New Delhi, Oct 20 (IANS): It is expected to affect 36 million Indians by 2013 but osteoporosis - a disease associated with brittle bones, fractures and painful recovery - remains one of the most undermined diseases in the country.

Going by figures from the Arthritis Foundation of India, it will become the next big health worry.

"The number of cases of osteoporosis has almost doubled in the last 10-15 years," Rajeev K. Sharma, senior consultant, orthopaedics, and joint replacement surgeon at Delhi's Indraprastha Apollo hospital, told IANS.

Almost one in three urban Indian women past the age of 45 has osteoporosis. Even men are not immune to it, as doctors say those in their old age do face the problem.

"It's a myth that men are immune to it," says Raju Vaishya, president of the Arthritis Care Foundation.

"Average life expectancy, which was around 46 in 1947, has increased to around 70 now. As life expectancy increases, diseases related to old age are also increasing," he says.

Doctors blame fast changing lifestyles, poor dietary habits and lack of exercise along with heredity.

"Dietary habits are changing very fast. More and more people are relying on junk or processed food instead of regular balanced diet which has calcium, Vitamin D and other minerals," says Vaishya.

Ashok Kumar, director, rheumatology at Delhi's Fortis Hospital, says: "A thin and small body frame, family history of osteoporosis, cigarette smoking, excessive alcohol consumption and low calcium diet form major factors leading to osteoporosis."

Apart from these, women in the post menopausal phase are most prone to the disease due to a decrease in the amount of oestrogen hormone which plays a vital role in maintaining bone density.

Unfortunately, osteoporosis can be detected through an X-ray only after 30 percent of the bone calcium is already gone. Doctors say prevention therefore largely depends on improving lifestyles.

"Between the age of 30 and 40, one should start taking care to avoid osteoporosis," says Sharma."

"Weight bearing exercises need to be done regularly. One should either go for weight training, yoga, push ups or exercises like swimming and cycling," he says.

On the dietary side, food rich in calcium, Vitamin D and minerals is required. A 20- minute exposure to sunlight is required daily for the body to start synthesising Vitamin D, fulfilling our body's requirement for it in a natural way.

"Ideal requirement of calcium for a woman is 400 mg/day, which can be obtained from best food sources such as milk and other dairy products as well as legumes such as pulses and kidney beans," says Ruhi Dewan, clinical nutritionist at Fortis.

Vaishya says, "Check up of bone strength, bone density and level of calcium etc should be done post 40, specially in menopausal women."

"Correcting lifestyle may help avoid osteoporosis."

"Although early detection and timely treatment of osteoporosis can substantially decrease the risk of future fractures, it is difficult to completely rebuild bone that has been weakened by osteoporosis. Therefore, prevention of osteoporosis is as important as treatment," adds Kumar.