Dairy

food

Nutrition experts tell us that milk products are rich sources of calcium and protein for growing strong bones and healthy teeth, but common sense tells us that milk is designed to grow baby cows, not people. Have we outsmarted Mother Nature by hijacking this bovine beverage for our own purposes? How does cow’s milk impact human health?

Dairy Basics

INGREDIENTS:

Milk sugar
Milk proteins
Milk fats
Minerals
Hormones

Dairy products such as milk, yogurt, cheese and cream—any foods made from the milk of other mammals—are a versatile and beloved staple food of the American diet. Dairy products were not part of the human diet until about 10,000 years ago, when livestock were first domesticated and we are told that these foods are essential to a healthy diet; yet, for 2 million years humans and pre-humans thrived without eating any dairy foods at all. We are told that the high levels of calcium in milk are important for the formation of strong bones and healthy teeth. Dairy products are also an inexpensive source of high quality protein. How could a food that our ancestors lived without for so long be considered essential to our health today? Were we designed to require the milk of another species for our own growth and development? Or have we outsmarted Mother Nature and found a way to be healthier than our ancestors by adding dairy to our diets?

Many people have trouble processing dairy foods, and most don’t even realize it. Since most of us in the West have been consuming dairy products every single day since we were very young, we may not make the connection between our symptoms and dairy foods. Some of the most common problems that can be caused by dairy include digestive disorders, asthma, upper respiratory tract infections, muscle and joint pains, urinary tract irritation, migraine, acne and eczema.

When we talk about milk, we are usually referring to cow’s milk. Cow’s milk is a complicated and highly specialized food designed to nourish and grow a baby cow. Therefore, it contains all kinds of interesting things—basic nutritional building blocks like proteins, fats, and carbohydrates, as well as minerals, vitamins, antibodies, growth factors, and other substances to stimulate the development of the little cow. The quality and amount of each of these components varies greatly, depending on the type of cow, how she is raised, and what she is fed. Let’s break milk down into its many parts to see what we are actually getting.

MILK SUGAR:  Lactose and Lactose Intolerance

What is lactose?

Lactose is the type of sugar found in all kinds of mammal milk—from human breast milk to cow’s milk to camel’s milk—the lactose is exactly the same. Lactose is a low glycemic index carbohydrate. Each lactose molecule is made of two individual sugar molecules–one glucose molecule linked to one galactose molecule. We can absorb glucose and galactose easily, but we can’t absorb them when they are linked together as lactose. So, when we are babies, and dependent on mother’s milk, we have a special enzyme in our intestines called lactase, which breaks the link and frees up the glucose and galactose, so that we can absorb them. Lactase is like a little pair of chemical scissors that cuts the lactose in half.

What is lactose intolerance?

If you ask me, lactose intolerance is not a medical problem; it’s simply a sign that you’ve grown up.

Between the ages of two and five, most humans lose most or all of their ability to produce lactase, so most of us are lactose intolerant to some degree. Before agriculture was born (at most 10,000 years ago), all humans naturally lost the ability to digest milk in early childhood, after weaning from breast milk. So, all of our hunter-gatherer ancestors were lactose intolerant. However, once people started eating dairy products regularly, a genetic shift occurred that allowed some people to keep the ability to digest milk into their adult years. These people are called “lactase persistent.” They essentially evolved the ability to digest milk over time. However, most of us still lose that ability, so by the time we are in grade school, we lack enough of the lactase enzyme to properly digest lactose. Without lactase, the lactose can’t be broken down and absorbed, so it continues on down the gastrointestinal tract, until it eventually encounters intestinal bacteria, who very much enjoy dining upon it. Unfortunately, they don’t break it into glucose and galactose for us. Instead, bacteria ferment the lactose, releasing lactic acid and gases in the process. Not only will these gases make you unpopular at parties, but they can cause you significant bloating, pain, and/or diarrhea, as well.

How common is lactose intolerance?

Approximately 75% of the world’s population is lactose intolerant, with the prevalence varying depending on ethnic background. Rates in Asia approach 100%. It is hard to know exactly how many Americans are lactose intolerant, but estimates suggest that approximately 15% of Caucasian Americans, 53% of Hispanic Americans, and 80% of African Americans may have lactose intolerance. Studies show that lactose intolerance may be a matter of degree for some people. If you are 100% lactose intolerant, you don’t make any lactase at all, while “lactose tolerant” people make enough lactase to digest about 92% of all the lactose they eat. But there are some people in the middle, who make a small amount of lactase. These people can get away with eating small amounts of dairy foods, but if they eat too much, they won’t have enough lactase to digest it, so they will get symptoms of lactose intolerance. Everyone’s tolerance is different. Even most people who test positive for lactose intolerance can get away with drinking up to a cup of milk per day without any significant symptoms.

How do I know if I am lactose intolerant?

If dairy products bother you, you can ask your doctor for a lactose intolerance test. If you are lactose intolerant, the lactose you eat will make it all the way down to your colon, where the bacteria ferment it and create hydrogen gas. This gas passes into your bloodstream, then into your lungs, and comes out in your breath. In the lactose tolerance test, you will be given some lactose, and then your breath will be tested for hydrogen gas. If you breathe out hydrogen gas after eating lactose, you are lactose intolerant. If dairy products bother you and your test result is negative, then you don’t have lactose intolerance, but you probably have trouble with other ingredients in dairy products, most likely milk protein (see below).

If I’m lactose intolerant, do I have to give up all dairy products?

