francis, an international board certified lactation consultant and researcher. The bottle feeding study findings were also presented in July 2008 at the International Lactation Consultant Association (http://www. ilca. org) (ILCA) Annual Conference.
The bottle study was designed to investigate changes in vitamin C levels that might occur during a typical bottle feeding time of 20 minutes, using both expressed human milk and infant formula, in both vented bottles and unvented bottles. The study looked at the amount of vitamin C in the milk when delivered through seven commonly used baby bottles. The purpose was to determine if exposure to air within a baby bottle during a simulated feeding affected the level of vitamin C, which is known to oxidize when exposed to air. Vitamin C is critical for health and growth in infancy. Medical research shows that children with low intakes of vitamin C are more vulnerable to develop frequent and more severe common day-to-day illness.
As milk is removed from the bottle by the infant, the milk is replaced by ambient air. Nutrient loss is likely caused by the oxidation of nutrients that takes place as air is introduced into the liquid. The amount of air moving through the milk and into the bottle depends on the bottle type, bottle shape, and bottle size. Vitamin C was examined because it is an essential nutrient and is easily degraded by heat, light, and air. Dr. Francis says that previous baby bottle studies have been conducted to evaluate the loss of vitamin C during the handling and freezing of human milk, but not on what happens during the feeding process itself.
"Handling and storage of breastmilk and formula can impact the levels of vitamin C," Dr. Francis says. "The ability to maintain vitamin C in bottle feeding appears to be influenced by bottle design." She adds that the degradation of the nutrient during a 20-minute feeding does not mean that the infant is getting insufficient vitamin C over the course of a day, but rather that the vitamin level is declining-in some cases quickly-during the duration of the bottle feeding.
Mature human milk was donated by anonymous volunteers for the study. The milk was standardized for vitamin C. In addition to studying effects on human milk, the study also examined two types of infant formula. The milks were delivered through seven different major brand baby bottles with five samples collected from each bottle: baseline, 5 minutes, 10 minutes, 15 minutes, and 20 minutes (see graph). Each sample was analyzed for vitamin C using normal-phase high-performance liquid chromatography, and each collection was completed in triplicate to ensure the consistency of results.
See graph, NutrientStudy (http://www. nutrientstudy. com). This graph demonstrates the loss of vitamin C. As an example based on the findings, a two-month old child, fed by bottle 10 times per day in 20-minute feedings, would take in approximately 13 mg of vitamin C with one bottle, and approximately 34 mg of vitamin C with a different bottle over a period of one day. The Food and Nutrition Board at the Institute of Medicine recommends a vitamin C intake of 40 mg per day for infants aged up to six months old.
"Maintaining optimal vitamin C levels over the course of a bottle feeding is of clinical significance to practitioners and parents," says Robin Hollen, a registered nurse, international board certified lactation consultant, and private practice lactation consultant. "For infants at high risk, such as those in neonatal intensive care or with compromised immune systems, vitamin C intake should be evaluated. Bottle shape, size, and venting should be considered."
The bottles used in the study were different in design in the way that air is replaced in the bottle as milk is removed. Two bottles had removable screw-off bottoms with a diaphragm in the base of the bottles. One bottle had an insert inside the collar of the nipple. One bottle has a vent system that allows air moving into the bottle to bypass movement through the milk, with no bubbles forming as milk is removed from the bottle.
Those bottles observed to have more bubbles forming in the milk had lower levels of vitamin C, an expected outcome given that exposure to air causes oxidative loss of vitamin C in many foods.
"Nutrition is an important area of study. Evaluating not only what we eat but how we eat can provide greater understanding of how to achieve optimal nutritional status. This is about looking at bottle design and other factors that can influence maintaining optimal nutrition levels of bottle-fed milk and formula," Dr. Francis says. "With even a basic understanding of possible differences between bottles, moms are armed with useful knowledge to help them make informed choices for their babies."
Dr. Francis emphasized that there are many other factors, including length of time and manner of storage, which are thought to impact nutritional levels of key nutrients. She adds that additional research is needed to fully understand how nutrients in breastmilk and infant formula are affected by handling, storage, and the delivery through a bottle.
As this data becomes available, changes may need to be made regarding the protocols recommended for the handling of human milk with regard to preserving the integrity of specific nutrients.
Almost two-thirds of women in the Unites States work outside of the home, according to the U. S. Department of Labor. The changes in lifestyle and economic activities of lactating mothers have led to an increase in the expression of human milk for later use in infant feeding. While breastfeeding is consistently recommended as the best choice for feeding infants, many infants are fed with a bottle. The expression, handling, storage and delivery of breastmilk or infant formula to infants through a bottle may diminish nutrient levels.
Recommendations for Moms
So what's a mom to do? Dr. Francis offers the following bottle feeding tips:
Select baby bottles that minimize air traveling through the bottle. Look for little to no bubbles forming in the milk as the baby feeds. Use breastmilk that is as fresh as possible. Use small bottles that minimize the amount of air at the top of the milk. When using infant formula, make it fresh for every feeding. Feed babies with small, frequent bottle feedings.
Footnotes
1) The study did not examine whether the observed differences would have any effect on infant health, a complex subject that is beyond the scope of the study.
2) The study did not involve infants, nor did the researchers study any potential impact on vitamin C intake for infants.
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