Cancer Chemoprevention through Consumption of African Leafy Vegetables: A review

Abstract

: Globally, 18.1 million new cancer cases out of which 9.6 million deaths occurred due to cancer in the year 2018. Consumption of vegetables and adopting a healthy lifestyle has been shown to be the way to reduce the risk of preventable cancer. The mechanisms in which vegetables prevent cancer occurrence, progression and survival are areas that have limited information hence knowledge gaps. The objective of this review is, therefore, to establish if African leafy vegetable could have chemoprevention potential against various types of cancers. The study selection was based on defined keywords (cancer chemoprevention and African leafy vegetables). A search was carried out on PubMed to retrieve all publications on cancer chemoprevention and African leafy vegetables. Only studies that met the search criteria were retrieved and the required data obtained. Data were synthesized by obtaining eight studies that met the criteria. The publications were analysed to establish whether African leafy vegetables could prevent cancer and the mechanisms of prevention. Amount or doses of the vegetable extracts used were also noted. The articles reviewed indicated that African leafy vegetables had a cytotoxic effect, or the vegetables contain anticarcinogenic effect in both human cancer cell lines and animal models. African leafy vegetables that had cytotoxic of anticarcinogenic effects were: Amaranthus, mustard, Ethiopian kale and Nauclea pobeguinii. Sweet potato leaves showed some compelling evidence of anti-cancer properties.