By Ryan Andrews & Brian St. Pierre
Exploring the pros and cons of this controversial food group.
We’re often asked whether dairy is good or bad. Short answer: It depends. In this article, we’ll help you make sense of the research — and the wildly different opinions — sharing everything you need to decide if dairy is for you.
Is dairy “good” or “bad”?
For most of us, milk was our first food.
As a species, we’ve consumed dairy (in some form or another) for millennia.
For centuries, milk has been seen as “good for us”. “Milk: It Does A Body Good” was even the tagline for a series of ads in the 1980s. Google “vintage milk ads” and you’ll see that promoting milk’s health benefits has a long history.
Nowadays, people aren’t so sure. Some say milk is full of “bad” fat, unhealthy chemicals, hormones, and impossible-to-digest proteins. That it’ll harm your GI tract, cause acne, make you a mucusy mess, and increase your cancer risk.
How can you decide what’s right for you?
Good news: There’s lots of research on milk and dairy.
Bad news: It’s complicated.
That’s why, in this article, we’ll look at what research says about dairy, what it doesn’t say, and where it’s undecided. Then, based on that scientific evidence, YOU can make a choice that aligns with YOUR goals and needs.
Here’s what we’ll cover.
- What’s actually in milk?
- Are some forms of dairy healthier than others?
- What does the research really say about how dairy affects your health?
- How do farming and processing practices influence milk’s nutritional value?
- Is dairy a necessary part of a healthy diet?
- Is dairy right for you as an individual?
How to read this article.
This article is comprehensive. Like, really comprehensive; nearly 10,000 words. If you’re not that interested in a deep dive into dairy, but still want the important take-home messages, you can easily navigate as follows.
Want to know how dairy will affect your health and fitness?
- Skip to “How does dairy relate to common health concerns?”
Want to explore which types of dairy are healthiest?
- Skip to “How do dairy types differ?”
If you’re a health and fitness professional:
- Skip to “If you’re a coach with clients asking for advice on dairy:”
Want to know the bottom line and make a decision about dairy for yourself?
- Skip to “What does this mean for you?”
Let’s get to it.
All dairy is not created equal.
Let’s start with an important point:
Just as the category of “meat” includes everything from wild-caught elk to hot dogs, “dairy” is a pretty large group of foods.
In North America, most of the milk that creates our dairy products come from cows, although you might see goat and sheep milk products such as cheese and yogurt in your grocery stores.
(Goat and sheep milk products are more common elsewhere in the world. Buffalo milk mozzarella (mozzarella di bufala) has long been a staple in Italy. If you’re in rural Mongolia, you might find yak milk and butter on the table. And if you’re on the Central Asian steppes, you can enjoy the slight buzz from the alcohol in fermented horse milk.)
In its natural form, milk is a mix of water, proteins, sugars, minerals, and vitamins. Its nutrient content reflects the type of animal it comes from (Fun factoid! Seal milk is over 50% fat!) as well as what the animal was fed.
How dairy is processed — whether it becomes skim milk, cheddar cheese, ice cream, yogurt, butter, ghee, etc. — will influence the percentages of water, proteins, fats, and other nutrients in the final product. We’ll look at this more below under “How do dairy types differ?”
In some places, dairy must be pasteurized — heated to kill dangerous pathogens. In other places (such as France), dairy may be unpasteurized in some forms, such as raw milk cheese.
Here’s a quick calorie comparison of a few dairy products:
And here’s the percentage of calories from fat, protein, and carbohydrate in each source:
All people are not created equal (in their ability to tolerate dairy).
As we’ll see in a bit, whether dairy is “nutritious” (or not) is only one part of the puzzle.
People vary in their ability to digest and tolerate dairy, whether because of genetics, age, or digestive health and intestinal microbiota.
Additionally, folks may choose (or avoid) dairy depending on taste, food preferences, culture and heritage, choices about consuming animal products, sanitation, or a variety of other criteria.
So even if dairy is theoretically “good”, depending on your unique makeup, it may or may not be “good” (or the right choice) for you.
What’s in dairy?
