IMPORTANT! YOU MUST READ THIS BEFORE CONTINUING:
Milk and the Calcium Paradox
by Ron Brown, Ph.D., B.Sc. Dietetics, author of The Body Fat Guide
COWS DON'T DRINK MILK—that is a fact that no one argues. Cows also don't eat dairy products like cheese and yogurt which are high in calcium and which are commonly marketed to humans to build strong bones. Yet, the calcium paradox describes how osteoporosis, a chronic loss of bone mass, occurs most often in nations with the highest intake of calcium and dairy products (Lanou, 2006). Women in the U.S. typically lose about half of their bone mass in a lifetime (Brown & Jaffe, 2000), with average losses of 1% for each adult-year. Older women have a higher risk for bone fracture than for breast cancer (Cauley et al., 2008).
Before people began to modernize their diet with agriculture and animal domestication to produce dairy products, prehistoric humans had thicker and stronger tooth enamel (Goodman, Armelagos, & Rose, 1980). It has been estimated that the daily calcium intake of preagricultural humans who had no dairy products was over 1,500 mg (Eaton et al., 1996). Lacking modern high-speed blenders, primitive people used stone tools to grind calcium-rich vegetables, nuts, and seeds.
Researchers like Weston Price searched the modern world investigating the dietary habits of societies with the best teeth and bone structures. But it is difficult to determine the dietary factors that promote good bone and dental health from these types of observational studies. If a remote mountain tribe with good bone and tooth development ate ox liver, than it was assumed that everyone should eat ox liver. This theoretical approach has not yielded good results in reversing the epidemic of bone and dental disease in Western societies. In his early 20th century masterwork, Orthotrophy, Herbert M. Shelton wrote, "That the free use of milk will prevent tooth decay is a fallacy that can be seen on every hand. There is no evidence of its superiority in providing for bone development." More recently, doctors Willet and Ludwig (2013) of Harvard Medical school noted that "Humans have no nutritional requirement for animal milk (p.788)."
Nevertheless, researchers continue to report that supplementing an inadequate diet with limited amounts of dairy products improves the diet. Such studies are often sponsored by food manufacturers and are designed to increase the appearance of a food's nutritional value. There are many foods other than dairy products that could easily supplement an inadequate diet, especially in providing more calcium. For example, FIGURE 1. shows that a cup of whole milk weighs 244 grams and contains 276 mg calcium. But 144 grams of orange plus 100 grams of collards weighs as much as a cup of milk and contains 290 mg calcium! More importantly, the calcium in the orange and collards comes with a better balance of other nutrients for bone building in humans, like iron, vitamin K, magnesium, etc.
Small amounts of dairy may contribute nutrients to a diet that is properly balanced to build bone, but it is the overall diet that is responsible for building bone, not the dairy products. This article will explain why no amount of dairy can deliver the optimal amount of nutrients needed to build human bone, blood, and human milk for breastfeeding. The marketing concept that consuming more cow milk is better for bones, teeth, and overall health actually has the opposite effect in humans. A person over 50 years old who desires to meet the Institute of Medicine's RDAs of 1,200 mg calcium and 700 mg phosphorus could never achieve these optimal amounts while ingesting a large amount of dairy products because cow milk does not provide the correct ratio of calcium, phosphorus, sulfur, and other nutrients required by humans. Infants, young children, and adolescents are harmed by the nutrient imbalances in cow milk as well.
Sulfur Amino Acids
For a young calf, cow milk, consumed straight from the producer, is nature’s perfect food, providing nutrients for rapid growth of bone and muscle. But humans, as well as mature cows, do not grow at the rate of young calves, and so dairy products are not properly matched to the nutrient needs of humans or fully grown cows. There is no doubt that dairy is a good source of calcium, but other factors in dairy related to the rapid growth needs of calves counteract this advantage in humans. For example, humans do not require the large amount of sulfur amino acids in protein supplied by a high intake of dairy foods. The Recommended Dietary Allowance (RDA) for protein is 0.8 mg/kilogram bodyweight, or about 10% of calories, but the average intake of protein in the Western diet is 15%–16% of calories. Researchers have long known that excess amounts of protein increase calcium excretion from the body (Margen et al., 1974). Doubling protein intake from 35 grams to 78 grams increases the body's calcium loss by 50% (Hegsted et al., 1981). Due to the high sulfur amino acid content of dairy protein, consumed in combination with sulfur amino acids in protein from animal flesh, eggs, grains, and legumes, dairy products not only fail to prevent osteoporosis, they may contribute significantly to the cause of bone loss by increasing the acid load within the body.
