By Amina Abdul Salam A healthy lifestyle with no smoking, regular exercise and an intake of calcium and vitamin D help greatly against developing osteoporosis, or brittle, easily breakable, bones. Osteoporosis is characterised by decreased bone mass. This leads to fragile bones which are at an increased risk of fracture. Bones that commonly break are the vertebrae in the spine, the bones of the forearm, and the hip. Dr Hend A. Essa, a research worker at the Food and Nutrition Department, National Research Centre, pointed out that osteoporosis can be classified as either primary (not related to another disease) or secondary (when an identifiable cause other than age or menopause is present). Osteoporosis can be secondary to such conditions as melanoma and hyperthyroidism, she said. The most common form is primary osteoporosis, in which no other disease is apparent. This is most frequently seen in middle-aged and older females. The most widely used method for diagnosis osteoporosis, says Dr Essa, is bone density, which is the measurement of bone mineral density (BMD), This is typically measured by dual-energy X-ray absorptiometry (DXA). Dr Essa said that there are some risk factors for osteoporosis. Women are much more likely to develop osteoporosis than men and the risk of osteoporosis increases with age. She stressed that the reduction of oestrogen levels in women at menopause is one of the strongest risk factors for developing osteoporosis. In addition, too much thyroid hormone can cause bone loss. This can occur if the thyroid is over-active or if the patient takes too much thyroid hormone medication to treat an under-active thyroid. Dr Essa also said that dietary risk factors for osteoporosis are more likely to occur in people who have a low-calcium intake. A lifelong lack of calcium plays a role in the development of osteoporosis. Low-calcium intake contributes to diminished bone density, early bone loss and an increased risk of fractures. Concerning osteoporosis prevention, Dr Essa said that adequate nutrition can reduce the impact of osteoporosis by half or more. Calcium is a key building block for the bones. Vitamin D helps the body absorb calcium. Milk, yoghurt, cheese and other dairy products have high levels of calcium, and also other key nutrients for bone health, such as phosphorus and protein. For vitamin D, cod liver oil, certain fish, such as salmon, tuna, mackerel, and sardines, may also be a good source, she said. Participation in regular exercise: exercise can help you build strong bones and slow bone loss. A healthy life style with no smoking is best.