An antibody or a functional part thereof capable of specifically binding beta amyloid, wherein the antibody or the functional part thereof comprises: a. (i) a light chain variable domain comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the sequence set forth in SEQ ID NO: 7, or a functional part thereof comprising three light chain CDRs having polypeptide sequences of SEQ ID NOs: 9-11; and (ii) a heavy chain variable domain comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the sequence set forth in SEQ ID NO: 8, or a functional part thereof comprising three.heavy chain CDRs having polypeptide sequences of SEQ ID NOs: 12-14; or b. the amino acid sequences of SEQ ID NOs: 7 and 8, wherein the antibody has been altered by introducing at least one, at least two, or at least three conservative substitutions into the sequences of SEQ ID NOs: 7 and 8; or c. (i) a light chain variable domain comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to a sequence selected from SEQ ID NO: 17 and SEQ ID NO: 19, or a functional part thereof comprising three light chain CDRs having polypeptide sequences of SEQ ID NOs: 21-23; and (ii) a heavy chain variable domain comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to a sequence selected from SEQ ID NO: 18 and SEQ ID NO: 20, or a functional part thereof comprising three heavy chain CDRs having polypeptide sequences of SEQ ID NOs: 24-26; or d. the amino acid sequences of SEQ ID NOs: 17 and 18, wherein the antibody has been altered by introducing at least one, at least two, or at least three conservative substitutions into the sequences of SEQ ID NOs: 17 and 18; or e. the amino acid sequences of SEQ ID NOs: 19 and 20, wherein the antibody has been altered by introducing at least one, at least two, or at least three conservative substitutions into the sequences of SEQ ID NOs: 19 and 20, wherein said antibody upon co-incubation with an Abeta1-42 monomeric and/or oligomeric peptide, inhibits the aggregation of the Abeta monomers to high molecular polymeric amyloid fibrils and, in addition, upon co-incubation with preformed high molecular polymeric amyloid fibrils or filaments formed by the aggregation of Abeta1-42 monomeric and/or oligomeric peptides, is capable of disaggregating the preformed polymeric fibrils or filaments, at a molar concentration ratio of 1:100 upon incubation for 24 hours at 37° C. a. (i) a light chain variable domain comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the sequence set forth in SEQ ID NO: 7, or a functional part thereof comprising three light chain CDRs having polypeptide sequences of SEQ ID NOs: 9-11; and (ii) a heavy chain variable domain comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to the sequence set forth in SEQ ID NO: 8, or a functional part thereof comprising three.heavy chain CDRs having polypeptide sequences of SEQ ID NOs: 12-14; or b. the amino acid sequences of SEQ ID NOs: 7 and 8, wherein the antibody has been altered by introducing at least one, at least two, or at least three conservative substitutions into the sequences of SEQ ID NOs: 7 and 8; or c. (i) a light chain variable domain comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to a sequence selected from SEQ ID NO: 17 and SEQ ID NO: 19, or a functional part thereof comprising three light chain CDRs having polypeptide sequences of SEQ ID NOs: 21-23; and (ii) a heavy chain variable domain comprising an amino acid sequence that is 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identical to a sequence selected from SEQ ID NO: 18 and SEQ ID NO: 20, or a functional part thereof comprising three heavy chain CDRs having polypeptide sequences of SEQ ID NOs: 24-26; or d. the amino acid sequences of SEQ ID NOs: 17 and 18, wherein the antibody has been altered by introducing at least one, at least two, or at least three conservative substitutions into the sequences of SEQ ID NOs: 17 and 18; or e. the amino acid sequences of SEQ ID NOs: 19 and 20, wherein the antibody has been altered by introducing at least one, at least two, or at least three conservative substitutions into the sequences of SEQ ID NOs: 19 and 20,