Since the first job of milk is to nourish a growing mammal, it’s a rich source of many beneficial nutrients, including:
- fatty acids such as:
- saturated, monounsaturated, and unsaturated fats
- CLA, aka conjugated linoleic acid
- trans-palmitoleic acid, a fatty acid with diabetes-protective properties
- carbohydrates such as:
- proteins such as:
- minerals such as:
- magnesium, a mineral needed for many body processes and bone health
- phosphorus, which also plays a role in bone health
- potassium, which helps your nervous and cardiovascular systems function
- fat-soluble vitamins such as:
- vitamin A
- vitamin D
- vitamin K2, an essential vitamin for bone and cardiovascular health that also helps regulate gene expression
- B vitamins such as:
- riboflavin, which supports energy levels and a healthy metabolism
- vitamin B12, which promotes nerve and blood cell health
- iodine, which is needed to make thyroid hormone
Let’s look at a few of these.
While all fresh dairy contains a variety of fatty acids, exactly how much fat is in dairy, and what that fat is made of, can vary depending on many things:
- which animal produces the dairy;
- which breed of a given animal (such as a cow);
- the animal’s diet and grazing patterns;
- the animal’s stage of lactation;
- what season the milk was collected;
- the altitude at which the animal lived;
- the sunlight it was exposed to;
- and so on.
Since ruminants convert feed into fatty acids during digestion, an animal’s diet can drastically change the fatty acid composition of its milk.
For example, cows that are grass-fed have significantly more beneficial fatty acids than conventionally fed cows: about two to five times more conjugated linoleic acid (CLA), and about 62% more omega-3 fatty acids.
How the milk is processed (after it’s collected) will also determine fat content. The fat content in skim milk (virtually zero) is quite different from the fat content in Brie cheese or whole milk.
One of the biggest benefits of dairy is its high protein content. In cow’s milk, about 80% of that protein is from the casein family of molecules.
Casein is a slow-digesting, high-quality protein that’s often recommended for gaining muscle and losing fat. It may have antioxidant effects and immune boosting properties; it may reduce triglycerides and high blood pressure.
On the other hand, casein has been associated with lymphoma, thyroid cancer, prostate cancer, ovarian cancer, and constipation/GI distress. These are associations, though, not proven causal relationships.
A1 and A2 beta-caseinAs with fats, different breeds of animals produce different subtypes of casein molecules (notably, A1 beta-casein & A2 beta-casein). Some research suggests that the different types of molecules may have different health effects.For instance, a small amount of observational research (mostly in animals) suggests that A1 beta-casein may be involved in the development of type 1 diabetes and heart disease. There’s also some evidence that milk containing A1 beta-casein can cause bigger digestive issues compared to milk containing only A2 beta-casein.
You may have also heard that dairy is addictive thanks to something called casomorphins. As the name implies, casomorphins are opioid peptides derived from A1 beta-casein. These compounds may have mildly addictive properties and influence gut health and bowel motility.
Yet other studies don’t find any these connections between casein/casomorphins, disease, and/or addictive behaviors, especially not in humans.
In the end, if we look at the reward potential of foods, the most “addictive” foods aren’t dairy foods but highly processed foods that contain a mix of refined starch/sugar, fat, salt and other flavor/texture enhancers (e.g. pizza, chips, cookies, ice cream).
Bottom line: There isn’t enough evidence to blame type 1 diabetes, heart disease, digestive issues, or your cheese obsession on A1 beta-casein. It’s certainly more complicated than that.
Whey, the second type of protein in milk, is perhaps the most well-known protein. If you’ve ever had a protein shake, you’ve probably had whey protein powder.
While often used as a muscle-building supplement, whey protein can also:
- lower triglyceride levels
- lower blood pressure
- improve the function of our blood vessels
- improve insulin function
- improve glucose control
- sometimes (but not always) lower total cholesterol and triglycerides, and
- increase total antioxidant capacity (by increasing glutathione levels).
It may also protect our liver (or help it heal when damaged). The two main whey proteins (alpha-lactalbumin and beta-lactoglobulin) seem to improve innate immune function, and whey tends to cause fewer allergies and intolerances than casein.
There’s also some conflicting evidence about whey protein and cancer, though a lot of the research on this topic has been done in rodents or as observational research on humans.
Some evidence suggests that whey protein can prevent cancer development and inhibit tumor growth of existing cancers. Yet some evidence suggests, in some cases, that whey might accelerate the growth of existing tumors.
Overall, more research indicates anti-cancer properties than cancer-promoting properties. In addition, if well tolerated, whey protein provides a host of other potential health benefits that other proteins do not (mostly due to its high cysteine content).
For most, the known benefits of whey likely outweigh the possible risks.
Aside from playing a role in bone health, calcium also enables our muscles to contract, our blood to clot, and our nerves to transmit messages. Getting enough calcium is important, but calcium retention is even more important. (For more on that, read all about bone health.)
