Understanding Lactose Intolerance: Causes and Solutions

About 65% of people worldwide struggle to digest lactose after they stop breastfeeding. This shows how common lactose intolerance is, especially among different ethnic groups¹. It’s a condition that makes it hard to digest the sugar in milk and dairy.

Lactose intolerance leads to symptoms like diarrhea, bloating, gas, and nausea². It’s important to know about it to keep your digestive system healthy and comfy.

Key Takeaways

• Lactose intolerance is a common condition where the body cannot fully digest lactose, the sugar found in milk and dairy products.
• It is typically caused by a deficiency in the lactase enzyme, which is responsible for breaking down lactose.
• Symptoms of lactose intolerance can include gas, bloating, diarrhea, and nausea, often occurring within 30 minutes to 2 hours of consuming dairy products.
• Lactose intolerance is more prevalent in certain ethnic groups, such as Asian Americans, African Americans, and Native Americans.
• Dietary changes, lactase supplements, and lactose-free or lactose-reduced products can help manage the condition.

What is Lactose Intolerance?

Overview of the Condition

Lactose intolerance means your body can’t fully break down lactose, a sugar in milk and dairy³. This happens because of a lack of lactase, an enzyme in the small intestine³. Without proper digestion, lactose moves to the colon, where it meets bacteria, causing discomfort.

Inability to Digest Lactose

Not having enough lactase leads to lactose intolerance⁴. This means you can’t digest and absorb lactose, causing symptoms⁴.

Many people worldwide suffer from lactose intolerance⁵. In the U.S., about 36 percent of people have it³. It’s more common in Africa and Asia than in northern Europe³.

Groups like African Americans, American Indians, Asian Americans, and Hispanics/Latinos are more likely to have it³. On the other hand, it’s less common among Europeans⁵.

This condition can lead to not getting enough calcium and vitamin D, which is bad for bones and might cause osteoporosis³.

“Lactose intolerance is a condition where the body is unable to fully digest lactose, the natural sugar found in milk and dairy products.”

Symptoms of Lactose Intolerance

People with lactose intolerance often face gastrointestinal issues after eating dairy or foods with lactose⁶. Symptoms like bloating, diarrhea, gas, nausea, and stomach pain are common⁶. These issues can start within 30 minutes to 2 hours after eating lactose and can vary in how bad they are.

Lactose intolerance happens when the small intestine doesn’t have enough lactase enzyme⁶. This makes it hard to digest lactose. Some people might just need to cut down on lactose, while others should avoid it altogether to feel better⁶.

Common Symptoms After Dairy Consumption

• Bloating⁶
• Gas⁶
• Diarrhea⁶
• Nausea⁶
• Abdominal pain⁶

Some people with lactose intolerance might also have ongoing symptoms like rashes, headaches, joint pain, feeling tired, and trouble focusing⁷. But, serious signs like trouble breathing, itchy skin, and swelling of the face and eyes could mean a food allergy and need quick medical help⁷.

To figure out lactose intolerance, doctors might use a diet without lactose, blood tests, hydrogen breath tests, or even a gastroscopy if symptoms are bad and don’t go away⁷. Treatment usually means eating less lactose, taking lactase supplements, and dealing with any other health issues that might make lactose intolerance worse⁷.

“Lactose intolerance is often not formally tested in adults, and many individuals may not even be aware that they have the condition.”⁸

Lactose intolerance mainly comes from not having enough lactase enzyme, which can happen at any time and is also caused by some health conditions like inflammatory bowel disease, Coeliac disease, infections, bowel surgery, or injury⁷. Sometimes, newborns can’t digest lactose well because their bowels are still developing, but this usually gets better as they grow⁷⁶⁸.

Causes of Lactose Intolerance

Lactose intolerance happens when the small intestine doesn’t have enough lactase enzyme⁹. This enzyme breaks down lactose, a sugar in milk and dairy. Without enough lactase, the body can’t digest lactose well, causing symptoms of lactose intolerance.

Lactase Deficiency

Several things can lead to lactase deficiency and lactose intolerance. Primary lactose intolerance is common in people from certain backgrounds. It happens when the body makes less lactase as people get older⁹¹⁰⁴.

Types of Lactose Intolerance

There are a few types of lactose intolerance:

• Secondary lactose intolerance can happen if the small intestine gets damaged by conditions like celiac disease or Crohn’s disease⁹⁴.
• Congenital lactose intolerance is a rare condition where the body doesn’t make much lactase from birth. It’s inherited from both parents⁹⁴.

Developmental lactose intolerance is rare in babies but usually goes away on its own⁴.

