Food Introduction Controversies

Early parenthood is filled with difficult decisions, one of the most potentially fraught being that of food—how to introduce it, when to introduce it, what to introduce.  And few things seem more fundamental to Naturopathic Medicine than how we recommend for parents to traverse this minefield—with the possible effects on gastrointestinal health (which we know can have huge ramifications for virtually all other aspects of health), allergy promotion/prevention and life-long relationships to food, it seems essential that we get this one right.  But what do we really know?  And how have we come about this knowledge?

There are three major areas of controversy currently raging around food introduction today:  iron, allergies and form.  Let’s take each one in turn.

Iron
On one side of this controversy are those who advocate for the introduction of iron-fortified oat or rice cereal as a baby’s first food, in order to prevent iron-deficiency anemia.  On the other side are those who instead believe that non-grain foods are the best for baby’s initial solids.  In this case, the cereal is really just a vehicle—it is used to deliver iron supplementation, not for any intrinsic nutritional value of the food itself.  Why is this even an issue?  What happens around the time of food introduction that makes iron a consideration?  Inter-uterine iron storage is sufficient in the human infant for approximately six months after delivery.  From this time onward, iron must come from breastmilk or formula and whatever foods are introduced.  After the 1950s, when breastfeeding was greatly reduced in this country, many children were found to be anemic after 6 months.  It was also discovered along the way that breastmilk has a very low amount of iron in it—much less than formula.  However, it was eventually also discovered that the iron in breastmilk, by virtue of the mixture of nutrients and cofactors present, is extremely well absorbed and carried quickly and efficiently deep into the tissues.  In a 1995 study it was found that healthy full term infants who were exclusively breastfed through 7 months and used complementary foods (but not iron-fortified cereals or supplements) had adequate hemoglobin levels through one year (Pisacane, et al).  Also, although there appear to be no studies investigating this issue in infants as of yet, we do know that adults who have levels of iron elevated beyond the normal range are at increased risks for diseases of oxidation, like heart/artery disease.  Certainly iron-deficiency can result in serious health issues and should be prevented, but with all mammals naturally experiencing a drop in hemoglobin in infancy (that rebounds to adult levels) the natural health advocate in me has to believe that evolutionarily there must have been a way to meet the iron needs of developing infants with diet, without supplementation, and without the need to use grains as a first food, with their theoretical potential for allergy promotion, palate setting (for sugars/simple-carbs over vegetables), and otherwise empty nutritional value (not to mention the absence of grains in the early human diet entirely, let alone as a first food).  What early non-fortified foods can support healthy iron levels in infants?  Lentils and other beans, sweet potatoes, dried fruits, dark leafy greens (but not spinach), tofu, sea vegetables, blackstrap molasses, and heme-iron from beef, lamb, egg yolks and dark meat poultry are all examples—there is in fact a current movement to bring such heme-iron sources into rotation earlier.  Would there be a time when an iron supplement, like fortified rice cereal, would be appropriate?  There are factors that put a child at increased risk for iron issues in infancy:  premature babies, babies with low birth weights (less than 6.5lbs), babies with mothers who have poorly controlled diabetes, and those fed cow’s milk instead of breast milk or iron-fortified formula during the first year of life.  These situations might make supplementation worthwhile.

Allergies
As of 2006-2007, the bulk of the research indicated that early introduction of solid foods (ie before 6 months of age for foods in general, and lack of delay beyond this age for some of the more potentially allergenic foods like diary, wheat, fish, eggs and nuts) could increase the risk of the development of allergies (Fiocchi et al).  Since that time, much of the research seems to be refuting this claim, making allergy and food introduction a huge topic of controversy.  Those on the other side of this coin are advocating for introduction between 4-6 months and actually making introduction of higher allergen foods a goal in the first year.  Obviously evidenced based medicine conclusions are based on an entire body of research, with the overall trend being the bottom line, meaning that this issue is still in flux by research standards, but even if we consider this problem from a theoretical immunological perspective, the ideal course of action is unclear—on the one hand, it makes sense that avoidance of potential allergens until such a time as the infant’s immune and digestive systems are more mature would result in a more favorable outcome, however, the immune system’s ability to recognize the difference between self and non-self is strongly tied to the idea of tolerance—small amounts of a protein, introduced at the right time and under the right conditions induce the immune system to recognize the protein as self, rather than something to be attacked.  In fact, one study from January of this year concluded that late introduction of solid foods was actually associated with an increased risk of allergic sensitization to food and inhalant allergies (Nwaru et al.).  And in February of this year a meta-analysis concluded that while avoiding exposure to tobacco smoke, avoiding a moldy environment, and avoiding exposure to furry pets and air pollutants are all useful for decreasing the risk of developing allergies, neither delayed food introduction nor avoidance of more potent dietary allergens could be recommended as a means of prevention (Muche-Borowski et al).  But we know from a naturopathic perspective that this issue is even more complicated than that—conventional doctors and researchers are often looking only at scratch or RAST testing or IgE antibodies to determine allergies, rather than IgG antibodies or other more subtle seeming symptomatic expressions.  Not to mention the potential long-term effects from early gut inflammation.  Still, the research pendulum certainly seems to be swinging in the other direction on this topic, and an ultimate recommendation remains to be seen.

Form
In the United States, the form in which solid foods are first introduced is invariably the same:  pureed.  The reasoning behind this form is fairly straight forward—prevention of choking.  On the other side of the controversy are those who advocate a more child-led approach called “baby-led weaning” (BLW)—the belief that babies who are allowed to feed themselves with a selection of finger foods are less likely to refuse foods or to become fussy eaters as they grow older, not to mention make life easier for food-preparing parents (2).  In my practice I advise parents to look for signs that a baby is ready to eat solid foods, rather than just adopting a one-size fits all approach to the timing of food introduction—signs including ability to sit up, and ability to grasp and grip food in their palms, showing an interest in solid foods, having one or more teeth and ability to push food out of the mouth.  It would follow from this advice that such a well prepared baby should be able to grasp soft finger foods and eat them.  Those advocating BLW point to possible difficulties with choking actually arising from pureed foods because babies are used to sucking food off spoons and don’t know whether to suck or chew when they encounter lumps.  In families with multiple children, it is often the case that by the third child parents have little time to puree a separate meal and the infants are often so eager to copy their siblings that they switch to finger foods much earlier.  Anecdotal evidence from some BLW promoting doctors in England suggests that babies left to their own discretion in determining food choices from an early age may actually also result in avoidance of items that are later determined to be foods to which the child has an intolerance.  Around the world, different cultures use vastly different foods as an introduction to solids.  Cooked broccoli spears or cooked carrot sticks are possible options in the US.  Although more research needs to be conducted in this area, BLW is very intriguing, and in my mind in line with Naturopathic philosophy of letting nature be the guide, as well as clinical observations of infant behavior.

Obviously, none of these controversial issues have definitive answers at this time, but the combination of continued research and the reliable application of time-tested Naturopathic principles will provide a path through the controversy wilderness.  For the sake of the long-term health and sanity of the parents and families in your practices, keep yourselves updated on these important issues of food introduction.