Tag Archives: weaning

Milking the (cash) cow?

Or, should I feed my one year old cow’s milk or infant formula?

The Skeptical Son is about to hit one year of age, which brings a few landmarks with it. MMR vaccination, standing up (albeit a little precariously), and a move from specialised (breast or infant formula) milk to regular, unmodified cow’s milk.

This latter point seemed pretty uncontroversial. The UK National Health Service and the American Academy of Pediatrics both recommend feeding cow’s milk to a baby beyond 12 months. The NHS explicitly states: “Infant formula, follow-on formula or growing-up milks are not needed once you baby is 12 months old”.

So I was intrigued to see infant milk formula products specifically targeted at the over one year olds, such as Aptamil 1+yr & 2+yrCow & Gate 1-2yr & 2-3yrHipp Organic growing up milk (from 12 months), and SMA 1-3yrs.

A look at the scientific literature, in line with the NHS and AAP guidance, backs up a move to cow’s milk at 12 months. Unmodified cow’s milk is not recommended before this age because it contains high levels of sodium, potassium, phosphorus, and calcium, and lacks vital nutrients, such as iron, vitamin C, and linoleic acid. As a baby’s diet becomes more varied and complex by the age of one, many of the nutrients previously gained from milk (breast or modified cow’s formula) is obtained from food. An infant can, in most cases, safely move to consuming cow’s milk, and it is only if a specific deficiency develops that they will need targeted supplementation.

http://www.flickr.com/photos/jelles/2902422030/

Cow by JelleS [CC-BY-2.0]

The NHS’s health information leaflet, however, says: “It is recommended that all babies aged from six months to 5 years are given a supplement that contains vitamins A, C and D, unless they are drinking 500ml (a pint) of infant formula a day (infant formula has vitamins added to it)”. This then brings us back to enriched infant formula.

The infant formula manufacturers appear obliged to acknowledge that breast milk is recommended for young babies (see disclaimer notice*), consistent with the World Health Organization’s guidance. All of them, though, promote their 1 year+ products as, variously, enriched with iron, vitamins C & D, GOS/FOS prebiotics and omega fatty acids. Advertising claims include milk formula that is “nutritionally superior” to cow’s milk, “has been specially developed to help meet the nutritional needs of toddlers”, and will “encourage your toddler’s natural friendly bacteria to thrive”.

So now I’m a little torn. Anaemia, avitaminosis and lactose intolerance are, evidently, serious conditions that need to be addressed, and products need to exist for these cases. But the marketing doesn’t seem in line with the healthcare advice: without looking into it, I was initially left with the impression that the specialised infant formulas represent the gold standard, containing everything that is needed to support my son’s “amazing development” [© Cow & Gate]. The adverts and packaging don’t suggest these products are for cases where a deficiency has been identified, rather it appears to play to the ‘don’t take any chances’ or ‘be on the safe side’ worry of parents. SMA, for instance, says “it is hard to know if they are getting all of the right nutrients they need at this important time”.

I guess this speaks to a wider problem with nutritional supplements, ‘superfoods’ and enriched dietary products, some of which make all manner of claims about health and well-being (see Andy Lewis’ Quackometer for more ‘Confusopoly of Diet’).

Anyway, now for a quick look at money, something that’s precious to many families. A 900g tub of Aptamil 1+ yr costs £8.49 (Sainsbury’s price). This means that a daily intake of 500ml will cost 79p (83.3g formula). An equivalent daily portion of whole cow’s milk costs 26p. Even adding in a multivitamin supplement works out at an extra 13p a day. Over a week this difference amounts to £2.80; over a year it’s a saving of around £145.

I should emphasise that the post-one year milk formulas seem completely legitimate products to sell and I’m far from claiming a conspiracy, but I explore it here simply to question whether their advertising is a little misleading. Of course, dietary products claiming all sorts of health benefits is not a new or isolated phenomenon, but I worry that the baby market particularly plays on the anxiety of parents that inclines them to prove themselves as perfect guardians.

Maybe I’m being overly cynical in suspecting that the manufacturers are being unreasonably opaque. Perhaps I’m too naïve in wishing that promotion of products that affect ours and our babies’ health was more honest. Would it be regulatory overkill to make infant formula products, in the same way as the breastfeeding disclaimer, carry an objective notice about cow’s milk and the current healthcare advice?

And on that ambivalent note, I shall end.

*The common wording across manufacturers’ websites and the prominent positioning of the statement (it is displayed any time one tries to click through to a product for the first time) suggests this is a statutory requirement. This would be interesting if it is, so any light that anyone can shed on this would be appreciated!

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The influence of early eating habits in children

Our little one, who is now 10 months old, seems to have got his eating sorted after a stubborn start. We started weaning around the World Health Organization’s recommended 6-month mark, using a mix of spoon feeding and baby-led weaning (more on that in later post). Since then, it has seemed apparent that some things have gone down better than others: scrambled eggs, yoghurt, cheese, toast, chicken, bananas and strawberries were all early hits, while broccoli, tomatoes and beef were swiftly rejected.

He seems to have developed an appetite for some foods after a unsure start, such as cucumber, carrot and apple. And this brought to mind a Naked Scientists podcast from a few months ago, which featured an interview with Marion Hetherington, Professor of Biopsychology at the University of Leeds, on children’s appetite and eating behaviour.

The full transcript is available here and the audio is available here. I’ve made a few summary points below, but do check out the full interview.

