sealPurdue Lifestyles and Education Briefs

February 2000

Lactose intolerant? Get milk

WEST LAFAYETTE, Ind. – A glass of milk may be the best medicine for those suffering from lactose intolerance.

Dennis A. Savaiano, dean of Purdue University's School of Consumer and Family Sciences and a specialist on lactose intolerance, says that consuming milk can help people recondition their digestive systems to accept dairy foods without discomfort.

His studies have found that controlled consumption – such as a half-glass of milk on a full stomach – can help the body build up a tolerance for lactose products.

"If you only consume dairy products once in awhile, you are more likely to have symptoms from them," Savaiano says. "Also, if you consume them by themselves, as opposed to as part of a meal, they tend to be transported throughout the intestine more rapidly and are more likely to cause symptoms."

Intolerance is the result of low adult levels of the digestive tract enzyme lactase, which breaks down the lactose found in milk and converts it into simple sugars that the body can use as energy. Without lactase, undigested lactose ferments in the intestines, causing unpleasant side effects such as bloating, gas and diarrhea.

Most adults don't produce enough lactase to completely break down the lactose from a large dairy meal. In fact, up to three-fourths of the world's population doesn't produce enough lactase to digest large amounts of dairy foods without some discomfort, says Savaiano, who has studied lactose intolerance for more than 16 years.

His studies have found that by consuming smaller amounts of milk several times a day for three or four weeks, lactose-intolerant people can train their digestive systems to break down lactose.

"Our studies have shown a really amazing adaptation of the large intestine of humans," he says. "The large intestines contain bacteria that help digest lactose. By altering the diet over time, bacteria more effectively digest lactose, making milk very well tolerated."

He recommends starting with one-quarter to one-half cup of milk with meals two to three times a day, and slowly increasing milk consumption.

For those people who experience only slight discomfort when consuming dairy foods, Savaiano offers the following tips to improve digestion of milk and dairy products:

• Eat dairy foods in moderation, and avoid eating large amounts at one sitting.

• Eat dairy foods as part of a meal, such as a cup of milk over cereal with fruit, or a glass of milk with dinner.

• Eat yogurts, which are well tolerated because they contain a lactase that helps the body digest lactose in the intestine.

• If necessary, use over-the-counter digestive aids.

CONTACT: Savaiano, (765) 494-8213;

Hand sanitizers no substitute for soap and water

WEST LAFAYETTE, Ind. – Instant hand sanitizers may not be everything consumers expect, according to a Purdue university professor who teaches sanitation practices for food service workers.

"Waterless, antibacterial hand sanitizers are marketed as a way to 'wash your hands' when soap and water aren't available, and they are especially popular among parents of small children," says Barbara Almanza, associate professor of restaurant, hotel, institutional and tourism management. "But research shows that they do not significantly reduce the overall amount of bacteria on the hands, and in some cases they may even increase it."

Almanza says a hand sanitizer can't take the place of old-fashioned soap and water at home or anywhere else.

"In terms of the regulations regarding food services, the Food and Drug Administration says hand sanitizers may be used as a supplement but not as a substitute for hand washing," Almanza explains. "By the same token, people should not use hand sanitizers in place of a good lathering with soap and water if it's available."

Almanza says the typical hand sanitizer, which is usually alcohol-based, strips the skin of the outer layer of oil, which normally prevents resident bacteria from coming to the surface.

"Generally, this resident flora is not the type that will make us sick," Almanza says, "but the assumption is that when you have an increase in overall bacteria, the chances are better that a disease-causing strain will be present."

Yet the manufacturers of these products can continue to claim that the sanitizers are up to 99.9 percent effective in killing germs because they were tested on inanimate surfaces rather than human hands.

"The physiological complexity of human skin makes it very difficult to use for testing of this nature," Almanza says. "The most clear and consistent results were going to come from using surfaces for which the variables can be controlled, and that's just not real life. Real life is not neat and tidy."

CONTACT: Almanza, (765) 494-9847;

Compiled by Sharon A. Bowker, (765) 494-9723;

Purdue News Service: (765) 494-2096;

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