By Eric Crampton 09/06/2017

A new paper out in the American Journal of Clinical Nutrition shows there’s an association between children drinking non-dairy milk, as opposed to cow’s milk, and lower heights. 

It would be tempting to take these results and make a case for ending Canadian dairy supply management, but there are better reasons for ending Canadian supply management.
The press release doesn’t link to the paper.

Children who drink non-cow’s milk — including other animal milk and plant-based milk beverages — are shorter than children who drink cow’s milk, new research suggests.

For each daily cup of non-cow’s milk they drank, children were 0.4 centimetres shorter than average for their age, according to a study published today in the American Journal of Clinical Nutrition. For each daily cup of cow’s milk they drank, children were 0.2 centimetres taller than average. […]

The study did not examine why children who drank non-cow’s milk were shorter on average than those who drank cow’s milk, however the authors hypothesize that children who drink non-cow’s milk may consume less dietary protein and fat than those who drink cow’s milk, resulting in reduced growth.

Here’s the link to the paper if you’re interested.

The press release talks about associations but doesn’t say anything about causality. Nevertheless, the author goes on about the lack of regulation of protein content in non-dairy milk.

And hey, maybe that’s what’s going on. Reduced protein intake could be doing it.

But it looks like the paper doesn’t control for other parts of kids’ diets. If it’s likely that kids on almond milk diets or soy milk diets are more likely to be on vegan diets overall or to have other weird diet issues that could also affect protein intake, it seems kinda odd not to adjust for other parts of the diet.

And while they exclude kids with growth-affecting disease from the study, they do include asthma. Some folks exclude dairy as part of trying to control asthma, and inhaled corticosteroids can suppress growth among kids (though they catch up later).

So it would be a bit premature to run the cross-price elasticities of milk with respect to non-dairy substitutes, multiply by the effect of supply management on milk prices to get the substitution into non-dairy because of supply management, then work out how much shorter supply management is making some Canadian kids.

Featured image: Endre Majoros / Flickr.

0 Responses to “Grow large with milk”

  • It is a fact that many adults are giving children diets that suit them, rather than the actual nutritional needs of the child. The current trend in diets seems to be demonising certain food groups, like dairy and gluten and trying to eliminate these from the diet. I have also heard of parents trying dairy-free diets in children to manage asthma. I wouldn’t assume in all cases it would be tied into a fully vegetarian or vegan diet with children nor try and correlate the data with that. I suspect in more cases than not it may simply be the children are not being given milk. With asthma, it depends on the severity and not all children need preventers and just rely on relievers.

    This probably does stand to reason, children while they have the same nutritional needs as adults have needs for increased nutrients for some things and need foods that are more nutrient dense. Nut milks are effectively coloured water, removing a food group out of the diet and replacing this with that certainly could be detrimental unless care is taken to adjust for the missing dietary components.

    Most dietary studies need to be observational in type, you couldn’t split children into groups and deliberately give one a diet with less nutrition to answer questions ethically and we just have to work around it. We have to do the same with many other types of studies. I disagree with the implication that this is about the milk industry, as we do need to investigate these things especially where there is this trend to removing food groups out of diets and doing this for children irrespective of their nutritional needs and especially where nut milks are not actually any sort of substitute for the foods cut out of the diet.

  • Thanks Michelle. No disagreement. I have had a longstanding issue with Canada’s dairy system, which hikes prices in rather regressive fashion, with high costs falling on poorer families there – and it also impedes free trade agreements between Canada and places like New Zealand. That’s the only reason for the end bit – much as I’d like to be able to blame something else bad on supply management, I don’t trust this study enough to be able to 🙂