This is my valedictory contribution, as a Senior Co‐editor, to the Maternal and Child Nutrition Journal, and it pleases me that the main article in this issue, by Pelto, Zhang and Habicht on Premastication, is so thought provoking. It addresses the practice of mothers and carers feeding prechewed food to infants. This practice has received little attention in the literature and has not been considered in the development of policy and practice, possibly because it is seen as unsavoury and unsanitary. However, it happens, and it seems to have done so for millennia in human societies. We thought that the topic needed to be developed a little more, and we invited a number of people interested in early childhood nutrition to document their first reactions to the paper so that we could provide these as additional contextualizing commentaries. There is no merit in repeating their points, but there are some general points that should be highlighted. The first is that of Anthony Williams, who said that premastication is ‘some way off the radar’ for clinical practitioners in Britain. Jules Tolboom's initial reaction probably reflects this, but he then reflected on his experience and his library to discover several reports and observations from societies worldwide of the practice of mothers and carers prechewing foods which are then fed to the infants. The extent of this practice cannot be assessed from any of these reports, because they are essentially anecdotal, and as Pelto et al. point out, there is a need to gather some systematic information on the practice. This information would need to address the prevalence and characterization of premastication in different societies, and a parallel assessment of its potential biological and societal benefits.
A perquisite for investigating premastication would need to be, as Penny Van Esterick implies, an opening of minds by many practitioners and policymakers involved in infant feeding. For example, infants as young as 10 days are reported to be receiving premasticated foods. More commonly, the age of introduction seems to be nearer 3–4 months, but none of these are really systematic data. Two of our commentators saw, when they respectively worked in South East Asia and East Africa, breast‐fed infants less than 6 months old whose diets were being complemented with premasticated foods. This timing of this established practice would offend current international guidance on infant feeding. This is, in a way, ironic because practices in such cultures that had not been influenced by feeding practices in affluent societies were used as models for developing the rationale and advice on the exclusivity of early breastfeeding and on the delayed introduction of other drinks and foods until after 6 months of age.
I find it unclear whether or not feeding premasticated foods is a ‘good or bad thing’; this would need to be explored. Part of the process of characterizing the practice would be to include a structured risk assessment (incorporating amongst other things considerations of the infants’ ages at the time of introduction of premasticated foods and the nature of the foodstuff) and a harm‐benefit analysis. As regards harm, Van Esterick and Fewtrell allude to the risk of transmitting pathogens: this would be a common anxiety, and amongst the commentators, and Pelto et al., there is some divergence of views about the possible influence of the practice on human immuniodefficiency virus (HIV) infection or protection. Additionally, Williams is concerned that premasticated foods might displace breastfeeding, and we also need to know more about the effects of the food on the functional properties of breast milk.
On the other hand, there seems to be an agreement that there may well be a number of nutritional benefits from the practice, as well as benefits from the digestive enzymes present in saliva. All of these points are hypothetical, and there are many knowledge gaps which need to be explored and prioritized. Two of these gaps which have not been mentioned relate to the age of introduction of foods other than breast milk in relation to developing immunotolerance and immunosensitization to food and other potential environmental antigens, and in the influence which exposure to pathogens through premastication might have in priming immune function and reducing the risk of allergy. The final comment by Gideon Lack discusses these points excellently.
I have taken a nutritional and microbiological approach to these papers, but as Van Esterick says, there is a much broader interdisciplinarity in the exciting perspective opened up by Pelto et al. We need to be sensitive to the cultural roots of premasticatory practices and to other related sociological and societal perspectives not least because these will help us to determine the relevance of premastication to practices in other cultures. Perhaps, when practices in such societies were used to inform international policy and practice, there was some selectivity in the experiences used, and premastication and diversification of the diet in early infancy were neglected. I think it really would be interesting to know how long mothers who practise premastication sustain breastfeeding of their infants. On the basis of Tolboom's comments, it is tempting to speculate that they do so for more than 6 months.
A serious consideration of the issues raised by Pelto et al. deserves the broader integrated approach proposed by Van Esterick in her commentary. Realistically, it is probably not likely that we will come to a point of encouraging mothers to practise premastication, but the topic does open up opportunities to explore what seems to have been and to still be a common practice and to reflect on the lessons that might be brought to bear on current policy and advice on feeding in infancy and early childhood. The paper is another reminder that we do not really know how to feed our infants, and at least one wonders that by studying premastication, for example, might one outcome be that international policy on breastfeeding will become more focussed on sustaining breastfeeding, than on ensuring its exclusivity?
This journal was set up to address the full interdisciplinary breadth of nutrition, and the challenges opened up by these commentaries and the article epitomize the essence of Maternal and Child Nutrition.