ABSTRACTWe will present a simplified approximate model showing how even small changes in the dielectric response result in substantial variations in the Hamaker coefficient of the van der Waals interactions. Since all the terms in the Matsubara summation depends on the variation of the dielectric response spectra at one particular frequency, the total change in the Hamaker coefficient depends on the spectral changes not only at that frequency but also at the rest of the spectrum properly weighted. The Matsubara terms most affected by the addition of a single peak are not those close to the position of the added peak, but are distributed over the entire range of frequencies. We comment on the possibility of eliminating van der Waals interactions and/or drastically reducing them by spectral variation in a narrow regime of frequencies.