A theme that keeps recurring in nutritional medicine is that degenerative diseases are caused, at least in part, by our modern diet, which contains too much sugar, fat, salt, refined flour, caffeine, alcohol, processed foods, and food additives. I routinely advise my patients, regardless of their specific medical problems, to try to clean up" their diet; that is, reduce their consumption of these junk foods" and to increase their intake of whole grains, fruits, vegetables, nuts and seeds, beans, and other unprocessed foods. The majority of people who follow that advice find that their health improves in some way. Many individuals report an increase in energy, less depression and anxiety, fewer headaches, better bowel and bladder function, and less fluid retention. They often sleep better, their joints do not hurt as much, and they are more alert and productive. Laboratory reports, such as serum cholesterol, triglycerides, liver enzymes, and uric acid also improve in many cases.

Specific medical conditions may also be relieved as a result of these general dietary changes. Patients with asthma, irritable bowel syndrome, peptic ulcer, gallbladder attacks, acne, psoriasis, high blood pressure, diabetes, angina, or other problems frequently find that their symptoms are better when they eat a healthier diet. Part of the appeal of improving your diet is that, even if it does not help, it rarely causes harm.

Diet and Bone Health
Considering that bone is living tissue, just like the rest of the body, it is likely that what you put in your mouth will determine in part how strong your bones will be. Many people believe that, aside from its calcium content, diet has little to do with osteoporosis. However, that assumption ignores the fact that bone tissue has diverse nutritional needs and engages in complex interactions with the rest of the body. It is improbable that our modem-day diet could be sparing our bones while damaging the rest of our body. Although it is impossible to determine the precise effect of diet on bone health, there is at least circumstantial evidence that the typical American diet promotes the development of osteoporosis.

There are three reasons that our modem diet might not be good for our bones. First, many of us ingest too much sugar, caffeine, salt, and alcohol. Consumption of each of these substances is reportedly associated with an increased risk of osteoporosis. Second, because of the way our food is grown and refined, today's diet probably contains much lower quantities of various vitamins and minerals than it used to. As you will learn later, some of these vitamins and minerals play a key role in maintaining healthy bones. Third, some of the processing techniques used by the food industry cause chemical changes in our food that may adversely affect the health of the tissues in our bodies, including bone. The possible influences of diet on bone health are reviewed next.

Sugar
In the early part of the nineteenth century, sugar was considered a condiment, rather than a major component of the diet. Back then, the average per capita intake of sugar was only about 10 to 12 pounds per year. Today, according to some statistics, the average American ingests approximately 139 pounds of refined sugar each year. That enormous quantity translates to about 41 teaspoons of sugar per day, or 19% of all of the calories we consume. Since refined sugar contains virtually no vitamins or minerals at all, it dilutes our nutrient intake, resulting in an across-the-board 19% reduction in all vitamins and minerals in our diet. Thus, because of our high intake of sugar we are getting less magnesium, folic acid, vitamin B6, zinc, copper, manganese, and other nutrients that play a role in maintaining healthy bones.

Ingesting sugar may also deplete our bodies of calcium. In one study, administering 100 grams (about 25 teaspoons) of sugar (sucrose) to healthy volunteers caused a significant increase in the urinary excretion of calcium. When the same amount of sugar was given to people with a history of calcium oxalate kidney stones or to their relatives, the increase in calcium excretion was even greater.) Since 99% of the total-body calcium is in our bones, this increase in calcium excretion most likely reflects a leaching of calcium from bone. This study suggests that a high-sugar diet may reduce the calcium content of bone, and that people with kidney stones or their relatives are especially susceptible to the adverse effects of sugar. Thus, the extent to which dietary sugar affects calcium metabolism is in part genetically determined, just as there is a hereditary component to osteoporosis risk. It is interesting to note that individuals with a history of kidney stones are at increased risk for developing osteoporosis.2 Researchers have also suggested that consumption of refined sugar is one of the factors that promotes kidney stones. Perhaps what people with kidney stones and osteoporosis have in common is an increased sensitivity to refined sugar.

