The drop hit women hardest, whose life expectancy fell by 0.4 of a year, while male life expectancy decreased by 0.2 of a year. However, Italian women can still expect to live longer on average than their male counterparts, with the average female lifetime estimated at 84.6 years compared to 80.1 for men.
Walter Ricciardi, president of Italy's National Health Institute, said that "imperfect lifestyles and disparity of access to health services" were to blame for the decline, at the presentation of the annual Osservasalute report in Rome.
The report is created by 180 researchers across Italy, using data from hospitals, universities, and national and regional institutions.
But the most striking divide was not one of gender, but of geography.
Northern Italians can expect to outlive those in the poorer southern regions, in some cases by as much as three years.
In the northern region of Trento, for example, the average life expectancy is 83 years (81.2 for men and 85.8 for women), while the average Campanian resident can expect to live just 80 years (78.3 for men and 82.8 for women).
Numerous factors could be behind this difference, including a lower birthrate in the south, but also fewer available economic resources. Health spending per capita amounts to an annual 2,255 euros in northern Bolzano, for example, but just 1,725 euros in Calabria.
Ricciardi, president of the National Health Institute, pointed out that at the turn of the century, southern Italians had had a higher life expectancy than those in the north, with the traditional diet, favourable climate, and typically laid-back lifestyle all serving to lengthen lives.
Since then, he said, lack of money had caused healthcare in the region to "move backwards".
"Lack of prevention, starting from minor response to cancer screening, later diagnosis, a reduced availability of innovative drugs, and lower rates of effectiveness and efficiency in healthcare structures," were all problems faced in the south of the country, Ricciardi explained.
These problems appear to have had an effect on the rate of amenable mortality - that is, the number of deaths which could reasonably have been prevented with effective and timely care.
Nationwide, the rate has dropped by three percentage points since 2010. This drop was barely perceptible in Lazio and Calabria, however, where it was of less than one percentage points, while Valle d'Aosta and Trento each saw decreases of more than ten points.
While eight regions - all of them in northern or central or Italy - had below average rates of avoidable mortality, four southern regions recorded levels significantly above the average. Lazio, Campania, Calabria, and Sicily, together with Piedmont in the north, all recorded high rates of mortality linked to quality of care.
Another problem facing Italy's healthcare system is the increase in chronic diseases, which affect four in ten Italians, Osservasalute said. These illnesses include, for example, diabetes, obesity, and high blood pressure.
And chronic diseases are not only affecting more Italians than ever, but they are affecting people from is an increasingly young age, a phenomenon which Ricciardi said "lowers quality of life and leads to increasingly unsustainable costs for the health service".