You’ve been starting your day with cereal and milk for as long as you can remember and you love to treat yourself to pizza, pasta with cream sauce or ice cream every now and then.
But lately, you’ve noticed you feel bloated and gassy after you eat foods like these. Sometimes, you even have diarrhea.
You might have lactose intolerance. “That’s a condition where it’s hard for your body to digest lactose, a sugar that’s found in dairy products,” said Vivek Kesara, MD, a family medicine specialist with Banner Health.
Lactose intolerance happens when your body doesn’t produce enough lactase, an enzyme made in your small intestine that breaks down lactose.
When lactose doesn’t get broken down in the small intestine, it reaches the colon where bacteria ferment it. That process can cause gas, bloating, diarrhea and other symptoms.
It’s important to know that lactose intolerance is not the same as a milk allergy. A milk allergy is a severe immune system reaction. Lactose intolerance is a digestive issue, not a food allergy.
Types of lactose intolerance
Lactose intolerance falls into these four categories:
- Primary lactose intolerance: “This is the most common type,” Dr. Kesara said. It’s also called lactase non-persistence and it’s when lactase production naturally decreases as you get older.
- Secondary lactose intolerance: “This type is caused by an illness or injury that damages the small intestine and reduces lactase production,” Dr. Kesara said. Celiac disease, Crohn’s disease and intestinal infections could cause secondary lactose intolerance. This type may improve when you treat the condition that’s causing it.
- Congenital lactose intolerance: This is a rare condition where babies are born without the ability to produce the lactase enzyme.
- Developmental lactose intolerance: This is temporary lactose intolerance in premature babies.
Symptoms of lactose intolerance
You’ll probably notice symptoms 30 minutes to two hours after eating or drinking dairy. Symptoms may vary based on how much lactose you eat and your tolerance to it. Some people can eat small amounts of dairy, while others have symptoms even after a tiny amount.
Common symptoms include:
- Bloating, diarrhea and gas
- Stomach pain or cramping
- Nausea
- Gurgling or rumbling sounds in the stomach
Are you at risk?
“About 65 to 70% of people worldwide lose their ability to digest lactose after childhood,” Dr. Kesara said.
While anyone can develop lactose intolerance, you may be at higher risk if you:
- Have lactase deficiency due to genetics
- Are of Asian, African, Hispanic, Indigenous or Ashkenazi Jewish descent
- Have secondary lactose intolerance from a digestive condition
- Have had intestinal surgery or cancer treatment
How is lactose intolerance diagnosed?
If you suspect you have lactose intolerance, your health care provider may recommend these tests:
- Hydrogen breath test: After consuming lactose, you breathe into a device that measures hydrogen levels. High levels are a sign of lactose intolerance.
- Stool acidity test. This test checks for acid in the stool caused by undigested milk products. It’s more commonly used in infants and young children.
If I have lactose intolerance, can I still eat dairy?
Many people with lactose intolerance can still have some dairy, in moderation. You can experiment to see what foods and amounts trigger your symptoms:
- Start with small portions spread throughout the day.
- Try aged, hard cheeses like cheddar, Swiss and parmesan, since they have less lactose.
- Eat yogurt with live cultures. The probiotics it contains can help you digest lactose.
- Minimize milk, soft cheeses and ice cream, which have high amounts of lactose per serving.
- Be sure to read labels, since many processed foods contain milk products.
It may help to keep a food diary so you can see what foods and what amounts of foods trigger your symptoms.
Here are some ways to reduce lactose:
- Drink lactose-free milk, which has the same nutrients as regular milk.
- Choose lactose-free options, like almond, soy or oat milk.
- Use over-the-counter (OTC) lactase products to help break down lactose and make dairy easier to digest.
If you limit dairy, make sure to get calcium from other foods like:
- Broccoli
- Almonds
- Canned salmon with bones
- Leafy greens
- Fortified non-dairy milk
When to see a provider
Lactose intolerance is common, but if you change your diet and your symptoms don’t improve, talk to a health care provider. Digestive issues could also be a sign of:
- Irritable bowel syndrome (IBS)
- Celiac disease
- Inflammatory bowel disease (IBD)
- Other digestive conditions
“Be sure to seek care right away if you have severe pain, bloody stools or uncontrolled diarrhea,” Dr. Kesara said.
The bottom line
Lactose intolerance happens when your body can’t digest lactose, a sugar found in dairy foods. Common signs include bloating, gas and diarrhea. If you have lactose intolerance, you may still be able to eat dairy as long as you don’t overdo it.
Your health care provider or a Banner Health specialist can help you find the best ways to enjoy the foods you like without having to deal with digestive issues.
