Mexico's drug war has raged with such intensity that the statistical life expectancy of the country's male citizens has dropped by several months, a new study revealed.

After the life expectancy had been increasing for decades -- men lived an average of 71 years in 2010 and an average of around 72 years by 2014 -- that trend seems to have been reversed by the unprecedented violence that gripped the country between 2005 and 2010, Voice of America reported based on a report by the American journal Health Affairs.

"The unprecedented rise in homicides after 2005 led to a reversal in life expectancy increases among males and a slowdown among females in most states," noted authors José Manuel Aburto, of the European Doctoral School of Demography, and Hiram Beltrán-Sánchez, of the University of California, Los Angeles.

The reversal was particularly startling in Mexican states most heavily affected by drug violence, such as Chihuahua, Sinaloa, Durango, Guerrero, and Nayarit, Voice of America detailed. In those jurisdictions, men lost an average of one year of life expectancy between 2005 and 2010.

The most dramatic change, though, occurred in the state of Chihuahua, which borders Texas and New Mexico and whose largest city is Ciudad Juárez, long known as one of the most dangerous municipalities in Mexico. In the state of some 3.6 million resident, the loss of life expectancy for men added up to a startling three years, the researchers found.

Homicide rates had jumped all across Mexico after then-President Felipe Calderón launched a military campaign against drug cartels in 2005, Quartz recalled. By 2010, the murder rate had risen to 22 incidents for every 100,000 inhabitants; it had been less than half that number when the raids first began in 2005, according to the magazine.

While investigators had expected to see an impact in the most affected areas and age groups, they were still startled by how widely the violence had shaped statistics. "It was a surprise that homicide rates had such a large effect at the national level," Beltrán-Sánchez noted.