As far as we know, lactose intolerance is not dangerous to your health. If you have lactose intolerance, there may still be ways for you to comfortably enjoy dairy products. There are many dairy products which contain little to no lactose. These include heavy cream (not half-and-half), sour cream, most hard cheeses (the bacteria used to age cheeses eat all the lactose), butter, and ghee (clarified butter). Read the product label; since all of the carbohydrates in dairy products are lactose, the higher the carbohydrate gram count, the higher the lactose content. If the carbohydrate content is 0 grams, then the product is virtually lactose-free. If you wish to eat foods that contain lactose, you may want to try an over-the-counter lactase product like “Lact-Aid®”, to help you digest lactose. Lactose-reduced milks are available, as well. Consuming dairy products with meals can also help to reduce the risk of uncomfortable symptoms.

MILK PROTEINS:  Casein and Whey

Remember Little Miss Muffett–the chick who sat on her tuffett, eating her curds and whey?

Well, she must have let her milk sit out too long and curdle. If you let milk curdle, what you get are curds (like the lumps in cottage cheese) and whey (the watery stuff that floats to the top). These are the two main protein groups in milk—the curds are made of casein proteins and the whey contains whey proteins. Curdling separates out these two groups into the clumpy caseins and the watery wheys.

Caseins

The casein portion of milk is protein-rich and contains most of milk’s calcium. Caseins are very sticky and clump together (casein has historically been used as the active ingredient in wood glue). Caseins are actually designed to form a clot in the stomach. Why in the world would a newborn want a lump of protein in its stomach? It’s ingenious, really—if the proteins don’t stick together, they get rapidly digested and absorbed. Digestive enzymes take longer to chew their way into the middle of the clump; casein is essentially an extended-release source of protein that is gradually broken down over a number of hours, rather than all at once.

Caseins are very difficult to digest compared to wheys, and cow’s milk contains a LOT more casein than human breast milk. Cow’s milk contains 3 to 4 times as much protein per cup compared to human breast milk because—hello—it’s designed to grow a baby cow, which is SO much bigger than a baby human and grows a LOT faster. A newborn calf can weigh between 40 and 100 pounds, depending on the breed, and gains about 1-1/2 pounds per day, so it needs a LOT more protein. Also, the ratio of caseins to wheys is very different in cow’s milk vs. human milk:

Cow’s milk protein ratio: 80% caseins and 20% wheys

Human milk protein ratio: 40% caseins and 60% wheys*

So, cow’s milk contains approximately 6 times more casein per cup than human breast milk does. How does the baby cow handle all of that sticky casein?

Well, first of all, a baby cow has a completely different digestive system than a baby human does. Not only does a baby cow have FOUR stomachs, the baby cow also has a special enzyme in one of its stomachs called rennet. This enzyme is designed to digest the large amount of casein in their mother’s milk. Rennet breaks up the casein clumps into digestible particles. Human babies do not have rennet.

Are cow caseins and human caseins different?

There are lots of differences between cow caseins and human caseins, but the biggest difference is that the major type of casein found in human breast milk is beta casein, and the major type found in cow’s milk is alpha S1 casein. Alpha S1 casein from cow’s milk is the most common cause of milk protein allergies. All types of mammal milk, including cow’s milk and human milk, also contain another type of casein called kappa casein, but kappa casein comes in two very different forms—a “ruminant” form (for animals with more than one stomach, like cows) and a “non-ruminant” form (for animals with only one stomach, like humans).

It is likely that these major differences between the types of proteins in cow’s milk vs. human milk, and the absence of rennet in the human digestive tract are largely responsible for the significant gastrointestinal distress that can occur in people who are sensitive to cow’s milk products.

* Milk composition varies depending on stage of breastfeeding; whey protein is very high in early stages (about 80% whey + 20% casein) and lower in later stages (about 50% whey + 50% casein).

 

Whey Proteins

Compared to caseins, whey proteins are softer, finer, much more easily digestible proteins. These proteins include lactoferrin, albumin, and lactalbumin. The whey portion also holds most of the milk’s lactose, as well as the IgA antibodies necessary to pass immune protection from mother to baby.

Human whey proteins are also different from cow whey proteins. The primary whey proteins in human milk are lactoferrin, albumin, and lactalbumin, whereas the dominant whey protein in cow’s milk is lactoglobulin.

MILK PROTEIN ALLERGY AND SENSITIVITY

True allergy symptoms

Many people who have trouble with dairy products do not have lactose intolerance; instead they have trouble with milk proteins. People with serious, true milk allergies are reacting to the proteins in the milk, not the lactose. A true (IgE-mediated) allergy will cause hives, swelling, flushing, rash, oral allergy syndrome (itching/burning in mouth/throat), and/or wheezing within 2 hours, and may require emergency treatment with epinephrine (“EpiPen®”) to avoid life-threatening anaphylactic shock. This is why people with true allergies should strictly avoid all dairy products.

How common is true milk allergy?

Cow’s milk protein allergy is the most common allergy in children, affecting 2 to 5% of children under the age of 3. Symptoms usually appear within two months or less of feeding the baby cow’s milk for the first time. The most common symptom of milk allergy in infants and young children is constipation. Other clues include: eczema, asthma, rhinitis (swollen/itchy nose and eyes), reflux, vomiting, and rectal bleeding. 10% of colic cases are due to cow’s milk protein allergy. Interestingly, if the nursing mother is consuming dairy products herself, her baby can develop an allergy to cow’s milk proteins through breastfeeding, but the risk is much lower (about 0.5%). In these uncommon cases, the mother is advised to remove dairy products from her own diet if she wishes to continue nursing her baby.

