Fructose Intake and its Association with Relative Telomere Length: A Cross-Sectional Study Among Healthy Lebanese Adults

Abstract

Telomeres are composed of repetitive sequences of six nucleotides (TTAGGG) that cover the ends of the linear chromosomes, and their role is to maintain genetic integrity and provide cellular stability. Shorter telomere length has been associated with increased incidence of diseases and poor quality of life. High consumption of sugar-sweetened beverages (SSB) was suggested to be linked with shorter telomere length, possibly because of their elevated sugar content, and specifically fructose, which may contribute to a biochemical environment that is characterized by high inflammation and oxidative stress. To our knowledge, no data are available on fructose intake and its association with relative telomere length (RTL). Hence, the aim of this study is to (1) assess the intake of dietary fructose (total, added and natural) in a sample of Lebanese healthy adults and (2) investigate dietary fructose (total, added and natural) as a predictor of short telomere length, while adjusting for other potential confounders. This study is a cross-sectional population-based study carried out on 282 healthy adults aged 18 years and older. Anthropometric and biochemical data were collected, and RTL was measured by amplifying telomere and single copy gene using real-time polymerase chain reaction (PCR). Dietary intake was assessed using semi-quantitative food frequency questionnaire (FFQ) and NutriPro software was used to calculate natural fructose intake (g/day) from fruit and vegetables. Added fructose intake was calculated as 50% of added sugars in food products and total dietary fructose intake was measured by summing up the intakes of added and natural fructose. The average intake of total dietary fructose was of 51.31 ±35.55g/day which represents 6.58 ±3.71% of the total energy intake (EI). Intakes of natural and added fructose were estimated at 12.28 ±8.59g/day and 39.03 ±34.12g/day (1.78 ±1.41% and 4.80 ±3.56% EI), respectively. Intakes of total sugar and total fructose were found to differ significantly across RTL tertiles. Older age, wider waist circumference and higher LDL levels were statistically significantly associated with shorter RTL. To assess the association between fructose intake (total, added and natural) and RTL, multinomial logistic analyses were performed. No significant associations were found. This study is the first from the Eastern Mediterranean region to investigate the association between fructose intake and telomere length. It documented high intake levels of fructose but did not find any significant association between telomere length and fructose intakes (total, added or natural). Larger studies, of longitudinal nature, are needed to better elucidate the relationship between fructose intakes and telomere lengths.