Deciding how to feed your baby is one of the first and most important decisions a new mother makes.
The benefits of breast-feeding are well-documented and doctors encourage mothers to breast-feed their babies for at least the first year, if possible.
Now, there may be one more reason why the breast is best.
Researchers in New Hampshire measured arsenic levels in the urine of 6-week-old infants and found formula-fed babies had arsenic levels 7.5 times higher than breast-fed babies.
While arsenic levels for all of the infants in the study were very low and well under allowed limits, the babies fed only formula had the highest concentrations of arsenic, followed by those who received formula and breast milk.
Exclusively breast-fed infants had the lowest levels of arsenic in their urine.
Must be something in the water …
According to the study, published in Environmental Health Perspectives, the water used to mix baby formula plays the biggest role in whether formula-fed babies are exposed to increased levels of arsenic.
Arsenic is a naturally occurring element found in bedrock, so it can seep into groundwater and soil. In large doses, arsenic can be deadly.
Michigan, like New Hampshire, is one of a handful of states with unusually high arsenic concentrations in groundwater.
Chronic exposure to arsenic in small doses, often from food or other sources people are not aware of, is more common, harder to detect and poses the greatest risk for babies, said William Bush, MD, pediatrician-in-chief, Spectrum Health Helen DeVos Children’s Hospital.
“Infants are in a rapid growth phase so they consume a much larger percentage of food relative to the size and weight of their body than a small child or adult does,” Dr. Bush said. “Any exposure to toxins, therefore, shows up in greater concentration.”
Water that comes from a city or municipal source must comply with federal regulations that limit the maximum amount of arsenic to 10 micrograms per liter. If you draw your water from a private well, the amount of arsenic in the water is not regulated.
Arsenic levels in well water from Kent, Barry and Allegan counties have been detected at 20 to 50 micrograms per liter, more than twice the maximum allowed for city water. Higher levels have also been detected in counties along the lakeshore.
Although it’s not clear whether the low levels of arsenic exposure in the study will turn out to be harmful, it’s worth knowing what’s in your water, Dr. Bush said.
What about the food?
Along with water and fish, rice is another primary source of dietary arsenic.
Many baby formulas are rice-based and parents often are counseled to use rice cereal as one of baby’s first sources of solid food. Reports have surfaced of high levels of arsenic in organic brown rice syrup, a sweetener used in juice and baby formula.
“If a mother can’t breast-feed, we suggest using dairy-based formula. For infants who can’t tolerate dairy, a soy-based formula,” Dr. Bush advised. “For babies ready to start on solid foods, oatmeal and other grains are good choices, along with pureed fruits and vegetables.”
Like you, your baby should eat a wide variety of foods. The more diverse their diet, the less likely they’ll be exposed to toxins from any single source, he added.