Which milk proteins cause allergy?

Any of the various proteins in milk can cause an allergy. The potentially problematic proteins in milk include casein (4 different kinds), whey, lactalbumin and lactoglobulin. Since 80% of the proteins in cow’s milk are caseins, allergy to caseins is more common than allergy to whey proteins. One type of casein—alpha-S-1 casein— is the most common culprit in true milk protein allergy sufferers.

If I’m allergic to cow’s milk, can I have sheep or goat’s milk instead?

Unfortunately, virtually 100% of those with a true cow’s milk allergy will also be allergic to sheep’s and goat’s milk, as well. Luckily, special formulas are available for babies who are allergic to cow’s milk. 80% of milk-allergic children outgrow their true milk allergy by the age of 5. However, many of these children continue to have gastrointestinal issues related to milk products many years later. [Note: those with milk protein allergy have about a 10% chance of also being allergic to soy protein, and about a 10% chance of being allergic to a protein in milk and undercooked beef called bovine serum albumin.]

How can I know whether I am truly allergic or just sensitive?

Luckily, there are several kinds of tests available for true milk allergy, but there are no reliable tests available for milk protein sensitivity, which may be even more common than true milk protein allergy. Dairy sensitivity is the cause of colic in some infants, and is a common cause of recurrent ear infections, sinus congestion, and reflux/swallowing problems in infants and young children. Like all food sensitivities, the only way to know if you or your child has milk protein sensitivity is to eliminate all dairy products from the diet for two to four weeks to see if things improve.

If I have milk protein sensitivity, do I have to avoid all dairy products?

In contrast to true allergies, sensitivities are not life-threatening, so you get to decide whether you continue to eat dairy proteins, how much, and how often. However, sensitivities can cause significant discomfort and even temporary disability in some people. If you discover that you have milk protein sensitivity, you may be able to tolerate low-protein dairy products. There are a few dairy products, which are extremely low in proteins, such as heavy cream (not half-and-half), butter, and sour cream. Read the label; if the product contains 0 grams of protein, it may not bother you. Keep in mind that 0 grams doesn’t mean that it’s guaranteed to be completely protein-free; there are often tiny amounts of proteins in these items. For example, butter is listed as having 0 grams of protein, but there is enough protein in it to bother some people. If butter bothers you, you may want to try ghee, which is clarified butter, and is virtually protein-free.

MILK FATS

Saturated Fat

Approximately 2/3 of the fat in whole milk is saturated fat; the rest of it is monounsaturated and polyunsaturated fat.

The saturated fat in milk fat is called butterfat, and is one of the most complicated mixtures of fats found in nature. The types and relative amounts of saturated fats in milk depend heavily on what the cow is eating, but the predominant saturated fatty acids in butterfat are usually: oleic acid, palmitic acid, and myristic acid.

Omega-3 Fatty Acids

The amount of omega-3 poly-unsaturated fatty acids in milk varies greatly, and depends on what the cow is fed. There are 3 essential omega-3 fatty acids: ALA, EPA, and DHA (see also FATS). Cow’s milk contains varying amounts of ALA, depending on what they eat. Grass-fed cows give milk that is higher in ALA.

Cow’s milk does not contain the other two omega-3 fatty acids, EPA or DHA. DHA is critically important for brain/retina development of the human baby’s brain, which is very different from a baby cow’s brain. Human breast milk does contain DHA, with the amount varying greatly depending on the mother’s own diet. Women eating traditional whole foods diets have much higher levels of DHA in their breast milk than women who eat a typical Western diet.

Trans Fat

You may be aware that trans fats are considered generally very unhealthy, particularly for the heart. However, the health risks associated with trans fats were connected to the trans fats found in industrially-produced hydrogenated vegetable oils. What many people don’t know is that there is a natural source of trans fats in the world— ruminant animals (animals with more than one stomach). Bacteria in the cow’s digestive tract turn unsaturated fatty acids, such as linoleic acid and alpha-linolenic acid, into trans fatty acids. These can then be absorbed by the cow, and incorporated into the cow’s milk and meat.

There are two naturally-occurring trans fatty acids in cow’s milk: conjugated linoleic acid (CLA) and vaccenic acid (VA). About 2-5% of the fat in dairy products consists of these natural trans fats. One cup of standard whole milk contains about 0.2 grams of trans fat. Note: pastured/grass-fed milk contains about twice as much CLA as grain-fed milk does.


Are the natural trans fats in dairy products unhealthy?

Ironically, the reason why there has been so much interest in these fats, particularly CLA, is because there have been numerous studies suggesting that CLA may have health benefits, namely anti-cancer properties in laboratory animals. There have been no human studies that have clarified this relationship, so we currently do not know if CLA has anti-cancer properties in people. Because industrial trans fats were determined to be associated strongly with heart disease risk, it makes sense to wonder whether dairy trans fats such as CLA may be bad for the heart. So far, the studies have been very mixed, and there is no conclusion yet one way or the other. Luckily, the amount of CLA that people take in from dairy products is quite small, so it may not matter whether it is good or bad for us. There are too few studies of VA to understand how it affects us. Not only that, even though we humans can’t make trans fatty acids from scratch, we are capable of converting some of the VA we eat to CLA, so whatever effects VA might have on us might be partly due to CLA. It’s complicated.

CALCIUM and bone health

Cow’s milk contains about 1 gram of calcium per liter, about 4 times as much as human breast milk. There is nothing special about the calcium in milk; it is just as easily absorbed as other forms of calcium from other sources.  People eating a typical Western diet absorb only about 40% of the calcium they consume.