Normally, biocarbonates in fruits and vegetables buffer acids as they are produced in the human body during metabolism (Lanham-New, 2008). Nevertheless, according to Arnett (2008), as excessive amounts of protein are metabolized, extracellular fluid around bone begins to become more acidic, and the concentration of positive hydrogen ions (H+) builds up in the fluid. To defend against this harmful buildup of acid, bone begins to release negative hydroxyl ions (OH–) to neutralize the hydrogen ions and form water. However, in the process of releasing these buffering hydroxyl ions, bone is also forced to release calcium (Ca2+) and phosphate (PO43–) that form bone and which are eliminated in the urine. It is important to note that the calcium released from bone does not directly buffer and neutralize the acid. Calcium ions have positive charges, which repel positive hydrogen ions rather than attract and buffer them. This helps explain why ingesting large amounts of calcium doesn't protect against the adverse effects of excessive protein intake.
Bone “casts” out calcium and other substances due to the action of bone cells called osteoclasts, with a “c.” Bone “brings” in calcium and other nutrients due to the action of bone cells called osteoblasts, with a “b.” In FIGURE 2., Arnett (2008) illustrated how osteoblasts are deactivated when extracellular fluid becomes more acidic, or when the fluid’s pH drops. Note how calcium, phosphate, and hydroxyl ions which form bone are released by active osteoclasts.
Therefore, even though dairy products like milk supply calcium, the acidic effect of an excessively high protein intake within the human body from consuming large quantities of milk intended to meet the needs of rapidly growing calves contributes to a drop in fluid pH, which turns off the action of osteoblasts to absorb the milk's calcium. At the same time, the lowered pH increases the action of osteoclasts to release calcium, phosphate, and hydroxyl ions from bone. The end result is that there is a net loss of calcium and other matter from bone. The more dairy products consumed, the higher the net loss! A National Dairy Council study confirmed this.
Researchers supplemented a test group with three 8–ounce glasses of milk a day, which significantly increased bone fracture rates compared to a control group that didn't receive the supplementation. The researchers concluded the rise in fractures was most likely due to a 30% increase in protein intake from cow milk (Recker & Heaney, 1985). Human milk, by comparison, is much lower in protein and sulfur amino acids, and does not cause this problem. No fracture-risk protection from cow milk consumption was found in prospective studies in Sweden in 2003 that followed 60,689 women over 11 years and in the Harvard Nurses’ Health Study in 1997 that followed more than 75,000 women over 12 years, or in meta-analysis studies in 2007 and 2005 that compared dairy consumption and fracture risk (Lanou, 2009).
Incidentally, osteoporosis drugs work by killing osteoclasts. You might think this is an effective way to avoid bone loss, and these drugs have been shown to increase bone mineral density (BMD). However, according to Small (2005), "...there is no precise and consistent relationship between a given increase in BMD and a specific decrease in fracture risk with osteoporosis therapy." Osteoclasts are necessary for normal, healthy bone turnover. Worn out bones in an adult human are normally cast out and gradually replaced with fresh, new, stronger bone every ten years, thanks to the balanced action of osteoclasts and osteoblasts. Upsetting this continuous bone turnover by killing osteoclasts interferes with the renewal of bone strength, which can lead to disastrous long-term adverse effects such as spontaneous fractures of the femur (Visekruna, Wilson, & McKiernan, 2008). Small concluded that, "Fracture risk depends on a number of variables that contribute to bone strength in addition to BMD, such as bone size, shape, architecture, and turnover." While Sally Field cheerfully promotes the osteoporosis drug Boniva, she may not be so cheerful ten years from now if her bone strength and bone turnover have been severely compromised.
The healthiest and easiest solution to prevent
osteoporosis is to lower your overall intake of protein by consuming fewer
high-protein foods, like dairy products. Ironically, at lower intake levels,
dairy products no longer provide any advantages over other natural foods, such
as fruit, nuts, and vegetables, in supplying calcium to the diet.
Campbell (2008) estimated the daily need for calcium on a low-protein, plant-based diet at about 400–600 mg, which is significantly less than the 1,200 mg currently recommended by the Institute of Medicine for adults over 50 years. Vegans in Western countries who consume at least 525 mg of calcium a day (Appleby et al., 2007) and 579 mg of calcium a day (Fontana et al., 2005) have fracture rates that are no better or worse than the rest of the population. Researchers found that the vegans had lower bone density than people consuming over 1,000 mg of calcium, but this applies to the rest of the population as well. Considering that the hip fracture rate in the United States is the highest in the world (Dhanwal, 2011), vegans and the rest of the Western population would have greater bone density and lower fracture rates by consuming calcium and other nutrients in amounts recommended by the Institute of Medicine.
