The natural food for human babies is breastmilk. However, at some point, children need to be weaned onto ‘solid food’. In the long term there is good reason, I think, for aiming for a childhood diet that is essentially ‘primal’ in nature. That means a diet based on foods like meat, fish, eggs, nuts, seeds, fruits and vegetables. What it doesn’t mean is a diet rammed full of starchy carbs and dairy products.
Some would counter such a diet with the claim that dairy products are essential for bone health, and that carbs supply valuable ‘energy’ for active, growing children. Let’s take the first of these assertions first – is milk and specifically the calcium it supplies really important for bone health. Thinking about this from an evolutionary perspective, this hardly makes sense. We probably haven’t been consuming dairy products in any meaningful way until a few thousand years ago. The paleontological record shows we, as a species, had a good, solid bone health until about 10,000 years ago (around the time we introduced grain). Apparently, we did fine without milk for about 2 million years, but now apparently we must have it for healthy bones. Seems a little odd.
The idea that milk and/or calcium do not play a huge part in bone building is also supported by some science. For example, in a review published in the journal Pediatrics, researchers cast a critical eye over 37 relevant studies, of which 27 found no relationship between dietary calcium or dairy product intake and measures of bone health [1]. Of the remaining studies, any apparent benefit was small. This review clearly deflates the notion that dairy products are ‘necessary’ for the normal growth and development of children.
Further evidence for the limited role of dairy products in building bone has come from a study published in the British Medical Journal which amassed evidence from 19 studies in the effects of calcium supplementation in children ranging from 3-18 years in age [2]. This mass of evidence found that calcium supplementation had no effect on bone density in the hip or spine, and very marginal benefits for bone density in the arm.
This study was accompanied by an editorial which highlighted the lack of evidence for the ‘benefits’ of not only calcium, but also dairy products, for bone health [3]. The editorial called for policy makers to revise calcium recommendations for young people and for a change in our assumptions about the role of calcium, milk, and other dairy products in the bone health of children and adolescents.
As for the idea that starchy carbs provide vital ‘energy’ for active growing bodies. Well, first of all, the body’s cells can run on carbohydrate (glucose), but this can be formed from other ‘macronutrients’ including protein. The absolute requirement for carbohydrate is, strictly speaking, none at all. Plus, if we were concerned about children getting enough calories, surely it’s fat we should be looking to to help here (seeing as it contains about twice as many calories per gram as carbohydrate). And finally, growing bodies rely mainly on protein to provide the raw materials necessary for this. The idea that children somehow ‘need’ starchy carbs just does not stack up.
Not only are dairy and starchy carbs of limited nutritional and health value, they can be positively problematic. For example, starchy carbs can upset blood sugar and insulin in a way that predisposes to issues such as weight gain and type 2 diabetes. And then we have the issue of ‘food sensitivity’.
Unwanted reactions to food can manifest in many ways including abdominal discomfort and bloating, irritable bowel syndrome, asthma, eczema and ear, nose and throat issues including enlarged tonsils, sore throat, glue ear and ear infections. While any food can, in theory, trigger such symptoms, experience (and some science) reveals repeat offenders to be dairy products and wheat. Within wheat, ‘gluten’ is often what gives rise to problem, and this protein is found in other grains such as oats, rye and barley.
Another potential symptom of food sensitivity is constipation. There is some evidence, for example, that milk can cause constipation in children [4,5]. And a study published recently has implicated gluten too [6]. In this study, researchers looked to see if the timing of introduction of gluten into a child’s diet appeared to have any bearing on risk of constipation at the age of 24 months. Timing may be important because, generally speaking, the sooner a foodstuff is introduced into a child’s diet, the more likely it is to provoke food sensitivity issues. Constipation was defined as less than 3 bowel movement per week or the presence of mainly hard stools for two weeks or longer.
Constipation was more likely in children who had been introduced to gluten at 6 months or earlier, compared to those who had later introduction of gluten to their diets. Earlier introduction was associated with a 35 per cent increased risk of constipation.
The researchers assessed the relationship between timing of introduction of cow’s milk and risk of constipation and found no association. However, they did find that a history of cow’s milk sensitivity in the first year of life was associated with a 57 per cent increased risk of constipation, which is consistent with other work linking cow’s milk with constipation (see above).
This study is epidemiological in nature, and cannot be used to conclude that gluten (or milk) causes constipation. However, my experience in practice leads me to believe that these foodstuffs are indeed a common cause of constipation and other gut symptoms in childhood (and in older individuals too). It is perhaps not too much of a surprise that these relatively recent additions to the human diet are common provokers of unwanted symptoms. And as I pointed out above, despite dietary dictats to the contrary, such foods offer relatively limited nutritional value. The problems with such foods and their lack of necessity in the diet should cause us to reconsider, in my opinion, if ‘cereal and milk’ really is a healthy, nutritious way to start the day.
References:
1. Lanou AJ, et al. Calcium, dairy products, and bone health in children and young adults: a reevaluation of the evidence. Pediatrics. 2005;115(3):736-43
2. Winzenberg T, et al. Effects of calcium supplementation on bone density in healthy children: meta-analysis of randomised controlled trials. BMJ 2006;333:775-778
3. Lanou AJ. Bone health in children. BMJ 2006;333:763-764
4. Heine RG, et al. Cow’s milk allergy in infancy. Curr Opin Allergy Clin Immunol. 2002;2(3):217-25
5. Daher S, et al. Cow’s milk protein intolerance and chronic constipation in children. Pediatr Allergy Immunol. 2001;12(6):339-42
6. Kiefte-de Jong JC, et al. Infant nutritional factors and functional constipation in childhood: the Generation R study. Am J Gastroenterol. 2 March 2010 [Epub ahead of print]
