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.