Pasteurization is one of those “miracles” of modern culture that may not be so miraculous, after all. Although the Center of Disease Control (CDC) paints a picture of raw, unpasteurized milk as a relative horror story, even doctors have doubted the benefits of pasteurization from the beginning. As it turns out, we’re fed a lot of myths about pasteurization — but I’ve learned the truth and will share it with you.
Let me start from the beginning: What does “pasteurized” mean? What can be pasteurized?
Essentially, pasteurization means to heat a liquid to a specific temperature meant to eliminate harmful bacteria it may contain.
The majority of research and debate center on raw milk, which is simply unhomogenized milk straight from the cow. However, other products are sometimes pasteurized including certain varieties of kombucha and aloe vera gel. Taking full advantage of pasteurization, juice like apple cider may also go through this process.
What about pasteurization of eggs? Although some sources encourage you to pasteurize eggs at home if you need to use them raw in a recipe, this is a different situation, as the process is completed at home rather than during manufacturing.
As I said, the CDC warns vehemently about the many terrifying dangers of raw milk, using phrases like “[it] can pose serious health risks to you and your family;” “make you very sick or kill you;” and “can cause serious illness, hospitalization or death.”
They herald pasteurization as the life-saving technique of the modern age: (1)
Pasteurization was invented during a time when millions of people became sick and died of tuberculosis, scarlet fever, typhoid fever, and other diseases that were transmitted through raw milk. Pasteurization has prevented millions of people from becoming ill.
The FDA weighs in, too: (2)
Unpasteurized milk is 150 times more likely to cause foodborne illness and results in 13 times more hospitalizations than illnesses involving pasteurized dairy products.
It sounds like the issue is pretty settled.
Except … what if it’s not?
What Is Pasteurization and Homogenization?
Pasteurization is a process discovered by French scientist Louis Pasteur in 1856. By discovering that certain microbes caused the spoiling of food products, he then used what he found to discover how this concept applied to germs and disease. How does pasteurization of milk work? Certain bacteria can’t live once they reach a certain temperature, so pasteurization kills those bacteria.
Why is it called pasteurization? To honor the man who invented pasteurization, of course! Pasteurization history actually reaches back further than Louis Pasteur in concept — the Chinese have been using heat to preserve since 1117, while Japanese and Italian texts between the 1400s and 1700s also document the process. (3, 4, 5)
Because tuberculosis was often carried in milk products, pasteurization was introduced in the late 1800s as a method known as the “low-temperature, long time process (LTLT),” or “batch pasteurization,” in which milk was heated to about 145 degrees Fahrenheit for 30 minutes. This is believed to have led to a dramatic drop in tuberculosis cases caused by milk — it’s not even considered a foodborne illness these days by the CDC.
1882 marked the beginning of commercial milk pasteurization, this time using high-temperature, short-time homogenization (HTST). Instead of the 30-minute heating time, milk was now heated to 162 degrees for just 15 seconds. (6) These temperatures can also kill bacteria such as E. coli, Staph. Aureus, enterocolitica, sakazakii, L. monocytogenes and Salmonella ser. Thyphyrium. (7)
In 1908, Chicago became the first city to legally require milk be pasteurized before sold. (8)
Another hope of pasteurization in the beginning was to reduce instances of milk allergy, where people react badly to cow’s milk proteins. Unfortunately, this benefit does not actually happen when you homogenize milk. (9)
Types of Pasteurization
There are a number of types of pasteurization which generally refer to the temperature and length of time required to kill certain bacteria. What are the different types of pasteurization?
According to the pasteurization temperature and time chart by the International Dairy Foods Association, these include: (10)
- 63ºC (145ºF) — 30 minutes — Vat Pasteurization (also called low-temperature pasteurization)
- 72ºC (161ºF) — 15 seconds — High Temperature Short Time (HTST) Pasteurization
- 89ºC (191ºF) — 1.0 second — Higher-Heat Shorter Time (HHST)
- 90ºC (194ºF) — 0.5 seconds — Higher-Heat Shorter Time (HHST)
- 94ºC (201ºF) — 0.1 seconds — Higher-Heat Shorter Time (HHST)
- 96ºC (204ºF) — 0.05 seconds — Higher-Heat Shorter Time (HHST)
- 100ºC (212ºF) — 0.01 seconds — Higher-Heat Shorter Time (HHST)
- 138ºC (280ºF) — 2.0 seconds — Ultra Pasteurization (UP) or Ultra High Temperature (UHT)
Low-Temperature Pasteurization: The lowest temperature option is significant because 145 degrees is below the temperature that kills the beneficial enzymes found in raw milk and only results in a slight denaturing of milk proteins. However, you’ll still lose some good probiotics. These can be restored by the process of fermentation (using good bacteria to re-culture milk) — which also makes milk more digestion-friendly. That is the second-best option to raw milk, in my opinion.
High-Temperature Pasteurization: HTST and HHST (also known as “flash” pasteurization) both result in significant protein denaturation. The natural enzymes and healthy bacteria in raw milk is killed off along with the potentially harmful bacteria and also results in a drop of nutrient quality originally found in milk. I do not drink or recommend pasteurized milk.