It is claimed that at ultra-low dietary calcium intake levels of 150–200 mg a day, researchers have never seen calcium balance disorders in people who eat a natural-food diet, which is said to be due to increased intestinal calcium absorption (Paterson, 1978). However, intestinal absorption alone cannot adequately compensate for an ultra-low dietary calcium intake. The body is also forced to secrete parathyroid hormone which releases calcium from bone, thus restoring normal serum calcium levels at the costly expense of drawing down calcium reserves from bone and harming bone health (Jorde et al., 2000). This homeostatic response explains why osteoporosis is a silent disease, producing few noticeable signs of calcium metabolic disturbances over time until fractures appear.
In an article titled “Preventing and Reversing Osteoporosis,” the Physicians Committee for Responsible Medicine (n.d.) cited the low calcium intake and low fracture rate of South African Blacks compared to Western nations in a study by Abelow et al. (1992). The article authors concluded, “...nor do low calcium intakes predict fracture risks.” But low calcium intakes do predict fracture risks when comparing the South African Black diet to other non-Western countries. For example, according to the same study, natives of Papua New Guinea have over twice the daily calcium intake of South African Blacks (448 mg calcium and 196 mg respectively) and have less than half the fracture rate of South African Blacks (3.1 and 6.8 per 100,000 respectively). The Papua New Guinea natives also consumed 16.4 grams of animal protein a day, which is 58% more animal protein than consumed daily by South African Blacks, thus showing that adequate intake levels of protein and calcium are important for bone health. It is the excessive intake of protein that disturbs calcium metabolism. Osteoporosis in people who consume adequate calcium is caused by factors that remove calcium from bone.
Consuming as much as 1,400 mg of calcium a day did not prevent a net loss of calcium in subjects on a high-protein diet (Allen et al., 1979). North Alaskan Eskimos who consume up to 2,500 mg of calcium and 400 grams of protein daily have middle-age osteoporosis rates that are 10-15% higher than Westerners (Mazess & Mather, 1974). By contrast, diets lower in protein and sulfur intake were found to be related to greater bone health in over 1,000 pre- and postmenopausal women (New et al., 2004).
To prevent osteoporosis, even vegetarians and vegans who avoid dairy products must take care to include a proper balance of fresh raw fruit and green leafy vegetables in their diets, and they must avoid excessive protein intake from eating large amounts of grains, legumes, tofu, soymilk, hummus, and high-protein nuts and seeds. For example, cashews, almonds, pistachios, and sunflower seeds have 13%–14% calories from protein, while there are only 4–5% calories from protein in low-protein nuts, like pecans, coconuts, and macadamia nuts. A veggie burger has over 35% calories from protein!
Dr. Campbell observed that adverse health effects begin to appear in people consuming a diet that totals over 10% calories from protein, yet, he noted that a typical vegan diet, which includes grains and legumes, has 13% total calories from protein! Not surprisingly, a study found no significant difference in the prevalence of osteoporosis between groups of vegans and omnivores, and that the disease progressed with age equally in both groups (Ho-Pham et al., 2009).
Thus, even with abundant amounts of fruit and vegetables, and use of other so-called alkalinizing supplements, no one should ingest excessive amounts of calories from protein, whether from plant or animal sources, and expect to avoid the acidifying effects that negatively impact health. Referring to an acid condition in the human body, Dr. George W. Crile, the father of physiologic surgery, wrote in Man—An Adaptive Mechanism, "...acidosis is a factor in many diseases—acute and chronic."
During World War I, Mikkel Hindhede (1920) placed the people of Denmark on a low-protein plant-based diet with less alcohol, and reduced the national death rate in one year by an astounding 34%! In the global flu pandemic of 1918, Denmark had the world's lowest mortality (Murray et al., 2006). Similar reductions in mortality have been replicated in laboratory animals fed a modified-protein diet with restricted amounts of the sulfur amino acid methionine (McCarty et al., 2009), which is most commonly found in meat and other high-protein foods. Elevated blood serum levels of homocysteine, which is derived from methionine, is a biomarker for cardiovascular disease (Ruijter et al., 2009). On the other hand, people with the highest serum concentrations of α-carotene, found in greens and other fruits and vegetables, had a 39% reduced risk of death (Li et al., 2010).
As in Denmark during WWI, the potential exists today for reductions in mortality and healthcare costs from a plant-based 5–6% protein diet. Unfortunately, the Danes had an unappealing bland diet imposed on them, and they quickly reverted to a high-protein diet after the war. They now have the highest per capita rate of osteoporosis in the world (Nationmaster.com, 2009). Fortunately, we have much more appealing foods we can use on a low-protein diet.
