High meat intake has been related to chronic diseases such as cancer and CVD. One hypothesis is that heterocyclic amines (HCA), which are formed during the cooking process of meat, can generate reactive species. These compounds can cause oxidation of lipids, proteins and DNA, resulting in oxidative stress, cell damage and loss of biological function. This association has been seen in vitro; however, it remains unclear in vivo. The aim of the present study was to investigate the association between oxidative stress and HCA intake, and oxidative stress and meat intake. Data were from the Health Survey for Sao Paulo – ISA-Capital (561 adult and elderly). Food intake was estimated by one 24-h dietary recall (24HR) complemented by a detailed FFQ with preferences of cooking methods and level of doneness for meat. HCA intake was estimated linking the meat from the 24HR to a database of HCA. Oxidative stress was estimated by malondialdehyde (MDA) concentration in the plasma, after derivatisation with thiobarbituric acid and quantification by HPLC/diode array. Analyses were performed using multivariate logistic regressions adjusted for smoking, sex, age, BMI, skin colour, energy intake, fruit and vegetable intake, and physical activity. A positive association between HCA intake and MDA concentration (OR 1·17; 95 % CI 1·01, 1·38) was observed, showing that HCA from meat may contribute to increase oxidative stress, and may consequently increase the risk of chronic diseases.

Antimutagenic properties of various dietary components have been investigated in many studies, in order to find compounds protective against the various steps of carcinogenesis. Indeed, cancer is now the principal cause of death in industrialised countries and treatment is still difficult. Thus, research in prevention is of extreme importance. While, the etiology of most cancers has an environmental component, colon or breast cancers are highly linked to dietary habits (up to 50% of colorectal cancers are due to diet; Riboli et al. 1996). In this context, Boutron et al. (1996) showed inverse correlation between consumption of dairy products and colorectal cancer in France.