Protein, Phosphorus, and Sodium
The American diet tends to contain too much, rather than too little protein. Studies have shown that excessive dietary protein may promote bone loss. With increasing protein intake, the urinary excretion of calcium also rises, because calcium is mobilized to buffer the acidic breakdown products of protein. In addition, the amino acid methionine is converted to a substance called homocysteine, which is also apparently capable of causing bone loss.

Animal studies have shown that excessive intake of phosphorus can cause osteoporosis, as well. The effect of dietary protein on osteoporosis might be explained in part by the phosphorus content of many high-protein foods because phosphorus does appear to have an adverse effect on bone health. High-phosphorus beverages such as colas (which also contain a lot of sugar and caffeine) are among the worst foods imaginable for someone trying to prevent osteoporosis.

Several studies have shown that individuals who consume a vegetarian diet have stronger bones later in life than those who eat animal flesh.9,10 However, other studies have failed to find a difference in bone mass between vegetarians and meat eaters.

A substantial minority of human beings also appears to be Susceptible to the effects of high-sodium intake. When these individuals ingest moderate amounts of salt, their urinary excretion of calcium increases markedly." In people with this sodium-dependent hypercalciuria, ingestion of too much salt probably increases the risk of both kidney stones and osteoporosis. In today's fast paced society, great emphasis is placed on readily available, easily prepared food, which can be stored on the shelf for prolonged periods of time. The food technology industry has developed many ways to achieve these goals. Unfortunately, the nutritional quality of processed, adulterated food is far inferior to that of fresh, perishable foods. Modern food is bleached, radiated, extracted with organic solvents, subjected to enormous temperatures and extremes of acidity or alkalinity, and contaminated with thousands of chemicals designed to preserve, texturize, color, or otherwise modify the food so that it will look, feel, and taste like the real thing.

Hundreds of articles have been written about how these harsh processing techniques can affect the nutritional value of food. One I example is the possibility that food processing can promote lysine deficiency. Lysine is one of the eight essential amino acids from which protein molecules are synthesized in the body. Studies have shown that when proteins are subjected to alkali treatment (as in the production of isolated soy protein or textured vegetable protein), a substantial amount of the lysine is destroyed.l2 Exposure of lysine to temperatures of 250¡C for one hour also caused significant losses of lysine.l3 Heating proteins even at moderate temperatures in the presence of sugars such as lactose, glucose, or sucrose can also destroy significant amounts of lysine.14 Thus, in the baking of pies, cookies, breads, and other grain products, where flour and sugar are heated together, substantial amounts of lysine may be lost.

You might assume that, with all of the protein in the American diet, it would be difficult to develop a deficiency of an amino acid. The problem is, however, that amino acid imbalance can be just as damaging as amino acid deficiency. Animal studies have shown that the ratios of essential amino acids in the diet are as important as the absolute amount of each. If a single amino acid, such as lysine, is being systematically destroyed by food processing, then ingesting more of all of the amino acids will not correct a relative lack of lysine.

It is therefore possible that millions of Americans are marginally deficient in Iysine, even if their diet is high in protein. The modern epidemic of herpes simplex infections is certainly consistent with that possibility. Lysine is known to inhibit the growth of herpes viruses and oral supplementation with Iysine has been shown to prevent recurrences of herpes simplex outbreaks in susceptible individuals.15, l6 Since the doses of lysine that were effective against herpes infections (312 to 3,000 mg/day) are similar to the amounts obtainable in the diet, it is possible that dietary lysine deficiency is a factor in the increased incidence of herpes simplex infections.

It is also possible that lysine deficiency contributes to the development of osteoporosis. Individuals with a rare genetic condition known as lysinuric protein intolerance develop osteoporosis during childhood. In lysinuric protein intolerance, a defect in the kidneys causes large amounts of lysine to be lost in the urine. Scientists have suggested that lysine deficiency is the cause of osteoporosis in individuals with this disorder.17 Although the typical American diet would not result in Iysine deficiency that severe, it is possible that prolonged, subtle lysine deficiency caused by harsh food processing techniques could have an adverse effect on bones.

Soil Factors
The reduction in vitamin and mineral intake resulting from refining of foods can be made even worse by farming techniques that deplete the soil of essential minerals. Traditional methods of farming include using manure and compost to increase the trace mineral content of the soil. In modern times, however, with the emphasis on producing higher crop yields per acre, farmers use large amounts of inorganic fertilizers, which are often deficient in important trace minerals and which may disturb soil mineral balance. For example, the use of ammonia as a fertilizer causes essential minerals such as magnesium' manganese, zinc, and copper to be leached from the soil.18 Repeated application of inorganic fertilizers, which are low in essential trace minerals, can further reduce the soil concentration of these trace minerals. Many scientists and nutritionists are unaware of the effect the depleted soil can have on the mineral content of edible plants i Indeed, nutrition textbooks often contend that mineral-deficient soil will reduce crop yield, but will not adversely affect the nutritional quality of crops that do grow. However, the facts indicate otherwise. The presence of a "goiter belt" in the midwestern United States attests to the fact that foods grown on iodine-deficient soil can cause iodine deficiency. The relationship between mineral concentrations in soil and food is also underscored by the epidemics of selenium deficiency that have occurred in cattle grazing in low selenium areas of the country. As another example, dairy cattle an horses are sometimes stricken by a condition known as grass staggers, characterized by unsteady gait and twitching and spasm of the muscles. This disorder can be cured either by supplementing the diet with magnesium or by adding magnesium to the soil.19 It appears that overuse of nitrates, phosphates, and potassium salts as fertilizers depletes the soil of magnesium and causes a deficiency of this mineral in grazing animals. In the Florida Everglades the soil is low in copper. Domestic animals grazing in this area develop copper deficiency which makes them unusually susceptible to sus~ taining bone fractures. But, when copper is added to their diet fractures no longer occur.20 In another study, the manganese content of turnips was directly related to the manganese content of -the soil. Addition of calcium carbonate to the soil (a common practice by modern farmers) decreased the accumulation of manganese by turnips.

