Dietary habits and the association of neopterin with niacin and tryptophan in university students

Abstract

Background: University students are potentially nutrient compromised as a result of social (demographics, socio-economic status) and other factors (such as transitioning from school to university - independent living). Poor eating habits compounded by lack of variety (including fruits, vegetables and dairy) may lead to students being at risk for malnutrition and non-communicable diseases of lifestyle. Adding to their stressful academic studies, the possible presence of chronic low-grade inflammation may negatively influence nutrition status, more so considering the effect of inflammation on malnutrition. Niacin is an essential nutrient and mild deficiencies are usually associated with irritability, memory problems, poor concentration and fatigue. The importance of this study was to investigate niacin micronutrient levels together with other biomarkers of nutrition, namely tryptophan and anthropometric indicators, in order to identify possible niacin deficiencies in apparently healthy individuals. Furthermore, it was important to investigate any presence of low-grade inflammation as this may have consequences for altered niacin and tryptophan micronutrient levels and nutrient metabolism among university students. Methods: A total of n=40 participants (70% female), with a mean age 23,6 ± 1,41 years, were recruited from the Faculty of Health Sciences at the University of Pretoria Prinshof Campus. Participants were divided into three malnutrition risk groups after completing questionnaires relating to university demographics, dietary habits and nutrition. Urine samples were collected for the assessment of niacin, tryptophan and the inflammatory biomarker neopterin via ELISA kits. Results: The mean BMI was 25.18 ± 5.14 kg/m2. The mean niacin and tryptophan levels were normal according to normative reference ranges. A total of n=19 (47.5%) participants had marginally above normal neopterin levels. There were no significant differences noted for niacin, tryptophan and neopterin between the malnutrition risk groups. However, neopterin correlated negatively with niacin, tryptophan and BMI, but positively with malnutrition risk scores. 1 in 4 participants consumed high-fat meat and processed foods daily and were at moderate risk for malnutrition. Less than 50% consumed dairy products or adequate servings of fruits and vegetables weekly with 85% of participants skipping at least one meal per day. Conclusion: Neopterin, as a relatively good marker of underlying inflammation, was negatively associated with nutrition parameters such as niacin and tryptophan. Although there were no deficiencies indicated by the niacin and tryptophan urine levels, university students may still be at risk for malnutrition as a result of underlying inflammation and the negative association of inflammation with dietary variables tested. Further research is required to support these findings.