While visiting my parents back in July, my mom voiced her concern about my calcium intake. Thanks to my continuing spinal issues, calcium is something I can’t afford to take for granted. That left me wondering what the science has to say about our calcium requirements and the best sources of calcium. The question I wanted to answer was: Do humans need dairy?
The History of Dairy
Before we dive into the current science on dairy and calcium, it’s important to know when, where and why humans started drinking milk in the first place.
It’s believed that milk from domesticated farm animals, including goats, sheep and early dairy cows, was first consumed by humans about 7,500 years ago in Central Europe. That’s when a group of people, mostly in farming communities, developed the genetic mutation that allowed adults to consume the milk sugar lactose into adulthood without getting sick.
Prior to that mutation, humans became lactose intolerant shortly after weaning, as most people still do. If you’re lactose intolerant as an adult, there’s a good chance your distant ancestors didn’t come from Central Europe.
Milk consumption during that period of human evolution provided a survival advantage. Domesticated farm animals provided an ongoing source of calories year round, even during the winter. Back then, heart disease and cancer weren’t the leading causes of death; it was starvation and communicable disease. If you were able to avoid starvation long enough and be healthy enough to reproduce, your genes got passed on to your children and eventually to those of us who aren’t lactose intolerant.
While 7,500 years may seem like a long time in human life terms, it’s a tiny speck of time in the evolutionary timescale. Our distant human ancestors diverged from the great apes about 20 million years ago. That means we’ve only been drinking the milk from other animals for the past 0.04% of our evolution. That’s still hard to comprehend. Let’s say you have $1,000. We’ve only been drinking milk for 40 cents of it. Less than a dollar of your one thousand. That’s not very much time (or money).
If your ancestors came from Central Europe, you only have a 5% chance of being lactose intolerant. But if your ancestors came from Asia, North America (indigenous populations) or Africa, you have a 95%, 80% and 75% chance, respectively, of being lactose intolerant. That means 65% of the human population can’t effectively digest milk and, therefore, consumes very little to none of it.
If more than two thirds of the human population can’t consume milk, I think it’s safe to say “humans” don’t need dairy, but what about those of us with the genetic mutation that allows us to digest lactose? Does our mutation mean the 35% of us who can digest dairy need it to be healthy?
The Nutrients in Milk
As far as I’m aware, there are no studies showing that people with the lactose gene need dairy to be healthy, but dairy is full of beneficial nutrients that all humans need. It’s also full of harmful elements, which I’ll cover below.
For the following nutrition analysis of milk, I’ll use 1 cup of 1% cow’s milk. Some people would argue that we should be drinking raw milk or full fat milk or skim milk, but 1% should provide a decent average of all of them.
Protein in Milk
One cup of cow’s milk contains 8 grams of protein, or roughly 31% of calories from protein. That’s a lot of protein. And the government recommends we get at least 20% of calories from protein, so maybe 31% is even better. But do we really need that much protein to be healthy?
Let’s look at human breast milk first. If we want to understand human milk consumption, let’s go back to the real beginning 20 million years ago and analyze the composition of milk specifically formulated for humans. It turns out that human breast milk has less than 1% of calories from protein. It’s roughly .8% protein or 30 times lower than dairy milk.
Adult humans can survive on only 2.5% of calories from protein, but the science seems to suggest we’re healthiest eating roughly 8-10% of our calories as protein.
Too much protein in nations eating the western diet may actually contribute to many of our top diet-related chronic diseases, especially cancer and kidney disease.
It also appears that too much protein actually contributes to bone loss and osteoporosis, contrary to popular belief. However, this has been hotly debated with several studies (mostly funded by the beef industry) calling this into question.
Some evidence suggests that high protein foods boost calcium absorption and the extra calcium secreted from our bodies is actually coming from excess calcium in the food that our bodies don’t need thanks to the higher rate of absorption. However, some of that calcium may be coming from our muscles, which may be as bad as pulling it from our bones, especially for older people.
I recommend reading Proteinaholic by Dr. Garth Davis for a thorough review of the history of our protein obsession and actual human protein needs.
While dairy does contain lots of protein, we actually need far less protein than we’ve been led to believe. Additionally, every single fruit, vegetable, legume, nut, seed and whole grain contains protein. For example, lentils also get 31% of their calories from protein and broccoli gets 33% of its calories from protein.
Calcium in Milk
One cup of cow’s milk provides 30% of our daily calcium needs (according to the RDA), or about 300 mg. We humans do need calcium in our diets to maintain healthy bones and even proper cellular function.
