With 255 of its citizens crossing the 100-years mark, little wonder the Chinese city of Rugao is renowned for the longevity of its centenarian residents.
The city, which is located in east China's Jiangsu Province, has a population of 1.45 million with more than 4,000 people above 90 years old and 40,000 above 80, according to the statistics.
The average life expectancy of this city is 75.59-4.59 and 9.59 higher than that of China and world average respectively.
Rugao is the only city, which lies in a low-lying and economically developed region among China's six 'longevity cities'.
Regular and healthy eating and sleeping habits and a favourable environment are believed to be the reasons for the people living long in Rugao.
A study by the Jiangsu Provincial Institute of Geological Survey showed that per kilogram of soil contained an average of 3.3 milligrams of iodine, 57.3 milligrams of zinc and 0.047 milligrams of selenium, generally higher than other regions, The Xinhua reports.
Experts here said selenium plays an important role in preventing humans from getting cancer, zinc is a key element in protein, while iodine is essential in forming the thyroid hormone.
A report released by the World Health Organization said that by 2009, the average life expectancy in China was 73.05 years, up from 71.4 years in 2000 and 72 in 2006.