For many people, eating dairy products can set off some unpleasant digestive symptoms, including flatulence. People who lack adequate amounts of a digestive enzyme that breaks down lactose, the sugar naturally found in milk and other dairy products, often suffer from flatulence after consuming even small amounts of dairy products.
Normal Digestion
Gas is a normal product of digestion that forms from the bacterial breakdown of undigested food, especially carbohydrates, in the large intestines. The National Institute of Diabetes and Digestive and Kidney Diseases says that people produce an average of 1 to 4 pints of gas per day and pass gas about 14 times daily.
Role of Lactase
Many dairy products contain high levels of the complex milk sugar called lactose. The lining of the small intestines makes an enzyme called lactase that aids in the breakdown of lactose into the simpler sugars glucose and galactose. Unlike lactose, the smaller molecules of glucose and galactose are readily absorbed into the bloodstream. Unprocessed lactose travels from the small intestines to the large intestines, where resident bacteria cause it to ferment, producing hydrogen and other gases, which ultimately leave the body as flatulence.
Lactose Intolerance
As infants, we produce high amounts of the enzyme lactase to process a milk-based diet. For most people, levels of lactase decline with age. According to the Mayo Clinic, many people lack sufficient lactase to efficiently break down lactose after the age of 6. The condition called lactose intolerance results when low levels of lactose cause symptoms of bloating, discomfort and gas after the consumption of dairy products.
In addition to age, genetic factors, illnesses and injuries can permanently suppress lactase production. American Indians, African Americans, Asians and Hispanics commonly have lactose intolerance.
Solutions
People who suffer from lactose intolerance can limit their intake of dairy products or choose products that have lower levels of lactose, such as cheddar and Swiss cheese or cultured products such as yogurt that make their own lactase. Some people can benefit from using over-the-counter lactase preparations.
Other Foods
In addition to limiting their intake of dairy products, people who suffer from flatulence after eating dairy foods might want to avoid eating them with other gas-causing foods. Other sugars, such as raffinose, found in beans, and the fruit sugars fructose and sorbitol can cause gas. With the exception of rice, other starchy foods including pasta, wheat, corn and potatoes commonly cause flatulence. Soluble fiber found in fruits, beans and oat bran; fatty and fried foods; and sodas all can cause gas and worsen the symptoms of lactose intolerance.