Ultra-High Temperature Pasteurization: Then, there’s the truly concerning option: Ultra-High Temperature (UHT) pasteurization. UHT milk can last over six months without ever being refrigerated and up to an additional three months once it’s opened and stored in the fridge. (11) The Weston A. Price Foundation explains in detail how “ultra pasteurization is an extremely harmful process to inflict on the fragile components of milk.” Their sources have suggested that the ultra heat treatment changes the molecular structure of milk so that it initiates an immune response (which is also one reason it could contribute to leaky gut). (12) People complain of a “burnt” or “cooked” taste to this kind of homogenized milk.
Don’t let labels fool you — I would never drink any form of UHT milk, no matter how friendly the advertising or how prominent the “USDA certified organic” symbol may be.
Pasteurization vs. Sterilization
Sometimes mistaken for the other, pasteurization and sterilization aren’t the same process. While pasteurization is specific to liquids and used to eliminate bacteria, sterilization removes all fungal, bacterial and viral growth from a large variety of items (food included).
Sterilization also uses heat sometimes but may also be done with radiation, chemicals or high pressure. It’s used less in food because it alters the way food tastes, but is a common practice in medical or cleaning routines.
9 Pasteurization Myths
Myth #1: Pasteurization doesn’t influence nutrient levels.
What is milk, anyway? Isn’t it just there to make your cereal wet?
Actually, unpasteurized milk is a powerhouse of nutrition. Raw milk nutrition facts boast 160 calories in eight ounces, plus 9 grams of healthy fat, 12 grams of natural carbohydrates and 9 grams of protein. That small glass has 30 percent of your recommended daily value for calcium as well as a vast amount of important vitamins and minerals. (13)
Pasteurization, on the other hand, significantly reduces nutrient content of milk or any liquid it’s used on (no matter what the FDA insists). (14) Some of the impacted nutrients are:
Vitamin A is a tricky one — eight ounces of raw milk contains about 10 percent of your daily recommended vitamin A intake. However, not only does pasteurization reduce the nutrient density of this milk, it also alters their chemical structure, making it less easy for your body to absorb the nutrient. (18)
Myth #2: Pasteurized milk contains less allergens.
Non-homogenized milk was once thought to cause milk protein allergy. That’s been disproven, as pasteurized milk also contains the same proteins that elicit that response. Unfortunately, the proteins in milk become denatured and, instead of acting as the delivery system they should, they are unable to function properly and transport nutrients throughout the bloodstream. (19, 20)
But did you know that raw milk may actually cause less allergies and possibly even protect from asthma? (21, 22) According to one review of many studies on raw milk, “Raw milk consumption may have a protective association with allergy development.” (23)
Myth #3: Raw milk is extremely dangerous and leads to many illnesses and deaths.
The CDC puts it lightly: “Healthy people of any age can get very sick or even die if they drink raw milk contaminated with harmful germs.” (1) But is that the whole truth? Certainly, harmful bacteria can cause illness and, in some cases, death — but some of the ones they name are often in other types of contaminated foods. Raw milk is far from the worst offender.
Dr. Chris Kesser painstakingly reviewed data regarding the “many” outbreaks described by the CDC to find some interesting results. In his analysis, which used a review that ended in 2008, dairy (including both unhomogenized and homogenized milk) was one of the smallest offenders when it came to foodborne pathogen outbreaks. (24) Other interesting facts you won’t learn from the CDC or FDA that Kesser uncovered include: (25)
- Not a single person has died from an illness caused by contaminated raw milk since the mid-1980s, although 10 million or more people consume it on a regular basis. (26) To put that in perspective, about 5,000 people in the U.S. die each year from these types of illnesses.
- The CDC reports included reports of “bathtub cheese”-related incidents as part of their figures on raw milk. This product, known as Queso Fresco, is an illegally cheese made from raw milk at home. It’s inherently dangerous, causes far more issues than traditional raw milk cheese and, in Kesser’s words, “distorts the data and makes raw milk seem more dangerous than it really is.”
- According to his calculations (removing Queso Fresco from the mix), between 2000–2007, a person had a 1 in 94,000 chance of catching a bacterial illness from raw milk. Of those, you would have had a 1 in 6 million chance of actually being hospitalized for the illness. (He compares this statistic to car crash deaths, a 1 in 8,000 chance, and death from a plane crash, which is a 1 in 2 million chance.)
- You are more likely to become sick from shellfish or die from eating raw oysters than to contract an illness from raw milk.
Much less scary, right?
Using slightly more recent data, we see that there were a total of eight outbreaks related to dairy between 2001–2010. This number includes all forms of dairy. In comparison, beef caused 28 outbreaks during the same length of time. (27)
Myth #4: Pasteurized milk helps develop strong bones and protect from osteoporosis.
Drink your milk! It’ll build strong bones!