  • A developing foetus can encounter tastes and odours derived from the mother’s diet and toxins from the environment, and this may affect later food preference.
  • Babies fed with breast milk are exposed to a greater variety of flavours than are formula-fed babies, and this can mean they are more willing to try new tastes.
  • Babies are primed to accept sweet tastes from birth, whereas bitter tastes are rejected. This means that we have to learn to like bitter foods but not sugary foods.
  • Parents may need to try their baby 8-10 times with a new flavour before the child will accept it, so parents shouldn’t give up after the usual 2-3 times. Also, there may be a sensitive period between 6-9 months in which to introduce new flavours and textures, after which it becomes harder for the child to accept a new food.
  • If a child of school age is fussy about trying new foods, then using rewards and social praise is an effective way of persuading them to test new tastes.
  • Setting healthy eating preferences early on is best to keep healthy eating going into childhood. Even if eating habits go awry in teenage years, many return to their early healthy eating habits as adults.

I thought this raised some interesting points, such as the persistance needed to introduce new tastes during a sensitive time window, and was worth highlighting.

It’d be interesting to know how these environmental factors interact with genetically influenced preferences, such as whether early exposure to broccoli, sprouts or cabbage can moderate the repulsion certain people have towards a compound in those foods. It has been suggested that ageing, smoking or illness may modify this genetically based food preference, and so it would be intriguing to know whether child eating behaviour did so too.

Where are the facts?

This was the demand from a very pleasant woman we met on a train a couple of weeks ago. She had been enquiring as to how our son, now 6 months old, was getting on with his sleeping and weaning. Not great on either count, since you ask.

She was, however, slightly taken aback that current medical advice is to start weaning at 6 months, rather than at 3-4 months as she was advised when she was raising her babies (30-40 years ago, at a guess). She was also a little dismayed that babies are now overwhelmingly placed on their backs to sleep, instead of on their front.

So, “where are the facts?”

Well, science doesn’t really work like this and scientists don’t deal with immutable facts. Research is conducted, evidence is gathered, and conclusions are drawn. And the cycle is repeated over and over and over again. Sometimes, the new evidence backs up the previous conclusions and those ideas become strengthened. Sometimes, however, the new evidence doesn’t match the previous conclusions, and so thinking may change. As such, scientists should always be prepared to change or modify their positions as new stronger, evidence emerges. In the case of babies sleeping on their backs, an accumulation of evidence over many years that showed a reduced risk of cot death that led to the change in received wisdom.

There are also different strengths of evidence and there some types of studies in which we can more confidence. A study that takes a part of a population, randomly splits them into test and control groups before monitoring the effects of a treatment versus control has far more power than a study that looks back in time at a population and tries to work out why some groups are different. Because of this, a new study, using a more reliable method may be carried out that modifies experts’ views. This is especially relevant for pregnancy and child development, as it’s hard to perform randomised controlled trials (the first type of study I mentioned above) with pregnant women and children, because parents are generally less likely to enter into anything they perceive as potentially risky.

In the case of weaning at 6 months, one only has to look at the expert review that forms the basis of WHO’s current advice to see that we aren’t dealing with cast-iron ‘facts’.

The experts concluded that 6-month exclusive (or predominant) breastfeeding is required to provide the right nutritional balance and to protect against gastrointestinal infection. After 6 months, solids should be introduced in order to meet a baby’s additional energy and nutritional requirements. There are even apparent benefits to the mother from exclusively breastfeeding for 6 months rather than 4 – mothers showed greater weight loss (if this is indeed desirable) and had a longer post-natal infertility period. It wasn’t cut-and-dried, though, as care must be taken to avoid iron deficiency in babies exclusively breastfed for 6 months, as well as special care in developing countries to ensure that babies are not malnourished as a result of poor maternal nutrition.

But, there are a few cautionary tales to add to this. First, there wasn’t a huge number of studies that looked at the health status of babies who had been exclusively breastfed for different periods to compare. Second, some of the studies that were included looked at a relatively small population of babies. Third, the studies differed in their quality and potential for bias, such as whether it was observational or whether it relied on self-reporting. Fourth, some studies didn’t show a difference in health status – is this because no effect was present, because the study design was weak, or because they hadn’t studied enough babies to show an effect? We don’t know.

This is not to undermine the advice of WHO and other health agencies – it is advice we’ve followed for our son – it just highlights how health advice is often formed and how it can be subject to change.

The potential for scientific judgement to be swayed over time also means scientists are generally more cautious and moderate than perhaps people expect or, indeed, want. It seems common for people to desire clear-cut and, above all, ‘correct’, advice. This is often reflected in sensational newspaper headlines that overstate tentative research findings, which is unhelpful in informing the public as to the true nature of the findings, as well as to the scientific process itself (see the BBC’s “Spoon feeding ‘makes babies fatter‘” versus this more reasoned analysis from NHS Choices).

This can, unfortunately, sometimes be used as a stick with which to beat scientists: “people were wrong about babies sleeping on their front, so how do you know you’re right now?” A temptingly persuasive argument to ignore those boffins, especially if they’re telling you things you don’t want to hear. But scientists (honest ones, at least) are always working from a position that is based on the best available evidence. If you reject this best available evidence, then you’re working from an even weaker position.

In the case of WHO’s advice on when to introduce solids, it made its judgement because all the evidence, despite some weaknesses, was pointing in that direction. So even though there is more research to be done – the report even acknowledges this and makes recommendations for new studies that should be carried out – it would be unwise to act against what the best available evidence is telling us. And it wouldn’t take a single study to come along to turn that around, it would take an accumulation of solid evidence that showed an opposite and consistent trend.

I didn’t quite manage to finish telling this to the lady on the train, though.