New research suggests ancient Roman gladiators maintained a mostly vegetarian diet and drank ashes as a "tonic."

Scientists looked at the bones from a gladiator cemetery dating back to the second or first century BC located in modern-day Turkey to reveal secrets of their ancient diet, the Medical University of Vienna reported. The region was once the city of Ephesos, which in its time was the capital of the Roman province of Asia and had over 200,000 inhabitants.

The research team used spectroscopy, stable isotope ratios (carbon, nitrogen and sulphur), to look at the collagen of the bone; they also observed the strontium to calcium ratio in the bone minerals.

The findings suggest these ancient gladiators ate a diet consisting mostly of beans and grains, which was also common in the region's "normal population." The gladiators may have been fed grain of inferior quality than what the average citizen consumed.

The researchers did observe much higher levels of strontium in the gladiators' bones when compared with the average population in that time period and region. This suggests gladiators had a higher intake of minerals from a strontium-rich source of calcium. Ancient literature has suggested Roman gladiators drank an ash-based beverage for extra minerals, and these findings may confirm this. Calcium is known to help build the bones, but is usually obtained through dairy products in modern times.

"Plant ashes were evidently consumed to fortify the body after physical exertion and to promote better bone healing," said study leader Fabian Kanz from the Department of Forensic Medicine at the MedUni Vienna. "Things were similar then to what we do today - we take magnesium and calcium (in the form of effervescent tablets, for example) following physical exertion." 

In the future the researchers hope to compare the bones of gladiators from other regions with local fauna to reveal differences in diet.

The findings were published in a recent edition of the journal PLOS ONE.