Designing food structure and composition to enhance nutraceutical bioactivity to support cancer inhibition.

Many types of bioactive molecules found in foods ("nutraceuticals") have been shown to exert anticancer activities, including curcumin, resveratrol, polyphenols, sulforaphane, anthocyanins, genistein, quercetin and lycopene. The potential health benefits of nutraceuticals are often not realized because of their poor water solubility, chemical instability, adverse taste profile, and low oral bioavailability. Carefully designed food matrices are being developed to overcome these problems. Nutraceuticals can be isolated from their natural environment, and then incorporated into functional foods, often with the help of delivery systems (such as emulsions, nanoemulsions, liposomes, biopolymer nanoparticles, and microgels). Alternatively, the stability and bioavailability of nutraceuticals can be improved by leaving them in their natural environment, but ingesting them with a specially designed "excipient food". The structure and composition of an excipient food is controlled so as to enhance the bioaccessibilty, stability, and absorption of the nutraceuticals in the gastrointestinal tract. This review article provides an overview of some of the most important anticancer nutraceuticals found in foods, then highlights the main factors impacting their bioaccessibility, absorption and transformation. Finally, it describes different types of delivery systems and excipient systems that can be used to improve the overall bioavailability of anticancer nutraceuticals.