Meatonomics (31 page)

Vitamin B
₁₂
is one nutrient some vegans might have a problem obtaining from plants, but not because it's not present naturally. In fact, neither plants nor animals are capable of independently producing B
₁₂
; the vitamin is produced only by bacteria.
⁶
These bacteria are typically present in unwashed vegetables, but not in the triple-washed, hermetically packaged vegetables most people eat today. Thus, while it's appropriate for strict vegetarians to take B
₁₂
supplements unless they grow and fertilize their own crops, this is merely the result of life in industrialized society and not a feature of body design. Furthermore, our bodies need only the tiniest amount of B
₁₂
. Those who
eat lots of meat may get too much, and high levels of B
₁₂
are associated with a higher risk of prostate cancer.
⁷

As to the argument that hominids have been eating meat for aeons, the archaeological record is less than conclusive. One school of thought posits that early humans were predominantly scavengers, not hunters, which explains the presence of animal bones at early human sites.
⁸
The theory that meat consumption in early humans was merely opportunistic, rather than the product of complex social activities like group hunting, tends to counter the argument that human evolution has been closely related to dietary changes like increases in animal protein consumption.

Another interesting line of research postulates that early humans were mainly prey, not predators, engaging in social behaviors like group living for self-defense rather than hunting. According to archaeologist Robert Sussman, our hominid ancestors were vegetarians who, because of body morphology, “simply couldn't eat meat.”
⁹
These early humans inhabited a hostile landscape populated by ten times more predators than today, and one in ten hominids became another animal's dinner. Sussman and others argue that the concept of early humans as hunters has been radically overstated; in fact, evidence suggests that systematic hunting did not begin until relatively recently within the total scope of human evolution.
¹⁰

While it is undeniable that humans have hunted for millennia, it does not follow that our bodies evolved to eat meat. We're opportunistic, intelligent, and highly capable of developing and using technology. To look at it another way, we readily build and use airplanes, although our bodies did not evolve to fly.

Through aggressive government marketing and artificially low prices, meatonomics encourages Americans to consume huge quantities of dairy. Each American takes in about 2 pounds of dairy every day. That's nearly three times the worldwide average and, according to experts, considerably more than our bodies can safely process.
¹¹
As with meat,
these high consumption levels damage our health and cost billions of dollars to treat. A brief overview of dairy's health effects shows why.

Mammals have mammaries. That makes us unique in the animal kingdom, both in producing milk and in drinking it when young. Milk is nature's way of promoting rapid growth and boosting the immune system of infants, which is why milk is stocked with antibodies and nutrients like protein, calcium, and vitamin C. For human babies unable to chew or digest solid food, milk is a great delivery vehicle for these nutrients. For adults and children past weaning age, however, a sizable body of research suggests otherwise. These studies find that when fed to non-infants, especially at the levels Americans consume it, dairy is not only unnecessary but harmful.
^¶
As Dr. Michael Klaper said, “The human body has no more need for cows' milk than it does for dogs' milk, horses' milk, or giraffes' milk.”
¹²

Consider protein, the building block of muscle and tissue development. Because natural selection among prey animals like cattle favors those whose young grow quickly, bovine infant formula, or cow's milk, has triple the protein content of human's milk. This high protein content helps calves gain 2 pounds a day during the first nine months of their lives. It also helps human children who drink lots of cow's milk grow faster than those who drink less.
¹³

This rapid pace of growth might appeal to parents who associate fast growth with good health. However, clinical studies question this need for speed, finding that children who grow quickly are more likely than others to develop cancer later in life.
¹⁴
Do human children really need to grow as fast as cattle? Maybe not. For one thing, unlike prey animals, human babies can afford to grow slowly because their parents protect them from predators.

