Milk Casein, Amyloid, Pasteurization, Homogenization

Milk is a very special food for mammalian babies. It provides essential nutrients; stimulates development of the gut; promotes the growth of the unique neonate gut flora; and kills everything else. Milk is anti-bacterial, anti-fungal and anti-viral. It is used in fruit orchards as a pruning tool dip to prevent the spread of disease between trees, and it is used as a foot dip after ceremonial walking on hot coals. But is cow's milk healthy for adult humans and is milk compromised by pasteurization and homogenization?

Mother's Milk is Fierce
Milk as it is transferred from breast to baby is loaded with molecular weapons for the protection of the baby's respiratory and digestive systems. Cells from the mother are transferred along with the milk and quickly spread out on the surface of the mouth and digestive system to patrol for pathogens. The mother's immune system detects potential risks as the baby's mouth contacts the mother's lymphatic system at the breast, and the antibodies that are subsequently produced are transferred into the milk. Enzymes in the milk digest bacterial cell walls and other milk proteins are converted into anti-bacterial peptides in the baby's stomach before ultimately being digested into amino acid nutrients. Many of the fat/lipid nutrients in milk are also anti-bacterial or anti-viral. Most of the carbohydrate in milk is the simple disaccharide lactose that most bacteria can't use for food. The remaining 10% of the carbohydrates are extensions of the lactose to make galacto-oligosaccharides (GOS, a.k.a. bifidus factor) that are toxic to all but the few bacterial species that make up the highly specialized microbial community of the human baby gut flora. (Cow's milk has an entirely different composition, e.g. lacks bifidus factor, and supports a different gut flora.)

Milk is Liquid Fat
It is hard to transport fat in water, because it isn't soluble. That is true for blood or milk. We have all heard about good and bad cholesterol, LDL and HDL, and the problems of transporting blood lipids from gut to liver to tissues. Specialized carrier proteins are needed for lipid transport in blood and the same is true for milk. Caseins are the milk proteins that coat droplets of fats that make milk white and then form digestible curds in response to the baby's stomach acid and digestive enzymes. We exploit the natural curd forming response of milk proteins and lipid droplets to form yogurts and cheeses.

Pasteurization and Homogenization Put Milk in the Dairy Case
Milk behaves optimally when immediately transferred from the mother's mammary tissue to the baby's digestive tract. Bacteria that contaminate breast milk are quickly killed by cellular and molecular defenses of the milk itself. Thus, breast milk has a long storage life at room temperature, chilled or frozen. The natural defenses of milk also permit regional milk banks, where donated milk is minimally processed and screened, for subsequent use by hospitals to avoid problems, such as necrotizing colitis, associated with the use of artificial feeding substitutes. Commercial preservation of cow's milk in stores has resulted in attempts to extend the shelf-life by heat treatment (pasteurization) to provide additional protection from microbial contamination and homogenization to prevent curd formation.

Milk is for Babies
So why isn't milk the perfect food? Part of the reason may come from the highly specialized and essential role of milk for mammals like people. Millions of years of extreme selection pressure have made sure that every woman produces ample milk for all of her babies. Until very recently, if the baby could not successfully nurse, it would die. That made breast milk the perfect food for babies and milk was integral to the development of the baby gut, baby gut flora and baby immune system. But that didn't mean that cow's milk would be a healthy commercial food for human adults.

Milk Processing May Accentuate Casein Amyloid Fiber Formation
Proteins are made of a long sequence of a thousand amino acids. At each of those thousand positions there is one of twenty different amino acids. Some of the amino acids are hydrophilic and bind to water, whereas other amino acids are hydrophobic and bind only to lipids. Proteins in water fold and unfold in thousands of alternative configurations until the final shape is reached in which there is not enough energy in the molecular vibrations and movements of the water molecules to knock the protein into an alternative shape.

Heating/pasteurization and torturous mixing/homogenization can force milk casein and fats into new configurations that make the proteins stackable into fibers/amyloids. These milk protein fibers may be of interest, because protein fibers are important in many diseases, e.g. type I diabetes, Alzheimer's disease. The problem with amyloids, is that these fibers form a natural repetition of the same amino acid on each of the stacked proteins. This repetitive amino acid, e.g. positively charged lysine or arginine, can provide a binding site for a similarly spaced, oppositely charged molecule, such as heparin, which is involved in dragging molecules from the surface into cells. Beta amyloid fibers with positively charged amino acids in a band along their edges are what kills nerve cells in Alzheimer's disease.

Research has recently demonstrated that milk casein forms amyloid fibers in response to pasteurization and homogenization. It would be interesting to know if these fibers bind to heparin and if these fibers are toxic to intestinal cells.

