Medical Contraindications to Milk Consumption
The primary medical contraindications to milk consumption are unpasteurized milk for all individuals (especially pregnant women, infants, and children), and lactose intolerance, which affects individuals with insufficient lactase enzyme activity. 1, 2
Unpasteurized (Raw) Milk Contraindications
High-Risk Populations
- Pregnant women, fetuses, newborn infants, infants, and children should completely avoid unpasteurized milk and milk products due to significant risk of foodborne illness 1
- Immunocompromised individuals, including those with HIV, should avoid unpasteurized dairy products due to increased risk of serious infections 1
Infectious Disease Risks
- Raw milk consumption is associated with multiple serious pathogens including:
Epidemiological Evidence
- Between 1998-2009, consumption of raw milk products in the US resulted in 93 illness outbreaks, 1837 illnesses, 195 hospitalizations, and 2 deaths 1
- 79% of these outbreaks involved at least one person younger than 20 years 1
- From 1993-2006,60% of dairy-associated foodborne illness outbreaks were linked to unpasteurized products, causing 1571 cases, 202 hospitalizations, and 176 deaths 1
Lactose Intolerance
Pathophysiology
- Lactose intolerance occurs due to insufficient small intestinal lactase activity and/or excessive ingestion of lactose 2, 3
- Most people (except those of Caucasian descent) experience decreased lactase activity at age 4-6 years 2
Clinical Manifestations
- Symptoms include bloating, flatulence, abdominal pain, and diarrhea when lactose reaches the large intestine 2
- Symptoms can be confused with cow's milk protein allergy, which is an immune-mediated reaction to milk proteins 3
Management Considerations
- Complete avoidance of dairy is often unnecessary as most lactose intolerant individuals can tolerate small amounts of milk 2
- Hard and semi-hard cheeses contain minimal or no lactose and are generally well-tolerated 2
- Yogurt with live bacterial cultures is often well-tolerated despite its lactose content due to the presence of bacterial lactase 2
Cow's Milk Protein Allergy
- True cow's milk protein allergy is an immune-mediated reaction to milk proteins (particularly casein or β-lactoglobulin) 3
- Can present with gastrointestinal symptoms similar to lactose intolerance, making diagnosis challenging 3
- Formula-fed infants with cow's milk protein allergy should receive formula with extensively hydrolyzed cow's milk protein or amino acids, not just lactose-reduced formula 3
Inflammatory Bowel Disease Considerations
- Lactose malabsorption is significantly more prevalent in patients with Crohn's disease involving the small bowel compared to those with colonic Crohn's disease or ulcerative colitis 4
- Factors beyond lactase enzyme activity may contribute to lactose malabsorption in Crohn's disease, including bacterial overgrowth and altered small bowel transit time 4
- Many IBD patients unnecessarily avoid dairy products due to misconceptions or arbitrary medical advice 4
Common Pitfalls in Management
- Unnecessarily eliminating all dairy products in cases of mild lactose intolerance, which can lead to inadequate calcium intake 2, 4
- Confusing lactose intolerance with cow's milk protein allergy, leading to inappropriate dietary interventions 3
- Failing to recognize that pasteurized milk maintains equivalent nutritional value compared to raw milk 1
- Claims linking pasteurized milk to autism, allergies, and asthma are based on anecdotes and not supported by scientific evidence 1
Practical Recommendations
- During acute gastrointestinal illness, temporarily stop all lactose-containing products until symptoms resolve 5
- For suspected lactose intolerance, consider a trial of lactose-reduced products or lactase enzyme supplements before complete dairy elimination 6
- For those with confirmed lactose intolerance, focus on lactose-reduced dairy options rather than complete elimination to maintain nutritional benefits 7