Conclusion
These studies indicate that modern farming practices deplete the soil of essential minerals, resulting in lower levels of these minerals in our food. The vitamin and mineral content of our diet is further reduced by overconsumption of nutrient-depleted foods, such as sugar and white flour. The net result is that the food we consume today contains far less of many vitamins and minerals than it did in the past. One of the major theses of this book is that chronic, low level deficiencies of a wide range of micronutrients may increase the risk of developing osteoporosis.

In summary, many factors related to the modern American diet may promote not only osteoporosis, but other chronic diseases, as well. A health-promoting diet is one that emphasizes fresh, unprocessed foods, such as whole grains, fruits and vegetables, nuts and seeds, and legumes Animal foods, dairy products, and salt should be used in moderation, and sweets, caffeine, refined flours, and chemical food additives should be avoided as much as possible. While some studies suggest that moderate alcohol intake improves health, others have shown that even small amounts of alcohol are not good for you. Certainly, excessive alcohol intake can cause many different problems, including osteoporosis. The human body is remarkably resilient and is capable of withstanding numerous stresses, but it is also true that the more closely you follow the principles of good eating, the healthier you will be.

Notes

1. Lemann, J., Jr., W. F. Piering, and E. J. Lennon. 1969. Possible role of carbohydrate-induced calciuria in calcium oxalate kidney-stone formation. No Engl J Med 280:232-237.

2. Lawoyin, S., et al. 1979. Bone mineral content in patients with calcium urolithiasis. Metabolism 28:1250-1254.

3. Yudkin, J., Dr. 1973. Sweet and dangerous. New York: Bantam Books, 112. Saffar, J. L, et al. 1981. Osteoporotic effect of a high-carbohydrate diet (Keyes 2000) in golden hamsters. Arch Oral Biol 26:393-397.

4. Schroeder, H. A. 1971. Losses of vitamins and trace minerals resulting from processing and preservation of foods. Am J Clin Nutr 24: 562-573.

5. Hollingbery, P. W., E. A. Bergman, and L K Massey. 1985. Effect of dietary caffeine and aspirin on urinary calcium and hydroxyproline excretion in pre and postmenopausal women. Fed Proc 44:1149.

6. Heaney, R P., and R R Recker. 1982. Effects of nitrogen, phosphorus, and caffeine on calcium balance in women. J Lab Clin Med 99:46-55.

7. Hernandez-Avila, M., et al. 1991. Caffeine, moderate alcohol intake, and risk of fractures of the hip and forearm in middle-aged women. Am J Clin Nutr 54: 157-163.

8. Spencer' H., et al. 1985. Alcohol-osteoporosis. Am J Clin Nutr 41:847.

9. Marsh, A. G., et al. 1980. Cortical bone density of adult lacto-ovo-vegetarian an omnivorous women. J Am Diet Assoc 76:148-151.

10. Marsh, A. G., et al. 1983. Bone mineral mass in adult lacto-ovo-vegetarian an omnivorous males. Am J Clin Nutr 37:453-456.

11. Silver,J., et al. 1983. Sodium-dependent idiopathic hypercalciuria in renal-stor formers. Lancet 2:484-486.

12. de Groot, A P., and P. Slump. 1%9. Effects of severe alkali treatment of prose on amino acid composition and nutritive value. J Nutr 98:45-56.

13. Breitbart, D. J., and W. W. Nawar. 1979. Thermal decomposition of Iysine. J Agric Food Chem 27:511-514.

14. Hurrell, R. F., and K J. Carpenter. 1977. Mechanisms of heat damage in prose

8. The role of sucrose in the susceptibility of protein foods to heat damage Br J Nutr 38:285-297.

15. Griffith, R S., A. L Norins, and C. Kagan. 1978. A multicentered study of Iysine therapy in herpes simplex infection. Dermatologica 156:257-267.

16. Griffith, R S., et al. 1987. Success of L-lysine therapy in frequently recurrence herpes simplex infection. Dermatologica 175:183-190.

17. Carpenter, T. O., et al. 1985. Lysinuric protein intolerance presenting as child hood osteoporosis. N Engl J Med 312:290-294.

18. Hall, R. H. 1981. The agri-business view of soil and life. J Holistic Med 3:15 166.

19. Ebeling, W. 1981. The relation of soil quality to the nutritional value of plant crops. J Appl Nutr 33(1):19-34.

20. Rose, E. F. 1968. The effects of soil and diet on disease. Cancer Res 28:2390 2392.

21. Hopkins, H. T., E. H. Stevenson, and P. L Harris. 1966. Soil factors and food composition. Am J Clin Nutr 18:390-395.