While dairy is an excellent source of calcium and is often the main source of calcium for people in North America, it doesn’t necessarily have to be.
In many parts of the world, cow’s milk is a very small part of the average diet, yet diseases associated with calcium deficiency (like osteoporosis) are uncommon. Instead, people get their calcium from leafy greens from the cabbage family (especially if cooked), calcium-set tofu, beans, some nuts and seeds, fish with bones, and even some seaweeds.
Interestingly, in certain cases, heavy dairy consumption can increase calcium losses. For example, when too many vitamin-A-fortified dairy products are consumed, it can weaken bones. That may be one reason not to go beyond the recommended three servings of dairy per day.
Fat-soluble vitamins: A & D
Traditionally, the milk of ruminant animals (such as cows, sheep, goats, or reindeer) eating grass and other foliage would naturally contain vitamins A and D.
With the advent of industrial agriculture and processing, as well as growing awareness of nutritional deficiencies, milk is now fortified with added vitamins A and D. This is less crucial in affluent countries like the United States or the UK, but important in poorer regions of the globe where malnutrition remains a real concern.
Yet, as with calcium, there are other ways to get these nutrients.
Sunlight is the best way to get vitamin D, but eggs, mushrooms, and fish liver also contain small amounts of vitamin D. If those aren’t enough, you can also supplement with vitamin D.
For vitamin A there are lots of options:
- Plant-based retinoids and carotenoids in plant foods like carrots, sweet potatoes, and spinach, as well as those same cabbage family leafy greens that supply a good dose of calcium (mustard greens, collard greens, turnips greens, and kale).
- Animal-based retinol (a readily absorbed form of vitamin A) in organ meats (like liver) and egg yolks.
Yes, there are hormones in milk. Even in organic milk. Let’s talk about those now.
Naturally occurring hormones
Most of the time, to produce milk, a mammal must have been pregnant. Dairy animals are thus in various stages of pregnancy and lactation, which can affect their milk’s hormone content.
For example, Pregnant cows may have hormone levels 20 to 30 times higher than milk from cows that are not pregnant and lactating.
That sounds scary, especially since higher blood levels of estrogen have been linked to some types of cancer, particularly breast cancer in women and prostate cancer in men, as well as recurrence of those cancers.
So researchers put it to the test (in mice, not humans). They gave mice 100 times more estrogen than was found in the milk of pregnant cows and it caused no increase in blood estrogen. Nothing at all. Only when the mice were given 1000 times the levels found in milk did they see a rise in blood levels of estrogen.
This is because steroid hormones are broken down by the liver after they are absorbed, which means they only increase blood levels when intake is incredibly high. (This is also why people who use steroids typically inject them rather than take them by mouth, to bypass the liver.)
While the mouse studies haven’t been replicated in humans, other human research has found no association between estrogens in milk and cancer incidence or cancer recurrence.
On the other hand, preliminary research suggests that even small increases in blood levels of estrogens and their metabolites may negatively impact the development of children during their most sensitive time periods — in the womb and around puberty. But the data here are limited.
In the end, dairy definitely has estrogens in it. Yet we don’t have convincing evidence that these estrogens enter our bloodstream or that they negatively influence health or development when consumed in milk or dairy.
Some conventional (non-organic) dairy farmers also use a hormone called bovine growth hormone (bGH) or somatotropin (bST) to increase milk production.
This, like the estrogen conversation above, has caused concern. Similarly, though, while those hormones appear in the milk, they don’t end up as hormones in humans. Instead, they’re broken down into peptides (smaller protein chunks) and never make it into our bloodstream.
In other words, your body process these hormones the same way it processes other types of protein.
In addition, these hormones have no biological activity in humans. And even if they did, they are present in minuscule amounts (about 1/1000 of a gram per liter of milk), with about 85-90% of that destroyed during pasteurization.
Hormones that we make ourselves
IGF-1 is a hormone that supports all types of growth in the body — muscle, bone, and other tissues. And consuming dairy does seem to increase IGF-1 levels in humans.
So, unlike the estrogens and growth hormones above, which are present in milk but don’t make it into the human bloodstream when we drink milk, IGF-1 is a hormone that we naturally produce, and it goes up when we drink milk.
On the one hand, growth is a good thing. For instance, if you’re building muscle (or want to keep the muscle you have) or trying to increase bone density, you may benefit from the anabolic (building) effects of IGF-1.
On the other hand, uncontrolled growth is not a good thing. Some folks worry that IGF-1 could cause cancerous tumors.
