Beta cells do not replicate after the age of 30 !

Beta cells, which make insulin in the human body, do not replicate after the age of 30, indicating that clinicians may be closer to better treating diabetes.

"We found that beta cells turnover up to about age 30, and there they remain throughout life," Buchholz said. "The findings have implications for both type 1 and type 2 diabetes."

Buchholz said there is active research in stem cell therapies to replace lost beta cells for both types of diabetes. "But with these new findings, it isn't clear how easy it will be to get the body to make more beta cells in adulthood, when it is not a natural process," he said. "At the surface, it seems like coaxing the body to do what it does naturally will be easier to accomplish."
　
www.llnl.gov/news/newsreleases/2010/Oct/NR-10-10-05.html