National Research Project
“The Role of Antioxidants in Cancer Etiology: Epidemiological and Statistical Models”
Plant-based foods such as fruit and vegetables, nuts, natural vegetable oils, and whole grains are crucial ingredients for a healthy diet. A large, consistent body of scientific evidence demonstrates that diets rich in plant foods provide protection against cardiovascular disease and several common types of cancer.
However,despite the consensus of the evidence about the health effect of plant foods, it still unclear which components of plant food based diet are protective and what their mechanism of action is. One of the hypotheses postulated to explain the protective effect of plant food, the antioxidant hypothesis, is based on their high content of bioactive molecules: dietary antioxidants reduce the risk of diseases by preventing cells to be damaged by free radicals.
Recent evidence suggests that it is the variegate composition of the plant food, an optimal mixture of different antioxidants, which is at the basis of their effect on health.
Co-operation among different antioxidants provides greater protection against free radicals injury than any single compound, thereby highlighting the importance of the synergic action of the antioxidants. The global antioxidant efficiency of food can be assessed by measuring their Total Antioxidant Capacity (TAC), defined as the ability of the extract to neutralize damaging oxidants. We aim to complete the database on the TAC available now for 34 vegetables, 30 fruits, 34 beverages, and 6 vegetable oils. The TAC database will be used to evaluate the dietary intake of TAC in a series of Italian case control studies and to assess if people at higher intake of dietary TAC are more protected against degenerative diseases respect to people at lowest intake of TAC. The study will give us indication also on the role played by different food groups in disease prevention. The epidemiological application of TAC can provide a new tool for investigating the relationship between dietary antioxidants and oxidative stress-related pathologies. The statistical analysis will be based on implementing standard regression models for categorical data, adding as comparison a Bayesian version. Model building will be performed based on both statistical and epidemiological requirements to study confounding and effect modification. Variable selection will follow the change of estimate method together to a structural approach minimize the chance of bias. Moreover, sensitivity analyses will be performed to assess the impact of misclassified exposure, selection bias and unmeasured confounders. The understanding of the role of plant foods as a “reservoir” of bioactive compounds which is able to delay the oxidative process leading to cell dysfunction, could supply valuable insights into the causation and prevention of complex