Promoting nutritious leafy vegetables in the Pacific and northern Australia

Abstract

A more traditional lifestyle, especially with respect to diet and exercise, is needed to address the alarming rates of obesity, heart disease and diabetes in Pacific Island countries and indigenous communities in northern Australia. Leafy vegetables should play an important role but are often regarded as “low status” foods and have received little research attention. This study found that, although certain leafy vegetables are popular in some countries, particularly Solomon Islands and Tonga, there is little knowledge of their health benefits. Leaf samples were collected in Solomon Islands, Samoa, Tonga, Kiribati, North Queensland and the Torres Strait Islands and minerals, carotenoids and polyphenols were analysed. To study genotype-environment interaction, different species growing at the same location (same soil) and common species growing at multiple locations (different soils) were included in the survey. The data, together with flavour and popularity, were used to make a “Top 12” nutritious leafy vegetable factsheet series, which was distributed in participating countries and published online (www.aciar.gov.au/News2013July). Outstanding species included Abelmoschus manihot (aibika, bele), Polyscias spp. (ete), Sauropus androgynus (sweetleaf), Moringa oleifera (drumstick tree) and Basella alba (creeping spinach). Aibika was high in iron, zinc, magnesium, manganese, protein and lutein; sweetleaf was high in iron, zinc, calcium, magnesium, manganese, sulphur, lutein, b-carotene and protein; ete was high in zinc and calcium and grows well on alkaline coral soils; drumstick was high in b-carotene, sulphur and selenium, and creeping spinach was high in magnesium and polyphenols. Reliable provision of quality germplasm, more nutrition education, including school food gardens which feature the most nutritious of the vegetables, and value chain research to improve shelf life and delivery of nutrients to consumers are recommended.