Mona Lisa Das | May 27, 2014 | 8.53 pm ISTTwenty-three-year-old Risa Monica loves all things food. A production professional in the city, Monica hails from the northeastern state of Meghalaya- famous for its love of pickled bamboos and spicy meat dishes. Shifting base to another region two years ago didn’t affect this foodie. She savours sambar, egg dosas, biriyanis and bisibele baath with the same ardour. However, ice creams do not make it to the top of her favourite food list. Not that she doesn’t like ice cream. Monica usually waits for the weekend to gorge on the icy delicacy, and when she does, she makes sure she eats those made solely out of fruits and doesn’t contain milk. Monica is among the many people in the world who are lactose intolerant. People suffering from lactose intolerance cannot digest lactose, a sugar found in milk. When lactose enters the digestive system, an enzyme called lactase breaks it down into glucose and galactose for further digestion. Lactose intolerant individuals have very low or insufficient amounts of lactase which is produced by the cell linings in the small intestine. CausesLactose intolerance is often genetically inherited and usually affects people when they reach adulthood, when their milk intake lowers. For example, Monica’s mother and brother too are lactose intolerant, each to a different degree. It may also occur as a genetic disorder also known as congenital lactase deficiency, wherein infants are unable to breakdown milk right from birth. However, this condition is very rare and often considered very dangerous as infants depend on breast milk in the initial months. Pre-mature babies too may show signs of lactose intolerance, but eventually are cured as their cell linings develop and begin producing lactase. “Infants are not usually intolerant towards breast milk, but they might be allergic to cow milk or infant formula. But it usually goes away after two yearsâ€, says Dr. Sahana Devadas, a pediatrician, and a neonatologist. Another cause of lactose intolerance could be when there is a problem with the intestine such as Crohn’s disease, Celiac disease, Ulcerative colitis, chemotherapy and gastroenteritis. Lactose intolerance can also be caused if a person is suffering from cancer or undergoing chemotherapy. Lactose intolerance is not the same as an allergy to milk. A food allergy occurs when our immune system is averse to a certain food protein.Symptoms Most lactose intolerant people do not consume milk directly, but can consume certain milk products or those that contain traces of milk products without problem. The common symptoms of Lactose intolerance are: abdominal bloating, cramps, flatulence, diarrhoea, nausea and vomiting.TestsThe two most common tests done to diagnose whether a person suffers from lactose intolerance are:Hydrogen Breath Test, where in the person drinks some amount of lactose and their breath is monitored over the next several hours for traces of hydrogen. High levels of hydrogen points to undigested lactose. Smoking or medication may affect the test results. Stool acidity test is one where the acid level in the stool is measured; more is the amount of undigested lactose, higher will be the acid level. This test is done on infants and small children on whom complex test can’t be performed. The other tests include blood test, intestinal biopsy, stool sugar chromatography and genetic diagnostics or DNA testing that gives definitive results. Since milk is a major source of calcium, the most common concern faced by those who are lactose intolerant is to have a proper calcium and Vitamin D intake. Alternatives for milk include soy milk, rice milk, coconut milk, etc. Yoghurt, spinach, broccoli, lettuce and salmon are some food items high in calcium. Though lactose intolerance is no handicap, those who do suffer from it need to be extra cautious, follow a lactose free diet and must keep a tab on what they eat, suggests Dr. Devadas.