Dairy promotes rapid cell growth, but this is a double-edged sword. One problem with this process is it spurs the development of both
healthy and unhealthy cells. As a result, cancer cells develop in ways that evade or overwhelm the body's natural capacity to attack and kill them. The biggest culprit in this area appears to be the protein casein, one of the main ingredients in milk. According to
The China Study
coauthor T. Colin Campbell, casein is an “exceptionally potent cancer promoter.”
¹⁵
This is
not
just a problem for milk or cheese gluttons. In fact, at levels well below the two pounds consumed by the typical American each day, research consistently finds dairy causes cancer.

Take prostate cancer, a disease which at least sixteen clinical studies link to dairy consumption.
¹⁶
In one study, men who drank more than two glasses of milk daily were found to have a significantly greater risk of prostate cancer than those who drank no milk.
¹⁷
The daily danger threshold of two glasses is
one less
than the USDA recommends and almost
two less
than the American average.

Among women, research finds that dairy—unfortunately, an equal opportunist—can cause both breast and ovarian cancer.
¹⁸
In the latter case, two large cohort studies find that women who consume just two servings of dairy daily—again,
one less
than recommended and
two less
than the average—have a significantly higher risk of ovarian cancer than those who consume less.
¹⁹
There's a pattern here: at consumption levels well below those the USDA recommends or Americans practice, dairy promotes disease.

The most surprising news about dairy may be its effect on bone density and health. We know that calcium is important to preserve bone density and prevent osteoporosis and that milk is an abundant source of calcium. But milk's acidic properties can affect our ability to fully utilize its calcium, and this can lead to some odd results. For example, a review of fifty-eight clinical studies evaluating the importance of dairy consumption to healthy bone growth in children and adolescents found no significant link between milk consumption—or calcium consumption—and healthy bone development.
²⁰
The authors of this study conclude:

Neither increased consumption of dairy products, specifically, nor total dietary calcium consumption, has shown even a modestly consistent benefit for child or young adult bone health. Conclusion: Scant evidence supports nutrition guidelines focused specifically on increasing milk or other dairy product intake for promoting child and adolescent bone mineralization.
²¹

Among older populations, research has yielded even weirder findings about dairy and bone health. A Harvard study found that women who drank two or more glasses of milk daily had a significantly greater risk of hip fractures than those who drank one glass or less weekly.
²²
And a study of elderly Australians found that those who consumed the most dairy had twice the risk of hip fracture compared to those who consumed the least.
²³
Coincidentally, as with prostate and ovarian cancer risk, the critical level at which dairy is risky for bone health—two servings a day—is below both the three recommended by the USDA and the nearly four servings (in milk or equivalents) consumed by Americans daily.

There are two reasons why consuming dairy can lead to problems with bone density like osteoporosis. First, dairy's acidic pH causes the body to release calcium (an alkali) from bone to counter the acid's effects and restore healthy pH.
²⁴
Second, high levels of calcium consumption over long periods of time impair the body's ability to regulate production of the hormone calcitriol, which controls calcium absorption and excretion.
²⁵
Inappropriate calcitriol production can lead to excessive release of bone cells and reduction in bone mineral density.

The body tends to adjust to higher and higher levels of calcium intake, that is, to raise its point of balance to equal the level of calcium consumption. This compensation mechanism means those who consume calcium supplements can suffer the same bone density problems as those who consume large quantities of dairy.
²⁶
One of the leading scientists in this field, the late Harvard nutritionist D. Mark Hegsted, wrote of the irony of this phenomenon:

As we encourage people to consume more calcium, their calcium requirement—as defined by calcium balance—increases, with no end in sight. Numerous population studies in the U.S. and elsewhere have analyzed the relationship between dietary calcium intakes and fractures, finding that surprisingly, high calcium intakes do not protect against fractures.
²⁷