This makes sense in theory, but milk consumption produces only a small rise in IGF-1 (about 2-10% above fasting levels). And it doesn’t appear that IGF-1 is a cause of tumor development.
It’s theoretically possible that higher levels of IGF-1 help existing tumors grow more rapidly, but research here is conflicting, and is mostly correlational or done in petri dishes (which don’t reflect the complex reality of the human body).
Interestingly, some research has shown that the intake of low-fat dairy is associated with a lower risk of colorectal cancer in people with high levels of circulating IGF-1. Which does not align with the idea that milk increases IGF-1 levels, increasing cancer development.
And all protein-rich foods, plant or animal, increase levels of IGF-1. So this isn’t an issue unique to milk.
Thus: Dairy’s IGF-1 connection to cancer is not consistent or strong.
Likewise, fears that “milk’s got all those nasty hormones” isn’t a scientifically backed concern.
How do dairy types differ?
Most of us intuitively suspect that eating a container of cultured yogurt is a little different from downing a pint of ice cream. (Let’s be honest: Has anyone ever chosen a glass of skim milk to drown their sorrows after a breakup?)
Dairy types differ based on:
- their percentage of various macronutrients (fat, carbohydrates, and protein) as well as micronutrients (i.e., vitamins and minerals, specific fatty acids, etc.)
- their type of processing
- their bacterial content
- how digestible they are, and how quickly they digest
- their fluid to solid ratio
You can have everything from pretty much pure fat (ghee, which is butterfat from which the milk solids have been removed) to almost entirely protein (e.g. casein and whey protein powders).
And of course, you can have dairy to which many ingredients have been added — sugar, salt, emulsifiers, flavorings, and so forth.
For most of us, breast milk is our first food. Milk effectively delivers water and important nutrients that we need to grow.
And, for many groups of humans, milk has been an important agricultural product. If your ethnic heritage included dairy farmers, you might benefit from milk and continue to be able to digest it (if you choose to consume it).
Adding milk to a calorie-deficient diet might help to increase muscle mass, decrease body fat and improve intake of important nutrients (protein, calcium, potassium, vitamin D). Although adding milk to a non-deficient diet doesn’t seem to have nearly the same effects.
Because of its relatively high water content, milk can be an effective way to replenish fluids, electrolytes and amino acids after workouts. And, at a population level, there’s no clear link between milk consumption and any diseases or health problems.
That doesn’t mean milk will always be healthy (or unhealthy) for everyone, all the time. The evidence is mixed and probably confounded by the fact that various humans respond differently to milk.
- Some folks can tolerate and benefit from milk, and choose to drink it. Some can’t, and don’t.
- If you choose to consume milk: As with all foods, it’s probably best to have milk in moderation, noting whether it causes any symptoms and discontinuing it if it bothers you.
Yogurt, kefir, and other cultured dairy products
If milk is left unrefrigerated, naturally occurring species of bacteria will ferment it. Humans figured this out a long time ago, and now purposely encourage milk to ferment to create products such as yogurts, kefir, cultured cottage cheese, skyr, quark, and aged cheeses.
These bacterially fermented / cultured products seem to be the most health-promoting, least risky, and best-tolerated and differ substantially from uncultured dairy.
- an abundant supply of probiotic organisms (which seemingly make our gut happier and healthier)
- bioactive lipids (fats) produced by the probiotic organisms
- lower levels of lactose (since the bacteria tend to digest the sugars)
- more easily-digested protein
- higher quantities of some beneficial nutrients (like vitamin K2)
Some research that’s found increased risks with certain dairy products often finds that the reverse is true with fermented dairy, which often decreases risk.
For example: Consistent yogurt consumption (along with other cultured and fermented dairy) seems to decrease risk of type 2 diabetes, obesity, and cardiovascular disease by improving the health of our GI tract, decreasing bodily inflammation, improving insulin sensitivity and blood sugar control, improving both innate and adaptive immune function, and being a satiating food (thanks to higher protein).
The verdict: Evidence strongly suggests that cultured and fermented dairy products provide many health benefits. Include them in your diet, if you want.
Findings on cheese have been mixed, but we know one thing for sure: Type of cheese matters.
Some cheeses are bacterially fermented/cultured and aged, and contain a lot of this friendly bacteria in their final form. They have a similar healthy nutritional profile as yogurt.
Other processed cheeses (e.g. American, nacho cheese sauce, cheese products, etc.) don’t. Many of these cheese types have other additives, such as soybean oil and artificial colors and flavors.
