Super Immunity (18 page)

Almost all Americans get more than enough protein daily. In fact, the average American consumes over 100 grams of protein, about 50 percent more than the recommended daily amount. Yet too many of us, including athletes, fitness enthusiasts, bodybuilders, dieters, and the overweight, turn to protein powders, protein drinks, and nutrition bars in a quest for even more protein.

The overall goal is to eat fewer animal products
in general so that we can reduce the amount of
protein from animal sources and increase the
amount of protein from plant sources.

It is true that a certain lifestyle, one involving vigorous and regular physical workouts, requires additional protein. For example, resistance training and endurance workouts can break down muscle protein and increase our need for protein to fuel repair and growth. But the increased need for protein is proportional to the increased need for extra calories burned from the exercise. As exercise increases our appetite, we increase our caloric intake accordingly—and our protein intake increases proportionally. If we meet the increased caloric demand from heavy exercise with an ordinary assortment of natural plant foods—vegetables, whole grains, beans, seeds, and nuts—we will get the precise amount of extra protein needed. A typical assortment of vegetables, nuts, seeds, beans, and whole grains supply about 50 grams of protein per 1000 calories. Don't forget, green vegetables are almost 50 percent protein, and when you eat more vegetables, it gives you your protein in a Super Immunity and anticancer package.

When the additional calories are derived from health-enhancing plant foods, you will get much more than just protein; these foods will supply you with a host of antioxidants to protect against the increased free radicals generated by the exercise. Nature planned this pretty well!

Take a look at this sampling of foods, shown with their caloric and protein content:

P
ROTEIN
C
ONTENT OF
C
OMMON
P
LANT
F
OODS

Consider that the maximum muscle mass the human body can typically add in one week is about one pound. That's the upper limit of the muscle fiber's capacity to make protein into muscle; any protein beyond that is simply converted to fat. Although athletes have a greater protein requirement than sedentary individuals, this extra is easily obtained through the diet; the use of protein supplements is not merely a waste of money, it is unhealthy.

Taking in more protein, especially animal protein, than your body needs is not a small matter. It ages you prematurely and can cause significant harm. The excess protein you are
not
using isn't stored by the body as protein; it is converted to fat, or it is eliminated via the kidneys. Eliminating excess nitrogen via the urine leaches calcium and other minerals from the bones and breeds kidney stones. Vegetable foods are alkaline. Animal products are acidic foods, and they require a huge output of hydrochloric acid from the stomach to digest them. This acid tide in the blood, after a high-protein meal, requires an equally strong base response by the body to neutralize the acid. We get the needed base contribution at the expense of our bones, which give up their minerals; our bones literally dissolve for that purpose into phosphates and calcium. This is a primary step in bone loss that leads to osteoporosis. Our high salt intake then further contributes to flushing our bone mass down the toilet bowl. The excessive stimulation of bone turnover also causes an increase in bone breakdown and remodeling, which can lead to osteoarthritis and calcium deposits in other tissues.

Exercise, not extra protein, builds strength, denser bones, and bigger muscles. When you artificially stimulate growth with overfeeding and excessive animal product consumption, you may achieve a heightened body mass index (a weight-to-height ratio), but this will add fat to your body as well. Let me caution you that a higher body mass index, even if that additional body mass is mostly muscle, is linked to an earlier death. Large football players have over twice the risk of early cardiac death than the general population, with many of them dying before their fiftieth birthday.
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Out of more than six hundred Olympic athletes on the East German 1964 Olympic team, fewer than ten are still alive today. Promoting muscular growth with supplements and steroids doesn't seem too wise, when seen in that context. Excessive body mass, even excessive muscular development from overeating high-protein animal products, is a risk factor for heart attacks and other diseases later in life.

We can't judge health by size; we must judge it by resistance to serious illnesses, longevity potential, and maintaining our useful vigor and athleticism into our later years. When you're trying to exercise for health and eat for health, one of your goals should be to reduce rather than increase animal food consumption and animal-derived protein.

A hormone known as “insulin-like growth factor 1” (IGF-1) is one of the body's important growth promoters in the womb and during childhood growth, but it also has some anabolic (or bodybuilding) effects in adulthood. A person's IGF-1 production is promoted by consuming more protein of a high biological value—which is to say, protein that contains all of the essential amino acids in the proportion that maximally promotes growth. The protein from animal products fits that description: it is of a very high biological value. Thus our society's mistaken preoccupation with maximizing size and growth through the high consumption of animal protein has driven up IGF-1 levels.

The production of IGF-1 takes place primarily in the liver, and its production is stimulated by something called “pituitary-derived growth hormone” (GH). IGF-1 is a key contributor to brain development, muscle and bone growth, and sexual maturation. The highest levels of IGF-1 occur during the growth spurt and the sexual maturation phase of puberty. The issue here is that
elevated
IGF-1 levels, resulting from today's animal-protein-heavy diet, have been linked to cancer; indeed, they are thought to bear considerable responsibility for the high rates of cancer in the modern world.