Sweet fruits, avocados, and raw, unsalted, low-protein nuts, such as pecans, macadamia nuts, and coconuts (which are also low in methionine), are some examples of the best foods that provide the necessary concentrated sources of energy from unrefined fat and carbohydrates in a plant-based diet to maintain bodyweight, while keeping overall protein intake at 5–6% of calories. See Sample Menus below.
the fear of dietary saturated fat causing you to eat an unhealthy,
unbalanced diet? See: Is
the Lipid Theory Dead? Also see:
Because teeth are bones, a low-protein, plant-based diet applies equally as well in preventing diseases of the teeth, gums, and jaw. Hafer (2001) reported that giving caries-resistant rats ammonia, which is naturally produced in high levels when excessive protein is metabolized, made the rats susceptible to dental caries. The World Health Organization (2003) reported that when the pH of saliva rises to an alkaline value of 7, it becomes super-saturated with calcium and phosphate, and remineralizes worn tooth enamel. Victoria Boutenko (2005) described how she raised her saliva pH by consuming large quantities of dark leafy green vegetables in green smoothies made with fruit. She recommended consuming two bunches or 1–2 pounds of leafy greens a day.
One case report claimed that a bone density test showed the subject's osteoporosis significantly improved and the risk of fracture was eliminated after a year of drinking two quarts of green smoothies a day (greensmoothiesblog.com, 2010). People who consume a high intake of vitamin K which is most abundant in leafy green vegetables like kale, parsley, collards, etc. have lower risk for cancer mortality, cardiovascular mortality, and all-cause mortality (Juanola-Falgarona et al. 2014). Shelton described Elmer McCollum's experiments, the great biochemist who discovered many vitamins, in which adding beet or turnip greens to a diet of whole wheat and water nearly doubled the growth size of rats.
In addition to excess sulfur from protein, bone loss occurs when dietary phosphorus intake exceeds calcium intake, which occurs independently of the absolute phosphorus intake level (Sax, 2001). Calcium binds with phosphorus in the blood to form calcium-phosphate. Excess phosphorus consumption lowers intestinal calcium absorption in animals (Koshihara et al., 2005). As phosphorus levels increase and calcium levels decrease in the blood, parathyroid hormone is released to restore calcium balance by increasing calcium absorption, releasing calcium from bone and causing the kidneys to excrete phosphorus. To avoid excessive phosphorus intake, nutrition authorities often recommend consuming at least a 1:1 molar ratio of dietary calcium to phosphorus to prevent bone loss (Kemi, 2010), which converts into a weight ratio of 1.3:1 (One mole of calcium, 40.08 grams, divided by one mole of phosphorus, 30.97 grams, equals 1.3. In other words, because calcium molecules weigh 30% more than phosphorus molecules, trying to combine equal weights of phosphorus and calcium molecules would leave you short calcium molecules unless you increase the calcium amount 30% by weight.)
The average calcium-phosphorus ratio in the spongy trabecular tissue of bone is 2.07:1, and 2.17:1 is the average ratio in the harder cortical bone tissue (Zaichick & Tzaphlidou, 2002; 2003). Based on normal reference ranges, the calcium-phosphorus ratio in blood serum for adults is 2.58:1 (Mahan, et al., 2012). The USDA reports a calcium-phosphorus ratio in human milk of 2.28:1. The median calcium-phosphorus ratio of human milk in studies reviewed by Jenness (1979) is approximately 2:1, while Feeley et al. (1983) estimated that the combined stages of breast-feeding in which milk nutrients decrease during weaning provides a total calcium-phosphorus ratio of 1.83:1. A ratio of 1.7:1 in human milk provided optimal retention for both phosphorus and calcium in the human fetus and in premature infants (Pelegano et al., 1991). Note that the developing human fetus and premature infant have a greater need for phosphorus for growth, which explains the lower calcium-phosphorus ratio in their diet.
Harvey and Marilyn Diamond, authors of Fit for Life, wrote in Living Health, "There should be a two-to-one ratio of calcium over phosphorus taken into the body (p. 240)." A 2:1 ratio or higher appears to be sufficient to build human bone, blood, and milk. Some researchers feel the RDA for calcium should be raised to 1,500 mg in older adults (Heaney, 1982), which would increase the dietary calcium-phosphorus ratio to 2.14:1. The dairy-free Bone Builder Diet at the end of this webpage provides 1,555 mg calcium. By comparison, the ratio of calcium to phosphorus in the Western diet can be as low as 0.25:1 or lower (Lamberg-Allardt, Karp, & Kemi, 2010). Instead of consuming twice as much calcium as phosphorus, many people consume two to four times as much phosphorus as calcium!