The verdict: Aged and cultured cheeses likely provide some health benefits. Enjoy processed cheese as an occasional treat, if you want.
Butter and ghee
Butter is a mix of butterfat and milk solids, while ghee is butterfat from which the milk solids have been removed (which makes it better for high-heat cooking, as there are no milk solids to burn).
While containing mostly saturated fats, they’re also about one-quarter monounsaturated fats, with about 4-5% polyunsaturated fats.
Although saturated fat isn’t the monster we once thought it was, that doesn’t exonerate it completely or give us free license to eat pounds of butter. (Sorry, BulletProof coffee lovers.)
Additionally, because of the churning process, butter is low in something called milk fat globule membrane compared to other dairy foods. This membrane encloses the fat and seems to prevent it from negatively affecting our blood cholesterol and lipoprotein levels.
Since butter only has half the membrane levels of cream, it can negatively affect blood lipid health, whereas cream (or other high-fat dairy that hasn’t been mechanically emulsified) doesn’t seem to do the same.
You may have heard a wine’s taste described as “buttery”. The taste comes from butyric acid, a short-chain fatty acid compound that is a byproduct of bacterial fermentation, which is found in all fresh dairy products and makes up about 3-4% of butter.
Butyrates have many known health benefits, such as improving metabolic health, inhibiting the growth of cancerous cells, and regulating immunity.
However, again, this doesn’t necessarily mean butter is a miracle supplement. Since our own intestinal bacteria also make butyrates from fermenting carbohydrates, it’s more likely that a high-fiber diet will give us the most benefits of butyric acid.
The verdict: While a little butter is definitely okay, it is certainly not a superfood. Enjoy in small to moderate amounts, if you want.
Ice cream and frozen desserts
You can probably guess that ice cream and frozen dairy-based desserts are less healthy than, say, fresh cultured kefir.
Although some may have a bit of protein or other nutrients such as calcium, they’re typically processed foods that contain sugar, salt, flavorings, oils, emulsifiers, and other things that make them tasty and hard to stop eating. (You can blame your brain for that.)
The verdict: Enjoy as an occasional treat, if you want.
So, how does dairy affect your health?
The short answer about dairy and health is:
- It depends.
- It’s complicated.
Health (or the lack of it) comes from a complex interaction between many factors — our overall diets, our activities, our lifestyles, our environment, our genetics, our age, and so on.
Additionally, nutritional research can be complicated.
Bear this in mind as you read the next section.
There is no “magic food” or “demon food” that will be the single factor determining your health, fitness, or body composition. Dairy is one small part of a much bigger picture.
Losing fat or maintaining a healthy weight
In general, dairy consumption seems to help people lose fat, or maintain a healthy weight. Yogurt and cultured dairy seem to help the most.
This is probably due to:
- the high-quality protein in dairy, which can be satiating (so we eat less overall)
- nutrients such as calcium and magnesium
- other unique compounds in yogurt and cultured dairy in particular, which may improve metabolic health, gut health, and other things that contribute to a healthy body composition
The verdict: If you choose to eat dairy, it can be a helpful part of a fat loss or weight management program.
Gaining muscle and athletic performance
Dairy is especially helpful for folks looking to gain or maintain muscle mass.
It is a rich source of whey and casein, two very high-quality proteins. Both have been shown to be among the most effective proteins to promote muscular growth as they are incredibly rich in essential amino acids — the ones we can’t make and need to get from our diet.
Plus, dairy can be a good source of extra energy if we need additional calories to add mass or recover from hard workouts.
The verdict: If you choose to eat dairy, it can be a helpful part of a muscle gain or athletic recovery program.
Osteoporosis and bone health
Bone health isn’t just about minerals; it’s also about getting enough protein and stimulating metabolic signals that tell bones to stay dense.
Dairy is a rich source of many nutrients that are important for bone health:
- vitamin D
- vitamin K2
The vast majority of the research over the past 40 years indicates that dairy consumption improves or maintains bone health while helping to prevent or slow bone loss. This is especially true for people who are active and eat a generally healthy diet, as these elements work together to build and maintain a strong and healthy skeleton.
While dairy helps bone health, we don’t necessarily need it for bone health.
You can have a strong and healthy skeleton with or without dairy, so long as you ensure adequate intake of important bone nutrients (calcium, vitamin D, vitamin K2, protein, etc.) and provide a bone-building stimulus, like resistance training.