Every type of lactose intolerance means the body can’t break down lactose well. Lactose is a sugar in milk and dairy products⁹.

“Lactose intolerance is different from dairy allergy, which is an allergic reaction to milk and dairy proteins. It can be serious. Lactose intolerance symptoms are not as bad. While you can’t have dairy at all with dairy allergy, you can still have some dairy with lactose intolerance, depending on how you feel.”

There’s no way to prevent or cure lactose intolerance. But, you can manage it by eating less lactose and using lactase enzyme supplements to help with digestion⁹.

Risk Factors for Lactose Intolerance

Lactose intolerance affects millions of people worldwide. The exact causes are not fully known, but some risk factors increase the chance of getting it¹¹.

Age is a big risk factor. As people get older, they often make less lactase enzyme. This enzyme helps digest lactose. In fact, most adults worldwide can’t digest milk well. Up to 40% stop making lactase between ages 2 and 5¹¹.

Being of certain ethnicities also raises the risk. People of African, Asian, Hispanic, or Native American backgrounds often have trouble with lactose. This is less common in Europeans¹¹¹².

• About 85% of Black adults in the U.S. can’t digest lactose, unlike 15% of White adults¹¹.
• In East Asia, up to 100% of people may have lactose intolerance¹³.
• But, only around 5% of Northern Europeans have trouble digesting lactose¹³.

Babies born too early and some health conditions can also make lactose intolerance more likely. These babies might have small intestines that aren’t fully developed. This can lead to lactose intolerance¹¹. People with Crohn’s disease, celiac disease, or small intestine bacterial overgrowth may also have trouble with lactose¹¹.

Certain cancer treatments can also cause lactose intolerance¹¹. Knowing the risk factors helps with early diagnosis and managing the condition.

Diagnosing Lactose Intolerance

To figure out if you have lactose intolerance, you might need to do one or more tests. The most common tests are the lactose tolerance test and the hydrogen breath test¹⁴¹⁵.

Lactose Tolerance Test

This test checks how your body handles a drink with lactose. First, they take a baseline blood glucose reading. Then, you drink a lactose solution and they check your blood sugar levels again. If your blood sugar doesn’t go up like it should, it could mean you’re not breaking down lactose well. This is a sign of lactose intolerance¹⁵.

Hydrogen Breath Test

The hydrogen breath test is another way to diagnose lactose intolerance. It looks for more hydrogen in your breath. This happens when lactose that wasn’t digested gets to your colon. You’ll fast before the test, then drink a lactose solution. They’ll check your breath for hydrogen levels. If the levels go up, it means you’re not digesting lactose right¹⁴¹⁵.

For babies and young kids, doctors might use a stool acidity test. This test looks for lactic acid and other signs that they’re not absorbing lactose well¹⁶.

“Diagnosing lactose intolerance is important for managing the condition and finding the right dietary adjustments.”

These tests help doctors see how bad your lactose intolerance is. They can then make a plan to help you feel better and eat right¹⁴¹⁵¹⁶.

Managing Lactose Intolerance Through Diet

There’s no permanent fix for lactose intolerance, but diet changes can help manage it¹⁷. Many people can handle up to 12 grams of lactose, like in 1 cup of milk, without issues¹⁷. By adding dairy slowly and eating it with food, many find relief from symptoms.

Tips for Reducing Lactose Intake

• Choose low-lactose dairy like hard cheeses, yogurt, and lactose-free milk¹⁸. Some cheeses have less than 1 gram of lactose, while nonfat dry milk powder can have up to 62 grams¹⁸.
• Find calcium and vitamin D in fish with soft bones, broccoli, leafy greens, oranges, almonds, and fortified cereals and juices¹⁷.
• Try lactase enzyme supplements to help digest lactose better¹⁹.

Lactose-Free and Lactose-Reduced Products

¹⁷ Lactose-free and reduced milk can help those with lactose intolerance eat less lactose¹⁸. You can find lactose-free milk in various types, and plant-based options like soy and almond milk are also good choices¹⁸. Hard cheeses, butter, and margarine are usually okay for those with lactose issues too¹⁸.

¹⁹ Lactose is in many foods, including milk, bread, cookies, and processed meats¹⁹. When reading labels, watch for milk, lactose, whey, and dry milk solids to spot lactose¹⁹.

¹⁹ For calcium, try plant-based drinks, veggies like bok choy, fish with bones, soy foods, beans, nuts, seeds, and blackstrap molasses¹⁹. Lactase pills and drops can also help with digestion¹⁹.

¹⁹ Working with a dietitian is key for finding lactose-free foods and getting enough calcium and vitamin D through diet or supplements¹⁹.

