Hazards of a 'healthy' trend? An appraisal of the risks of raw milk consumption and the potential of novel treatment technologies to serve as alternatives to pasteurization

Background: Milk is a nutritious and healthy dietary component of many adults and infants, all over the world. For numerous reasons, the consumption of raw, unpasteurized milk is a growing trend. This practice may, however, be risky as raw milk consumption has potentially severe health consequences. Scope and approach: In the midst of the fierce debate and controversy, it is important to find support in rigorous scientific evidence. In this review, the contemporary epidemiological significance of raw milk, as well as the scientific basis and justification for milk pasteurization, are presented. The hazards associated with raw milk consumption, the primary sources and routes of microbial contaminants into milk, as well as factors that may predispose milk to microbial contamination, are explored. Relevant livestock commensal microbiota and diseases, environmental sources and pathways, as well as post-pasteurization contamination are considered. Some of the motivating factors driving raw milk consumption and the purported benefits of drinking unpasteurized milk are examined. Furthermore, the main scientifically verified differences between pasteurized and unpasteurized milk are discussed, and attempts are made to refute some of the biased claims regarding the human health benefits of raw milk. Given that many raw milk enthusiasts are skeptical of pasteurization, we explore the potential of some novel treatment techniques that could serve as alternatives to pasteurization. Key findings and conclusions: Scientific evidence shows that pasteurization is so far, the primary, incontrovertible safeguard for milk and it only slightly alters the nutritive and organoleptic profile of milk. There are a number of novel technologies, which seem to be milder and if properly optimized in the near future may serve as suitable alternatives to pasteurization. It is anticipated that these technologies or a reasonable combination of key processes, will enable the production of milk and milk products that are microbiologically safe, yet publicly accepted.