Supervisors info:
Ανδρονίκη Νάσκα, Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Βασιλική Μπουντζιούκα, Επίκουρη Καθηγήτρια, Τμήμα Επιστήμης Τροφίμων και Διατροφής, Πανεπιστήμιο Αιγαίου
Christopher P. Nelson, Associate Professor, Department of cardiovascular sciences, University of Leicester
Summary:
Background: Telomere length (TL) is an important biomarker causally related to several degenerative chronic diseases. Antioxidant vitamin and mineral intake is suggested to alleviate the negative effect of oxidative stress and chronic inflammation, hence reducing the development of chronic diseases.
Objective: The aim of the study was a) to investigate whether the regular uptake of i) vitamins and/or minerals by supplements, and ii) dietary micronutrient intake is associated with leucocyte telomere length (LTL), b) to explore potential determinants of regular supplement use, c) and to examine the association between nutritional status of participants with LTL.
Material and Methods: This is a cross-sectional study using data collected from 422,693 UK Biobank volunteers aged between 40 and 69 years old, during 2006-2010. LTL was calculated as the ratio of telomere repeat number to a single–copy gene and was loge-transformed and standardized (z-LTL). Data regarding micronutrient intake by supplements was recorded at baseline assessment using a self-administered touchscreen food frequency questionnaire, while dietary micronutrient intake assessment was carried our through self-reported web-based 24hr recall diaries. The association between micronutrient intake by supplements or diet and z-LTL was evaluated using sequential multivariable linear regression models after adjusting for multiple demographic, lifestyle and clinical covariates.
Results: About 50% (n=131,810) of the sample with complete data on all covariates (n=261,204) self-reported regular supplement intake. Multiple determinants of regular supplement use were identified including age, educational level, physical activity, adherence to Mediterranean diet, ethnicity, smoking status, obesity, LDL cholesterol or GFR measurement and presence of diabetes mellitus or vascular disease. Micronutrient dietary intake was similar between regular supplement and non- regular supplement users. Overall supplement intake was not associated with z-LTL. However, negative associations of small magnitude of z-LTL with regular vitamin B (regression coefficient (95% confidence interval): -0.019SD (-0.041SD; 0.002SD), p=0.079) and vitamin B9 (-0.027 (-0.054; 0.000), p=0.054) supplement intake were observed. The combined intake of vitamin B/B9 was associated with smaller z-LTL (-0.07 (-0.11; -0.03), p=0.001), equivalent to 3 years of age-related change in z-LTL. Results from the multivariable regression models for the dietary intake revealed a negative association of z-LTL with pantothenic acid (-0.019 (-0.033; -0.005), p=0.005) and vitamin B6 (-0.018 (-0.030; -0.005), p=0.005) and a positive association with magnesium (0.021 (0.002; 0.041), p=0.034) and folate (0.014 (0.0004; 0.027), p=0.043). Regardless, only the association of z-LTL with pantothenic acid and vitamin B6 reached Bonferroni significance of 0.006. Among supplement users, riboflavin (vitamin B2) (0.021 (0.001; 0.041), p=0.043) and vitamin D (0.018 (0.005; 0.030), p=0.005) were positively associated with z-LTL, whilst iron was negatively associated with z-LTL (-0.024 (-0.043; -0.005); p=0.013).
Conclusion: Overall micronutrient supplement intake was not associated with telomere length, while vitamin B and B9 regular uptake by supplements was associated with z-LTL. However, associations were equivalent to a year or less of age-related change in LTL. Taking into account the small effect of the aforementioned associations and their small clinical importance as well as the fact that any relationship between telomeres and micronutrients requires high intakes such as those achieved by taking supplements, any relevance to the role of micronutrient intake on telomere length remains unclear. Further prospective epidemiologic studies (observational or experimental) are essential to investigate the mechanisms by which micronutrients are related to telomere length and impact on age-related diseases.
Keywords:
Micronutrients, Telomere length, Chronic diseases, Antioxidants, Supplements
