Key Takeaway
Randomized crossover trial found no difference in lactose intolerance symptoms between raw milk and pasteurized milk, debunking the claim that raw milk lactase aids digestion
Summary
Stanford randomized, double-blind, crossover trial directly testing the widespread claim that lactose intolerant individuals can better tolerate raw milk due to intact lactase enzyme. This is one of the only rigorous RCTs specifically testing raw milk digestibility claims.
Methods
- 16 adults with confirmed lactose intolerance
- Hydrogen breath testing to confirm lactose malabsorption
- Randomized crossover design (3 periods)
- 8-day washout between each period
- Three conditions: raw milk, pasteurized milk, soy milk (control)
- 16 oz (2 cups) consumed in morning after overnight fast
- Symptoms tracked for 8 hours post-consumption
Key Results
- No significant difference in symptoms between raw and pasteurized milk
- Raw milk hydrogen levels: 62 ppm
- Pasteurized milk hydrogen levels: 58 ppm
- Soy milk (control): 19 ppm
- Symptom scores nearly identical for raw vs. pasteurized
- Lactase in raw milk does not survive gastric digestion
- Blinding was effective (participants couldn't identify which milk)
Figures
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Limitations
- Small sample size (n=16)
- Single dairy source
- Short-term assessment (8 hours)
- Only tested one dose (16 oz)
- Did not test grass-fed or A2 milk specifically
- Limited to young adults