Cow’s milk intolerance rare in young adults

NEW YORK (Reuters Health) – Young adults with
gastrointestinal disturbances may blame cow’s milk for their
symptoms. While some type of allergic reaction may be involved,
Finnish researchers report, intolerance to cow’s milk is
usually not the cause.

In a previous study, Dr. Laura Paajanen of the Foundation
for Nutrition Research in Helsinki and her team found evidence
that gastrointestinal problems in school-age children were
sometimes due an intolerance to cow’s milk. They conducted the
current investigation to determine the cause of similar
discomfort in young adults.

The researchers surveyed 827 young men and women ages 16 to
21 about gastrointestinal symptoms related to food, and then
conducted more detailed examinations in 49 individuals who
reported such symptoms and 29 who did not.

Roughly 10 percent of the study participants reported
having severe gastrointestinal symptoms, usually food-related,
in the previous year. Twenty-four percent of all the study
participants said cow’s milk caused them gastrointestinal
discomfort, and 13 percent did not drink milk.

When the researchers had a subgroup of people with
gastrointestinal symptoms drink milk and a placebo beverage
containing soy, they found milk induced symptoms in just 2 of
the 23 study participants who completed the test. Four of 47
study participants carried a gene associated with lactose
intolerance.

However, study participants who had gastrointestinal
problems did show higher levels of markers of immune system
activity within their intestines and in their blood. They were
also twice as likely as people without symptoms to carry a gene
associated with autoimmunity.

The findings suggest that some type of allergic reaction to
food may cause such gastrointestinal symptoms, but that cow’s
milk is rarely the cause, the researchers report.

Paajanen and her team note that people who avoid dairy
products because of a mistaken belief that they are
lactose-intolerant may run the risk of missing out on important
nutrients.

SOURCE: American Journal of Clinical Nutrition, December
2005.