Up to 90 percent of South Asians may be lactose intolerant. Lactose intolerance, which is due to the inability to digest milk sugars, is a common disorder caused by a deficiency of the lactase enzyme in the digestive system. Lactose intolerance is three times more common in South Asians than in other populations.

Symptoms

• Stomach bloating
• Cramping and/or pain
• Gas
• Nausea
• Loose stools or diarrhea

Diagnosis

There are diagnostic tests, such as the hydrogen breath test, that can help diagnose lactose intolerance, but these tests are usually unnecessary. If a person suspects lactose intolerance, he or she should try eliminating milk products from his or her diet for two weeks to see if the symptoms resolve.

Foods Containing Lactose

The following is a list of some foods that contain lactose. Not all of them are obvious, so it is important to read food labels to determine if lactose is present. 

The following foods contain lactose:

• Dairy products, including fat free, 1%, 2% and whole milk
• Some breads
• Margarine
• Salad dressings
• Candies and sweets made with milk

The following foods can be substituted for those that contain lactose:

• Yogurt with "active" or "live" cultures may be easier to digest than pasteurized yogurt
• Certain cheeses (cheddar and Swiss have less lactose)
• Soy-based milk (choose calcium fortified) or other soy food products

Calcium

People that cannot consume dairy products because of lactose intolerance should ensure that they are getting enough calcium through non-dairy sources. Below are examples of non-dairy sources of calcium.

• Certain vegetables (such as spinach, broccoli and okra)
• Oranges and calcium-fortified orange juice
• Almonds
• Soy products (such as soy milk and tofu)

Calcium requirements vary among individuals. Speak with your physician to determine how much calcium you should be getting in your diet. 

Other Treatment Options

Aside from substituting the foods listed above, simply eating less dairy foods throughout the day may reduce or eliminate symptoms of mild lactose intolerance. Lactase enzyme preparations, such as Lactaid®, may also help reduce symptoms.

When to See the Doctor

Contact your physician, if:

• Your symptoms continue or worsen despite restricting lactose.
• You develop any new symptoms such as blood in your stools, vomiting or persistent stomach pain.

Last Reviewed: 2012