I have raw cream from grass fed cows in my morning coffee and my three daughters never tasted formula.

Simple Remedies

Simple is usually best. Traditional herbal cures are tried and true. I learn a lot about biology by studying what works in herbal medicine. Some simple plant products, such as Vicks Vaporub, are very potent cures for what typically ails you. Castor oil is an excellent topical pain killer.

Herbs and spices excite our senses and dominate cuisines. Cultures are identified by their food, but the use of particular plant materials to food is not a random act of history, nor is it limited to the regions where the herbs and spices first appeared. Research by Paul Sherman at Cornell, and others has shown that herbs and spices that are used in a culture are also the most effective at inhibiting pathogens and parasites where that food is traditionally served.

I must talk about some related experiences that touch on the same subject, but are simply fun explanations of cultural practices. Milk is used in some interesting cultlural practices, because it has very potent anti-viral, anti-bacterial and anti-fungal components -- milk keep newborns well nurished, but also safe from nasty germs, etc. while the immune system the baby matures. Two astoundingly disparate applications of milk come to mind: pruning fruit trees and walking hot coals. I have observed both. I previously worked with plant pathologists and I watched pruners sanitize their shears in milk between trees. The milk stopped the spread of viruses and bacterial pathogens. I also observed firewalking in the Sri Mariamman temple in Singapore. The firewalkers stepped from the coals into a pool of milk to stop infections of their singed feet. In both examples, milk provided an abundance of anti-microbial molecules that were retasked from protecting babies to protecting trees or adult feet.

Herbs and spices are plant products that are toxic to plant pathogens or herbivores, which are retasked to protect people. Some of these, such as the curcumin in turmeric, are potentially more effective that commercial drugs. I want to point out some of the common plant materials that are very useful in our diets and to remedy common infections, aches and pains.

My current champion cure-all is Vicks Vaporub. This thick ointment has the pleasant scent of its ingredients, menthol, eukalyptol, camphor and terpentine. I associate the smell with childhood treatment for congestion. I also remember that my father used to rub it on his arthritic hands to loosen them up before a day’s work. There is a solid physiological basis for the action of Vicks. Many of the ingredients are powerful antibiotics effective against a variety of bacteria and fungi. Vicks is one of the most effective topical treatments for athlete’s foot and ringworm fungal infections. The menthol is cooling, because it binds to the cold sensing receptors and it is an effective analgesic and anti-inflammatory, because it triggers acupuncture like responses through the vagus nerve. I would also try Vicks on autoimmune conditions of the skin, because of both the anti-inflammatory and anti-bacterial properties. I have even seen Vicks recommended for the same reasons for the treatment of acne. TMJ pain and inflammation apparently responds to the menthol.

Castor oil binds to heat detecting receptors of the skin and works similarly to hot pepper capsaicin. Castor oil can be used to stop many aches and pains in arms and legs by topical applications. Since most of these plant products act through the pain sensors in the skin, they don’t actually penetrate to the joints involved, but rather they trigger release of neurotransmitters from nerves that do penetrate to the sites of interest. I also think that the use of castor oil packs applied to the skin of the abdomen, may have systemwide anti-inflammatory impact.

Garlic is the most anti-bacterial of the herbs, but most of the common herbs added to food probably affect the gut flora and shift it to a more anti-inflammatory composition. Many herbs and spices are used as topical cures for acne, because of their combined antimicrobial and anti-inflammatory qualities. Plant materials are very potent. They contain many compounds that are highly effective at low concentrations in neutralizing plant pathogens and herbivores, and so they are also very potent in their impact on the bacteria of our gut and potential on our own systems. Plants are powerful, but just because they are natural does not mean that they are safe. Plants are also rich sources of poisons. Domesticated plants are safer, because we have selected for variants that have lower levels of the compounds that the plants need to otherwise protect themselves. This also means that the compromised varieties need to be sprayed with antibiotics, e.g. apple trees sprayed with streptomycin, fungicides and herbicides. We have traded one group of plant toxins for manmade toxins. All this aside, plants are necessary for our health, but it is better to browse over many different plants than eat a lot of just one. Grains are a relatively recent addition as large components of the human diet, and should also be limited because of their high starch and inflammatory omega-6 oil content.

Turmeric, red pepper and black pepper are commonly ground together and used to enhance many dishes in a variety of different cuisines. It turns out that the curcumin in turmeric and the capsaicin in red pepper are very potent anti-inflammatory agents, but they are enzymatically modified as they are absorbed through the intestines. The black pepper piperine inactivates the enzymes of the intestines and enhances the effectiveness of the other two chemicals. Thus, there has been a lot of trial and error optimization in the use of spices. It makes a lot of sense to eat the way that locals eat when traveling.