Calcium is one of our main building blocks, and it’s also a regulator for acidity. Humans are healthiest within a relatively small pH range between 7.35 – 7.45. When our bodies have an increased acid load, from chronic illness or from eating too much acid-forming foods like animal protein, the body mobilizes calcium to bring the pH back to the normal range. Most of that calcium comes from our bones and then gets secreted when we go to the bathroom. That means if you eat more protein, you also need to eat more calcium to make up for the calcium loss it causes.
This daily calcium requirement is based on the government’s recommended dietary allowance (RDA) of 1,000 mg of calcium for healthy adults, but where did that number come from? Is it based on the science or something else? We’ll look at that in more detail in the RDA section below. Until then, it’s important to note that unbiased scientific studies show that we actually need closer to 500 mg of calcium per day.
Dairy contains a lot of calcium, but it’s not the only source. You can also get your calcium needs met from fortified non-dairy milk, fortified juices, dark leafy greens, legumes, fruits and vegetables. In fact, most fortified non-dairy milk and juice contain more calcium than unfortified dairy milk. Check the labels next time you go to the store to see for yourself.
While most plant sources of calcium are not as bioavailable as liquid sources such as milk or fortified non-dairy milk, our bodies are still very good at extracting it. We just need to eat more to get our needs met, which most people eating a whole-food plant-based (WFPB) diet do anyway. Kale, broccoli, bok choy and a few other plant sources of calcium actually have higher absorption rates than dairy.
While not scientific, I tracked my nutrition using MyFitnessPal for 6 weeks and found that I averaged between 600 and 800 mg of calcium per day eating WFPB No-Oil. Most days, my diet consisted of oats, ground flax & chia seeds, homemade brown rice milk and fruit for breakfast; a giant Garden Salad with dark leafy greens and assorted vegetables, a hummus veggie sandwich or potatoes, and more fruit for lunch; and stir fries with brown rice, pasta or potatoes for dinner.
Those plant sources of calcium met my calcium needs. We’ve since started using fortified almond milk instead of brown rice milk just to make sure we’re getting enough calcium and vitamin D.
Potassium in Milk
One cup of milk has 366 mg of potassium or 10% of the RDA. To put that into perspective, one medium banana has 422.4 mg of potassium or 12% of the RDA. One medium potato has 896.7 mg of potassium or 25% of the RDA. One cup of kale has 329 mg or 9% of the RDA. One cup of cantaloupe has 427.2 mg or 12% of the RDA.
The vast majority of Americans, 98%, don’t get even the minimum recommended amount of potassium of 4,700 mg per day. Referring back to my nutrition tracking, I averaged only 3,000 mg per day of potassium and I consistently eat the richest sources of it: bananas, cantaloupe and potatoes.
It’s easy to see how non-vegans have a hard time getting enough potassium since so many of them have food phobias relating to the foods highest in potassium, such as bananas and potatoes.
While milk does have potassium, plant sources have it in much higher amounts and we all need to eat more of those to get our daily potassium needs met.
Phosphorus in Milk
Phosphorus is still not as well understood as many of the other nutrients, but we do know that our bones are made up of both calcium and phosphorus. Some studies show that we need both calcium and phosphorus flowing through our systems at the same time for our bones to make the best use of each. This is why some people view milk as a perfect food: because it has both calcium and phosphorus in abundance.
However, most phosphorus in the American diet comes from whole grains. Dairy ranks number three after meat. There have been no documented cases of phosphorus deficiency when sufficient calories are consumed unless a genetic disorder is present. This is mainly because all foods contain phosphorus.
Rather, the bigger concern with phosphorus is getting too much of it, which has “been associated with increased rates of cardiovascular disease and mortality in subjects with or without kidney disease.”
Iodine in Milk
Iodine is an important nutrient for a multitude of reasons, one is to prevent hideous goiters from forming due to thyroid dysfunction. Most iodine in milk comes from the disinfectants used to clean the milking equipment, not from the milk itself.
We get the majority of our iodine from fortified foods like salt and dairy (in the US), but we can also get it from sea vegetables and supplements. Seaweed also appears to have several other health benefits, such as preventing and fighting cancer.
Vitamin B2 (Riboflavin) in Milk
Vitamin B2, also called Riboflavin, is used by many processes throughout the body from blood to brain. It’s critical that we eat foods containing B2 on a daily basis. The RDA of B2 is 1.1 mg/day for men and 1.3 mg/day for women. That’s not very much.
One cup of 2% milk has .5 mg of B2. Fortified breakfast cereals have 1.7 mg per serving. Instant oats have 1.1 mg per serving. One cup of mushrooms has .6 mg. One ounce of almonds has .3 mg. And one cup of quinoa also has .3 mg.
