Proto-Indo-European Roots

Root/Stem: *éd-
Meanings:  to eat
Cognates (45): Greek edó (I eat), Doric edóda (food, eating)
Latin edere (to eat)
Common Celtic *itó (I eat), - can be a result of PIE *pit- ? > 
Old Irish ithim (I eat), Irish Gaelic ith (to eat)
Common Germanic *et- (to eat), > 
Gothic itan, Old Frankish & Old Swedish & Old English etan, Old High German essan, Middle English ete
Swedish ata, Icelandic eta, German essen, Afrikaans eet, Dutch eten, Frisian ite, Faroese eta
Avestan ad- (to eat)
Sanskrit admi (I eat), atti (he eats)
Thracian esko- (to eat) 
Armenian utem (I eat)
Common Anatolian *ed- (to eat), > 
Hittite at-, Nesian et-, ud-, Palaic ata, Luwian at-
Common Baltic *e.sti (to eat), > 
Lithuanian e.sti (to eat), Latvian est, Old Prussian íst, Sudovian éstun, ést
Common Slavic *esti (to eat), *edmi (I eat), > 
Old Church Slavonic jasti, Ukrainian isti (to eat), Belorussian esci, Bulgarian jam (I eat), Macedonian jadam (I eat), Serbo-Croatian & Slovene jesti, Czech jísti, Slovak jest', Polish jes'c', Sorbian jesc, Russian jest' (to eat), jem (I eat).
Notes: An ancient athematic verb, together with 'to be', 'to do', 'to give' is one of the most important verbs in all Indo-European languages. Sociolinguistics states that all most common words in the language are always short - the same goes with this word. 
The supporters of the Nostratic theory find the traces of the same stem in Uralic and Altaic languages, which is one more proof that maybe it was one of the first verbs born by the humanity.