According to The linguistics encyclopedia (2002), p.237:
"Taboos may even cause the loss of a word, as in the classical Indo-European case of the word for 'bear'. [...] Avoidance of the term is thought to have occurred in the northern Indo-European regions, where the bear was prevalent, and another name, (employed, perhaps, not to offend it), was substituted in the form of *ber- 'brown'; that is, 'the brown one'."Now, upon reading accounts like this, the first question that comes to me is this: How can one know with any degree of certainty that this word had been displaced in Germanic, Baltic and Slavic because of taboo and not because of garden-variety lexical replacement? In Slavic, 'bear' is replaced by a new word meaning 'honey-eater', unrelated to Germanic's choice of 'brown one'. This is exaggerated as a 'circumlocution' in keeping with the assumption of taboo but if these sorts of creative epithets constitute in themselves evidence for taboo replacement, then could we not then claim that any new word coined is a "circumlocution" or "taboo" for the original term? Should we start insisting that Latin aqua 'water' is a taboo replacement for *wódr̥ too? It's rather convenient to pin taboo explanations on the vocabulary of obscure northern cultures that lacked written records.
Sure, no one can deny that the bear was a powerful symbol to northern European cultures for millennia, but if we replace 'bear' in the above quote with 'pickle', the emptiness of this taboo assumption becomes a little clearer.