Dispelling nutrition myths, ranting, and occasionally, raving


Can peanut consumption prevent allergies?


Last week the headlines all boasted that feeding babies peanuts could prevent peanut allergies. A new study in the New England Journal of Medicine assigned children thought to be at high risk for peanut allergy development to either an exposure group or an avoidance group. It was found that 10.6% of the infants in the exposure group tested positive for peanut allergy at 60 months of age, versus 35.3% of infants in the avoidance group. I’m not quite as convinced as the headlines that this is a cure for peanut allergy. Certainly, there was a large difference between groups. However, we have seen in previous research that peanut exposure in allergic children may increase tolerance, although not to the extent that they would be able to safely munch on a peanut butter and jam sandwich for lunch.

This may be a matter of semantics, and it’s purely my own interpretation, but I think that the current study provides more support for the stance that peanut (and likely other allergens) avoidance in at risk children increases the likelihood of allergy development. More so than the consumption of peanuts decreases the risk of peanut allergy.

Peanut allergy does not occur upon the first exposure to peanuts. It usually occurs upon the second exposure. Although it may occur upon subsequent exposures, this is unlikely in the case of peanut allergy. I can’t help but wonder how this may have effected the results. The authors don’t mention whether or not the infants in the study had been exposed to peanuts prior to enrolment. I can’t help but wonder if this could have affected the results in some way. There is also the question as to whether the withdrawal of infants from the study was a result of the development of peanut allergy in the consumption group, or perhaps discovery of the absence of allergy in the avoidance group. Could this have significantly affected the results? Adherence was quite good, over 90% in both groups, however, reasons for withdrawal could still have an impact on the results.

While the infants included in the study were all identified as being at risk of developing peanut allergies due to either the presence of eczema and/or egg allergy, these are not necessarily the best ways to identify risk. The children at greatest risk of developing peanut allergy are those who have an immediate family member (i.e. a parent or sibling) who has a peanut allergy. The children in the study would be at greater risk than those without eczema or other allergies but they would not necessarily be those at greatest risk. Perhaps infants at greatest risk would benefit from early peanut exposure, perhaps not. Perhaps infants in the general population would benefit from early peanut exposure, perhaps not.

Okay, so, I’m sure that parents are wondering what all of this means. Firstly, what many of the news articles are failing to impart is that the current guidelines recommend waiting until 6 months of age before introducing solids. Introducing peanuts, or any solid foods, at younger ages is not recommended as infants do not have fully developed digestive systems. Peanuts and peanut butter may also be choking hazards for infants, please be sure to use age appropriate foods and supervise your infant during feeding. Finally, this research supports the current guidelines which indicate that there is no reason to avoid providing your infant potentially allergenic foods at the same time that you introduce other foods. Regardless as to whether or not early introduction reduces the risk of allergy development or later introduction increases risk, at this point we know that there is no benefit to waiting, and there may be disadvantages to doing so.

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Why is under 6 months too young for solid food?

I was actually a little bit shocked when I read an article about the introduction of solid foods to infants. According to a new study from the US, nine percent of parents are feeding their children solid food when they’re as young as four weeks of age! I knew that many parents weren’t following the current guidelines, which recommend waiting until six months of age to introduce solid food. Previous guidelines recommended 4-6 months of age and advised parents to watch for cues that their child was ready to begin on solid food. Many health care practitioners, unfortunately, have been slow to adopt the newest recommendations so it’s understandable that parents are confused.

I think that parents might be more accepting of the guidelines if they knew the reasoning behind them. It’s one thing to tell someone what to do. It’s another all together to give them a valid reason regarding why they should do it. There are many reasons why parents start their children on solid foods before they’re 6 months of age: lack of time for breastfeeding (if maternity leave is over and your workplace isn’t accommodating, pumping all that milk is quite a commitment), lack of money for formula, the misguided notion that it’s a developmental milestone (like walking and talking) and a child starting solid food at four months is “more advanced” than a child starting at six, the also erroneous belief that it will help the baby to sleep through the night.

The current guidelines were developed based on nutrient needs of infants and their digestive systems. Breastmilk is a highly nutritious food for babies (not to mention the benefits of maternal and infant bonding provided by breastfeeding). Weaning infants too soon deprives them of that free source of nutrients and energy. Breastfeeding is protective against gastroenteristis and respiratory infections during infancy and may have longer-lasting protective benefits. In turn, introducing solid food too early may be detrimental to their developing digestive systems.

The risks and benefits of introducing solid foods to babies should be clearly outlined to new parents by their healthcare providers so that they can make the best choices that they’re able to for their children.

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Can you increase IQ through diet?

Recent research out of Australia has found that childhood IQ is linked to dietary patterns according to an article in Science Daily. The study looked at the eating habits of a group of children at6 months, 15 months, and two years of age and then looked at their IQs at 8 years of age. Apparently the children who consumed healthier diets had higher IQs than the children who consumed more “junk” food. While I think this is great, of course it’s good to see that there are positive benefits to eating a healthy diet, I was also a little curious about how they controlled for other factors which may have contributed to IQ levels. I read the full article and was pleased to see that they controlled for things such as maternal education and socioeconomic factors. The one thing that I had expected them to control for was parental IQ. Surprisingly, to me, they didn’t. Now, it’s been a long time since my psych degree but I’m pretty sure that the strongest predictor of IQ is parental, especially maternal, IQ. Why wouldn’t the researchers have controlled for this factor? I hate to disparage a study that is showing benefits to healthy eating but I also think that it’s important to be objective. Please, continue to feed your children a healthy diet.

Besides the fact that the researchers failed to control for the most important contributing factor to IQ, I don’t really think that IQ is all that meaningful a measurement of intelligence, nor is it a predictor of success. A high IQ doesn’t mean that you’re smarter than other people it just means that you’re better at the type of test they’re administering. It’s kind of like a mental BMI. Most people know that it’s not a great measure but we don’t really have anything better.


Baby’s first food

As a dietitian I often field questions from my friends who are starting their babies on solids. The other day I received an email from a friend whose pediatrician suggested that she start her 6-month-old baby on a single-grain iron-fortified baby cereal. She was concerned about a rice cereal she had found and was helpful enough to send me a link to the product details. This Gerber Baby Cereal Rice claims to be “the ideal choice for baby’s first solid food”. One look at the ingredient list told me that this was not the case. My biggest concerns were: 1. the fact that skim milk powder was the second ingredient (the current recommendation for infant feeding is that babies should not be given cow’s milk until at least nine months of age as it can be difficult for them to digest – their digestive systems continue to develop during infancy), 2. Potato maltodextrin? Why does a baby cereal need a sweetener? This is a disturbing addition to me. I’m also not convinced that the additions of the three types of oil are necessary, or beneficial. Ideally, the baby should continue to be breastfed after the introduction of solids and should be obtaining necessary fats from breastmilk.

I also would like to point out a problem with the pediatrician’s advice. Giving baby cereal as a first food is no longer the best practice recommendation. The current recommendation is to start babies off on ANY iron-rich food. Baby cereal is only iron-rich because it’s fortified. Why not start your baby off on something that doesn’t contain added oils, milk, or maltodextrin? You can give your baby meat, poultry, eggs (yes, even the whites!), beans, legumes, tofu…

If you do decide to start with a baby cereal, make sure that you give it a good shake before you prepare it as the iron has a tendency to sink to the bottom of the box. Also, please read the labels. If you’re not sure about a product, do what my friend did and ask a dietitian. Try to choose a product that is a single grain that’s fortified but that doesn’t have loads of unnecessary added ingredients.