“Effectively managing lactose intolerance through a balanced, lactose-free diet and the use of lactase supplements can help individuals with this condition lead a healthy, symptom-free life.”

¹⁷¹⁸¹⁹

Lactose Intolerance in Children

Lactose intolerance is when the body can’t break down lactose, a sugar in dairy products, in kids²⁰. It’s less common in kids than in adults, but parents and doctors should know about it²¹.

How soon symptoms start can depend on the child’s race²⁰. White kids usually start showing symptoms after they turn 5. But African-American kids might start as young as 2²⁰. Kids who were born early, or who are African American, Jewish, Mexican American, American Indian, or Asian American, are more likely to have lactose intolerance²⁰.

Good nutrition is key for kids, so handling lactose intolerance is important²⁰. Kids need different amounts of calcium as they grow, from 200 mg for babies to 1,300 mg for teens²⁰. Calcium helps bones grow and stay strong, and it can prevent diseases²⁰. Kids under 1 year need a vitamin D supplement of 400 IU daily, and kids over 1 year need 600 IU to help absorb calcium²⁰.

Symptoms of lactose intolerance can start within 30 minutes to 2 hours after eating foods with lactose²⁰²¹. Sometimes, it can come from a family history and start in the teen or adult years²⁰.

To treat lactose intolerance in kids, you can change their diet and use lactase enzymes, which you can buy over the counter²⁰. It’s not the same as a milk allergy, and it doesn’t seriously harm the body²⁰. But, it’s best to see a doctor if you think your child has lactose intolerance²⁰.

Understanding lactose intolerance in kids and working with doctors can help parents make sure their kids get the nutrients they need while managing this common issue²².

Living with Lactose Intolerance

Living with lactose intolerance means being careful with food choices and reading labels well. Lactose, a sugar in dairy, is also in many processed foods like bread and salad dressings²³. It’s important to know what to look for and find good alternatives²⁴.

Reading Food Labels

For those with lactose intolerance, reading food labels is key. Lactose can be hidden in ingredients like whey and milk byproducts²⁴. Look for lactose-free or lactose-reduced options to avoid bad reactions²³.

Most people with lactose intolerance can handle up to 12 grams of lactose at once²³. But eating more or dairy throughout the day can cause problems²³. Luckily, there are many lactose-free and reduced dairy products available²³.

It’s not just about avoiding dairy. People with lactose intolerance should watch out for lactose in processed foods too²⁴. Reading labels and choosing lactose-free options helps manage the condition and eat well²³.

Switching to a lactose-restricted diet can be tough, especially if family and friends eat dairy²³. But with some research and planning, it’s possible to live well while managing lactose intolerance.

“Lactose intolerance does not require complete avoidance of dairy products but rather moderation based on individual tolerance levels.”²⁴

By knowing where lactose is found, reading labels, and finding alternatives, people with lactose intolerance can manage their condition. This helps them eat a balanced, nutritious diet.

Lactose Intolerance vs. Milk Allergies

Lactose intolerance and milk allergies are not the same thing. They have different causes and symptoms. Lactose intolerance happens when your body can’t break down the sugar in milk, called lactose. A milk allergy is when your immune system reacts to proteins in milk²⁵.

Milk allergies usually start in young kids. Up to 75% of kids grow out of it by their teens²⁶. Lactose intolerance often shows up later and can be mild or severe²⁶.

Lactose intolerance can cause gas, bloating, and stomach pain. Dairy allergies might lead to hives, trouble breathing, and diarrhea²⁶.

Seeing a doctor is key to figuring out if you have lactose intolerance or a milk allergy²⁶. They might use tests like the hydrogen breath test or check your blood sugar after you drink something with lactose²⁵.

For lactose intolerance, you can try lactose-free or low-lactose foods. But if you’re allergic to milk, you need to avoid all dairy²⁶.

“It is estimated that 45% of the population suffer from a food intolerance.”²⁷

In short, lactose intolerance and milk allergies are different. They need different tests and treatments. Knowing the difference helps you stay healthy and feel good²⁵²⁶²⁷.

Lactose Malabsorption and Intestinal Bacteria

Lactose is a key part of a balanced diet, found in dairy products. But, those with lactose intolerance can’t digest it well, leading to stomach issues²⁸. This problem, called lactose malabsorption, is being studied, especially how it affects gut bacteria.

When lactose isn’t digested, it meets gut bacteria in the colon. This can cause fluid and gas, making people feel bad²⁹. The link between lactose malabsorption and gut bacteria is complex and interesting²⁸.