Ingestion of large amounts of sugar has another effect on the body that may promote osteoporosis. Dr. John Yudkin, a British physician, has been studying the effects of dietary sugar for more than thirty years. Yudkin found that ingesting large amounts of sucrose by healthy volunteers causes a significant increase in the fasting serum cortisol level. Cortisol is the primary corticosteroid l (cortisonelike hormone) secreted by the adrenal gland. Although corticosteroids have important biological functions, an excess of these hormones can cause osteoporosis. Indeed, doctors are reluctant to prescribe corticosteroids precisely because they can cause severe bone loss. Yudkin's work demonstrated that eating too much sugar is in a way analogous to taking a small amount of cortisone, which could cause your bones to become thinner. This possibility is supported by a study on hamsters, in which feeding a diet containing 56% sucrose caused osteoporosis, despite adequate intake of calcium.3

Refined Grains and Flour
Another significant dietary change occurring during the past century is an increase in the consumption of refined grains, such as white bread instead of whole wheat bread, and white rice instead of brown rice. During the refining of grains and flour the nutrient-rich germ and bran portions are removed, resulting in a significant loss of vitamins and minerals. For example, when whole wheat is refined to white flour the following percentages of selected vitamins and minerals are lost: vitamin B6 (72%), folic acid (67%), calcium (60%), magnesium (85%), manganese (86%), copper (68%), zinc (78%).4 Since grains make up about 30% of the average diet, consumption of refined grains would have a substantial impact on the total daily intake of micronutrients (vitamins and minerals). Because nearly 50% of the typical American diet is composed of nutrient-depleted sugar and refined grains, the intake of many important micronutrients is probably much lower than it was during the previous century

Caffeine
Caffeine is found in coffee, tea, cola beverages, and certain pain medications. Substances similar to caffeine are also present in chocolate. Caffeine has certain pharmacologic (druglike) effects in the human body and is known primarily as a stimulant of the central nervous system. Tens of millions of people depend on caffeine to help them wake up in the morning and to stay alert during the day. Athletes sometimes use caffeine to enhance their performance.

Although the dangers of caffeine have long been a topic of debate, it is well known that caffeine is an addictive substance. Withdrawal from caffeine after prolonged use usually results in severe headaches, which can last several days. It is also well known that excessive caffeine use is a cause of anxiety and insomnia.

Nutrition-oriented practitioners and some conventional doctors believe that caffeine can also cause certain other problems in susceptible individuals. Problems attributed wholly or in part to caffeine include fibrocystic breast disease, cardiac arrhythmias (heart rhythm disturbances), diarrhea, constipation, abdominal pain, elevated serum cholesterol or blood sugar, high blood pressure, and chronic migraines or other headaches. There is evidence that caffeine may also promote heart disease and cancer, although the studies in this area are conflicting.

It should not be surprising that a substance that appears to cause problems in so many different systems of the body would also adversely affect bone tissue. Most of the evidence is circumstantial, but studies do suggest that caffeine ingestion may contribute to bone loss. In one study, thirty-one women ingested a cup of decaffeinated coffee on three different occasions. In two of the cups, caffeine was added at concentrations of 3 mg/kg and 6 mg/kg of body weight, respectively. The excretion of calcium in the urine during the next three hours was significantly greater after caffeine ingestion than after decaffeinated coffee. The increases in calcium excretion were 50% and 69%, respectively, after low and high doses of caffeine.5 These results demonstrate that ingestion of caffeine causes excess calcium loss from the body in the short term.

Another study suggests that this effect of caffeine is not just limited to the short term. Calcium balance, a measure of the amount of calcium retained in the body, was assessed in 168 women between the ages of 35 and 45. The results showed that calcium balance decreased with increasing dietary intake of caffeine. In other words, women who habitually ingested a great deal of caffeine retained less calcium than did those who used little caffeine. Women who consumed 50% more caffeine than average had an estimated; reduction in calcium balance of 6 mg/day.6 Although 6 mg/day might seem like a small amount, a loss of that much calcium every day for years would add up to a significant degree of bone loss.

The potential consequences of caffeine ingestion on bone health was assessed in a study of 84,484 women the ages of 34 and 59. In 1980, each of the women completed a questionnaire pertaining to their intake of various foods and beverages. During the ensuing six years, there was a positive association between caffeine intake and the risk of sustaining a hip fracture. That is, the risk of a hip fracture increased with increasing levels of caffeine intake. Women who consumed the most caffeine (above the 80th percentile) had nearly three times as many hip fractures as women who consumed the least caffeine (below the 20th percentile).7 One possible confounding factor in this study is that women who use caffeine also tend to smoke cigarettes, which are known to contribute to the risk of osteoporosis. It is possible that some of the risk attributed to caffeine intake was actually due to tobacco. However, the weight of evidence suggests that anyone interested in maintaining healthy bones should avoid excessive caffeine intake.

Alcohol
Consumption of excessive amounts of alcohol is a known risk factor for osteoporosis. In a study of ninety-six male chronic alcoholics): ages 24 to 62, 47% had osteoporosis. Among those under the age of 40, 31% had osteoporosis.8 Although a similar study has not been done on women, it is likely that drinking too much alcohol would also promote osteoporosis in women. The effect of moderate alcohol consumption on bone health is not known.