Phosphorus is most often found in high-protein foods like dairy products, meat, grains, legumes, and high-protein nuts. Phosphorus levels are lower in low-protein coconuts and macadamia nuts, especially measured by calorie. Macadamia nuts and dates have about half the amount of phosphorus per calorie (0.22 mg) as oranges (0.42 mg). Potatoes (0.83 mg) and whole wheat bread (0.82 mg) have almost 3 times more phosphorus per calorie than bananas (0.29 mg). One baked potato or two cups of white rice has as much phosphorus as five large bananas. Lean beef (0.95 mg) is higher in phosphorus per calorie than almonds (0.87 mg). Two-percent cow milk is about twice as high in phosphorus per calorie (1.84 mg) as lean beef, and phosphorus in no-fat milk (2.9 mg) is over 10 times higher per calorie than in macadamia nuts. Many sweet fruits, with the exception of citrus, figs, and papayas also have higher phosphorus levels than calcium, although the absolute amount of phosphorus in fruit is low compared to dairy, grains, meat, nuts, and legumes. Nevertheless, all these foods need to be balanced with calcium supplied from dark leafy green vegetables. Do not substitute wheatgrass juice for raw leafy greens because wheatgrass juice has a very poor calcium to phosphorus ratio of only 0.34:1 (Meyerowitz, 1999).
Cow milk has only a 1.3:1 calcium to phosphorus ratio, which is below ratios of 2:1 in human bone and 2.28:1 in human milk. Thus, it is mathematically impossible for cow milk alone to supply the proper ratio of calcium and phosphorus necessary to produce human milk and bone in adults, no matter how much milk is consumed. Additionally, only 32% of calcium is absorbed from pasteurized milk and cheese (Lanou, 2009). Calcium is not as bioavailable for human nutrition in pasteurized milk compared to raw milk (Kramer, Latzke, & Shaw, 1928), while phosphorus bioavailability remains stable. FIGURE 3. shows how the calcium: phosphorus ratio in milk is inverted when calcium bioavailability is reduced, which may explain the calcium paradox in which populations that consume the most dairy products have the most osteoporosis.
Phosphatase, an enzyme in raw milk that is responsible for calcium utilization in forming bone, is deliberately destroyed through heating by dairy producers to indicate that the milk has been adequately pasteurized. Also note that the bioavailability of calcium supplements give no indication if the calcium is useable by the body. In addition, Campbell (2008) found that a diet with 20% calories from casein, a phospho-protein in cow milk, was carcinogenic when fed to rats. The same amount of soy protein or wheat protein, which are not phospho-proteins, were not carcinogenic when fed to rats. Ohnishi and Razzaque (2010) demonstrated that phosphorus toxicity causes bone deformities and premature aging in laboratory animals. Compared to a healthy group fed a 2:1 calcium to phosphorus ratio, lab animals fed a 0.9:1 ratio had abnormal tooth development and enamel formation (Jekla, Krejcirovab, Buchtovac, & Knoteka, 2011).
Researchers of the previously cited study on North Alaskan Eskimos (Mazess & Mather, 1974) claimed that the "moderate phosphorus intake" of the Eskimo was unrelated to Eskimos' high osteoporosis rate. Yet, dietary phosphorus and protein naturally co-exist in animal foods as phospho-proteins. Therefore, consuming up to 400 grams of protein a day implies that Eskimos were actually consuming excessive amounts of phosphorus to account for their osteoporosis despite their high calcium intake, especially when combined with Eskimos' high sulfur intake from protein.
College womens' calcium retention increased when they consumed 1500 mg calcium and only 800 mg phosphorus with a calcium-phosphorus ratio of 1.88:1, but increasing their phosphorus intake to 1400 mg with a calcium-phosphorus ratio of 1.07:1, "resulted in much less satisfactory utilization of calcium" (Leichsenring, Norris, & Lamison, 1951). The researchers concluded, "a factor of considerable importance in the relatively poor utilization of calcium by human subjects is the amount of phosphorus regularly included in the diet." Bone mineral content and bone mineral density in postmenopausal women was lower in omnivores who consumed 10% more phosphorus than lacto-ovo-vegetarians, even though the omnivores also consumed 10% more calcium (Tylavsky & Anderson, 1988).
Cow milk contains over 6.5 times more phosphorus than human milk (Lenstrup, 1926), and has been linked to tetany (muscle cramping) when fed to newborn human infants (Gardner et al., 1950). After examining serum calcium and phosphorus levels in his patients, Melvin E. Page, D.D.S. noted that "a high phosphorus level may be responsible for inflammation of the gums" (Page & Abrams, 1972). Page recommended his patients avoid milk, cheese, and all refined foods. Unfortunately, Page also attempted to correct the hormonal imbalances in his patients' serum with glandular extracts, which does nothing to correct the disturbed mineral metabolism that caused the hormonal imbalances in the first place. Hormones are merely messengers in the body, and opposing their function without correcting the cause of the hormonal imbalance amounts to shooting the messenger or turning off the fire alarm without putting out the fire.