Did you hear that as a kid, too? Unfortunately, a scientist by the name of Pottenger noticed a problem with theory back in 1946. When he fed animal subjects pasteurized milk, he discovered that they weren’t getting enough nutrition and that they had significant “skeletal changes and deficiencies in development.” Several subjects fed pasteurized milk died, while all the subjects drinking raw milk remained disease-free, fertile and healthy for multiple generations. (28)
Pottenger also noted that it was virtually unknown what impact pasteurization would have on milk’s “growth-promoting factors that determine the skeletal development of our children.” (29)
Myth #5: Pasteurization is good for digestion.
Pasteurized milk is not necessarily any easier on your stomach than raw milk. Because of the denatured protein and destroyed enzymes, it’s likely that the natural enzymes present in raw milk aren’t available in significant quantity. (31) Your pancreas then has to work overtime to produce those enzymes so that you can digest pasteurized milk.
Myth #6: All raw milk is dangerous and contaminated, regardless of farming practices or how it’s obtained.
The CDC also warns that milk that isn’t pasteurized will likely still become contaminated. (1) However, the quality of farm the milk comes from absolutely matters. For example, on a farm with organic farming practices where cows are grass-fed, not given hormones and treated humanely, the cows are much less likely to carry disease, unlike those raised in small, unsanitary spaces.
There are many other questions you can ask a local farmer to verify the quality and sanitary nature of the raw milk he or she sells. Use this guide as a baseline. Other important factors include information on cows per farm space and what safety measures a farmer takes to keep milk sanitary and verify its safety.
Myth #7: Pasteurized milk is safe and part of a healthy diet.
While pasteurized milk is responsible for less illnesses than raw milk, it can also contain pathogens after pasteurization has occurred. (25)
There are other problems to consider as well. For example, the way pasteurized milk impacts insulin levels may affect the formation of certain diseases. One study concludes by saying that: (32)
Both restriction of milk consumption or generation of less insulinotropic [raw] milk will have an enormous impact on the prevention of epidemic western diseases like obesity, diabetes mellitus, cancer, neurodegenerative diseases and acne.
Others are concerned that pasteurized milk from dairy cows given synthetic growth hormones may be causing an unknown health burden. After all, it seems very likely that hormones in the food we eat are likely to impact sexual maturation — however, this hasn’t been definitively proven. (33)
While the U.S. government’s MyPlate website includes the dairy group as necessary part of nutrition (and foolishly recommends low-fat dairy), Harvard’s Healthy Eating Plate removes the category altogether and encourages limited dairy consumption (one to two cups a day of milk, for example). Harvard devised the Healthy Eating Plate as a scientifically sound response to the lobbying-motivated MyPlate provided by the USDA, recommending a diet that is mostly healthy and disease-preventing based on available research.
Myth #8: Pasteurization creates the best-tasting product.
The “indigenous milk microflora” (the good bacteria) in raw milk and their related products give them a rich, delicious taste. On the other hand, pasteurized milk is devoid of the yummy taste. (34) This is especially true for UHT milk, which consumers often complain has a “cooked” flavor which gets worse the longer the milk has been on the shelf.
Myth #9: There are no ethical concerns with regulations on milk pasteurization.
While there are far more issues than I have time to touch here, the raw milk industry is positive for local communities. On the other hand, there are many environmental and ethical concerns involved in conventional milk production. (35) These are important to consider in your opinion of pasteurization as well as conventional dairy as a whole.
I hope you’re convinced now that raw milk offers many benefits to your health. According to research, raw milk:
- Contains butyric acid which regulates insulin sensitivity (36)
- Has a higher concentration of conjugated linoleic acid than pasteurized milk, which is important for weight management, blood sugar, immune function, allergies and more (37)
- Has higher omega-3 content (38)
- Provides high amounts of vitamin B2 (23)
- Could help eradicate H. pylori infection (39)
To find a raw milk producer in your area, search on Farm Match.
The benefits of goat’s milk are incredible, especially when compared its pasteurized counterpart.
- Helps fight anemia and symptoms of bone demineralization (40)
- May help support lower levels of inflammation and better gut health in the elderly when compared to homogenized cow’s milk (41, 42)
- Digests better than cow’s milk (43)
Risks and Side Effects
While raw milk truly isn’t as dangerous as we’ve often been led to believe, there is a chance of raw milk outbreaks of bacterial infection, as with some other foods. If you choose to buy raw milk, be aware that it’s not legal to do so in all 50 states. You should also be cautious of farming practices and make sure that any raw milk you consume is fresh and tested for pathogens regularly.
Pasteurization is the process by which milk (or other liquids) is heated for a period of time to remove all bacteria from it. While this was introduced to protect from harmful infections, it also degrades the quality of raw milk by removing good bacteria and denaturing milk proteins.
Nine dispelled myths about pasteurization include:
- Pasteurization doesn’t influence nutrient levels.
- Pasteurized milk contains less allergens.
- Raw milk is extremely dangerous and leads to many illnesses and deaths.
- Pasteurized milk helps develop strong bones and protect from osteoporosis.
- Pasteurization is good for digestion.
- All raw milk is dangerous and contaminated, regardless of farming practices or how it’s obtained.
- Pasteurized milk is safe and part of a healthy diet.
- Pasteurization creates the best-tasting product.
- There are no ethical concerns with regulations on milk pasteurization.