Conversely, you can have low bone density even with dairy intake, if you eat poorly in general and don’t exercise (or if there are other factors involved, such as hormonal issues).
In other words, dairy doesn’t have to be make-or-break for bone health. (See what we did there?)
The verdict: In general, dairy consumption can help bone health. But you can get enough calcium and other bone-friendly nutrients without dairy.
Recent research indicates that there’s no significant association between the intake of dairy products and increased risk of cardiovascular disease (CVD) and stroke.
Often, dairy is associated with a slightly decreased risk (especially for stroke). That includes full-fat dairy, which in countries that regularly grass-feed their cows (such as Australia), is associated with a decreased risk of heart disease. This relationship is inconsistent in the US, however, likely due to different agricultural practices.
The fatty acid profile of dairy probably affects its behavior (and health effects) in our body. Since an animal’s diet dramatically influences its fatty acid content, and cultured/fermented dairy seems to behave differently than non-cultured, the relationship between CVD and dairy probably depends a lot on what animals were fed, and what type of dairy people eat.
The verdict: If you are active and eat a well-balanced diet, moderate dairy consumption is unlikely to put you at risk for cardiovascular disease or stroke, and might decrease risk (depending what dairy you choose).
The recently-updated reports from the World Cancer Research Fund International and American Institute for Cancer Research provide the most comprehensive compilation of research on the associations between dairy foods, red meat, and processed meat and various cancers.
The conclusions provide further confidence that dairy products and milk are associated with a reduced risk of colorectal cancer and that high intakes of milk and dairy are not associated with increased risk of breast cancer. Previously, it was suggested that dairy intake was associated with breast cancer, so this is an interesting update.
Dairy intake also does not increase the risk of bladder cancer or gastric cancer and is not associated with risk of pancreatic cancer, ovarian cancer, or lung cancer. They found the evidence for prostate cancer risk is inconsistent (which agrees with other evidence we’ve cited).
It’s important to note that the vast majority of research here is observational, and therefore can’t fully predict true cause and effect relationships.
And it’s also important to note that even when dairy is associated with an increased risk of cancer, the overall calculated contribution from dairy to cancer risk is very small. Dairy is dwarfed by much larger contributors, such as smoking, obesity, alcohol, lack of activity and sun exposure.
The verdict: Current research indicates that overall dairy intake does not pose increased risk of several types of cancer, but this is certainly an area where we need more research.
Dairy-related allergies, sensitivities, and intolerances
Some people simply can’t tolerate dairy. If you’re one of them, you might already know. But dairy allergies, intolerances, and sensitivities aren’t always so easy to identify.
Here’s what each one is, how to know if you have it, and what that means for you and dairy.
An allergy is defined by a particular immune response that is rather immediate.
If you’re having an allergic reaction to dairy, you’re most likely not going to feel it in only your digestive system, but also elsewhere: skin, respiratory system, mouth and throat, etc. Think: itching, swelling, hives, and potentially difficulty breathing.
If you’ve had a reaction like this to dairy, consult with a doctor to get allergy testing done. You can also try an elimination diet. Dairy allergies are most common in children, but can also occur in adults.
If you have a dairy allergy, you should avoid dairy.
Milk contains simple sugars such as galactose (a monosaccharide) and lactose (a disaccharide of glucose and galactose).
Some of us can digest these sugars well, some of us can’t.
In order to do so, we need to produce lactase and galactose-1-phosphate uridyltransferase, the enzymes that break down lactose and galactose, respectively. This depends on:
- our genetic background;
- our age (we’re more able to digest milk sugars when we’re younger);
- our intestinal health or microbial environment; and
- the friendly bacteria in the dairy products themselves (if they’re fermented).
If we can’t digest lactose properly, it passes intact into the large intestine. It then ferments, producing gas, bloating, stomach cramps, and diarrhea. Fun times.
If we can’t digest galactose properly, we may have a genetic disorder known as galactosemia. This is more serious, and newborn babies may be screened for it.
As biological organisms, humans have consistently evolved to meet the demands of their food environment, and many groups of people worldwide have independently evolved the ability to digest lactose (known as lactase persistence). In most cases, these populations (such as northern Europeans or East Africans) have traditionally been dairy farmers.
Some people who are lactose intolerant can, however:
- digest non-cow dairy (such as goat milk);
- digest fermented dairy (such as kefir);
- digest low-lactose dairy (such as cheese); and/or
- digest dairy if they take probiotics or lactase supplements.
There are also lactose-free dairy products available.