While pan-fried beef liver appears to contain the most B2, fortified breakfast cereals and mushrooms have more B2 than dairy so we can easily meet our RDA of B2 with plant-based foods.
Vitamin B12 in Milk
B12 is critical for brain, cardiovascular and nervous system health. Luckily, we only need 2.4 micrograms per day; a tiny amount. Plus, our bodies are very efficient at storing it. If you stop consuming B12 today, your body has enough stored up to last 2 to 3 years!
B12 is actually not a vitamin, though. It’s synthesized by microbes that live in the soil, untreated water and the intestines of animals and bugs (that we sometimes consume in fruits and veggies).
Vegans are at an increased risk of B12 deficiency because most B12 in the western diet comes from animal products, especially meat, dairy and eggs. However, some studies have shown that vegans aren’t the only people deficient in B12; so are meat eaters.
“A careful look at 3,000 men and women in the ongoing Framingham Offspring Study found 39 percent with plasma B12 levels in the ‘low normal’ range….Nearly 9 percent of the study population fell below the current deficiency level.”
As we get older, our ability to absorb B12 goes down, and there simply isn’t as much of it naturally occuring in our foods anymore thanks to the hyper-sanitization and over processing of them.
The best source of B12 to ensure you get an adequate and consistent supply is from a supplement. A lot of people object to taking supplements and claim B12 is the reason we’re supposed to eat meat, but that belief isn’t accurate.
If you drink out of the nearest lake or stream like our ancestors did, you’ll likely get all the B12 you need. Of course, you’ll also likely get dysentery, cholera and a host of other nasty diseases, but you’ll probably be just fine in the B12 department. Or, you can just take a B12 supplement costing pennies a day.
It’s also important to note that most livestock is given B12 supplements because they don’t get enough of it either, especially livestock raised in a Concentrated Animal Feeding Operation (CAFO). Additionally, the overuse of antibiotics in livestock tends to kill the microbes that produce B12. That means most of the B12 from animal products comes from supplements given to the animals, not from natural sources.
The Anti-Nutrients in Milk
In order to fully answer the question, “Do humans need dairy?” we also need to look at the bad stuff. The anti-nutrients in milk and dairy.
Cholesterol in Milk
Dietary cholesterol may not be as harmful as saturated fat in terms of heart disease, but it still raises blood serum cholesterol. If you’re a cholesterol denier like so many are these days, I encourage you to read my last blog post, “Why You Should Ignore Industry Funded Studies.” It looks at 3 frequently cited studies that show how Big Food and Big Pharma use nutrition studies to cast doubt where none exists so you keep buying their products.
Dairy, mainly cheese, is the leading source of cholesterol in the western diet, and dietary cholesterol raises blood serum cholesterol, which causes heart disease just like smoking causes cancer. Plants, including nut butters, contain no cholesterol.
Saturated Fat in Milk
One cup of 1% milk contains 1.5 grams of saturated fat. Saturated fat actually raises blood serum cholesterol more than dietary cholesterol making it worse in terms of heart disease risk. We should strive to reduce our intake of saturated fat as much as possible. It should be as close to zero as possible.
Trans Fat in Milk
One cup of 2% milk contains .2 grams of trans fats. That may not seem like a lot, but trans fat is by far the worst type of fat we can consume. Before we realized how bad trans fats were for human health, most of our intake came from vegetable derived sources like hydrogenated vegetable oils (think Crisco shortening).
However, over the past 15 years, the ratio has flipped and now 50% of our trans fats come from animal sources. The trans fats have been there all along, but now people eating the western diet are getting a larger percentage from those sources than from vegetable derived trans fats.
IGF-1 in Milk
Insulin-like Growth Factor-1 or IGF-1 is a cancer promoting hormone that our bodies naturally produce to maintain normal cell growth and function. However, we can increase the amount of it floating around in our bodies by consuming it in the foods we eat, mainly from animal sources like meat and dairy. The only way to significantly reduced the negative effects of IGF-1 is to eat a plant-based diet.
Hormones in Milk
You may have heard of the Bovine Growth Hormone used to make cows grow faster and produce more milk, but it’s not the only mammalian hormone in milk. There are multiple, including estrogen. And studies show that “the presence of steroid hormones in dairy products could be counted as an important risk factor for various cancers in humans.” Especially prostate and breast cancer.
According to Dr. Greger, “All animal-based foods contain sex steroid hormones, such as estrogen. These hormones naturally found even in organic cow’s milk may play a role in the various associations identified between dairy products and hormone-related conditions, including acne, diminished male reproductive potential, and premature puberty.”