Some research points to probiotics as a way to help with lactose intolerance. Probiotics are good bacteria that can help keep the gut healthy²⁹.

Lactose malabsorption affects people differently around the world³⁰. About 68% of people worldwide lose the enzyme to break down lactose as they get older³⁰. In the U.S., around 36% of people can’t digest lactose, especially some ethnic groups³⁰.

To diagnose lactose malabsorption, doctors use tests like the hydrogen breath test. It correctly spots the issue 78% of the time and is very accurate³⁰. To manage it, people often eat less lactose or choose products with less lactose³⁰.

Understanding how lactose malabsorption, gut bacteria, and gut health are linked is still growing²⁸. As we learn more, new ways to handle lactose intolerance might come, using probiotics and other foods²⁹.

“The evolution of milk secretion and its ancient origins” (Oftedal O.T., 2012) gives us a peek into how lactase persistence has changed over time.

Genetic Causes of Lactose Intolerance

Genetics are key in making people lactose intolerant. The main reason is lactase nonpersistence, where the body makes less lactase after being a baby³¹. Sometimes, congenital lactase deficiency, a rare condition, means the gut doesn’t make much lactase from the start³¹.

Lactase Nonpersistence

Lactase nonpersistence, or adult-type hypolactasia, is the top genetic cause of lactose intolerance. It’s when lactase levels drop after weaning, making it hard to digest lactose³¹. This issue is common, affecting about 75% of adults worldwide³².

Congenital Lactase Deficiency

Some people are born with congenital lactase deficiency, where the gut barely makes lactase. This rare genetic issue is much less common than lactase nonpersistence³¹.

Scientists have looked into the genes behind these lactose intolerance types. They found certain genetic changes that lead to inherited lactose intolerance³¹³²³³.

“Genetics play a significant role in the development of lactose intolerance, with the most common cause being lactase nonpersistence, where lactase production declines after infancy.”

Non-Genetic Causes of Lactose Intolerance

Genetics are a big part of lactose intolerance, but other factors can also play a role. Some medical conditions, infections, and injuries can lower the amount of lactase. This enzyme breaks down lactose.

Crohn’s disease³⁴ is one cause of lactose intolerance. It’s a chronic condition that can harm the small intestine and make it hard to produce lactase. Celiac disease³⁵ is another condition that can lead to lactose intolerance. It’s an autoimmune disorder that affects the small intestine.

Having too many bacteria in the small intestine can also cause lactose intolerance. Some infections and diseases³¹ can damage the small intestine and lower lactase levels. This makes it hard to digest lactose.

Some treatments, like cancer therapies, can also make you lactose intolerant. These treatments can harm the small intestine and reduce lactase production. This means you won’t be able to digest lactose well³¹.

“Approximately 65 percent of the human population has a reduced ability to digest lactose after infancy.”³⁴

While genetics are key in lactose intolerance, other factors can also play a part. Knowing about these causes can help people manage their symptoms and get the right medical help.

Conclusion

Lactose intolerance is a common issue that affects people all over the world³⁶. It comes from genetic changes, epigenetic effects, and environmental factors³⁶³⁷³⁸. But, there are ways to handle the symptoms and make life better for those with it.

By controlling lactose intake, people with this condition can live healthier and feel better³⁶³⁷³⁸. They can try a diet without lactose, use lactase supplements, and eat foods with probiotics³⁸. There are many lactose-free and low-lactose foods out there, making it easy to eat well without discomfort³⁷.

In short, lactose intolerance is common but can be managed with diet changes, supplements, and lifestyle tweaks³⁶³⁷³⁸. Knowing what causes it, spotting the signs, and using the right strategies can make a big difference. It can lead to better health and a happier life.

