Telomere attrition and mitochondrial DNA variations are implicated in the biological aging process and genomic stability can be influenced by nutritional factors. This study aims to analyze the relative telomere length (rTL) and mitochondrial DNA copy number (mtCN) in aged individuals and their association with plasma folate and vitamin B12 levels. This community-based cross-sectional study involves 428 subjects (<60 years: 242 & ≥60 years: 186). Quantitative real-time PCR was used to measure rTL and mtCN variation, and radioimmunoassay to measure plasma folate and vitamin B12 levels. The subjects in the ≥60 years age group have significantly shorter telomeres and lower mtCN compared to the <60 years age group. A significant positive correlation was observed between the rTL and mtCN, and both of them were positively associated with plasma folate and vitamin B12 levels. In the ≥60 age group; folate and vitamin B12 positively correlated with rTL and vitamin B12 with mtCN. The study revealed a decline of rTL and mtCN with age in the Indian population and their association suggests that they may co-regulate each other with age. In conclusion, folate and vitamin B12 may delay aging by preventing the reduction in rTL length and mtCN.

中文翻译：

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相对端粒长度和线粒体 DNA 拷贝数随年龄的变化：与血浆叶酸和维生素 B12 的关联

端粒磨损和线粒体 DNA 变异与生物老化过程有关，基因组稳定性可能受营养因素的影响。本研究旨在分析老年人的相对端粒长度 (rTL) 和线粒体 DNA 拷贝数 (mtCN) 及其与血浆叶酸和维生素 B12 水平的关系。这项基于社区的横断面研究涉及 428 名受试者（<60 岁：242 名和≥60 岁：186 名）。定量实时 PCR 用于测量 rTL 和 mtCN 变异，并使用放射免疫测定法测量血浆叶酸和维生素 B12 水平。与 <60 岁年龄组相比，≥60 岁年龄组受试者的端粒明显更短，mtCN 更低。在 rTL 和 mtCN 之间观察到显着的正相关，它们都与血浆叶酸和维生素 B12 水平呈正相关。≥60岁年龄组；叶酸和维生素 B12 与 rTL 呈正相关，维生素 B12 与 mtCN 呈正相关。该研究揭示了印度人口中 rTL 和 mtCN 随着年龄的增长而下降，并且它们的关联表明它们可能随着年龄的增长而相互调节。总之，叶酸和维生素 B12 可以通过防止 rTL 长度和 mtCN 的减少来延缓衰老。