We are taught that milk is essential for the growth and health of children, especially for nurturing strong bones, because it is such a good source of calcium. Yet, despite the fact that Americans eat more dairy products than people in most other countries, we still have a much higher rate of osteoporosis than many other countries. Osteoporosis seems to follow a similar worldwide pattern to many other “diseases of Western civilization.” While we are not yet entirely sure what it is about the Western diet or lifestyle that is responsible for increased risk for osteoporosis in Western countries such as the U.S., as you will see below, it does not seem to be related to lack of calcium or dairy products in our diets.

We are not generally asked to consider the other elements of our diet that are important to bone strength. Some other considerations include:

  • Vitamin D, which is critical to our ability to use calcium to build bone
  • Plant food anti-nutrients, such as phytic acid and oxalates, which interfere with calcium absorption
  • Refined carbohydrates (there they are again…), which raise cortisol levels, setting the stage for bone loss

Do dairy products strengthen our bones?

In a large epidemiological study that followed post-menopausal women for 18 years (Feskanich 2003), it appeared as if Vitamin D, NOT calcium or dairy products, was associated with reduced risk for hip fractures. Milk itself is not a significant source of Vitamin D. Most milk in the US has been fortified with Vitamin D since 1933.

Recent examination of the epidemiological evidence (Bischoff 2011) found no association between milk intake and protection from hip fractures in women, even in women who drank 3-4 glasses of milk per day. There was not enough data to come to a conclusion in men.

A thorough review of all available studies done in children and adolescents found that calcium intake and dairy intake did not improve bone density:

“Currently, available evidence does not support nutrition guidelines focused specifically on increasing milk or other dairy product intake for promoting child and adolescent bone mineralization.” [Lanou 2005]

 

A 2007 analysis of the best available studies of adults, including a handful of randomized controlled trials, found that neither calcium supplements nor dairy products reduced the risk of hip fractures in men or women. In fact, calcium supplements were associated with a 64% increase in risk for hip fracture. [Bischoff-Ferrari 2007]

MILK HORMONES

How does cow’s milk grow a cow, and why should you care?

Job number one of all mammal milks is to make baby mammals GROW. To grow, you need proteins, fats, and carbohydrates to build body parts, and milk has all of those ingredients. However, just pouring ingredients into an animal doesn’t cause growth unless the hormonal conditions are just right. Think about it this way: you can pour all the food you want into a 45 year old woman but she will NOT get any taller.

How does the body know what to do with all the nutrients you are pouring into it? Should the nutrients be stored for later use? Burned for energy? Or turned into new cells? What types of cells? Bone? Muscle? Liver? All of these decisions are made by HORMONES. So, Mother Nature not only gave milk all the ingredients needed for growth, she also included the directions about how to grow, when to grow, and what parts should grow. These directions come in the form of hormones called growth factors. As we digest the caseins and whey proteins in cow’s milk, they are broken down into growth factors that send signals to our body. Please note that I am not referring here to added bovine growth hormone (added BGH). I am referring to the naturally-occurring hormones in cow’s milk that are supposed to be there for the sake of the baby cow. This is why no milk can ever be labeled “free of growth hormone”—all cow’s milk, even from the healthiest, most humanely-treated, organically-raised, grass-fed cow, contains growth hormones.

Does cow’s milk affect human hormones?

Whey proteins in milk cause our insulin levels to rise. In fact, milk (which has a low glycemic index and therefore doesn’t cause our blood sugar to spike); causes our insulin levels to rise more than pure sugar does. I know that most of us think of insulin simply as the hormone that keeps our blood sugar in check, but this is really not its primary purpose. Insulin is the mother of all growth hormones; it is intimately involved with all aspects of growth (see: Carbohydrates).

Whey proteins in milk also signal our body’s Growth Hormone (or GH; also known as somatotropin) levels to rise. GH is critical for growing taller.

Casein proteins in milk tell our body’s IGF-1 levels to rise by as much as 30%. IGF-1 stands for “Insulin-like Growth Factor-1.” Cow’s milk also contains some IGF-1, which is identical to human IGF-1, but we are not sure if cow IGF-1 is absorbed by people.

GH and IGF-1 work together to grow longer bones and larger organs. They tell cells to multiply. Humans produce this same combination of hormones during puberty, which is why teenagers go through a dramatic growth spurt.

Cow’s milk also contains the pre-hormone 5-alpha-pregnanedione, which can be converted into dihydrotestosterone. Dihydrotestosterone is associated with risk for prostate cancer as well as breast cancer.

Does cow’s milk make children grow more or mature faster?

All of these special signaling hormones in milk are designed to make a baby cow grow bigger, so it makes perfect sense that cow’s milk might also contribute to the growth of children. Let’s see what the research says.

A number of epidemiological studies find an association between how much milk pregnant women drink and how much their babies weigh at time of delivery, but again, it is hard to be certain that milk itself was the only reason for higher birth weights. IGF-1 in mother’s blood, whether it is her own IGF-1 or whether she absorbed it from cow’s milk, cannot cross the placenta. However, IGF-1 may have effects on the placenta itself, which can in turn affect how babies grow.

A number of epidemiological studies have found that children between 2 and 5 years old who drink more milk tend to be taller. Studies of older children and teenagers are not as well-designed overall, and the results are very mixed. We do know is that it is probably not the calcium in the milk that is making children grow faster or taller, because intervention studies (better able to show cause and effect) do not find any connection between how much calcium children get and how much they grow.

