British researchers say they have determined the optimal time to begin introducing solid food into an infant’s diet, claiming that phasing it in alongside breast milk may reduce the child’s risk of developing food allergies.
According to the new study, infants are largely intolerant of solid food before four to six months of age. This is due to the body’s inability to recognize solid objects as food, often turning the infant’s immune system against the food, which leads to the development of an allergy. Now, British doctors argue that gradually incorporating solid food into the child’s diet with breast milk after the 17-week mark significantly reduces his or her risk of becoming allergic to certain foods.
"Mothers should continue to breastfeed beyond introducing solids into the diet so the immune system can benefit from the immunological factors in breast milk that educate the immune system," lead researcher Kate Grimshaw, allergy specialist at the University of Southampton, told HealthDay. "My theory was that if food allergens — those things that infants actually become allergic to — aren't there at the same time as the breast milk, the breast milk can't educate the immune system."
In other words, children who grow allergic to peanuts may have benefited from the introduction of peanuts alongside their mothers’ breast milk, so that their body could accustom itself to (foreign) peanuts in the presence of (familiar) food.
Grimshaw and her colleagues recruited 41 children who had developed food allergies by age 2. They compared this cohort with 82 children without food allergies. The team found that children who had developed allergies began eating solid food substantially earlier than children with no allergies — roughly, at age 16 months and earlier. Children with allergies were also more likely to stop breastfeeding once the mother introduced a form of cow’s milk protein, either cow’s milk itself or some processed variant.
While researchers aren’t certain what makes breast milk support immune health during solid food’s introduction, the team speculates that the antibodies found in breast milk may act as a buffer for solid food shocking the system. Dr. Vivian Hernandez-Trujillo, director of allergy and immunology at Miami Children's Hospital, argues that the study failed to adequately explain the reasons behind the correlation.
"Unfortunately, we still don't have all the answers when it comes to food allergies," Hernandez-Trujillo told HealthDay. "It appears that breastfeeding may be protective, but we still don't know why.”
Even if the findings aren’t substantiated causally, parents may want to consider heeding the study’s findings if only given the increasing rates of childhood allergies. Rates are decidedly low, according to the Centers for Disease Control and Prevention (CDC) — around four to six percent of all children have a food allergy — however, the rates have increased 18 percent between 1997 and 2007. In 2006, 88 percent of schools had at least one child enrolled who suffered from a food allergy.
Aside from possibly preventing or diminishing the severity of food allergies, scientists have conferred a wealth of benefits for breastfeeding. Among them are a reduced risk for autism, Sudden Infant Death Syndrome (SIDS), a tiny reduction in the risk for leukemia, decreased risk of asthma, eczema, childhood onset diabetes, and decreases in childhood obesity and dental problems.
The present study’s findings agree with the World Health Organization’s claims that women should nourish their children exclusively through breastfeeding for the first six months of the child’s life before deciding to transition to solid food or some combination of the two.
"It also supports the American Academy of Pediatrics' breastfeeding recommendations,” the researchers conclude, “that breastfeeding should continue while solid [foods] are introduced into the diet and that breastfeeding should continue for one year or longer, as mutually desired by mother and infant.”
Source: Grimshaw K, Maskell J, Oliver E. Introduction of Complementary Foods and the Relationship to Food Allergy. Pediatrics. 2013.