DEAR DR. BLONZ: I recently watched a video on YouTube saying that the pasteurization process destroys critical enzymes needed to assimilate calcium from milk. Do you have any information as to whether this is true? -- E.B., Puma, Ariz.
DEAR E.B.: There are enzymes in raw (unpasteurized) milk, and some are indeed destroyed by the process of pasteurization. The question, though, is whether these enzymes are essential for the assimilation, or absorption, of the calcium in milk. The answer here is no -- or at least it has never been demonstrated in any study I have been able to find.
The enzymes in raw milk -- and there are a number of them -- come either from the cow or from bacteria that might be present. One of the main cow enzymes in milk, for example, is called plasmin. It is a protein-digesting enzyme that, if left to act, will eventually degrade the milk protein, leading to clumping and the development of "off" flavors and odors.
Please understand that while the pasteurization of milk does not make it a sterile product, it does help destroy potentially harmful microorganisms that can cause spoilage or disease. It does this by knocking out some, but not all, of the enzymes and bacteria. Pasteurized milk still needs to be refrigerated because the cold serves to slow bacterial growth and enzymatic action. All this explains why milk goes bad if it is allowed to sit too long or is stored at the wrong temperature. The storage time of milk can be extended if the milk product is processed with a higher temperature (ultra-pasteurized) and then packaged in aseptic containers.
The YouTube video you cite was incorrect if it stated that the enzymes in raw milk are needed for us to absorb calcium and other mineral elements. What you are hearing smacks of an unscientific milk attack. There are those who really do not like milk, and feel it is an unhealthy food.
It is up to each individual to decide whether he or she wants to consume milk or any dairy product. Not everyone wants to drink milk, and not everyone has to. Our freedoms allow us to make our own food choices. There is a growing amount of nonsense online, so when you encounter new information, I encourage you not to be influenced before checking out the facts from a reliable source. A good way to debunk claims is to investigate whether there is any scientific foundation to the concepts. Often, you can do this by searching among reliable sources such as government websites (ending in .gov) or academic ones (ending in .edu). I have a list of reliable sources at my blonz.com site (blonz.com/nut.htm).
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.