Perspective: Moving Toward Desirable Linoleic Acid Content in Infant Formula

Title: Perspective: Moving Toward Desirable Linoleic Acid Content in Infant Formula

We are excited to share that the peer-reviewed publication  “Perspective: Moving Toward Desirable Linoleic Acid Content in Infant Formula” was published in Advances in Nutrition. Perspective: Moving Toward Desirable Linoleic Acid Content in Infant Formula | Advances in Nutrition | Oxford Academic (oup.com)

This paper provides a narrative review of the current knowledge, knowledge gaps, and future research needs in the area of human milk fatty acid  (FA) composition, with a particular focus on exploring appropriate intake levels of the essential FA linoleic acid in infant formula.

A/Prof Beverly Muhlhausler, Research Director of the Nutrition and Health Program in the Health and Biosecurity Business Unit in CSIRO Australia,  “I think the key message is that there is still a considerable uncertainty about what the optimal level of DHA, ALA, LA is for infants. Infant requirements are going to vary according to the age of the infant and the stage of development but also other factors such as the infants’ weight, genetic background and potential health issues.”

We have interviewed one of the authors A/Prof Beverly Muhlhausler, Research Director of the Nutrition and Health Program in the Health and Biosecurity Business Unit in CSIRO Australia, to discuss the creation and key outcomes of the peer-reviewed paper.For a full version of the interview, please click here.

Human milk (HM) is considered an optimal source of nutrition for infants.
Exclusive breastfeeding is recommended for infants up to 6 months of age, with continued breastfeeding thereafter in conjunction with appropriate complementary feeding until 2 years of age or beyond
To meet the immense energy demand of a newborn baby, human milk contains a lot of fat, providing around 50% of the infant’s energy. Fat is composed of several different fatty acids (FA). More than 200 different fatty acids have been identified in human milk.

The concentration and composition of fatty acids varies greatly between individuals and is influenced by many factors, including genetics, diet, and lifestyle. To make things even more complex, the types of fatty acids also change throughout the time the infant is breastfed: from the very first milk (the colostrum), to the milk produced in the first few days and to weeks later.

The most abundant FAs in HM (>50% of the FAs) are saturated fatty acids, followed by MUFAs (monounsaturated fatty acids) and PUFAs (polyunsaturated fatty acids).
PUFAs of various carbon chain lengths can be further classified as n–3 or n–6.
HM n–3 and n–6 PUFAs include the essential fatty acids (EFAs) linoleic acid (LA; 18:2 n–6) and α-linolenic acid (ALA; 18:3 n–3), ranging between 5%–30% and 0.3%–2% of total FA, respectively, as reviewed previously. However, these levels may vary depending on various maternal nutritional, lifestyle, and genetic factors.

LA and ALA are the predominant dietary PUFAs and the main substrates to produce the long-chain PUFAs (LCPUFAs), particularly arachidonic acid (ARA; 20:4 n–6) and DHA (22:6 n–3).

Dietary intakes and the balance of dietary LA and ALA, and preformed n-6 and n-3 LCPUFAs in early life nutrition has the potential to affect LCPUFA status and thus impact immune, neural, adipose tissue development and healthy growth.

HM substitutes (i.e., infant formula) should provide a safe and nutritionally adequate alternative if full breastfeeding is not possible.
Nutrient levels in formula should ideally be adequate for all infants, while recognizing that optimal levels may not be the same for all, depending on genetic, other biological, and environmental factors.

The recommendations for the FA composition of infant formula have been guided partly by data on Human Milk composition as well as by what is known about infant FA requirements. However, as these factors are variable depending on e.g. maternal dietary habits and environmental factors, controversy remains about the optimal FA composition of infant formula, including the levels of n-3 and n-6 PUFAs.

Danone Research & Innovation organized a series of roundtable discussions with a group of 8 world renown experts in this field to review the (strength of) currently available evidence for defining the most appropriate infant formula FA composition for healthy term infants, with a particular emphasis on levels of Linoleic Acid (LA). Key knowledge gaps and future research needs were identified.

A/Prof Beverly Muhlhausler “These round table discussions were really aimed at bringing together key academic experts in the field of fatty acid composition in infant nutrition and the relationship to infant health. We were brought together to discuss the scientific evidence that’s available in this field and the strength of the evidence in particular areas. We identified key knowledge gaps, future research needs and brought that together in the form of a peer-reviewed publication”.

The round table discussions resulted in the peer-reviewed publication  “Perspective: Moving Toward Desirable Linoleic Acid Content in Infant Formula”.

The key findings of the paper are:

• Current scientific (mainly preclinical) evidence suggests that a relative high LA intake may reduce n-3 LCPUFA synthesis and/or accretion resulting in a lower DHA status. Low DHA status early in life is considered suboptimal. ​
• A clear gap in knowledge exists regarding the potential impact of LA and ALA levels in infant formula in the presence of preformed LCPUFAs (DHA and ARA) as in current formulas.
• An urgent need exists for well-designed clinical intervention trials to create clarity about optimal and safe levels of LA and long-term implications on functional health outcomes

Find out more about our research into Growth & metabolism here: Growth & Metabolism Research | Nutricia Research