Using replica exchange molecular dynamics (REMD) and united atom implicit solvent model we examine the role of backbone hydrogen bonds (HBs) in A beta aggregation. The importance of HBs appears to depend on the aggregation stage. The backbone HBs have little effect on the stability of A beta dimers or on their aggregation interface. The HBs also do not play a critical role in initial binding of A beta peptides to the amyloid fibril. Their elimination does not change the continuous character of A beta binding nor its temperature. However, cancellation of HBs forming between incoming A beta peptides and the fibril disrupts the locked fibril-like states in the bound peptides. Without the support of Hbs, bound A beta peptides form few long beta-strands on the fibril edge. As a result, the deletion of peptide-fibril HBs is expected to impede fibril growth. As for the peptides bound to A beta fibril the deletion of interpeptide HBs reduces the beta propensity in the dimers making them less competent for amyloid assembly. These simulation findings together with the backbone mutagenesis experiments suggest that a viable strategy for arresting fibril growth is the disruption of interpeptide HBs.