Studies to date do not find any association between milk intake and age of menarche (first menses) in girls.

So, milk may contribute to the growth of children, and if this is true, we are told that it is a good thing. But is it? We know we are supposed to drink human breast milk early in life, and that human breast milk is designed especially for our growth needs. The problem is that we are only supposed to be receiving this special growth-promoting drink when we are babies and need to grow a LOT, very quickly. Should we be drinking cow growth formula every day of our lives? What might you logically expect to happen if your body is being forced into growth mode all the time, when it shouldn’t be? Is there such a thing as bad growth?

Dairy products and cancer risk

Well, sure—cancer is, hands down, the scariest form of growth, and IGF-1in particular is famous not only for promoting the growth of normal cells; it is also infamous for promoting the growth of cancer cells.

Some epidemiological studies in adults show an association between dairy products and increased risk for prostate cancer, while other epidemiological studies suggest that milk may reduce the risk for colon and bladder cancer in adults. Now, remember that epidemiological studies cannot prove cause and effect, and therefore cannot prove that drinking more milk is the reason for any of these confusing associations. The same is true for the studies cited above that show an association between dairy products and height. These are just observations. It could be instead that the people studied ate more calories, or more carbohydrate, or fat or protein, and that’s why they grew taller, or got cancer. Cancer is a very complicated disease, and dairy products are a very complicated group of foods. It is nearly impossible to tease out any real connection between these two things in epidemiological studies.

Therefore, it is not surprising that two very recent reviews of all pertinent studies of dairy products and cancer risk both concluded that there is not enough evidence to say whether dairy products increase or decrease the risk of various types of cancer.

Dairy products and body weight

Since milk stimulates insulin spikes, it would make sense to wonder whether milk increases our risk of obesity and the many other health problems associated with hyperinsulinemia (high insulin levels). See also: Carbohydrates.

You may have heard commercials claiming that people who eat dairy products tend to weigh less. Unfortunately, it seems not to be true:

“Of 49 randomized trials assessing the effect of dairy products or calcium supplementation on body weight, 41 showed no effect, two demonstrated weight gain, one showed a lower rate of gain, and five showed weight loss…Consequently, the majority of the current evidence from clinical trials does not support the hypothesis that calcium or dairy consumption aids in weight or fat loss.” [Lanou and Bernard 2008]

 

MISCELLANEOUS BIOACTIVE PEPTIDES IN MILK

Proteins in cow’s milk and human milk break down during digestion into smaller pieces called “peptides”, some of which have special biological functions.

Peptides with opioid (narcotic) properties

Some milk peptides have natural opioid properties; opioids you may be familiar with include narcotic medications such as morphine and codeine.

So, do milk opioids act like narcotics in our bodies? The natural opioids present in milk are apparently very weak, and may only have effects on the lining of the digestive tract, since it is unclear if they can be absorbed into the bloodstream, let alone cross the blood-brain barrier and make it into the brain. As you may know, opioids act to slow down the activity of the gastrointestinal tract (which is why narcotics tend to cause constipation), so it is possible that some sensitive people may experience this as a side effect of milk products. Some people point to the fact that there are opioid peptides in milk to support the notion that dairy products are addictive and sedating; however, there are no human studies to help us understand the role that these opioids play in our bodies.

Do dairy products cause acne?

Acne is a disease of Western civilization, in that it is not found in peoples who eat a traditional whole foods diet. This pattern strongly suggests a dietary cause.

In the past 5 years, researchers have begun conducting studies that are shedding light on the diet-acne connection. Two main dietary suspects are emerging from these early studies: dairy products and refined carbohydrates.

The whey portion of milk contains a growth factor called betacellulin. This growth factor binds to something called the Epidermal Growth Factor Receptor (EGFR), which stimulates the pilosebaceous unit (the follicle) to overproduce sebum (mixture of natural skin oils and skin cells), which can lead to acne lesions.

The whey portion of milk stimulates insulin and IGF-1 production, and these in turn can stimulate acne formation. High glycemic index and refined carbohydrates also stimulate insulin secretion.

Interestingly, low-fat dairy products contain much more whey protein than full-fat dairy products, so low-fat dairy products are more powerful triggers of risky insulin spikes than full-fat dairy products.  The less fat a dairy product contains, the more whey protein it tends to contain.  Therefore, non-fat dairy products contain the highest percentage of whey proteins.  Since non-fat dairy products and refined carbohydrates both trigger insulin spikes, the worst case scenario would then be a non-fat yogurt with added sugar, or a sweetened skim milk product (such as non-fat chocolate milk).  Some people believe that chocolate cause acne breakouts.  Plain milk chocolate has not been properly studied yet, but it would make sense that this food, which contains both milk proteins and sugar, might contribute to acne.

We still need more studies to clarify these connections. While there have been a number of human clinical studies, we need larger, randomized, properly-controlled clinical trials that look specifically at these suspects.

Does milk cause iron deficiency anemia?

In babies less than 12 months old, cow’s milk increases the risk of iron deficiency. There are several theories about why this is. One theory is that the proteins in cow’s milk interfere with the absorption of iron from the baby’s intestines. Another theory is that, in about 40% of babies, cow’s milk causes microscopic bleeding from the baby’s digestive tract, and since blood contains iron, the baby loses a little bit of iron every day. This is one of the reasons why parents in the U.S. are advised not to feed cow’s milk to babies under one year of age.

Does milk increase mucus production in the sinuses, throat, or lungs?

