Li, H., Tsao, R. and Deng, Z. 2012. Factors affecting the antioxidant potential and health benefits of plant foods. Can. J. Plant Sci. 92: 1101-1111. Phytochemicals, such as carotenoids, phenolics and glucosinolates, in plants and plant-based foods are able to reduce the incidence of non-communicable diseases such as cardiovascular diseases, diabetes, stroke and different types of cancer due to their antioxidant potential. A brief summary of the in vitro and in vivo evidence and how post-harvest storage and processing conditions can affect the health benefits is presented in this review. Genetic, environmental conditions and physiological factors may modify the composition and amounts of these compounds present in plants, thus affecting the in vitro antioxidant activities. Such changes in combination with degradations after digestion can significantly affect the bioaccessibility and bioavailability of phytochemicals. The main objective of this review is to provide updated information on the effects of various factors such as genetics, environment, post-harvest storage and processing on the bioactive components, and knowledge of these factors can lead to multidisciplinary strategies to maximise the bioavailability and health potential of foods.