Scientists first noted that higher levels of sex hormones such as estrogen and testosterone were associated with breast cancer; more recently, insulin and IGF-1 have been demonstrated to be important promoters of cancer as well. The connection between increased IGF-1 and cancer has been recognized for many years. In fact, cancer drugs targeting the IGF-1 pathway began to be developed in the late 1990s, and over seventy clinical trials have begun since then, many with encouraging results.
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Since IGF-1 plays a key role in tumor growth, reducing IGF-1 levels by dietary methods is now considered by scientists to be an effective cancer-prevention measure.

IGF-1 is crucial for growth and development in childhood, as noted earlier; but if levels remain high during adulthood, it speeds aging, reduces immune function, and promotes cancer. Conversely, reduced IGF-1 has been associated with enhanced lifespan.
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Our nation's mistaken overemphasis on protein, with the resulting elevation of IGF-1 levels, has clearly played a destructive role in the exploding cancer epidemic of the last hundred years. Excess intake of refined carbohydrates can also have a detrimental effect on IGF-1 levels. The intake of those carbohydrates leads to an increase in the production of insulin, which regulates energy metabolism (while also increasing production of IGF-1 and decreasing production of IGF-binding proteins).
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Type 2 diabetes, in which the body can't properly use what insulin there is, is associated with breast, colon, and pancreatic cancer, and there is evidence that insulin-mediated stimulation of IGF-1 production is partially responsible for this increase in cancer.
¹⁵

Due to decreased secretion of growth hormone (GH), IGF-1 levels naturally decline with age. On average, serum IGF-1 is approximately 150 nanograms per milliliter at age fifty, and 100 nanograms per milliliter at age eighty.
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Since GH can stimulate muscle growth, it used to be prescribed by some alternative-medicine physicians, who promoted it as an anti-aging hormone. However, studies found that restoring GH to youthful concentrations was not beneficial; in fact, GH treatment increased mortality in elderly and ill patients, and increased diabetes and glucose intolerance in healthy adults.

Today there is a tremendous amount of evidence regarding the lifespan-enhancing effects from
lowered
levels of IGF-1 in adulthood.
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Not only do higher IGF-1 levels promote cancer, but they also increase potential for dementia. Elevated circulating IGF-1 levels have been found to promote Alzheimer's disease, and reduced IGF-1 has been found to reduce symptoms of neuro-degeneration.
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In tissues that require IGF-1 for proper function in adulthood, “local” production of IGF-1 in exercised muscle tissues compensates for the lower circulating IGF-1 levels. In other words, lower levels are longevity-promoting and without apparent drawbacks.
¹⁹

The body's cells are replicating all the time. As cell damage takes place, high circulating IGF-1 levels promote the replication of cells that might not have progressed into malignant tumors if not for the IGF-1 stimulation. IGF-1 stimulation is involved in a number of processes relevant to tumor growth: proliferation, survival, adhesion, migration, invasion, angiogenesis, and metastatic growth.
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Higher levels of IGF-1 have been associated with almost all cancers, though the largest amount of data available is for the most common cancers—of the breast, prostate, and colon. The European Prospective Investigation into Cancer and Nutrition (EPIC) found that elevated IGF-1 levels were associated with a 40 percent increased risk for breast cancer in postmenopausal women.
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In the Nurses' Health Study, high IGF-1 levels were associated with a
doubling
in risk of breast cancer in premenopausal women.
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Four meta-analyses have also associated elevated IGF-1 levels with breast cancer.
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Elevated IGF-1 levels have also been associated with colorectal cancer, in research that demonstrated that IGF-1 promotes spread of colorectal cancer cells.
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Finally, a 2009 meta-analysis of forty-two studies concluded that elevated circulating IGF-1 is associated with increased risk of prostate cancer.
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The combined effects of reduced IGF-1 and low levels of systemic inflammation have been proposed as a mechanism by which centenarians (those one hundred and older) are protected from cancer. Cellular inflammation is caused by excess free radicals and reactive oxygen species, as discussed earlier, and can be prevented by proper nutrition. So it is easy to see why the present dietary practices are so cancer-promoting. If you want to live to one hundred and thrive, you will require low levels of circulating IGF-1 and high levels of anti-inflammatory molecules. Genes signaling to enhance cells' DNA repair mechanisms to fight changes that could lead to cancer are supported by higher levels of anti-inflammatory molecules and plant micronutrients, and lower levels of IGF-1. The combined effect of a high-phytochemical diet resulting in reduced inflammation and oxidative stress, coupled with reduction in IGF-1, is the secret to maximizing longevity and cancer protection.
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Amino acids are the individual building blocks of protein. Nine are called “essential,” meaning that the body cannot make them from other amino acids. As noted earlier, consuming dietary proteins that are more “complete” in all essential amino acids—such as animal-source protein—causes larger increases in IGF-1 than does protein not as biologically complete and with more
non
essential amino acids. Generally, people with higher intake of animal products have much higher plasma IGF-1—that is, IGF-1 as measured in the blood—than those with lower intake.
²⁷
In women, after adjusting for caloric intake, no association was found between fat or carbohydrate intake and IGF-1, but animal protein and milk drove up IGF-1 to risky levels. This suggests that a diet lower in animal protein is the most modifiable factor to maintain a lower and healthier level of IGF-1.
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Interestingly, saturated fat intake does not raise IGF-1 directly, but because it is associated with lower levels of IGF-binding proteins, it increases circulating free IGF-1 even further.
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IGF-1 levels are also notably lower in vegans.
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