Many people believe this to be true (this is why choral directors and voice coaches often advise singers to avoid dairy products prior to performances), but there have been no studies yet that can confirm or deny this belief. If you suspect this is true for you, remove dairy products from your diet for two weeks to see it makes a difference.

BOTTOM LINE ABOUT DAIRY PRODUCTS:

Milk is not necessary for human life or health, and is therefore optional.

Babies under one year of age should not drink milk because it increases their risk of iron-deficiency anemia.

Mothers who drink milk during pregnancy are more likely to have larger babies

Children under 5 who drink more milk tend to be taller, but this is not due to the calcium in milk.

Dairy products do not strengthen children’s bones.

Adults who drink milk do not have a lower risk of osteoporosis.

Milk whey proteins raise our levels of insulin and other growth hormones, which may increase our risk for a variety of health problems.
Many people are sensitive to or allergic to dairy products and feel better when they avoid them. Areas affected tend to be the gastrointestinal tract, skin, and upper respiratory tract. The most common problems include:

    • lactose intolerance
    • constipation
    • reflux
    • sinus congestion
    • recurrent upper respiratory tract infections
    • asthma
    • acne
    • eczema
    • severe constipation, especially in children under 3 yrs of age

My opinion about dairy products:

There is plenty of strong evidence that dairy products can cause health problems and no good evidence that dairy products are beneficial to health, therefore, eating them for health reasons doesn’t make sense to me.

As with most foods, if you enjoy them, and they don’t seem to bother you, then you may choose to include them in your diet. However, the only way to know if they bother you is to remove them from your diet for several weeks (I would recommend one month) and see how you feel without them. If you choose to eat them, just be aware of the potential risks involved.

Since the most troublesome ingredients in dairy products are 1) milk proteins and 2) lactose, I would recommend choosing full-fat dairy products, since these are lower in proteins and lactose than low-fat versions, are more satisfying (therefore you may eat less of them), and they taste better to many people.

References

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Benhamou A et al. An overview of cow’s milk allergy in children. wiss Med Wkly 2009; 139(21-22): 300-307.
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  • Des

    Hi Dr. Ede, if I eat mostly meat and avoid dark leafy green vegetables, should I be concerned about calcium deficiency?

    • http://diagnosisdiet.com/ Dr. Ede

      True calcium deficiency is rare, because blood calcium concentrations are maintained at the expense of bone calcium. However, to the best of my knowledge, the current calcium requirements are falsely elevated (determined by balance studies), and there should be adequate calcium in an all-meat diet. Osteoporosis is not a disease of calcium deficiency anyway, and that is the disease that leads public health officials to worry about calcium.

      • Des

        Thank you

    • Alicia

      I read somewhere, I think Chris Masterjohn, that Inuits (not much veggie food) can get serious calcium deficiency if they go too long without, basically, sardines. Why not add some small whole fish to your diet, for peace of mind? I’m semi paleo myself, so I certainly don’t think there is anything wrong with meat, but any kind of mono-diet is probably not going to serve you well, including one of mammal muscle, or even mammal muscle and organ meats. What I understand of the Weston A Price research, there weren’t any of his conspicuously healthy cultures eating nothing but mammal meat/organs. Even the ones that ate mostly mammal were also eating some fish or plant food as supplement. My guess is there’s a reason for that.

      • http://diagnosisdiet.com/ Dr. Ede

        Hi Alicia

        If you can locate the source of the calcium deficiency claim I would be happy to read it and comment on it. I do eat some fish, including some small fish with bones sometimes.

  • Des

    Good morning Dr. Ede, what’s your take on probiotics? People in the Paleo community like Chris Kresser , Mark Sisson, Robb Wolf and the like talk about the importance of healing the gut with probiotics such as kefir, yogurt, saurkraut, kimchi, kombucha and the like-

    • http://diagnosisdiet.com/ Dr. Ede

      I have not yet fully reviewed the literature myself, and do plan to do so (another thing on the very long to-do list), however, I am suspicious of this theory, because 1. The single most important determinant of the types of gut bacteria we house is our diet, not what kinds of bacteria we eat. You can eat all the “good” bacteria you want, but if you’re not feeding them what they want to eat, they will not hang around. 2. My understanding from listening to a recent NPR news item about probiotics is that there is little/no evidence to support their use. 3. All of my own GI issues went completely away without any probiotics, using dietary strategies alone. 4, What reading I have already done has not clarified anything, only made things more confusing–always a bad sign.

      • Des

        Hi Dr. Ede, but if we’re mostly eating meat, is that enough “food” for gut bacteria to stick around?

        • http://diagnosisdiet.com/ Dr. Ede

          I don’t know enough about this topic yet to comment. Will be covered when probiotics are covered.

    • Des

      Wow. So, everything I thought I knew about dairy, nuts/seeds, veggies and fruit is backwards. I am so relieved that I can walk into my organic butcher, pick up the essentials, grab some “dessert-like treats” like a bunch of bananas once in a while ((hey, life’s about enjoyment!) and call it a day. I can’t tell you how anxious I use to get about grocery shopping. Here’s what it use to look like, three times a week: I would grab a huge cart and proceed directly to the produce isle ( because veggies and fruits are essential, right??). I would load up on organic kale, broccoli, Swiss chard, spinach, avocados and fruits. The whole time I’m anxious: were these fruits and veggies sprayed with chemicals? Are they truly organic? Should I be buying local? I need more beta carotene (as I grab 20 carrots). So then I walk over to the dairy section reading every label to try to fine a good probiotic ( because probiotics are essential, right??). To my disappointment, I can’t find anything raw because it’s illegal in Canada, I think. But pastured dairy doesn’t contain all the beneficial bacteria to help my gut flora…I get depressed. And what full fat, they don’t often make full fat kefir. I settle for a 2% milk kefir and walk away. So now I feel I need some ” healthy snacks.” so I go down to the nut section to try to find the least offensive nut. Almonds..cashews…these nuts contain too much omega 6. Crap. Maybe I should forget the nuts. I reach for the macademias to feel better. Weird how food can have that effect on us. Guilt. I’m finally done my shopping. Luckily I’m Paleo, so no need to stress about cereals and grains. But I should grab some saurkraut , in case the kefir isn’t enough food for my intestines.