It’s surprising that so many people avoid soy consumption because it contains phytoestrogens, or plant estrogens, that have been shown to prevent and fight cancer. Meanwhile, they continue to consume dairy which has real mammalian estrogen that is virtually identical to human estrogen and has been linked to both prostate and breast cancer (as well as the much feared man-boobs).
Antibiotics in Milk
The presence of antibiotics in milk is hotly contested, mainly by the dairy industry, and very little scientific evidence exists to suggest that the antibiotics given to farm animals makes its way into people who consume them. This video talks about one study, but it’s far from conclusive.
However, the biggest concern with antibiotics shouldn’t be how much gets ingested, but rather, how much is being given to farm animals, especially dairy cows.
The FDA estimates that 80% of all antibiotics used in the US are given to livestock. The overuse of antibiotics to treat infections, speed growth and boost production has created so-called “superbugs” that are resistant to normal antibiotics. This practice is quite literally risking all of our lives.
Nutrients Missing in Milk
Milk has a lot of essential nutrients, and some harmful ones, but it’s lacking in three of the most important nutrients that are only found in plants: fiber, phytonutrients and antioxidants. While dairy and other animal products like eggs have trace amounts of antioxidants, they don’t have enough to be beneficial to human health and nearly all of them are destroyed in cooking.
Where’s the Fiber?
The RDA of fiber has been recently increased from 25 grams to 28 grams, which is still too low to prevent or reverse many of our common illnesses, especially colorectal cancers, heart disease and diverticulitis. To maximize the protectiveness of fiber, we need at least 30 to 35 grams of fiber, and ideally over 40 grams per day.
You’re limited by the number of calories you can and should eat in a day based on your height, weight, sex and age. If you’re consuming high calorie foods like meat, dairy and eggs that contain no fiber, you’re crowding out foods that have fiber in abundance, like fruits, vegetables, legumes, seeds, nuts and whole grains.
Eating a WFPB diet, Amelia and I consume an average of 40 to 45 grams of fiber per day. I’m eating a 2,000 calorie diet. If I replaced a quarter of my calories (500) with animal products, I would immediately reduce my daily fiber intake to 30 grams, the minimum recommendation based on the science.
Let’s say I swap out my whole plant foods for 500 calories of processed foods. That will drop my fiber intake by another 8 to 10 grams, down to roughly 20 grams per day. But even that is still more than the average American who consumes just 15 grams of fiber per day!
The only way to achieve the government’s conservative fiber RDA is to eat mostly whole plants, probably at least 75% of calories. (Notice how the fiber RDA is conservative while both calcium and protein are double what we actually need.)
Where are the Phytonutrients
“Plant-based foods contain more than 100,000 different disease-preventing nutrients—more specifically, more than 100,000 phyto-nutrients, phyto for the Greek word for plant.” These phytonutrients, many of them unknown or at least not fully understood, work together synergistically to keep us alive and healthy.
Vitamin C is one phytonutrient that we must consume from the foods we eat or we risk getting scurvy, a disease that used to plague pirates due to their lack of plants on long voyages. Plants are the only source of Vitamin C…for humans.
Carnivores like lions and tigers, and omnivores like bears and dogs create their own Vitamin C. All carnivores and the vast majority of omnivores don’t need to eat Vitamin C to survive. Only herbivores do. Stop and think about the implications of that biological fact for a minute….
Where are the Antioxidants?
Antioxidants are those little powerhouse molecules that constantly search our systems for heart disease and cancer-causing free radicals. Once found, the little antioxidants destroy the agents of disease so we can go on living and reproducing.
Antioxidants are found abundantly in plants with only tiny, insignificant amounts in animal products. The best sources are herbs and spices, followed by berries, other fruits, vegetables and whole grains.
The average American gets less than half the recommended daily amount of antioxidants. Again, the number of calories you consume in a day is limited so if half of your calories are coming from foods that contain no antioxidants, it’s not surprising that everyone is running at a deficit. You would need to eat nearly twice the calories you’ve been eating, all from plants, to get the antioxidants your body needs to effectively fight disease.
Recommended Dietary Allowances (RDA)
The RDA got its start back in World War II when the US government wanted to make sure its military personnel and citizens were getting enough to eat. The percentages were based on reasonable assumptions at the time plus a safety margin, and the values were updated every 5 to 10 years.
Unfortunately, the USDA got involved back in the 1950’s. Since they represent the farming industry first and “the people” second, they influenced the RDA’s upward, especially for nutrients contained abundantly in animal products, like calcium and protein.
The RDA for calcium is roughly 1,000 mg per day. It ranges from 800 to 1,200 based on age and sex, but for most people it’s 1,000 mg. However, several studies have shown that we only need 500 to 700 mg of calcium per day to be healthy, unless you eat a lot of animal protein.
