Hong Kong Med J 2014;20:79–81 | Number 1, February 2014
DOI: 10.12809/hkmj134123
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
COMMENTARY
Zero tolerance to trans fatty acids in infant
formula? Fears, fiction, and facts
Alex TL Siu; Anthony WK Ng, MRCP, FHKAM (Paediatrics); Charles YC Wong, MD, FRCP
Department of Paediatrics, Tsuen Wan
Adventist Hospital, Tsuen Wan, Hong Kong
Corresponding author: Dr ATL Siu (charx.siu@gmail.com)
Despite counselling that breast is best, a
new mother
elects to bottle feed at the hospital's newborn
nursery:
Mother: Is the newborn formula that
the
hospital is providing safe?
Doctor: This is one of several that are rotating through. Hong Kong Government had tested and found them safe.1
Mother: So it contains no harmful substance like trans fatty acids (tFA)?
Doctor: It has tFA, but in miniscule quantity, well within acceptable limits.
Mother: But my baby will be fed 6 times a day for months, each feed containing a very small amount of harmful tFA… Is that good?
Doctor: This is one of several that are rotating through. Hong Kong Government had tested and found them safe.1
Mother: So it contains no harmful substance like trans fatty acids (tFA)?
Doctor: It has tFA, but in miniscule quantity, well within acceptable limits.
Mother: But my baby will be fed 6 times a day for months, each feed containing a very small amount of harmful tFA… Is that good?
Do our frontline health care workers know
enough about the effects of tFA in infant formula
to properly advise clients? Is this mother’s fear of
miniscule amounts of tFA in newborn infant formula
justified? When the formula label lists tFA content as
zero, is this the whole truth and not just fiction? This
article briefly presents the essential facts.
On 8 July 2013, the South China Morning
Post (SCMP) published its own commissioned
investigation carried out by an independent
laboratory on the tFA content of several Mainland
China baby formula brands.2 Although the product
labels stated zero tFA content, 0.4-0.6 g of tFA was
found in the serving size of several brands. China
follows the Codex Alimentarius Commission
guidelines on tFA-free labelling, limiting to <3% of
total fat content, a boundary not breached by any
of those investigated. In response, official Chinese
government press agency Xinhuanet published
an editorial accusing the SCMP of demonising
Mainland Chinese formula, preying on the public’s
lack of understanding regarding tFA.3
Adding to this controversy, one brand of
formula sold in Hong Kong recently notified local
hospital nurseries that its newborn formulation will
change from 0 g to 0.014 g tFA per serving size.4
Currently there are no specific requirements for
nutritional composition of infant formulas in Hong
Kong—only recently, has a legislative proposal been
drafted to follow codex guidelines for food intended
for infants under 36 months of age.5 Whilst this apparently
increased amount of tFA per feed remains
minute, protracted intake in our newborns from
multiple daily feedings is a prima facie indication for
further evaluation. It is the onus of each individual to
manage their nutritional intake; the same cannot be
applied to newborns.
Trans fatty acids are a type of
unsaturated
fatty acid, in which the carbon double bond is in the
trans-isomer configuration. Developed in the early
1900s, tFA bridge the gap between solid and liquid
lipid products.6 Fully hydrogenated, saturated fatty
acid chain molecules line up in an orderly fashion
and maximise intermolecular forces, producing
solid fats. Trans fatty acids which are partially
hydrogenated, unsaturated fatty acids, have kinks in
the molecular tails, preventing stable interactions.
This property allows margarine, comprised mainly
of tFA, to be semi-solid, and spreadable right out of
the refrigerator. Production is cheaper compared to
other semi-solid oils, and partially hydrogenated oils
extend their shelf life, making them a popular choice
for processed food manufacturing.
Studies have shown an inverse correlation
between tFA consumption and good health. While
both saturated and unsaturated fats have the negative
effect of increasing low-density lipoprotein
cholesterol levels, tFA have the additional adverse
effect of lowering ‘good’ high-density lipoprotein
levels.7 The alleged health hazard is an increased
risk of atherosclerotic coronary heart disease, which
is said to double with every 2% caloric increase of tFA
consumption instead of carbohydrates; the equivalent
effect is matched by saturated fats with a 15% increase.8
Although the exact biochemical mechanism has not
been fully elucidated in human studies, mouse studies
suggest that this may be due to suppression of the response to transforming growth factor–β in
the vascular endothelium.9
Trans fatty acids are found naturally in
bovine
milk, due to natural hydrogenation reactions in
ruminant physiology. While the Codex Alimentarius
prohibits the use of commercially hydrogenated oils
in infant formulas, milk fat is often used in formula
production; for this reason, there is an acceptable
tolerance of <3% tFA composition.10 Human breast
milk also contains tFA in low levels, which vary
according to the mother’s diet; breastfeeding
mothers are advised to be aware of and reduce dietary tFA intake
for the health of both the parent
and the child.11
In 2003, the World Health Organization
recommended that tFA should be limited to less than
1% of daily caloric intake.12 As shown in the Table,13 14 15 16 17
many developed countries have since implemented
new nutritional regulations in attempts to cull
the harmful effects of tFA on society. Since 2003,
Denmark has banned the use of industrially
produced tFA in food products.18 By 2006, Canada
and the United States had mandated labelling of
foods with more than 0.2 g and 0.5 g of tFA content
per serving, respectively.19 20 In 2008, California
banned all restaurants from cooking with tFA.21
![](https://www.hkmj.org/system/files/79-table.jpg)
Table. The regulation type and details of trans fatty acids (tFA) in several countries 13 14 15 16 17
Evidently, tFA provide no known benefit
to
human health.22 At the time of writing of this article,
the Hong Kong SAR Government (HKG) had no
regulations to restrict tFA levels in food23—there
are only policies regarding nutritional labelling,
and guidelines advising the public to reduce
consumption.24 Hong Kong Consumer Council
has published multiple articles in its CHOICE
magazine, alerting the public on this health issue and
investigating tFA levels in local delicacies such as
egg tarts, buns, and swiss roll cakes.25 26 27 28 With all this
literature directed at tFA, it is surprising the HKG
has yet to legislate content level restrictions.
Frontline doctors are duty-bound to
advise
parents on details such as tFA content in baby formula
and the consequence of its intake. Only adequate
information can hope to enable patients to have true
autonomy of choice. In addition to being encouraged
to breastfeed their newborns, all mothers should be
encouraged to limit their own personal intake of tFA.
Hong Kong Consumer Council advises the public to
reduce tFA consumption by checking nutrition labels
and choose food with less tFA (eg no margarine,
shortening, etc), and use less butter and lard to
cook. The HKG should aim to follow the example of
Denmark. They start off by informing the public and
call for a public debate on the issue. Then lead up to
proposing and implementing legislation to limit tFA in infant
diets down to near-zero levels. As always,
new mothers should be provided with appropriate
information: "breast is best", but should formula
feeding remain the mother's choice, accurate and
credible information on the potential consequences
of such choices should also be provided.
References
1. Family Health Service,
Department of Health, Hong Kong.
Infant feeding (Newborn to six months old). Available
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2. Tsang E, Wei L, Sun C.
Trans-fat found in mainland China
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Jul 2013.
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Accessed 28 Jul 2013.
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Abbott Laboratories Limited; Jul 2013.
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Assembly Bill No. 97. 2008-07-
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