A high-phosphorus diet induced gingival (gum) inflammation in rats (Lütfioğlu et al., 2010). These findings strongly suggest that muscle cramping and gum inflammation in humans may be symptoms of excess dietary phosphorus. Muscle cramping may be directly related to the initial lowering of serum calcium as phosphorus levels rise, which eventually triggers the parathyroid glands to release calcium from bone. In addition, hunter-gatherers who ate large amounts of acorns, pine nuts, and pistachios, which are high in phosphorus and low in calcium, had high rates of dental caries (Humphrey et al., 2014).
In her book on using a low-phosphorus diet to correct behavioral problems in children, Hafer (2001) asserted that successfully treating calcium metabolic disorders, including bone disorders like osteoporosis, is only possible with low-phosphate food. Hafer pointed out that cow milk contains excessive phosphorus for humans, and, because calcium metabolism is controlled solely by the blood phosphate level, Hafer asserted that high blood-phosphate levels which occur from excessive milk intake produce bone disorders independently of calcium intake levels, high or low.
When blood serum levels of phosphorus rise above normal (hyperphosphatemia), calcium serum levels drop (hypocalcemia) and the parathyroid glands respond by releasing parathyroid hormone, PTH (Slatopolsky, 1996), which removes calcium from bone to increase serum calcium levels. The excess serum calcium-phosphate product formed, if not eliminated by the kidneys, may be deposited in soft tissue (Block et al., 1998) causing vascular calcification and kidney stones.
Román-García et al. (2010) demonstrated that increased vascular calcification is directly related to decreased bone mass in rats fed a high phosphorus diet. Oliviero et al. (2011) described how calcium phosphate crystals are deposited within joints to cause arthritis. Chen et al. (2005) examined how eye lens calcification occurs in cataracts, and Schrier (2007) described a condition called "Abnormal Circulating PTH" which links hyperphosphatemia with cataracts. Cataracts related to disturbed parathyroid function have been observed in human patients (Lyle, 1948; Weinstein, 1933). Secondary hyperparathyroidism, hyperphosphatemia, and hypocalcemia have been associated with cataracts in kittens (Bassett, 1998; Stiles, 1991). Rats developed cataracts when fed a diet of dairy (Chen et al., 2012; Richter & Duke, 1970). Greater intake of milk was associated with cataract prevalence in India (Bhatnagar et al., 1989). In addition to these soft tissue changes related to high phosphorus intake, Hur (n.d.) claimed that skin wrinkling also occurs as calcium is transferred from bone to soft tissue.
The link between hyperphosphatemia and soft tissue calcification could help explain why fasting and calorie restriction (CR) increases longevity. By reducing food intake, CR allows the kidneys to catch up on excreting excess dietary phosphorus, thus reducing the amount of calcium-phosphate product that is stored in soft tissue and helping to reduce aging. Without restoring the right balance of phosphorus intake and output, soft tissue calcification goes on silently, year after year. Restoring phosphorus balance is not a question of "alkalinizing" your body with more minerals. It's a question of reducing excess dietary phosphorus intake.
Hafer (2001) criticized the concept of a Ca:P intake ratio for overlooking the independent calcium and phosphorus regulatory mechanisms in the body (e.g., intestinal absorption and kidney filtration), and she suggested it is more important to keep phosphorus intake levels low. Although Sax (2001) noted that bone loss (resorption) is lower when calcium intake is increased, studies in humans have shown that high calcium intake does not completely counteract the effect of excess phosphorus (Lamberg-Allardt et al., 2010). Intestinal phosphorus absorption is more than twice as efficient as calcium absorption (Razzaque, 2011). Therefore, if greater calcium-phosphorus molar ratios are required for bone formation, humans likely developed on a diet that is more than twice as rich in dietary calcium than phosphorus—which is reversed in the Western diet. Similar to humans, many lab animals also have intestinal-renal systems that regulate calcium and phosphorus absorption; nevertheless, according to Nutrient Requirements of Laboratory Animals published by the National Academies Press, these animals have healthier bones on diets with high Ca:P ratios ranging between ~1.66–2:1. Schoolchildren also have fewer dental cavities when consuming a higher Ca:P ratio (Lin et al, 2013).
To summarize: calcium intake is effective in protecting against bone loss when the Ca:P ratio is high. However, when serum phosphorus rises to a critical level, serum calcium levels fall and bone loss occurs as the parathyroid glands release calcium from bone, regardless of the Ca:P ratio of the food eaten. Thus, dairy products' high phosphorus content can lead to critically high blood-phosphate levels that disturb calcium metabolism and cause bone loss, even though dairy products contain calcium. Non-fat milk has twice the phosphorus per calorie as whole milk. Similar to excess sulfur in protein, the harmful effects of excess phosphorus are not prevented by extra calcium. Toxic sulfur and phosphorus levels along with poor calcium bioavailability explains why consuming excessive dairy products from cows causes osteoporosis.