Source Links

1. Lactose intolerance-Lactose intolerance – Symptoms & causes – Mayo Clinic – https://www.mayoclinic.org/diseases-conditions/lactose-intolerance/symptoms-causes/syc-20374232
2. Lactose Intolerance – https://www.hopkinsmedicine.org/health/conditions-and-diseases/lactose-intolerance
3. Definition & Facts for Lactose Intolerance – NIDDK – https://www.niddk.nih.gov/health-information/digestive-diseases/lactose-intolerance/definition-facts
4. Lactose intolerance symptoms and treatments – https://www.nhsinform.scot/illnesses-and-conditions/nutritional/lactose-intolerance/
5. Lactose Intolerance – https://my.clevelandclinic.org/health/diseases/7317-lactose-intolerance
6. Lactose Intolerance – NIDDK – https://www.niddk.nih.gov/health-information/digestive-diseases/lactose-intolerance
7. Lactose intolerance – https://www.nhs.uk/conditions/lactose-intolerance/
8. Lactose Intolerance vs. Dairy Allergy – https://www.webmd.com/digestive-disorders/lactose-intolerance-or-dairy-allergy
9. What Causes Lactose Intolerance? – https://www.webmd.com/digestive-disorders/causes-lactose-intolerance
10. Lactose intolerance – https://www.mountsinai.org/health-library/diseases-conditions/lactose-intolerance
11. Lactose Intolerance – Cause, Symptoms, Diagnosis, Treatment – https://www.webmd.com/digestive-disorders/digestive-diseases-lactose-intolerance
12. Lactose Intolerance – StatPearls – NCBI Bookshelf – https://www.ncbi.nlm.nih.gov/books/NBK532285/
13. Lactose intolerance: MedlinePlus Genetics – https://medlineplus.gov/genetics/condition/lactose-intolerance/
14. Lactose intolerance-Lactose intolerance – Diagnosis & treatment – Mayo Clinic – https://www.mayoclinic.org/diseases-conditions/lactose-intolerance/diagnosis-treatment/drc-20374238
15. Lactose Tolerance Tests: MedlinePlus Medical Test – https://medlineplus.gov/lab-tests/lactose-tolerance-tests/
16. Lactose Intolerance – https://www.aafp.org/pubs/afp/issues/2002/0501/p1845.html
17. Eating, Diet, & Nutrition for Lactose Intolerance – NIDDK – https://www.niddk.nih.gov/health-information/digestive-diseases/lactose-intolerance/eating-diet-nutrition
18. 16171–Managing Lactose Intolerance (patient handout view) – http://www.healthsystem.virginia.edu/docs/per/managing-lactose-intolerance/handout_view_patient/@@getDocument
19. Managing Lactose Intolerance – Unlock Food – https://www.unlockfood.ca/en/Articles/Allergies-and-Intolerances/Managing-lactose-intolerance.aspx
20. Lactose Intolerance in Children – https://www.nationwidechildrens.org/conditions/health-library/lactose-intolerance-in-children
21. Lactose Intolerance in Children | Children’s Hospital of Philadelphia – https://www.chop.edu/conditions-diseases/lactose-intolerance-children
22. Lactose Intolerance in Infants & Children: Parent FAQs – https://www.healthychildren.org/English/healthy-living/nutrition/Pages/Lactose-Intolerance-in-Children.aspx
23. Lactose intolerance: Learn More – What can lactose-intolerant people eat? – InformedHealth.org – https://www.ncbi.nlm.nih.gov/books/NBK534631/
24. Tips for Living with Lactose Intolerance | North Shore Gastroenterology – https://www.northshoregastro.org/2021/11/19/tips-for-living-with-lactose-intolerance/
25. Lactose intolerance vs. dairy allergy – https://www.medicalnewstoday.com/articles/is-lactose-intolerance-an-allergy
26. Lactose Intolerance vs Dairy Allergy – https://www.usdairy.com/news-articles/milk-allergy-vs-lactose-intolerance
27. Do You Have A Milk Allergy Or Milk Intolerance? | YorkTest – https://www.yorktest.com/us/blog/milk-allergy-or-milk-intolerance/
28. Lactose Maldigestion, Malabsorption, and Intolerance: A Comprehensive Review with a Focus on Current Management and Future Perspectives – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6265758/
29. Update on lactose malabsorption and intolerance: pathogenesis, diagnosis and clinical management – https://gut.bmj.com/content/68/11/2080
30. PDF – https://med.virginia.edu/ginutrition/wp-content/uploads/sites/199/2018/07/Lactose-Intolerance-July-18.pdf
31. Genetics of Lactose Intolerance: An Updated Review and Online Interactive World Maps of Phenotype and Genotype Frequencies – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7551416/
32. Genes and lactose intolerance – https://www.sciencelearn.org.nz/resources/2016-genes-and-lactose-intolerance
33. Lactose intolerance: diagnosis, genetic, and clinical factors – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3401057/
34. Lactose intolerance – https://medlineplus.gov/download/genetics/condition/lactose-intolerance.pdf
35. Lactose intolerance and malabsorption: Clinical manifestations, diagnosis, and management – https://www.uptodate.com/contents/lactose-intolerance-and-malabsorption-clinical-manifestations-diagnosis-and-management
36. Lactose Intolerance, Dairy Avoidance, and Treatment Options – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6316316/
37. Lactose Intolerance – an overview – https://www.sciencedirect.com/topics/medicine-and-dentistry/lactose-intolerance
38. Lactose Intolerance – an overview – https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/lactose-intolerance