Children who are allowed to be picky eaters are more likely to develop allergies in later part of their life, warn scientists.
Since time immemorial, mothers have been told to protect their young ones by avoiding high-risk foods during pregnancy and breastfeeding to protect them from potentially dangerous reactions.
As compared to the traditional belief, there is now a growing belief that the best way to avoid allergic reactions is to meet the problem head-on and expose children to foods like peanuts in infancy.
Three large studies have been undertaken at the King's College London, Cambridge University and Duke University in North Carolina to determine the best way of protecting children against harmful reactions to food.
According to Professor Gideon Lack from King's College, until recently mothers were told to breastfeed for up to six months before introducing their babies to other food, and keep them away from possible allergens until the age of two or three.
The idea, he said, was to "wrap the infant up in a sort of immunological cocoon and not expose them to proteins that could launch allergic reactions."
"There is a possibility that we were achieving the reverse of our intentions through this avoidance policy," the Telegraph quoted him as saying.
Starting in 2006, the researchers began following 640 babies, half of whom were judged to be at high risk of food allergies, to see if exposing them to traces of peanuts in their early years causes them to develop adverse reactions.
Previous research at Cambridge suggested that feeding small doses of peanut flour to allergic children every day for 30 weeks could raise their tolerance to safe levels, enabling most of the group to eat 32 peanuts with no reaction by the end of the trial.
As studies into allergies have typically followed small groups over brief time periods, there is still no firm evidence over whether desensitising children to foods like peanuts is temporary or permanent.
'The biggest thing is not to let mothers feel guilty about whatever choice they make, because at this point we really don't know the best answer," Hugh Sampson from the Mount Sinai School of Medicine's food allergy institute in New York, said.
The study has been published in the journal Nature.