212 Diet Wise
Lactose intolerance test
Where the onset is less serious and the symptoms less dramatic, alactasia
may go undiagnosed for years.
The simplest proof of lactose intolerance is a lactose challenge test.
The patient fasts, then consumes 25 mg of lactose, the equivalent amount
to around 0.5 liter (about two cups) of milk. No other foods or drink are
allowed for the subsequent three hours, during which time the patient is
monitored for the development of symptoms of intolerance, such as gas,
abdominal cramps, bloating, or diarrhea.
The results are not always reliable and several repeat testings may
be wise before the diagnosis is dismissed outright.
More sophisticated testing may include a biopsy of the intestinal
mucosa and an analysis of its lactase activity.
Treatment
For the majority of people, avoiding lactose is the best course of treatment.
Most adults, with a little attention to detail, can get all the nutrients they
need without recourse to milk, though since the problem is less serious than
an allergy this exclusion need not be comprehensive.
If you feel you must have dairy products, they may be predigested
or taken with a lactase supplement, such as Lactade®.
Hidden lactose
It isn’t always easy to recognize lactose in manufactured foods. Whey is
obvious, but sometimes even this is disguised as ‘emulsifiers.’ Lactose may
also be present in ‘milk-free’ infant formulas, in sweets and fudges; even in
bread.
Conversely, hard cheeses and cream may be well tolerated, as may
be plain (dark) chocolate. However, cottage and cream cheeses do contain
significant amounts of lactose, since they are not fermented.
Prolonged boiling reduces the lactose content of milk. However,
pasteurization is too short a process: these days just fifteen seconds
(minimum) at 162 °F/72°C.