OSTEOPOROSIS: The Fractured Truth
By Alex Strande, N.D., Ph.D.
Osteoporosis, the very word strikes fear into people’s hearts, conjuring up images of frail hunched-over little old ladies with ribs so fragile they can fracture from coughing, and hips that break when they step off a curb. Calcium is the first thing most people think of when osteoporosis is mentioned. HRT is probably the second. But the standard view of osteoporosis prevention and treatment is largely founded on myths. One myth is that osteoporosis is caused by calcium deficiency.
Open any medical textbook and you will find that osteomalacia is a disorder resulting from under-calcification of bones. Osteoporotic bone is normal in quality but reduced in quantity: all the minerals as well as the protein matrix that holds those minerals in place have been leached away. Osteoporosis is emphatically not a calcium deficiency disorder. Rather, it is an imbalance between the intake/absorption and the excretion of bone building materials including calcium, that occurs with increasing age.
Another myth is that osteoporosis is an estrogen-deficiency disease, so hormone replacement therapy (HRT) is an effective therapy for it. Age-related bone loss begins to occur in people following standard Western dietary and lifestyle patterns, at about 40 years of age. The hip-fracture rate for white women begins a steep climb between 40 and 44, as her levels of estrogen have not significantly dropped, although progesterone production is often falling. So it is clear that declining estrogen levels are not the primary trigger of the bone-thinning process.
Interestingly, women living in Asian and African cultures with low osteoporosis rates, tend to have much lower estrogen levels throughout their lives than do Western women. They begin menstruating several years later, and go through menopause several years earlier. These differences are related to their high physical activity level, low calorie and fat consumption, and high fiber intake, which lead to lower body-fat levels than those of Western women and markedly different bowel flora composition.
Body fat is a major site of estrogen production. In addition, the Asian and African women excrete far more estrogen in their bowel movements than do Western women on high-meat, high-fat diets.
Since calcium is the major mineral in bone, however, its metabolism has been studied more thoroughly than that of magnesium, phosphorus, zinc, boron and the other minerals contained in bone. Calcium balance refers to the interplay between the intake, absorption and excretion of calcium. Our bodies selectively absorb only a small fraction of the calcium we consume. If we absorb more calcium in a day (from food and/or supplements) than we excrete, we will be in “positive calcium balance”. If we excrete more than we absorb, “negative calcium balance” results. It is not deficient intake of calcium that causes osteoporosis, but rather being in negative calcium balance day after day, year after year.
The Recommended Daily Intake (RDI) of calcium is 800 mg for adults, and 1000 mg for postmenopausal females. Yet most of the world’s population consumes only 300-500 mg of calcium per day, and osteoporosis and fractures in such countries are significantly lower than in Western countries with high daily recommended and actual intakes. Maintaining an adequate calcium intake is easily accomplished on a diet of fresh and dried fruits, vegetables, (especially green leafy vegetables including sea vegetables like dulse, kelp and nori), nuts, seeds (particularly sesame seeds), whole grains and legumes.
Our bodies absorb on average only 20%-30% of the calcium we consume. The higher the amount of calcium consumed, the lower the percentage absorbed. As we get older, however, decreased production of stomach acid reduces our ability to absorb calcium (and other minerals). Drugs that neutralize stomach acid or inhibit its production lower calcium absorption even further. Alcohol and the oxalic acid in tea, coffee, chocolate and some other foods reduce calcium absorption.
Some fat must be present in the intestines in order for us to absorb calcium from foods (so skim milk is next to useless as a calcium source). Raw unsalted nuts and seeds and avocado are excellent sources of healthy fats that help boost calcium absorption.
The calcium in green leafy vegetables is absorbed about twice as well as the calcium in milk and other dairy products. Exposure to sunlight stimulates the body to produce vitamin D, which increases calcium absorption to the same degree.
Men are seven times less likely than women to suffer clinical effects of osteoporosis, because apart from having heavier bones to begin with, they tend to perform more exercise — especially muscle-strengthening exercise — than women.
Disuse of muscles causes rapid weakening of bone. In the weightless environment of space, astronauts suffer profound loss of skeletal mass despite vigorous physical activity.
High protein intake is also a factor. Daily protein intake, and particularly animal-protein intake, is clearly correlated with fracture risk in different populations. Plant proteins do not carry the same risk. A U.S. study, the largest of its kind ever conducted, measured the bone density of vegetarians and non-vegetarians, and found that by the age of 65: male vegetarians had lost an average of 3% of their bone mass, male non-vegetarians had lost an average of 18%, female vegetarians had lost an average of 7%, female non-vegetarians had lost an average of 35% of their bone mass.
Excessive sodium (salt) consumption increases calcium excretion. This compromises the kidney’s ability to return calcium to the bloodstream. We need less than 500 mg of sodium per day, yet many Americans eat from 4 to 8 grams per day.
Caffeine has similar effects to sodium. Researchers at the University of California, San Diego, found that drinking just two cups of coffee per day throughout adulthood significantly reduces bone density.
From a naturopathic point of view, there are plenty of nutrients, especially bio-available liquid extracts of herbs that can help build your bone mass — both directly and via hormonal support.
Alex Strande is a Microbiologist and Naturopath. He can be reached at (949) 553 1882 for questions and appointments.
Return to the July/August Index page