A new study suggests that Mexico's drug violence was so bad at its peak that it apparently caused the nation's male life expectancy to drop by several months.

Experts say the violence from 2005 to 2010 partly reversed decades of steady gains, noting that homicide rates increased from 9.5 homicides per 100,000 people in 2005 to more than 22 in 2010. That has since declined to about 16 per 100,000 in 2014.

The study published on Tuesday in the American journal Health Affairs says "the increase in homicides is at the heart" of the phenomenon, though deaths due to diabetes may have also played a role.

"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," according to the study, published by Jose Manuel Aburto of the European Doctoral School of Demography, UCLA's Hiram Beltran-Sanchez and two other authors.

The study's authors found that life expectancy for males in Mexico dropped by about six-tenths of a year from 2000-2010.

Men lived an average of 71 years in 2010, a figure that edged up to around 72 years by 2014. Figures published by Mexico's National Statistics Institute showed a life expectancy of 70.9 years in 2000.

The study found that in five of Mexico's most violence-plagued states - Chihuahua, Sinaloa, Durango, Guerrero, and Nayarit - men lost an average of one year of life expectancy between 2005 and 2010, while in the border state of Chihuahua alone, the loss added up to a startling three years.