Dietary fibres from Brassica vegetables bind heterocyclic amines in vitro (abstract only)

An association between the intake of heterocyclic amines (HAs) and development of cancer have been observed in epidemiological studies, while in other studies no such correlation has been found. HAs are mutagenic/carcinogenic compounds formed at low levels via the Maillard reaction during cooking of animal tissue. Animal studies have shown that dietary fibre (wheat bran, sorghum and pectin) may reduce the amount of HAs, for example IQ and MeIQx, that can be absorbed from the diet. This might have significance for tumour initiation, since the concentration of carcinogens in the bloodstream determines the initiating event. A diet high in dietary fibre has been suggested to protect against various Western diseases including colorectal cancer. Crude extracts of a Brassica variety have been shown to considerably reduce the mutagenic effect of Trp-P-1 and Trp-P-2, but the reason behind this effect is not known. The main objective of he present study was to verify the binding effect of different dietary fibres to HAs and to study the influence of boiling on the binding capacity. Six different types of Brassica vegetables, were obtained from a local supermarket, freeze-dried and milled. The HAs investigated were DMIP, Trp-P-1, Trp-P-2, PhIP, AαC, MeAαC, Norharman and Harman. The different HAs were binding to various extent to the dietary fibres: DMIP did not bind at all, and MeAαC and Trp-P-1 showed better binding than the rest of the HAs, a result that may be related to their molecular structures. Furthermore, this study showed that boiling of cabbage did not considerably affect the binding capacity.