      • http://diagnosisdiet.com/ Dr. Ede

        Too funny:) I like to believe that good nutrition is actually very simple. We are the only animals on the planet who agonize over these things–sometimes we are too smart for our own good!

        • Des

          And how!

  • Des

    Continue…

    Finally I make my way to my organic butcher. I feel at ease. I grab some pastured eggs, ground bison, ghee, liver, duck fat, smoked salmon and chorizo to snack on my way home. I’m in and out in about 4 minutes.

    I’m not saying I will never eat a piece of fruit, or a vegetable ever again. What I’m saying is, I feel free!

    Thanks Dr. Ede

    • http://diagnosisdiet.com/ Dr. Ede

      Cool–that’s a wonderful way of thinking about it. Thanks for the questions you’ve sent and your story, and I’ll keep slogging away until I have found better answers to them. Enjoy!

      • Des

        Thanks! I know you have a long to-do list, but I will appreciate any new updates. I’m interested in your blog because I’ve got my brother on a strict no veg diet to cure his SIBO. So far, he has been feeling great (other than a mild stomach upset from eating too much pâté). I’ll keep the community posted on his path to recovery.

  • http://www.facebook.com/snooptaco Elaine Shields

    Hi Dr. Ede,

    So if heavy cream is low in lactose and low in casein, why does it hurt my stomach when no other form of dairy seems to? I’ve always been able to enjoy dairy without it causing G.I. discomfort, with the exception of heavy cream. Just curious!

    • Leaf Eating Carnivore

      Most “Heavy Cream” is actually an ultrapasturised (long lived) mix of cream, milk, and carrageenen (seaweed extract) added to make it thick and stable – and cheaper to produce. Your distress may stem from the processing and/or those latter fractions. Given your tolerance of other dairy, I would suspect the latter, especially since I have read similar complaints.

      Always read the labels.

      Also, you might want to go to Dr. Mercola’s site and read his recent post on what the FDA is currently allowing, and is proposing to allow, in dairy products, without labeling. Furthermore, some of the so-called big chain “Organic” dairy suppliers have been on occasion been fingered for using CrapMilk.

      Organic Valley does produce a pasturised but unadulterated and pastured heavy cream. And I seem to remember someone mentioning that Trader Joe’s might have a similar product.

    • http://diagnosisdiet.com/ Dr. Ede

      Hi Elaine
      In addition to LEC’s info below, all I can add is that if you continue to experience stomach pain even with pure heavy cream (Trader Joe’s sells heavy cream without any additives), then you may simply need to avoid it to feel weel. I just did a literature search to see if I could find information about the actual components of heavy cream–in particular I was interested in hormone concentrations) but was not able to find any information to help you understand what you may be reacting to. The types and ratios of fats in dairy products are unique and you may be having difficulty with the cream fats themselves? We are each different and have to do our own experiments. I wish I could be more helpful…

  • http://diagnosisdiet.com/ Dr. Ede

    Hi Elaine

    Interesting question. Dairy foods are incredibly complex and contain a variety of compounds which we are not designed to handle. You may be having trouble digesting the types of fats in cream, for example, and/or there could be hormones or other factors that are within the fatty fraction of milk which are affecting your system in some way. Maybe you are especially sensitive to the small amounts of protein that do exist in cream? I wish I had a better answer for you…

    • http://www.facebook.com/snooptaco Elaine Shields

      Okay thanks for the explanation. Perhaps it’s just too much of a good thing!

  • Elaine

    Hi Dr. Ede,

    I did an experiment with dairy about 3 weeks ago after not having any for about a month. (Previously I was only limiting it.) Even after a month had passed, I still had cravings! I started with a serving of organic full- fat yogurt, and my reaction to it was so extreme. While I didn’t get even a headache, my cravings were overwhelming and I went to get more yogurt within a few hours. After a few days of basically binging on yogurt, the other side effects became severe enough that I was forced to stop eating it, despite the cravings being so intense. It made me feel incredibly sedated, as well, as if I had been drugged. I was just laying around, unable to do anything, stuffing my face with more dairy. It was ridiculous. I also had some abdominal distress, and then days after consuming the dairy I developed eczema across my back and down both of my arms. I also developed some acne, asthma, and insomnia, all of which lasted for several days.

    It took me cutting dairy out in order to really tell how badly my body reacts to it! I thought I would share in case there is anyone out there who is debating eliminating it. I still don’t know which “part” of dairy I’m reacting to it, but I don’t really care…I think it’s safe to say it is not a healthy food for me to consume.

    The worst symptoms I experienced were the sedation/foggy brain/intense cravings, so I am very interested in learning more about the opioid properties of milk. Is if possible to have a “leaky” blood-brain barrier or something? Or am I just super sensitive to the weak level of opioids found in milk?

