Micronutrients intake, dietary patterns and chronic inflammation in advanced age in New Zealand

Abstract

‘Inflamm-aging’, also known as chronic inflammation, has been found in the pathogenesis of age-related conditions and is considered to be the key to successful aging. Some micronutrients have been suggested to play an anti-inflammatory role, however, the evidence in advanced age are limited. This thesis aims to contribute to the gaps in the literature on micronutrients intake and systemic inflammatory markers as well as to identify anti-inflammatory dietary patterns for the advanced age in New Zealand. The present study investigated associations of dietary vitamin A, B1, B6, B12, D, E, zinc and selenium intake with C-reactive protein (CRP) level, and investigated associations of micronutrients composite score with CRP level. We identified dietary patterns and examined its association with CRP level. A total of 420 participants from the Life and Living in Advanced Age, a Cohort Study in New Zealand (LiLACS) who completed two 24-hour multiple-pass recalls (24hMPR), and CRP levels ≤10mg/L were recruited. Regression models were used to examine these relationships adjusted for demographics, lifestyle characteristics, Body mass index (BMI), medical history and use of anti-inflammatory drug. No association was found between CRP level and dietary micronutrients intake. Further, no association was found between the micronutrients composite score and CRP level. In Māori, light alcohol intake (2-4 times per month) was found to be associated with lower CRP level compared with those who never drink. In non-Māori, age is inversely correlated with CRP. We identified four dietary patterns for each ethnic group, which were labelled ‘Healthy’, ‘Pescatarian’, ‘Westernised’ and ‘Soup based’ for Māori, and ‘Westernised’, ‘Pesco pollo vegetarian’, ‘Fish and seafood’ and ‘Plant-based diet’ for non-Māori. We did not observe any association between dietary patterns and CRP. In non-Māori, women are more likely to follow the ‘plant-based’ diet and less likely to follow the ‘Westernised’ diet; ex-smokers are more likely to consume fish and are less likely to be a vegetarian compared to those who never smoked. In Māori, people from a higher social-economic background are more likely to have fish and soup based diets compared to those from the lower social-economic background. We recommend cautious interpretation of these findings. A larger prospective cohort study is needed to explore these relationships. Findings from this study have added to the limited evidence pertaining to age-related inflammation of those living to advanced age.