In this excerpt from the Nov/Dec 2011 edition of Journal of Family Health Care, Independent Registered Dietitian, Katie Kennedy, offers a practical guide for parents on specialist and dairy-free milks. To read the article in full, subscribe here.
Dairy-free diets, specifically those free from cow's milk and cow's milk products are most commonly encountered by health care professionals when supporting families seeking to manage lactose intolerance or cow's milk protein allergy (CMPA). Up to 15 per cent of infants may exhibit symptoms typical of CMPA, such as colic, constipation, vomiting and gastro oesophageal reflux (GOR).
Suitable milk alternatives for infants
The most common form of lactose intolerance in infants is caused by secondary lactase deficiency, often following gastrointestinal infection precipitating damage to the delicate villi tips where lactase is produced. Treatment of this condition typically does not require long-term elimination of lactose from the diet, indeed small and varying amounts of dietary lactose may still be tolerated until normal gut function is restored.
By contrast, CMPA, caused by an inappropriate immune response to cow's milk proteins, requires complete and often longer term elimination of milk and milk products from the diet, thus increasing the likelihood of nutritional deficiencies amongst poorly managed children. The first line choice of milk alternative for formula fed infants diagnosed with CMPA is an extensively hydrolysed formula (eHF) or amino acid-based formula (AAF). Their use should be preceded by consultation and recommendation by a GP, dietitian or health visitor.
The soya question
There has been controversy in the past surrounding the use of soya formula (SF). Concerns largely stem from the presence of isoflavones, naturally occurring phytochemicals, in the soya protein isolate used to produce SF. Despite the agreed lower potency of soya isoflavones, questions have been raised regarding the potential hormonal/ reproductive health consequences of feeding SF to infants. However, to date, such concerns have been based on data from in vitro/animal experiments alone, largely involving the administration of high dose purified isoflavones rather than SFs fed in nutritionally relevant quantities.
Study of adults given SF
The only study to follow up adults fed SF as infants was published by Strom and colleagues in 2001. In the main, this study showed no significant difference for men or women fed SF or MF when compared to breastfed infants, for over 30 measures relating to sexual maturation and reproductive history. Authors concluded that there was no evidence for long-term adverse health outcomes amongst adults fed SF as infants.
Of more significance is the observed cross-reactivity between cow's milk and soya proteins, particularly in non-IgE mediated allergy. Approximately 14 per cent of children with IgE mediated CMPA may also react to soya protein, and this figure is likely to be higher amongst individuals with non-IgE mediated allergy.
Milk alternatives for toddlers and older children
Other types of mammalian milks such as goat, sheep and buffalo products and formula milks based on these are not appropriate for the treatment of milk allergy due to the high potential for cross-reactivity between proteins. However, a variety of plant-based milk alternatives are available for use as a main milk source for children over, or in cooking/food preparation from weaning onwards. The protein quality of plant-based milk alternatives is also a consideration; soya beans, from which soya milk alternatives are produced, are the only plant-based food to contain all eight essential amino acids and possess a protein digestibility corrected amino acid score (PDCAAS) similar to that of milk and meat protein.
Weaning and beyond
A great variety of dairy-free replacements for key dietary staples such as spreading fats, cheese, yogurts, ice creams and creams have become available in larger supermarkets and health food stores over recent years. The majority of such are based on soya and are extremely palatable and easy to use in standard recipes. They are suitable for incorporation into the diets of other family members who do not require a dairy-free diet.
Following the introduction of EU-wide allergen labeling directive (2003/89/EC) which became mandatory in November 2005, manufacturers of all pre-packed foods are legally obliged to declare within ingredients listings any food allergen (including milk and milk products) added as a deliberate ingredient, however small the amount. However, caution is advised when purchasing fresh items without such labelling from outlets such as restaurants, delicatessens and bakeries.
Implementing a dairy free diet for infants and toddlers poses a number of challenges for families and appropriate, ongoing support and monitoring is needed to ensure successful, safe management which optimises growth and normal dietary behaviours. Health professionals must be familiar with the variety of alternatives and options for substitution of key dairy staples and feel confident discussing their relative merits with parents. Basing advice on current scientific evidence will improve patient confidence and outcomes and help to avoid unnecessary dietary restrictions.
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