The EPIC-Oxford study found that vegans who eat more than 525 mg of calcium per day had the same bone fracture rates as meat eaters while vegans consuming less than 525 mg/day had a 30% higher fracture rate than meat eaters.
By influencing the RDA’s upward, our government helped Big Food increase sales of their most profitable products: meat, dairy and eggs. Most of these recommendations have little or no basis in nutrition science. Rather, they were selected to increase profit margins.
Best Way to Achieve Bone Health
Contrary to clever marketing campaigns funded by the dairy industry and the US government checkoff programs, humans do not need dairy to be healthy. In fact, just the opposite is true: humans should avoid dairy to be healthy. The beneficial nutrients found in dairy can be found in more optimal forms and amounts in plants, along with fiber, phytonutrients and antioxidants that aren’t found in animal products.
In terms of bone health, recent studies in Europe have demonstrated that high dairy consumption is associated with HIGHER bone fracture rates, not lower. And higher milk consumption has also been linked to increases in cancer, heart disease, stroke, diabetes and most other diet-related diseases.
By far the best way to ensure bone health and to avoid osteoporosis in later years is to get adequate calcium, phosphorus and potassium from plant-based sources like kale, broccoli and fortified non-dairy milk.
You also need to get a good supply of Vitamin D, which helps in bone growth. Getting adequate sunlight each day (15 to 30 minutes) is the best way to meet your Vitamin D needs, but if you live far from the equator or work indoors all day, you may need to take a vitamin D supplement or consume fortified non-dairy milk, especially in the winter months.
Additionally, you need to take a vitamin B12 supplement, even if you’re not a vegan.
Finally, several studies show that weight-bearing exercises throughout life significantly contribute to bone health and density. Even if you’ve never done weight-bearing exercises before, today is a great time to start. Try Yoga, Tai Chi, Brisk Walking, Hiking, Biking, Strength Training, etc. Please be careful, though, especially if you’re out-of-shape. You should consult your doctor first before starting a new exercise program.
Environmental and Ethical Issues with Dairy
As a vegan environmentalist, I would be remiss if I didn’t mention both the environmental and ethical implications of consuming dairy products.
Environmental Impact of Dairy
An average dairy cow produces 120 pounds of excrement per day. With more than 9 million dairy cows, that’s over 1 billion pounds of waste generated every day, just in the US.
There is no requirement to treat or process farm animal waste like there is for human waste so all of that manure accumulates and contaminates the soil, air, groundwater and nearby lakes and streams.
It’s estimated that dairy alone contributes 4% of the manmade greenhouse gases. The animal industry as a whole contributes more greenhouse gases than the entire transportation industry.
Dairy also uses large amounts of water for the cows and in the production process. It’s estimated that one gallon of milk requires 1,000 gallons of water when you include the food grown to feed the cow, the water that the cow drinks, and the water used in the cleaning and production processes. Dairy is a very inefficient use of water, which is now in short supply in many parts of the world.
Most dairy cows are fed an unnatural diet of GMO grains. If you haven’t yet, I highly recommend reading The Omnivore’s Dilemma by Michael Pollan. This book goes into detail about the harmful environmental consequences of GMO monocrops used mainly to feed livestock.
Each of us has the ability to minimize our environmental impact on this tiny blue speck we call home. Reducing animal product consumption, including dairy, is the single most important change you can make to ensure our children inherit a livable planet.
Dairy is Scary
The treatment of most farm animals in the US and around the world is beyond horrendous. It’s an abomination. The dairy industry is perhaps worse than the meat industry in terms of animal treatment and conditions.
Dairy cows have been selectively bred, engineered and pumped full of chemicals to make them grow faster, with larger udders to produce more milk. Compared to dairy cows in the 1950’s, the typical cow now produces 6 times more milk per day. They suffer from painful mastitis, infections and sores.
They’re repeatedly impregnated for 4 to 6 years so they continue to produce milk. Their babies are taken away, sometimes immediately, but usually within a couple of days. Male calves are either killed immediately or sold for veal. Female calves are raised to replace older cows that are taken to slaughter when their milk production falls below the acceptable level.
Cows are social, intelligent animals. They form strong bonds with their offspring and other cows. They each have unique personalities, which become apparent after spending a short amount of time with them.
Humans do not need dairy to be healthy. Rather, dairy makes us unhealthy. That means there is no survival reason to consume dairy products. We can get all the nutrients we need from plant-based sources with far fewer environmental impacts and much less cruelty.Please share your thoughts in the comments below. And please share with your friends to help spread the word about healthy plant-based eating.