The new proof comes from skeletal remains of Stone-Age hunter-gatherers, who resided in what is now Morocco more than 13,700 years ago, the BBC reported.
The researchers said that individuals ate a lot of high-carbohydrate nutty foods, and their teeth's poor condition suggested that they were often in agony.
Scientists analysed the dental condition of 52 skeletons discovered at the Grotte des Pigeons complex at Taforalt in eastern Morocco over the past decade.
All except three individuals showed tooth decay, with cavities or other lesions influencing more than 50 per cent of the surviving teeth.
In some, the oral health was in such a bad condition that destructive abscesses had developed in them.
Wild plant remains at Taforalt indicated that these Stone Age hunter-gatherers were frequently eating sweet acorns, pine nuts and pistachios, with snails too being popular.
The research has been presented in PNAS.
--ANI (Posted on 07-01-2014)