Enzyme Treatment for Lactose Intolerance

Delicious and satisfying, milk and milk products contain a variety of important nutrients such as calcium and riboflavin, which are important for good health. However, millions of people are unable to enjoy a cold glass of milk because they suffer from a condition known as lactose intolerance. These individuals lack an enzyme called lactase in their intestines that is necessary for breaking down lactose, the main type of sugar found in milk.

Problems like these are what keep the U.S. Department of Agriculture’s Agricultural Research Service humming. In this case, chemist Virginia Harris Holsinger, who joined the ASR after completing her education at Virginia’s College of William and Mary in 1958, was able to find a solution.

Holsinger is a specialist in dairy products, specifically whey and whey beverages. In the early 1980s, her research unit was approached by Alan Kligerman, who operated a family dairy business. He sought a way to create a milk substitute to serve those who were lactose intolerant.

Normally, human beings’ small intestines produce lactase to break down lactose so that it can be absorbed into the bloodstream. For those who lack this enzyme, within just an hour of eating dairy foods like milk, cheese, or ice cream, they may experience painful gas, bloating, cramps, or other stomach discomfort. The condition occurs in almost 75 percent of the world’s population, in varying degrees. It occurs naturally, and of course, most sufferers eventually begin to avoid milk products altogether.

Holsinger began working on creating a milk variety comprised of sugars that had already been broken down so that lactose intolerant individuals’ systems didn’t have to do it for them. She developed a process whereby lactase from non-human sources, namely fungi, broke down a significant portion of the lactose in milk into simple sugars, glucose, and galactose. The research proved successful, as the majority of lactose intolerant people who consumed this modified milk were able to digest it with no problems.

This research formed the basis for Kligerman’s Lactaid brand milk and dietary supplements business, which launched with great success in the mid-1980s. Holsinger’s research was later modified for use in other products, such as ice cream and yogurt.  Johnson & Johnson bought Lactaid, Inc. in 1991. The brand continues to be a worldwide success, operating as a unit of J&J’s McNeil Nutritionals division.

The U.S. military approached Holsinger, seeking help in developing a modified version of dehydrated milk powder that the military could distribute for use by lactose-intolerant soldiers. By collaborating with U.S. Army researchers and with scientists who had conducted research at Lactaid, Holsinger was able to dry blend a lactase enzyme from a fungal source that would break down milk lactose inside the stomach, under normal stomach acid conditions. The product proved to have a long shelf life, maintained its nutritional advantages once reconstituted, and even tasted good.

Holsinger’s research also helped with the development of Beano, which was also produced by Alan Kligerman. The product helps people that have a tendency to produce excess gas to digest vegetables. The product is now produced by GlaxoSmithKline. Holsinger also created a spray-dried, dehydrated butter powder that can replace shortening, as well as a whey/soy drink mix that was designed to be used as a nutritional supplement for children in developing nations. This was part of a project that Holsinger participated in to develop formulated foods for emergency use and to find ways to use donated food products—the U.S. Agency for International Development’s Food for Peace program. Her work also led to the development of reduced-fat mozzarella cheese, which is now used widely in the USDA’s National School Lunch Program.

In 1999, Holsinger retired as leader of the Dairy Products Research Unit at ARS's Eastern Regional Research Center in Wyndmoor, Pa. She was inducted into the ARS Hall of Fame in 2000.

Holsinger passed away from breast cancer in 2009 at the age of 72.