The best way to tell if you have lactose intolerance is to keep a detailed food log that tracks your symptoms or try an elimination diet.
If you are lactose intolerant, you can experiment with different options to see what you can tolerate. If your symptoms are persistent, avoid dairy.
Other types of dairy sensitivity
Some people are sensitive to dairy but lactose isn’t the problem. Instead, they may be intolerant or sensitive to something else in milk, like casein, whey, or other immunoglobulins (types of proteins) in milk.
When our immune system reacts to some component of milk, we can have digestive symptoms along with other food intolerance symptoms, such as inflammation, skin rashes and acne, irritated respiratory passages, and so forth.
The process for determining dairy sensitivity and intolerance is the same as for lactose intolerance: Keep a detailed food log that tracks your symptoms, or try an elimination diet.
Ultimately, only you can decide if the occasional slice of pizza or bowl of ice cream is worth the potential digestive discomfort. Make the decision with your eyes wide open, aware of the tradeoffs, and based on your goals and values.
If you have another type of dairy sensitivity, you can experiment with different options to see what you can tolerate. If your symptoms are persistent, avoid dairy.
How do dairy farming and milk processing matter?
Organic versus conventional dairy farming
Many people assume that organic means better.
In some ways, that can be true.
Organic dairy usually comes from cows who are fed better, as it comes from cows receiving only organic feed and getting at least 120 days of pasture grazing yearly, providing at least 30% of their food during that grazing period.
Keep in mind that organic doesn’t require that cows are only fed grasses and hay. They can still be fed grains and other feed, as long as they are organically produced. Still, the majority of organic dairies report that at least half of the animals’ food comes from pasture.
Why does that matter? As we’ve seen, diet strongly affects dairy quality.
The amount of pasture that cows have access to can influence the protein, fat, and carbohydrate content of the milk. The most nutritious dairy comes from healthy animals that spend most of their time outdoors on fresh pasture eating lots of grass supplemented with hay, root veggies, and grains.
Organic dairy will also come from cows that have not been given hormones or antibiotics.
The concern with antibiotics is that the drugs some farmers use to prevent infections in cows are also used to treat infections in humans. Antibiotic resistance is a significant problem as it is, so consuming trace amounts of antibiotics in milk might make the problem of resistant bacteria worse.
As we covered earlier, bovine growth hormone (bGH) is sometimes used by conventional farmers to increase milk production. Though this hormone is not shown to have adverse effects on humans, it’s regarded as inhumane by organic farmers and animal rights activists due to the fact that it forces cows to produce more milk than they’re meant to, and can increase the risk of infection, which means they need antibiotics.
Remember, though, that although it may contain smaller amounts, organic milk does have hormones in it. All milk does (including human breast milk).
Pasteurization and homogenization
Raw milk goes through processing to keep it safe for human consumption. It ferments unless refrigerated, and bacteria and viruses can be transmitted from animals to humans in the course of handling.
Pasteurization heats milk in a vat to temperatures that microorganisms cannot tolerate, killing them in the process.
Homogenization crushes milk fat globules so small that they cannot rise to the surface and form a cream layer. This helps mix added fat-soluble vitamins such as the vitamins A and D.
As far as health implications go, processing milk can sometimes result in higher amounts of lactose. This is one of the reasons raw milk is promoted by some, although the risk of milk-borne disease increases substantially when milk is kept raw.
Importantly: The risk of bacterial infection from raw milk, in general, outweighs any speculative health concerns about pasteurization. Before the advent of modern food safety measures and pasteurization, raw milk routinely killed people, especially children, via infectious diseases.
Nerdy fact: Homogenization didn’t gain acceptance until the 1930s when cardboard and opaque milk containers were introduced. Before then, the cream line was visible through glass bottles and used by consumers to gauge the richness and desirability of the milk.
Environmental and ethical concerns
Some people choose not to consume dairy for environmental and/or ethical reasons.
Livestock production around the world is complex. Generally speaking, animal products require more inputs (water, feed, energy, etc.) than crop products like tubers and legumes, and tend to produce more harmful outputs (waste, greenhouse gas emissions, etc.)
Now, this isn’t always the case, as a lot depends on what type of land is being used for livestock grazing and feed production. Still, in developed countries, most dairy products come from concentrated animal feeding operations (farms where animals are raised in confinement) which can be environmentally harmful and are regarded as inhumane by animal rights activists.
