Pasteurization is right up there with hand-washing and vaccines as one of the greatest public health achievements in human history. But just like the other things on that list, it has its detractors. Loud ones.
Fact-checking organization Full Fact recently responded to an Instagram post that has totted up over 70,000 likes at the time of writing, one of many espousing the bullshit disputed idea that unpasteurized “raw” milk is a health food. So, we felt the time was ripe for a reminder of why science tells us that chugging untreated pints of the white stuff is often a very bad idea.
What is pasteurization?
Named for French scientist Louis Pasteur, who demonstrated that applying heat could prevent wine and beer from going bad in the 1860s, pasteurization is the process of heat-treating milk to kill harmful microbes and increase shelf-life.
There are a few different methods, but all involve the milk being heated to specific temperatures and held there for a predetermined period of time, which has been calculated as sufficient to kill the bacteria, like Mycobacterium tuberculosis, that can be hiding inside.
You may also have seen products labeled as “UHT”, which stands for ultra-heat treated. This is a more extreme form of pasteurization involving higher temperatures and sterile packaging, allowing these kinds of products to be stored out of the fridge for months at a time.
Milk is not the only foodstuff that gets pasteurized. Other examples of foods that can be heat-treated include fruit juices, flour, and Pasteur’s original research subject, alcoholic beverages.
Why do some people drink raw milk?
Almost as soon as pasteurization became standard practice, the controversy began. According to the Science History Institute, some local media organizations were asking questions about “cooking” milk as far back as the early 20th century, and the skepticism from some quarters has never really gone away.
Over the decades, many claims have been made about the supposed benefits of unpasteurized dairy products. Here are a few of them.
“It tastes better.”
Some people simply say they prefer the flavor of raw milk. There are also some artisanal cheeses that are traditionally made with raw milk, which connoisseurs may be tempted to sample.
This is one that’s difficult to disprove with scientific research. Suffice it to say, even if you do think it tastes a bit better, most would agree the risks of raw milk (see below) significantly outweigh this.
“It’s easier to digest.”
Some have claimed that treating milk with heat to kill the bad bacteria has a knock-on effect of killing probiotic organisms that secrete lactase, the enzyme that breaks down lactose and that those with lactose intolerance are lacking.
There is no scientific evidence to back up this claim. Raw milk still contains lactose and there’s no indication it contains lactase. The pasteurization process is also not the cause of lactose intolerance, which we know from genetic evidence has been around for thousands of years.
“It’s healthier.”
Some suggest that the pasteurization process negatively affects the nutritional profile of the milk by degrading nutrients like calcium, essential for healthy bone development. There have also been claims about the supposed immune benefits of raw milk.
Much of this is also tied in with wider skepticism around consuming processed foods, or supposedly “unnatural” products.
The evidence suggests that pasteurization does not alter the nutritional content of milk in any significant way. Even where some studies have found decreases in the levels of certain vitamins after heat treatment, these are not vitamins that are found at particularly high levels in milk and thus can be obtained from other, more important dietary sources.
There is some evidence that children raised on farms have a lower incidence of some allergies and autoimmune conditions, and improved immune function, which some have attributed to raw milk consumption. Importantly, though, even these studies agree that there would need to be a better way of mitigating the very real risks from raw milk before more widespread consumption could be recommended.
“It’s fine as long as it’s tested/organic/from a clean farm.”
Some believe that as long as they trust the farm where their raw milk comes from, it is safe to consume.
However, in reality, there is no way to completely remove the risk. Even farms that regularly test for microbes in their milk may miss low levels of contamination that can still get you sick. Organic farming practices can’t prevent contamination either, and even the healthiest animals can harbor bacteria that pose a threat to humans.
What are the risks of drinking raw milk?
As well as citing evidence that largely debunks the claims made by the anti-pasteurization league, health authorities like the US Food and Drug Administration (FDA) have repeatedly warned about the dangers of consuming raw milk.
The most obvious, and the reason pasteurization was adopted in the first place, is the risk of foodborne illness.
The Centers for Disease Control and Prevention (CDC) explain that raw milk can carry several different bacteria that pose a risk to human health, including Campylobacter, Brucella, and Listeria. In fact, they say raw milk is “one of the riskiest foods” to consume.
Infection with any of these species could see you saddled with days of diarrheal misery, but there are some potentially serious consequences too, particularly for those who may be more vulnerable such as children and pregnant people. It’s not unheard of for humans to contract bovine tuberculosis from raw milk, and some of these other infections can cause complications including kidney failure.
It’s because of these risks that raw milk is illegal to purchase in several US states, and cannot be sold in high street stores in the UK.
The verdict? Pasteurized milk is much safer and no less healthy
In a world where some people genuinely debate the utility of good hand hygiene, it’s probably not surprising that raw milk has so many staunch supporters. But all the evidence suggests that consuming unpasteurized dairy is, at best, no better for you and, at worst, a one-way ticket to the ER.
If only there were an easy way to drastically reduce all the risks…
All “explainer” articles are confirmed by fact checkers to be correct at time of publishing. Text, images, and links may be edited, removed, or added to at a later date to keep information current.
The content of this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.
Source Link: People Are Once Again Claiming Raw Milk Is Good For You – Here’s Why It’s Not