According to some of its online advocates, unpasteurized or "raw" milk can "heal" the gut, boost the immune system, prevent allergies, promote healthier skin, and even contribute to bodybuilding. Perhaps more common is the idea that pasteurization – the heating process to kill harmful bacteria in the milk – reduces the amount of vitamins and "good" bacteria in the drink, so that raw milk is supposedly better for you. Recent media reports suggest that this perception is fueling a growing demand for raw milk that some farmers like to respond to.
So, what do the scientific evidence say? There is some data to suggest that pasteurization may have little effect on the nutritional content of milk. However, drinking raw milk carries the risk of serious and potentially fatal infections.
A 2011 meta-analysis compared the results of 40 studies examining the effects of pasteurization on the vitamin level in milk. It was found that pasteurization reduced the amount of vitamins B1, B2, C and folic acid in the milk. However, the authors also concluded that the amounts of these vitamins, apart from vitamin B2, were initially so low that milk was not an important food source for them.
They also found some of the published scientific evidence that raw milk could provide some protection against allergies. However, the many environmental factors in agriculture prevented clear conclusions.
Another 2015 study looked at how often 983 babies under 12 months had fever and respiratory infections such as colds (as recorded by their parents). It compared those with raw milk and those with UHT milk (ultra-high temperature milk) heated to a much higher temperature (135 ° C) than regular pasteurization.
The authors concluded that drinking raw milk In the first year of life, the risk of fever and respiratory infections could be reduced by about 30% compared to UHT milk. They said that a method of removing pathogens from milk with minimal processing could have a huge impact on baby's health, considering how common these infections are.
However, it is important to point out that this is not the case. The same applies to raw milk, which has protective powers for anyone who drinks it. It is also important to remember that babies under the age of 12 months are usually given recommended breastmilk or milk because they can not obtain all the nutrients from cow's milk. Perhaps most importantly, those young infants are particularly vulnerable to the pathogens contained in raw milk, which can endanger even healthy adults.
The average human body contains about 39 trillion individual bacterial cells – more than the total number of human cells in the body. We need a mix of microorganisms, perhaps commonly known as "good" bacteria, to ward off the bad ones.
With microorganisms found everywhere from the Antarctic to the seabed, it is perhaps not surprising that they are commonplace on average dairy farms. Some harmful bacteria associated with raw drinking milk are Mycobacterium bovis (the causative agent of bovine tuberculosis), Campylobacter Salmonella Listeria and the toxin-producing E. coli .
Research has shown that drinking raw milk can cause infection with these pathogens. In Colorado, in 2015, 12 people became infected after consuming raw milk with a drug-resistant strain of Campylobacter jejuni . Although no one died, one person was hospitalized and all had symptoms ranging from bloody diarrhea to stomach cramps and headaches. Similarly, in Wales, 18 cases of Campylobacter infections were reported in 2017 by persons who had been drinking raw milk.
Due to the hazards associated with raw milk, the sale is often strictly regulated. For example, in most UK countries, it can only be sold by registered manufacturers using approved production methods. The farms must be inspected twice a year and the milk must be labeled with a warning and examined four times a year for the presence of pathogens. In Scotland, the sale of raw milk for drinking is prohibited, as in Canada and Australia.
Evidence of the benefits of raw milk consumption is inconsistent, but research generally suggests that the potential contamination of raw milk with harmful bacteria is too great a risk compared to perceived health benefits.
This article was republished from The Conversation under a Creative Commons license. Read the original article.