What is osteoporosis?
Osteoporosis or bone loss is a disease in which bone becomes more brittle and prone to fracture. The bones which are most susceptible to fracture are hip, spine and wrist. During osteoporosis the bone mineral density is reduced and bone cellular structure is weakened. Clinically osteoporosis is defined as bones with a bone mineral density (BMD) of 2.5 standard deviations (measured by DEXA) below the peak bone mass. The DEXA test takes about 10 minutes and uses only very low radiation.
Our bones are not static. There is continuous build-up and removal of calcium in our bones. There are two kind of cells in our bones: osteoblasts and osteoclasts. The osteoclasts removes calcium and bone mass form the bones. The osteoblasts add calcium to the bones and fill the empty spaces. In a healthy individual the osteoblasts and osteoclasts work together to maintain bone health. Osteoporosis starts when is equilibrium is disturbed. For women, estrogen is important for bone health but there are other important factors such as diet. It has been shown that diets rich in animal protein increase the rate of bone loss and that even consuming a lot of dairy products, which are very rich in calcium, actually accelerates osteoporosis.
Treatment and prevention of osteoporosis
Treatment of osteoporosis is very difficult. It is recommended to prevent osteoporosis and this starts by having a healthy lifestyle: a good diet and regular exercise.
- Exercises – Exercises which put some stress on your bones, will eventually strengthen them. It is well known that astronauts lose a lot of their bone mass. During their weightless stay in space, their bones don not experience any strain and start to loose calcium. The opposite is also true: weight-bearing exercises will increase bone density of our arms. But we should not do such extreme sports: regular walking, jogging, swimming, yoga are even doing household tasks will keep our bones strong. Lying down in the sofa and watching TV will leech the calcium out of your bones! If you decide to sit back during menopause you can loose up to 20 percent of bone mass in the first five to seven years.
- Stop smooking – Smoking will also accelerate osteoporosis. It has been demonstrated that smoking reduces the bone mass by up to 25 percent.
- Medication – Hormone Replacement Therapy will protect against osteoporosis, but is has side effects.
- Healthy diet – Your diet should contain enough calcium. There are different recommended levels (800 mg calcium/daily, 1200 mg calcium/daily) but many people can have healthy bones with only 400 mg calcium/daily or less. It is debatable of we need that much calcium. Studies have shown that babies absorb more calcium from mother’s milk than from cow’s milk, despite the fact that cow’s milk contains four time the amount of calcium. More important seem to be other factors in your diet: eating mainly vegetable proteins, not too much dairy products, enough zinc, boron, vitamin C, vitamin D, vitamin K and vitamin B6. Vitamin K is very important for your bone health. It can be found in green vegetables (broccoli, spinach, kale), beans, egg yolk and soybean oil.
Consumtion of soy also seems to reduce osteoporosis. Isoflavones help in the preservation of the bones and fight osteoporosis. In China and Japan, osteoporosis is very rare after menopause, despite their low consumption of dairy products. But their intake of soy and soy isoflavones is rather high, compared to Europe and North America. The isoflavone which is responsible for bone building is daidzein. Isoflavones seem to inhibit the activity of osteoclasts (which break down bone), while stimulating the activity of osteoblasts (which build bone).