On the contrary, high intakes of calcium
lead
to high fracture rates. In Hong Kong, daily calcium consumption is less than 500 milligrams per day, and females suffer hip fractures at the rate of thirty-five cases per hundred thousand people. Americans consume at least twice as much calcium, averaging about 1,000 milligrams per day. Yet our per capita incidence of female hip fractures is three times higher than Hong Kong's.
²⁸
This research is consistent with other studies that find bone fractures are more common in Western countries, where dairy consumption is high, than in countries where little dairy is consumed.
²⁹

The studies on calcium and hip fractures are not exactly breaking news—they were published in the 1980s and '90s. Moreover, modern research suggests that people seeking to improve bone density should exercise more and eat plant-based calcium sources like kale and spinach (a plan that seems to work for herbivores like horses and elephants). Why then do Americans still turn, somewhat futilely, to dairy and calcium supplements for bone health? We do so because despite the high correlation between dairy consumption, calcium intake, and hip fractures, the dairy industry and the USDA continue to recommend that Americans aged nineteen to fifty consume 1,000 milligrams of calcium per day. This recommendation appears to have one goal: to sell dairy products.

For many, it will be astounding to learn that kids don't need cow's milk and would actually be better off without it. Why is this news so astonishing? Because just as we know the sun rises in the east, we know children
need milk
to grow up big and strong. Yet one of the pieces of information to emerge from recent studies is that kids grow
up healthier when they
don't
consume significant amounts of dairy (other than their own mothers' milk) or other animal protein. Certainly, children need their own mothers' breast milk while in infancy. But otherwise, and after the age of weaning, there is little in the clinical literature to suggest that children need cow's milk or other animal foods for healthy development.

In fact, studies show the opposite. Girls who develop too quickly, for example—a phenomenon associated with drinking cow's milk—are more likely to develop breast cancer later in life.
³⁰
In one study of British girls, researchers found fast growth was associated with more than a 50 percent greater risk of breast cancer, leading the authors to conclude that “women who grow faster in childhood and reach an adult height above the average for their menarche [first menstruation] category are at particularly increased risk of breast cancer.”
³¹
This heightened cancer risk may stem from the fact that other than in infancy, mammals' bodies are simply not designed to drink milk. After humans are weaned, we stop secreting both the enzyme rennin that breaks down milk protein and the enzyme lactase that digests lactose (milk sugar) and transforms it into sugars that our body can use (glucose and galactose).

Doctor Benjamin Spock wrote the bestselling book
Baby and Child Care
and, a decade after his death, remains one of the most influential pediatricians on the planet. Spock staunchly opposed feeding cow's milk or other animal foods to children of any age. In the “Foods to Avoid” section of his book, Spock wrote:

Meat:
Children who grow up without developing a taste for meat, poultry, or fish will carry a tremendous advantage through life. Their tastes will not be oriented toward these products, all of which contain fat and cholesterol that can contribute to weight problems, heart disease and some cancers. They will also be at much less risk of infection with the bacteria that often taint meat products.

Dairy products:
Nondairy milk, particularly soy milk has real advantages over cow's milk and other dairy products. These
products are free of animal fat, animal protein, and lactose sugar, while still providing excellent nutrition.
³²

A number of children's doctors agree, including Dr. Frank A. Oski. While serving as director of pediatrics at Johns Hopkins University, Oski said, “There's no reason to drink cow's milk at any time in your life. It was designed for calves, not humans, and we should all stop drinking it today.”
³³

Are eggs really the “perfect protein”? They do provide protein and other nutrients. But they're also an abundant source of cholesterol; a single large egg contains 212 milligrams of the stuff. Because ingested cholesterol is never necessary but always harmful to our bodies, that's 212 milligrams more than we need and two-thirds more than the USDA's liberal, recommended daily maximum of 300 milligrams.
³⁴
The Jekyll-and-Hyde nutritional personalities of eggs seem to fit a pattern familiar in animal foods—they contain some helpful nutrients, but they also include plenty of disease-promoting substances. In the case of eggs, research has created controversy in the scientific community over whether their nutritional benefits outweigh the risks associated with their high cholesterol content.