RealMilk.com sums up alot of the issues and studies:
NUTRIENT DEGRADATION BY PASTEURIZATION:
Vitamin C ,
Many studies have linked consumption of pasteurized milk with lactose intolerance, allergies, asthma, frequent ear infections, gastro-Intestinal problems, diabetes, auto-Immune disease, attention deficit disorder and constipation. During a period of rapid population growth, the market for fluid pasteurized milk has declined at 1% per year for the past 20 years. Fewer and fewer consumers can tolerate pasteurized (and ultrapasteurized) milk (Don’t Drink Your Milk, Frank Oski, MD, 1983).
The Protective components of Milk are generally destroyed in Pasteurization process:
PROTECTIVE COMPONENTS: Raw milk contains numerous components that assist in:
Killing pathogens in the milk (lactoperoxidase, lactoferrin, leukocytes, macrophages, neutrophils, antibodies, medium chain fatty acids, lysozyme, B12 binding protein, bifidus factor, beneficial bacteria);
Preventing pathogen absorption across the intestinal wall (polysaccharides, oligosaccharides, mucins, fibronectin, glycomacropeptides, bifidus factor, beneficial bacteria);
Strengthening the Immune System (lymphocytes, immunoglobulins, antibodies, hormones and growth factors) (Scientific American, December 1995; British J of Nutrition, 2000:84(Suppl. 1):S3-S10, S75-S80, S81-S89).
PASTEURIZATION HARMFUL: Many of these anti-microbial and immune-enhancing components are greatly reduced in effectiveness by pasteurization, and completely destroyed by ultra-pasteurization (Scientific American, December 1995; British J of Nutrition, 2000:84(Suppl. 1):S3-S10, S75-S80, S81-S89).