How many lactose intolerant people in the us

Lactose intolerance can start at birth or can develop suddenly later in life, even if the individual has never had a problem with dairy before. Lactose intolerance in infants is caused by a mutation of the LCT gene, resulting in life-long intolerance.

In adults, the disorder is caused by decreasing activity of the LCT gene, resulting in an increasing inability to digest lactose as an individual ages.

Lactose intolerance is generally harmless but its symptoms can cause extreme discomfort. Symptoms of lactose intolerance appear after consuming lactose or dairy and include:. You need calcium throughout your life to grow and have healthy bones. This condition is called osteoporosis.

If you have lactose intolerance, you can change your diet to make sure you get enough calcium while also managing your symptoms. The NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. How common is lactose malabsorption? Who is more likely to have lactose intolerance? What are the complications of lactose intolerance? Lactose Free Milk: This is milk with lactase added to it.

The lactose is broken down for you. You'll also see it called "lactose reduced". Lactose reduced milk tastes sweeter but does not have sugar added to it. Soymilk: There is no lactose in soymilk. It's high in protein but be sure to get it with calcium added. Many people with lactose intolerance do fine with yogurt. The natural bacteria in yogurt help break down the lactose. Aged Cheeses : Aged, hard cheeses like cheddar, Swiss, parmesan, and Monterey Jack are very low in lactose.

According to the National Digestive Diseases Information Clearinghouse, some 30 million to 50 million Americans are lactose intolerant, including up to 75 percent of African Americans and American Indians and 90 percent of Asian Americans.

Common symptoms include nausea, cramps, bloating, gas and diarrhea that begin about 30 minutes to two hours after eating or drinking foods containing the milk sugar lactose. The use of lactase enzyme tablets or drops or lactose-reduced milk and similar products can help the lactose intolerant digest dairy products. Sherman's study concludes that adults from Europe can drink milk because their ancestors lived where dairying flourished and passed on gene mutations that maintain lactase into adulthood.

The research, he said, is an example of Darwinian medicine, a new interdisciplinary field of science that takes an evolutionary look at health, and considers why, rather than how, certain conditions or symptoms develop.

Sherman, for example, recently investigated why spices are used and why morning sickness occurs.