Researchers found that when babies were exposed to cow's milk in the form of baby formula in the first 15 days after birth, they were protected from developing an allergy to milk protein later in life. (Jonathan Hayward/Canadian Press)

Exposing an infant to cow's milk in its first 15 days of life may protect it from a dangerous milk allergy later on, new research suggests.

The new findings are a slight departure from the recent advice of medical authorities such as Health Canada, who recommend exclusive breastfeeding for the first six months, "as it provides optimal nutritional, immunological and emotional benefits for the growth and development of infants," according to the federal department.

Researchers found that when babies were exposed to cow's milk, in the form of baby formula, in the first 15 days after birth, they seemed to be protected from developing an allergy to milk protein later in life. In a prospective cohort study, they tracked 13,019 infants and found that those who consumed formula early on were 19 times more protected from cow's milk protein allergy, or CMPA, than babies who consumed formula after the first 15 days.

CMPA can cause skin rashes, respiratory issues and, in very rare cases, shock and death in babies.

The scientists believe the early exposure offers a "vaccination effect" in infants, meaning it has protective value. Based on the findings, they recommend mothers expose their babies early to formula, though they still stress the importance of breastfeeding. Those who choose to breastfeed might want to consider offering a bottle of formula per night, they suggest, adding that more conclusive studies are needed before more concrete advice can be given.

The study was not randomized, meaning it can't rule out that the results are due to factors other than the infants' formula eating.

The study was conducted by Tel Aviv University researchers and is published in the July issue of the Journal of Allergy and Clinical Immunology.