Er... not quite correct -
"According to a statistical research, only twelve emperors lived up to seventy years or older. The average life of an emperor was forty-three years, excluding unnatural deaths caused by regicide or accident. Yet the average life of a Buddhist priest in history was seventy-seven years. Nearly one-third of the emperors died between the age of 20 and 40; one-third died between 41 and 60. By contrast, almost no Buddhist monk died between 20 and 50. Thirty-three percent of them died when they were 70 to 79 and thirty-one percent lived more than 80 years." Go figure
Well, what makes you think that monk lives longer is because of no sex and not the vegetarian diet. Also, you very sure all the monks abstain from sex 100%?