This doesn’t mean non-dairy alternatives are necessarily “good” though — for instance, some concerns have been raised over water depletion from almond farming, which of course is used to create almond milk. Some non-dairy “milk” options are more sustainable than others. (For an in-depth examination of this, see Andrews R. Eating to Prevent the Apocalypse April 2017).
In short, environmental and ethical concerns are legitimate reasons to abstain from dairy if you feel passionate about them, but make sure to also research the alternatives if you’re seeking truly ethical and/or environmentally sustainable options.
What does all this mean for you?
Start by asking yourself a few questions.
1. What matters most to me?
In making food decisions, you may be focused on longevity, or gaining muscle mass, or clearing up a health issue, or sustainable agriculture, or finding a convenient snack the kids will eat, or any number of other values, goals, and priorities.
You may like cheese so much you’ll eat it even if it gives you a stomach ache because you’ve decided that life isn’t worth living without a good Camembert.
There’s no “right choice”. There are only choices that work more or less for you.
2. What works for me as an individual?
Your body is unique. Your life is unique.
You may tolerate dairy, or not. You may like it, or not.
It’s your call.
3. What fits into my routine and daily life? What do I enjoy?
Whether you’re feeding yourself, or an entire family, whether you’re a road warrior or homebody, whether you’re a hard-training athlete or couch potato, your routine and daily life will shape your food choices.
Greek yogurt may stack easily in the office fridge; whey protein might be a convenient and portable sports supplement; a latte may fill you up when you’re on the go and can’t get solid food; goat cheese or Parmesan might help you enjoy a salad more, and so on.
There are many ways and reasons to consume dairy… or not.
4. What am I noticing about myself?
If you think you may have a dairy intolerance, start keeping a food symptoms journal. Observe as much as you can — what you ate, when you ate it, what physical signs you’re experiencing, and so forth.
Over time, look for patterns.
5. What’s reasonable?
Be sane. Don’t get all spun up about finding the “perfect” choice or “following the rules”.
Simply try to find better choices (however you define them), where you can, and let the rest be.
If you can tolerate and enjoy dairy, moderate consumption (1 to 3 servings daily) is probably fine, especially if one or two of those servings are yogurt or other cultured/fermented dairy products, and if you consume that dairy in the context of a generally healthy diet.
Here at PN, we think of food choices as continuums rather than “dos and don’ts”. Here’s what it might look like for dairy:
If you DO choose to eat dairy:
Understand the differences between dairy products.
If you want to keep dairy in your life, get to know the wide range of dairy types available, and experiment. Try products made with goat or sheep milk (or give that Mongolian yak butter tea a shot).
Consider choosing fermented / cultured dairy more often.
Bacterially produced products such as yogurt, kefir, skyr, quark, aged cheeses, and other fermented and cultured dairy products seem to be the healthiest options.
Many types of dairy are highly processed and contain lots of sugar, salt, and other stuff you don’t necessarily want lots of. “Frozen yogurt” might sound healthy, but in health terms, it’s pretty much the same as ice cream.
Keep things in perspective.
Eating healthy — and even meeting your goals — doesn’t require perfection.
So if you decide you want to keep eating dairy, remember that while some types of dairy may be more health-promoting than others, indulging sometimes is okay — even good for you.
If you decide to give up dairy and then slip up, don’t sweat it.
Either way, have that ice cream, cheddar cheese, or whatever else you want to splurge on. Enjoy it, and then get back to your usual routine.
If you choose NOT to eat dairy:
If you have a dairy allergy, intolerance, or sensitivity, you have ethical or environmental concerns about dairy, or you simply don’t want to eat it…
You don’t need dairy in order to be healthy.
Get the nutrients you need from other sources.
Plan your menus to get enough protein, minerals, and so on from other foods.
Get help if you need it.
If you need more guidance with uncovering and exploring food sensitivities, with shopping and reading food labels, with planning a menu that accommodates your choices, or any other nutritional question, consider getting coaching (and/or consulting your health care professional as needed).
If you’re a coach with clients or patients asking for advice on dairy:
As the evidence currently stands (read: not yet definitive), the known health benefits of dairy most certainly outweigh the suspected harms, on average.
But individual people are not research averages. Each unique person needs to see how dairy makes them feel, and determine if it’s right for them. That’s a good thing. People need to feel in charge of their own journey.
Don’t engage clients in theoretical debates, give them strict “rules”, or scare them. Instead, coach them through the discussion respectfully. Encourage them to keep a food journal and learn to be their own scientist.
Look to deepen your coaching relationship and understand your client’s perspective, while helping them feel in control of their choices.