FIGURE 4. shows the extremely high phosphorus and sulfur content of cow milk (Masters & McCance, 1939) compared to an equal amount of human milk (McNally, Atkinson, & Cole, 1991). Notice how the amount of phosphorus in cow milk is much more excessive than sulfur.
The high acid load of dairy products means they cannot balance other acid-forming foods as can green vegetables. Although a study found no protection from bone fractures when women consumed more than 750 mg of calcium a day (Warensjö et al., 2011), the researchers did not control for the increased amount of acid-forming phosphorus and sulfur associated with higher levels of calcium when greater amounts of dairy products are consumed. If dairy products are eaten, they should be consumed in small amounts in place of other acid-forming foods like grains, legumes, nuts, eggs, and flesh, and they should be balanced with green vegetables. Whey is the only dairy product that doesn't have a net acid load, primarily because it is high in potassium and low in protein, but its calcium-phosphorus ratio is 30% lower than milk and therefore it is a poor bone-building food.
The Dietary Reference Intake (DRI) of the Institute of Medicine's Food and Nutrition Board recommends adults over age 50 consume 700 mg phosphorus and up to 1,200 mg calcium daily—a calcium-phosphorus ratio of 1.71:1 that no amount of cow milk could ever provide! For a 154-pound person eating a 2,000-calorie diet, this calculates to 0.35 mg of phosphorus per calorie or about 10 mg phosphorus per kilogram bodyweight. In selecting the criteria for estimating the phosphorus RDA, the Food and Nutrition Board (1997) wrote, "the requirement will be based on the intake associated with maintenance of serum Pi [inorganic phosphorus] at the bottom end of the normal range."
Additional amounts of phosphorus are required for young people. The amount of phosphorus per gram of dietary protein averages 12-16 mg (National Kidney Foundation, 2005). This amount is similar to the German Association for Nutrition recommendations of up to 12.6 mg of phosphorus per kilogram bodyweight, which researchers Nordin and Smith set at 12.2 mg phosphorus per kilo bodyweight (Hafer, 2001). At this amount, a 1000-pound calf requires 5,000-6,000 mg of phosphorus a day (National Research Council, 1978). The Merck Manual stated that daily dietary phosphorus intake levels under 1,000 mg are sufficient to treat early stages of kidney disease in humans. Other researchers have treated kidney patients with low-phosphate diets at ~ 8 mg phosphorus per kilo of bodyweight. The median daily phosphorus intake in the adult population is 1242 mg. At 1400 mg phosphorus, mortality rates begin to rise (Chang et al., 2013), and mortality also rises when phosphorus per calorie exceeds 0.35. Drinking cow milk designed to supply over 5,000 mg of phosphorus a day to a calf makes little sense for humans.
Three 8-ounce servings of 2% cow milk, as recommended by USDA Dietary Guidelines for Americans and Canada's Food Guide, contains 687 mg of phosphorus, which is 98% of the RDA for phosphorus, and 30% above the recommended amount of sulfur amino acids. In combination with phosphorus and sulfur amino acids from additional foods like meat, eggs, potatoes, legumes, and grains which are eaten to meet calorie requirements, recommended milk and dairy product consumption causes calcium imbalances from toxic phosphorus and sulfur levels.
For example, 153 grams or a bit less than 5.5 ounces of part-skim-milk mozzarella contains 1,196 mg calcium and 708 mg of phosphorus, which almost perfectly meets the recommended dietary allowance for calcium and phosphorus for people over 50. Ignoring for the moment that only one-third of this calcium is bioavailable due to pasteurization, and that mozzarella has a high overall net acid load due to its concentrated source of protein, you may think mozzarella is a highly nutritious dairy product to include in your diet. However, your body receives only 389 calories from this amount of mozzarella. What's wrong with that? Well, this leaves you short of meeting your daily energy requirement by about 1800 calories or more even though you have already reached close to your phosphorus limit. How will your body manage the excess phosphorus consumed by eating another 1800 calories of food for energy? Even for weight-loss purposes, you may still need to eat at least another 1000 calories or more. You could add empty calories from refined oils and refined carbohydrates that have had all the minerals stripped away, but empty-calorie foods damage bone, blood, and nerve tissue.
The problem is that dairy products as well as flesh foods provide few calories per mg of phosphorus, making them impractical foods for use in large amounts to sustain health. Fat-free milk has almost 3 mg phosphorus per calorie, which is double the amount in whole milk. By contrast, many fruits and low-phosphorus nuts easily meet energy requirements while providing much lower amounts of phosphorus per calorie (phosphorus caloric density). Macadamia nuts provide more than 10 times less phosphorus per calorie than fat-free milk. Green vegetables contain a high amount of phosphorus per calorie, but this is not a problem because green vegetables contain so few calories by weight.
