How is lactose intolerance managed in adults?

Management of Lactose Intolerance in Adults

Most adults with lactose intolerance can tolerate 12-15g of lactose (approximately one cup of milk) without significant symptoms, and management should focus on individualized dietary modification rather than complete dairy elimination. 1

Pathophysiology and Prevalence

Lactose intolerance results from inadequate intestinal lactase enzyme activity, leading to undigested lactose passing into the colon where it is fermented by bacteria, causing symptoms such as:

• Abdominal pain and bloating
• Excessive gas
• Diarrhea

The prevalence varies significantly by ethnicity:

• 10-15% in Northern European descent
• Up to 60-80% in Asians, Blacks, and Latinos
• Up to 90-100% in Chinese and American Indians 2, 3

Diagnosis

Diagnosis can typically be made through:

1. Detailed symptom history - focusing on temporal relationship between dairy consumption and symptoms
2. Dietary manipulation - trial elimination of lactose-containing foods with symptom monitoring
3. Confirmatory testing (if needed):
   • Hydrogen breath test
   • Lactose tolerance test 3

It's important to note that many individuals who believe they have lactose intolerance may not actually have impaired lactose digestion, making proper diagnosis essential 3.

Management Approach

1. Dietary Modification (First-Line)

• Determine individual tolerance threshold: Most adults with lactose intolerance can tolerate 12-15g of lactose (approximately one cup of milk) without significant symptoms 1
• Gradual introduction: Start with small amounts of dairy and gradually increase to determine personal tolerance level
• Strategic consumption: Consume dairy products with meals rather than on an empty stomach
• Choose lower-lactose dairy options:
  • Hard cheeses (cheddar, Swiss)
  • Yogurt with live cultures (contains bacteria that help digest lactose)
  • Lactose-reduced or lactose-free dairy products 2

2. Lactase Enzyme Supplements

• Take lactase enzyme supplements before consuming lactose-containing foods
• Effectiveness varies between individuals and products 4

3. Ensure Adequate Calcium Intake

• Monitor calcium intake if dairy consumption is limited
• Consider calcium-fortified non-dairy alternatives (soy milk, almond milk)
• Calcium supplements may be necessary if dietary intake is insufficient 3

4. Probiotic Considerations

• Evidence for probiotics in managing lactose intolerance is mixed and insufficient
• Some specific probiotic strains with β-galactosidase activity may help with lactose digestion, but more research is needed 4, 5

Special Considerations

Colonic Adaptation

• Regular consumption of small amounts of lactose may improve tolerance through colonic adaptation
• This occurs as colonic bacteria adapt to metabolize lactose more efficiently
• Completely eliminating lactose may reduce this adaptation 6

Secondary Lactose Intolerance

• Can occur temporarily following gastroenteritis, inflammatory bowel disease flares, or chemotherapy
• May resolve once the underlying condition improves 7

Medication Review

• Some medications contain lactose as an excipient
• Review medication list for potential sources of lactose in patients with severe intolerance 7

Common Pitfalls

1. Unnecessary complete dairy elimination: Most lactose-intolerant individuals can tolerate small amounts of lactose
2. Overlooking hidden sources of lactose: Lactose is often used as a food additive in processed foods, baked goods, and medications
3. Inadequate calcium intake: Restricting dairy without ensuring adequate calcium from other sources
4. Misattribution of symptoms: GI symptoms may be incorrectly attributed to lactose intolerance when other conditions (IBS, FODMAP sensitivity) may be responsible 2

By following these management strategies, most adults with lactose intolerance can minimize symptoms while maintaining adequate nutrition and quality of life.