Lucian, Octogenarians 3-5
“Homer claims that Nestor, obviously, the wisest of the Achaians, lived more than three generations, a man the poet explains to us was best trained in both mind and body. And the prophet Teiresis, well tragedy has him living through six generations. It might be credible that a man dedicated to the gods and who followed a reverent diet might live as long as possible.
It is recorded that whole clans of people are very long-lived thanks to their way of life—for example, the people of the Egyptians called holy-authors, the exegetes of myth in Assyria and Arabia, and the people the Indians call Brahmans, men who pursue philosophy with precision. There are also the people called the magoi, that prophetic clan dedicated to the gods among the Persians, Parthians, Bactrians, Khoasmians, Arians, Sacae, Medes, and among many other barbarian people. The magoi are strong and live many years because they learn to use magic and eat with considerable discipline.
There are, in addition, entire peoples who are long-lived: for example, some people record that the Sêres live up to 300 years. According to some authors, this is because of the weather; others claim that it is their soul or their diet that is responsible for the length of their lives—for, they claim that the whole nation drinks only water. It is reported that the people of Athos live 130 years or that the Chaldeans live over a hundred and that they rely on barley bread as a medicine to keep their vision sharp.”
Νέστορα μὲν οὖν τὸν σοφώτατον τῶν Ἀχαιῶν ἐπὶ τρεῖς παρατεῖναι γενεὰς Ὅμηρος λέγει, ὃν συνίστησιν ἡμῖν γεγυμνασμένον ἄριστα καὶ ψυχῇ καὶ σώματι. καὶ Τειρεσίαν δὲ τὸν μάντιν ἡ τραγῳδία μέχρις ἓξ γενεῶν παρατεῖναι λέγει. πιθανὸν δ᾿ ἂν εἴη ἄνδρα θεοῖς ἀνακείμενον καθαρωτέρᾳ διαίτῃ χρώμενον ἐπὶ μήκιστον βιῶναι. καὶ γένη δὲ ὅλα μακρόβια ἱστορεῖται διὰ τὴν δίαιταν, ὥσπερ Αἰγυπτίων οἱ καλούμενοι ἱερογραμματεῖς, Ἀσσυρίων δὲ καὶ Ἀράβων οἱ ἐξηγηταὶ τῶν μύθων, Ἰνδῶν δὲ οἱ καλούμενοι Βραχμᾶνες, ἄνδρες ἀκριβῶς φιλοσοφίᾳ σχολάζοντες, καὶ οἱ καλούμενοι δὲ μάγοι, γένος τοῦτο μαντικὸν καὶ θεοῖς ἀνακείμενον παρά τε Πέρσαις καὶ Πάρθοις καὶ Βάκτροις καὶ Χωρασμίοις καὶ Ἀρείοις καὶ Σάκαις καὶ Μήδοις καὶ παρὰ πολλοῖς ἄλλοις βαρβάροις, ἐρρωμένοι τέ εἰσι καὶ πολυχρόνιοι διὰ τὸ μαγεύειν διαιτώμενοι καὶ αὐτοὶ ἀκριβέστερον. ἤδη δὲ καὶ ἔθνη ὅλα μακροβιώτατα, ὥσπερ Σῆρας μὲν ἱστοροῦσι μέχρι τριακοσίων ζῆν ἐτῶν, οἱ μὲν τῷ ἀέρι, οἱ δὲ τῇ γῇ τὴν αἰτίαν τοῦ μακροῦ γήρως προστιθέντες, οἱ δὲ καὶ τῇ διαίτῃ· ὑδροποτεῖν γάρ φασι τὸ ἔθνος τοῦτο σύμπαν. καὶ Ἀθῴτας δὲ μέχρι τριάκοντα καὶ ἑκατὸν ἐτῶν βιοῦν ἱστορεῖται, καὶ τοὺς Χαλδαίους ὑπὲρ τὰ ἑκατὸν ἔτη βιοῦν λόγος, τούτους μὲν καὶ κριθίνῳ ἄρτῳ χρωμένους, ὡς ὀξυδορκίας τοῦτο φάρμακον·
Sounds logical doesn’t it.