OBJECTIVE: High quality diets, characterized by nutrient-rich foods, are one of the foundations for health and well-being. Indicators of diet quality, antioxidants, are associated with protection against cardio-metabolic diseases. This study explores relationships between plasma antioxidants and cardio-metabolic risk among Aboriginal people in Australia.

DESIGN: As part of a community-driven health promotion programme, we conducted a cross-sectional study including a health-behaviour questionnaire, plasma antioxidants and cardio-metabolic risk markers (anthropometric-, blood pressure measurements, fasting glucose, glycated haemoglobin, lipids, C-reactive protein and albumin-creatinine-ratio) continuous and categorized into population-specific cut-offs. Antioxidants (β-carotene, β-cryptoxanthin, lycopene, lutein-zeaxanthin, retinol and alpha-tocopherol measured using HPLC) were applied to a principal component analysis, which aggregated these into a single component. Linear regression models were applied to investigate associations between the antioxidant component and cardio-metabolic risk markers.

SETTING: Community in a remote area in Northern Territory, Australia.

PARTICIPANTS: A total of 324 Aboriginal people, mean age 35.5 [range 15-75] years.

RESULTS: Antioxidant component levels were higher among those with higher self-reported vegetable intake (p<0.01), higher among those with higher self-reported fruit intake (p=0.05) and lower among current smokers (p=0.06). Linear regression revealed an inverse association between the antioxidant component and C-reactive protein (β= -0.01, p<0.01) after adjusting for confounders.

CONCLUSION: Higher plasma antioxidant levels, indicators of diet quality were associated with lower levels of high-sensitivity C-reactive protein in this Aboriginal population in remote Australia. This association suggests plasma antioxidants may be protective against inflammation; however, longitudinal studies are needed to examine this potentially protective relationship.