MAKING NO BONES ABOUT IT
The number of Indians affected by osteoporosis is rising. Improving nutrition is the only way out.
We are dependent on our bones for every small movement. Bones support the whole weight of our bodies so that we can stand up, sit down, and move around. We take these for granted when we are young. But these simple acts of daily living become difficult as we get older and our bones get weaker.
Medical advances have increased our life expectancy and also the burden of age- related health problems like osteoporosis. Osteoporosis literally means ‘ porous bones’. Osteoporotic bones become weak and fragile, so fragile that fractures can occur with mild trauma. Osteoporotic fractures involve very high economic and social costs and have a significant negative impact on the quality of life of patients. Women, especially after menopause, are more likely to suffer from osteoporosis compared to men.
An alarming finding is that Indians, especially those from the low socio- economic group, tend to have osteoporotic fractures at a much earlier age compared to the people from the western countries. Studies by the National Institute of Nutrition, Hyderabad, ( NIN) have shown that the average age at which women from poor socioeconomic group suffer from hip fracture is only about 57 whereas fractures usually occur after 75 in well- nourished populations. Apart from hip fractures, osteoporosis can cause vertebral micro- fractures which cause persistent back pain. A large number of vertebral fractures go undetected because back pain is often not considered serious enough to seek medical care.
Osteoporosis is a silent disease and fractures can occur without any warning or signal. However, osteoporosis can be detected early by assessment of bone mineral density ( which indicates strength) using specialised equipment called dual energy X- ray absorptiometry ( DXA). Studies by NIN and other research centres in India assessing the bone mineral density of various population groups have shown a high prevalence of osteoporosis. Although
osteoporosis affects people late in their lives, its seeds are sown early. When children grow, their bones become progressively stronger due to increase in the bone mineral density throughout childhood and adolescence. Its peak is reached in the early 20s, which is known as the peak bone mass, and no future increase in bone mass is possible after that. Under- nutrition during childhood and adolescence leads to low peak bone mass in the youth and with age- related loss in bone minerals, osteoporosis sets in.
How does one prevent this debilitating disease? A balanced diet with adequate calcium, vitamin D and protein along with regular weight bearing physical activity is the key to preventing osteoporosis. In addition, maintaining a healthy weight and avoiding cigarettes and alcohol help in main- taining strong and healthy bones.
Calcium is the most important bone- forming mineral. Good sources of calcium include dairy products like milk, yoghurt and cheese; leafy vegetables like spinach and amaranth; pulses like chana dal and rajma; oilseeds, especially sesame seeds; and spices like cumin seeds, pepper and cloves.
Moreover, the food source of calcium is just as important as the amount of calcium intake. Calcium from milk is highly bio- available: A higher quantity of it is absorbed from the gut and can be utilised for mineralisation of bones. On the other hand, calcium from plant sources has low bio- availability. It is difficult for diets without milk to be adequate in calcium.
Absorption of calcium is dependent on vitamin D. Reports from different parts of the country have shown that a large proportion of Indians suffers from vitamin D deficiency. This is surprising in a sunny country considering that sunlight exposure is essential for adequate vitamin D. But really, how many of us expose ourselves to the sun for at least 15 minutes every day? Not many. Apart from our indoor habits that preclude sunlight exposure, pollution could also play a role in this deficiency. Pollution can block ultraviolet rays which stimulate vitamin D synthesis in the skin.
Apart from diet, physical activity plays an important role in development and maintenance of bone mass. Weight- bearing activities such as brisk walking, jogging, stair climbing, and dancing are especially important for improving bone density as well as improving muscle strength.
As life expectancy increases and the population continues to grey, osteoporosis is likely to increase. Prevention of osteoporosis by improving nutrition is therefore of paramount importance. Improving calcium intake would require increasing the availability of dairy products at an affordable cost and exploring newer, cheaper food sources of calcium. Strategies should target younger age groups for optimal development of peak bone mass and older individuals to reduce age- related bone loss.
Dr Bharati Kulkarni Deputy director, Clinical Division, National
Institution of Nutrition