Regulating your phosphorus intake helps limit excessive intake of protein and sulfur in your diet as well. To keep within your phosphorus limits, you must regulate your diet's:
Consuming large amounts of pasteurized dairy fails to meet all three criteria: It has a high phosphorus caloric density, especially low-fat dairy; pasteurized dairy has poor calcium bioavailability which inverts the calcium-phosphorus ratio; and it is easy to exceed a healthy intake of the absolute amount of phosphorus when the diet contains dairy.
"Milk times three is good for me? Milk times three...toxicity!" One medium-sized 12-inch cheese pizza contains more than two-day's worth of phosphorus (1,838 mg). Many other fast food items are also high in phosphorus. For example, two McDonalds sausage biscuits with egg have 988 mg phosphorus. Even vegetarians who eat whole natural foods are at risk of consuming too much phosphorus. In Orthotrophy, Shelton noted that vegetarians are harmed by the great amount of grains they eat. Whole grain wheat flour contains almost two and a half times as much phosphorus (346 mg) as lean beef (145 mg) and almost four times as much as whole milk (91 mg). The typical vegan diet containing grains and legumes with 13% of calories from protein has 1,781 mg of phosphorus, 795 mg of calcium, and an inadequate calcium-phosphorus ratio of 0.44:1 which is sufficient to cause elevated serum phosphate levels and soft tissue calcification. Sample 2,000-calorie menus from the United States government My Plate nutrition program contain a daily average of 1885 mg phosphorus and 1436 mg calcium with a calcium-phosphorus ratio of 0.76:1.
Take this Bone Loss Quiz.
The adult skeleton normally loses and replaces 400 mg of calcium a day (Williams et al, 1997). Whether bone suffers a net loss of calcium depends on factors that cause the body to either retain or remove additional amounts of calcium from bone. In addition to excess phosphorus and protein, salt, caffeine, alcohol, refined carbohydrates, lack of sunshine, and lack of weight-bearing exercise are some other factors that contribute to bone loss (Vegetarians in Paradise, 2009). Even an excess of natural, unrefined carbohydrates can cause bone loss (See Fruitarian Diets: How to Make Them Healthy).
If possible, use a nutrient counter to analyze your diet every now and then to make sure you are keeping your protein intake at approximately 5–6% of the calories needed to maintain a healthy bodyweight. This is the best way to ensure the maintenance of healthy, strong bones. Here is a Diet Analyzer Excel spreadsheet I created to analyze the protein, fat, carbohydrate, calories, calcium, and phosphorus content in grams of fruit, nuts, and vegetables. The analyzer totals the percentages of calories from macronutrients as well as the calcium-phosphorus ratio.
If you are not a vegan, you can add other foods to the Diet Analyzer by copying information from the link to the USDA at the bottom of the spreadsheet. However, don't be surprised to see your protein intake immediately skyrocket to 10%, 15%, or more if you add grains, legumes, and animal foods to your diet. See the bottom table.
sample raw vegan Bone-Builder Diet includes blended soups, salads,
and smoothies made with:
In conclusion, about a 2:1 calcium-phosphorus ratio appears to be the optimal ratio in the diet of most animals for ideal bone development. This appears to apply to humans as well. Healthy kidneys normally excrete more phosphorus than calcium, thus raising the serum calcium-phosphorus ratio to 2.5:1. However, there is a limit to how much kidney and intestinal regulation can maintain normal serum levels if the diet is poor. A diet inadequate in the proper balance of minerals forces the body to sacrifice minerals from bone to maintain the serum at normal levels. A diet high in dairy products can never provide the proper mineral balance for humans to maintain bone and overall health.
The best way to save your bones and teeth from osteoporosis,
dental decay, and related bone problems is to at least follow the RDA for calcium
and phosphorus as part of a properly balanced diet. But according to an analysis by Chang et al. (2013),
almost no adult in the United States comes even half way to meeting the RDA for both calcium and
phosphorus in the proper ratio of 1.42-1.71:1. The researchers found that
the median values for phosphorus and calcium intake were 1242 mg and 758
mg respectively with a calcium-phosphorus ratio of only 0.61:1. Dairy
consumption must account for a large part of this problem. In addition to
providing low calcium bioavailability, the more pasteurized dairy you
consume the quicker phosphorus intake rises, and the
less likely you are to succeed in meeting the RDA for calcium and
phosphorus in the proper ratio. Only a properly balanced diet of natural
foods with plenty of raw green leafy vegetables and fresh fruit with
adequate amounts of nuts and seeds can save your bones and teeth.
5–6% Protein, Raw, Vegan Sample Menus:
Calories from Protein in Grain, Legume, and Animal Foods:
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