Page 8 - Swsthya Winter Edition Vol 1 Issu 3 DEC 2020 Circulation copy BP

OPINION

An overview of

lactose intolerance

Dr Sridhar Kalyanasundaram
Consultant Neonatologist, Head of Neonatology
Al Zahra Hospital, Dubai, UAE

Introduction:
Lactose intolerance:
The main sugar in both breast milk and other animal milks
is lactose. The newborn babies have a surge in lactase In the newborn period and in the first 2-3 months of life,
enzyme levels to enable appropriate digestion of the lactose many parents are concerned about the watery stool pattern,
in milk, but over time, the enzyme level drops and a degree diaper rash and colic in babies. Many physicians consider
of lactose intolerance is very common. In this article, we will these as evidence of lactose intolerance and advice stool
review some aspects of the role of lactose in milk, as well as tests (including reducing sugars, stool pH etc.). There is
an overview of lactose intolerance. also significant confusion due to the overlapping features
of lactose intolerance and cow’s milk protein intolerance.
Lactose and Lactase: There is a normal range of lactase levels in babies, and as the
enzyme upregulates with time (with consistent exposure to
Lactose is a disaccharide formed by glucose and galactose lactose in milk), this resolves. Appropriate and adequate
linked via a β-1→4 glucosidic bond, and is hydrolyzed by skin care of the nappy area to avoid rash (avoiding pressure
β-galactosidase (lactase), an enzyme bound to the brush during cleaning, preventive use of barrier nappy cream)
border membrane of mainly the upper small intestine and avoiding overfeeding to avoid exposure to a high lactose
of suckling mammals. This enzyme is upregulated in the load are the only measures needed in breast feeding babies.
immediate newborn period and over time, the levels
reduce. Lactose is the most abundant carbohydrate of most Colic is a transitional phase in the infant’s development, and
mammalian milk types, and mammalian milk is the only though a degree of lactose intolerance could contribute, it is
known natural source of significant amounts of lactose. not justified to substitute breast milk for this reason.
Human milk contains approximately 70 g/L of lactose, and
in exclusively breast-fed infants lactose constitutes about The benefits of breast milk far outweigh any transient
40% of the daily energy consumption; for comparison, discomfort the baby faces-and simple reassurance that the
bovine milk contains approximately 46 g/L of lactose. The problem is transient and supporting the family should be
monosaccharides, glucose and galactose, are both actively adequate. If the baby is partly on infant formula feeds for
absorbed in the small intestine once lactose is broken down any reason (difficulty in exclusive breast feeding, family
by lactase enzyme. choice etc.), a trial on low lactose infant formula could

Role of lactose in milk

Galactose is a major component of oligosaccharides,
and via galactosylation it is incorporated in glycolipids
and glycoproteins where it serves multiple roles in early
human development. Galactose is incorporated into brain
myelin lipids, and it has been suggested that lactose in
mammalian milk might have a role as a substrate for the
synthesis of these galactolipids. The stable concentration
of lactose is important in maintaining a constant osmotic
pressure in human milk. Lactose also aids the absorption
of calcium. In breast milk, many carbohydrate-based
bioactive compounds, such as oligosaccharides like human
milk oligosaccharides (HMOs), are attached to lactose,
and lactose by itself can act as a prebiotic when it passes
undigested through the gut. Lactose does not stimulate the
reward center in the brain, and so, unlike other sugars, does
not provoke eating for taste (promoting need based feeding,
not greed based!). It also has a much lower impact on dental Dr Sridhar Kalyanasundaram
caries risk compared to sucrose.

8 Volume: 1 I Issue: 3 I 2020