Lactose Intolerance
A person who is lactose intolerant is someone who does not have enough of the enzyme called lactase in their gut. Without lactase, they aren't able to completely break down lactose, the naturally occurring sugar found in milk. For both babies and mothers, the symptoms of lactose intolerance can be very distressing, but they can also be easily managed.
What is lactose?
Lactose, a carbohydrate, is the sugar found in human breast milk, cows' milk,
goats' milk, standard formula milks and in milk products. It provides energy,
aids absorption of calcium and magnesium, and promotes growth of useful
intestinal bacteria.
Before lactose can be absorbed by the body, it must be broken down into its component sugars, glucose and galactose.
In normal digestion lactose is broken down in the small intestine by an enzyme called lactase. A deficiency of this enzyme results in the undigested lactose passing to the large intestine. There it draws water into the bowel and is fermented by natural bacteria to produce acids and gases.
Common symptoms of lactose intolerance
The symptoms of lactose intolerance are caused by the fermentation of lactose
in the gut.
Symptoms include: excessive flatulence (wind), bloating and abdominal discomfort, watery diarrhoea, and in infants very acid stools which can cause scalded buttocks. Occasionally constipation can result. Lactose intolerance over time can contribute to poor growth.
Though both lactose intolerance and milk allergy can cause some similar symptoms, and may exist together, lactose intolerance is not a cause of eczema or respiratory symptoms.
Lactase levels
People who produce no lactase, or only low levels of lactase, are said to be
lactase deficient. It is extremely rare for an infant to be born with
insufficient lactase levels. Human milk is high in lactose and most babies and
young children digest lactose well. Ability to digest lactose decreases with
age.
Why does a deficiency of lactase occur?
Most lactose intolerance in infants is termed secondary, usually occurring
after an intestinal infection. Lactase is produced on the surface cells of the
small intestine's lining. If the lining is damaged, lactase is the first enzyme
to be lost. Some causes of damage are: acute gastroenteritis, particularly
rotavirus, giardia, protein allergy and intolerances, bowel surgery, untreated
coeliac disease, and some antibiotics.
Secondary lactose intolerance is usually only temporary and in time lactase
levels return to normal.
Treatment for Baby or Toddler
Be guided by your doctor or paediatrician. For breast fed babies diagnosed with
secondary lactose intolerance, continued breast feeding is usual in all but
severe or prolonged cases. For formula-fed infants, a lactose-free cows'
milk-based formula such as Karicare De-Lact is usually recommended. Soy formula
contains no lactose and is an option for older children. But changing an infant
of under six months to soy formula in secondary lactose intolerance means
introducing a new protein to a damaged gut and risks development of allergy to
soy protein.
Remember that all baby's solid foods should also be lactose-free. Read food labels and avoid foods containing milk. Lactose-free formula or long-life lactose-free milk can be used in cooking for babies over eight months.
A gradual return to normal drinks can be tried after about four weeks. Introduce one bottle of lactose-containing formula on the first day, two on the second day, and so on, until the usual feeding routine has been re-established. When reintroducing milk products, begin with small amounts of those lowest in lactose.