  • http://www.facebook.com/snooptaco Elaine Shields

    Hi Dr. Ede,

    I did an experiment with dairy about 3 weeks ago after not having any for about a month. (Previously I was only limiting it.) Even after a month had passed, I still had cravings! I started with a serving of organic full- fat yogurt, and my reaction to it was so extreme. While I didn’t get even a headache, my cravings were overwhelming and I went to get more yogurt within a few hours. After a few days of basically binging on yogurt, the other side effects became severe enough that I was forced to stop eating it, despite the cravings being so intense. It made me feel incredibly sedated, as well, as if I had been drugged. I was just laying around, unable to do anything, stuffing my face with more dairy. It was ridiculous. I also had some abdominal distress, and then days after consuming the dairy I developed eczema across my back and down both of my arms. I also developed some acne, asthma, and insomnia, all of which lasted for several days.

    It took me cutting dairy out in order to really tell how badly my body reacts to it! I thought I would share in case there is anyone out there who is debating eliminating it. I still don’t know which “part” of dairy I’m reacting to it, but I don’t really care…I think it’s safe to say it is not a healthy food for me to consume.

    The worst symptoms I experienced were the sedation/foggy brain/intense cravings, so I am very interested in learning more about the opioid properties of milk. Is if possible to have a “leaky” blood-brain barrier or something? Or am I just super sensitive to the weak level of opioids found in milk?

    • http://diagnosisdiet.com/ Dr. Ede

      Hi Elaine
      Again, thank you so much for sharing your valuable experiences with us here. I will be looking more closely at dairy soon, too–I am suspicious that the fat fraction of dairy may contain substances that throw some people out of ketosis (by raising insulin levels), or cause cravings or weight gain in sensitive individuals. I personally can relate to your dairy issues, as I have nearly identical responses to dairy foods. Among my patients with binge eating, the only food groups they ever binge on are carbohydrates and/or dairy products. Rather telling in and of itself…

      • http://www.facebook.com/snooptaco Elaine Shields

        That is definitely telling! I forgot to mention I gained FIVE pounds in those two days. No idea if it threw me out of ketosis because I wasn’t testing then, but that certainly corresponds.

        • Laura Sprague

          I am glad I stumbled upon your post. I too was addicted to yogurt. Yogurt took the place of ice cream. I can never get enough yogurt or ice cream. I have taken ALL dairy out of my diet. Lost 7 pounds in one week. Now I am waiting to see if any other symptoms disappear like the rashes I get on my face, the itchy scalp. Oh, and my hot flashes have reduced by about 95%.

  • james

    Hello Dr Ede,

    I just started browsing your blog and I love it :)
    I am about to start a 2 months experiment where I remove all dairy (except ghee and butter) and plant foods. I’ll keep you posted.

    Cheers!
    James

    • http://diagnosisdiet.com/ Dr. Ede

      Hi James

      I’m so glad to hear that! I will be on the edge of my seat, eagerly awaiting your dairy report:)

      Cheers to you!

  • Gregg Sheehan

    Your blog IS meat. You put the essential facts needed for our intellectual growth in front of us in a readily digestible form. All my life (59 years) I’ve been refusing to listen to people telling me that the meats I love to eat are bad for me, or the full cream I enjoy with my desserts is somehow bad for me. I’ve consistently avoided foods advertised as “low-fat”.

    In the last two months my wife and I have each lost 8kg, primarily because I’ve cut a lot of sugar and carbs out of our diet and concentrated on higher fat content. We are probably each within 5-10kg of our ideal weight now and although I’ve only recently found your blog, it has helped me understand food science better and will pave the way for me to maintain our newer healthy frames. It has given me an easy “go to” website to which I can send the people interested in what we are doing in order to make their own discoveries.

    Up until now my eyes have glazed over when trying to digest the sort of facts that you present. The way in which you do present your information makes it very easy to understand and assimilate.

    Thanks very much from a Kiwi.

    • http://diagnosisdiet.com/ Dr. Ede

      Dear Kiwi Gregg
      Sounds like you and your wife are doing great! Congratulations! Thank you for your very kind words about the website. I am so glad that you and your mates are finding it useful:)

      • Gregg Sheehan

        It is nearly 1am here and I’m still reading your site. ;-)

  • Anna

    Is your opinion of raw milk the same? Raw milk is generally believed to be less harmful and easier to digest. I do notice some constipation from drink a large amount of raw milk, but no other symptoms, I usually find it very nourishing and filling.

    • Karien

      That would be my question also! I just read the book of Ramiel Nagel about curing tooth decay, and read a lot about Weston Price. Raw milk seems to be very different from store-bought milk, especially for our bodies.
      Karien from The Netherlands

  • pleaseletsfixthis

    I question whether these results are different for people with different genetic backgrounds. For example, fair-skinned people of Northern European descent have low rates of lactose intolerance and absorb more Vit. D from the sun in winter especially in northern climates, which is why they test differently on the metrics of lactose intolerance and Vit. D deficiency than people with genetic ancestry nearer the equator. They also have higher rates of osteoporisis, which may suggest that they are being given bad information in these agendas to stop dairy consumption (i.e. they may actually need the nutrients in dairy more than those of other genetic backgrounds because their mechanism for bone nutrition evolved differently because of the long winters in the north).

    Also, “Mother Nature” is a suspect term. Nature is not female and I question whether a “scientist” using this term has some psychological distortions affecting his/her thinking clearly. It’s just “Nature”.

Last Modified: Oct 10, 2012 at 7:25am