When my first child was born in 1971, the prevailing wisdom was that you could feed infants cereals, fruits and vegetables beginning at a month of age, when the swallowing mechanism had matured. (This did not apply to high protein foods, like cow's milk or eggs.) In fact, the majority of infants in the 1970s were fed solid food, albeit softened or pureed, by six weeks of age. (Known as beikost Figure 10.) My daughter at a month or two of age particularly liked bananas, and her face just lit up when we gave her a taste.
But when I offered her daughter, my 6-week-old granddaughter, a piece of banana which her mother had so enjoyed, my daughter grabbed it from my hands as if it were poison. Her child was not to have any solid food, even pureed, until she was 6 months old. This is the current recommendation of most medical organizations. So what changed since the 1970s? Did new research correct our thinking? Was there some horrible consequence of the early introduction of foods?
Surprisingly, the only thing that changed was "expert opinion." We who practice medicine like to believe that we are "evidence based" -- that adamantine research dictates what we do. In part due to a concern that early food exposure might cause allergies, the American Academy of Pediatrics and the World Health Organization recommend no solid foods until baby is 6 months old. But a review of research on the topic found very little support for this. Published in the Journal of Family Practice in 2009, its authors found that allergy, obesity and other illnesses did not correlate with early introduction of solids. (The only possible exception was children from families with eczema, and here research is conflicting.) In fact, early food initiation appears to be protective against allergy. A study in the journal Pediatrics followed 1,612 children from birth to kindergarten and found wheat allergy to be more than four times higher in those who had had no cereal grains before 6 months of age. In other words, it appeared that early cereal exposure protected infants against wheat allergy.
Let's take peanut allergy in children, now a mini-plague. Some elementary schools have had to remove peanut products altogether. Feeding of peanut products is now, likewise, forbidden before 6 months of age and often withheld longer. What real evidence supports this? A study comparing Jewish children in England with those in Israel found 10 times as much peanut allergy in the English children, who are not allowed peanuts, as in the Israeli children, whose peanut consumption is earlier and greater. A new study published in the New England Journal of Medicine February 23, 2015 finds feeding a peanut butter product to infants starting at 4 months old -- currently anathema -- is highly preventive of peanut allergy: By age 5, 13.7 percent of the non-fed children were allergic, as opposed to 1.9 percent of the nut-fed group. This is a huge difference. If this isn't nuts enough, pregnant and nursing mothers have been advised to avoid peanuts, to protect their infants against allergy. A recent publication suggests the opposite advice: eating peanuts while pregnant appeared to protect the infants against peanut allergy.
Advice, however expert it might be, can be well-meaning, filling a scientific void, or can be tilted by pharmaceutical companies. A JAMA study found 87 percent of guideline-making doctors had financial relationships with industry. I'm not saying formula manufacturers, who might sell more product if fewer calories competed, exerted influence, but this type of thing has been known to happen, however subtly. Whatever the reason for the change in infant feeding practices, opinions get entrenched and spread like memes, and everyone gets stubbornly comfortable with them. For instance, a government panel recently changed its guidelines on cholesterol: It isn't bad for you after all. This was not based on new research; it was a more honest look at existing information. It's time this was done with infant feeding practices.
My two daughters and their whole generation, despite being near-omnivorous as infants, grew up healthy, and attended schools where hardly anyone had serious food intolerances, and there weren't nut-free tables. Rampant obesity wasn't the problem it is today either. Perhaps when my grandchildren become parents, the pendulum will have gone back to where the data says it should be. And my great-grandchildren will be able to enjoy bananas.