Introduction: Telomeres are nucleoprotein complexes at the ends of chromosomes that are under the control of genetic and environmental triggers. Accelerated telomere shortening is causally implicated in the increasing incidence of diseases. The Mediterranean diet has recently been identified as one that confers protection against diseases. This review aimed to identify the effect of each component of the Mediterranean diet on telomere length dynamics, highlighting the underlying molecular mechanisms. Methods: PubMed was searched to identify relevant studies to extract data for conducting a narrative review. Results: The Mediterranean diet alleviates clinical manifestations in many diseases. Focusing on autoimmune diseases, the Mediterranean diet can be protective by preventing inflammation, mitochondrial malfunction, and abnormal telomerase activity. Also, each Mediterranean diet constituent seems to attenuate aging through the sustenance or elongation of telomere length, providing insights into the underlying molecular mechanisms. Polyphenols, vitamins, minerals, and fatty acids seem to be essential in telomere homeostasis, since they inhibit inflammatory responses, DNA damage, oxidative stress, mitochondrial malfunction, and cell death and induce telomerase activation. Conclusions: The Mediterranean diet is beneficial for maintaining telomere dynamics and alleviating age-related illnesses. This review provides a comprehensive overview of cross-sectional, observational, and randomized controlled trials regarding the beneficial impact of every constituent in the Mediterranean diet on telomere length and chronic disease management.

Telomeres are part of chromatin structures containing repeated DNA sequences, which function as protective caps at the ends of chromosomes and prevent DNA degradation and recombination, thus ensuring the integrity of the genome. While telomere length (TL) can be genetically inherited, TL shortening has been associated with ageing and multiple xenobiotics and bioactive substances. TL has been characterised as a reliable biomarker for the predisposition to developing chronic pathologies and their progression. This narrative review aims to provide arguments in favour of including TL measurements in a complex prognostic and diagnostic panel of chronic pathologies and the importance of assessing the effect of different pharmacologically active molecules on the biology of telomeres. Medicines used in the management of cardiovascular diseases, diabetes, schizophrenia, hormone replacement therapy at menopause, danazol, melatonin, and probiotics have been studied for their positive protective effects against TL shortening. All these classes of drugs are analysed in the present review, with a particular focus on the molecular mechanisms involved.

Background: Diabetes is a rapidly growing global morbidity issue with high prevalence, and the associated dysglycemia leads to complications. Patients with type 2 diabetes mellitus (T2DM) often experience elevated anxiety levels, affecting their quality of life and diabetes management. This study investigated quercetin, a nutraceutical and potential senolytic with antioxidant activity, to detect its possible positive effect on the bio-clinical measurements and routine health of patients with T2DM. Methods: This prospective randomized controlled trial (RCT) investigated the clinical usefulness of quercetin in patients with T2DM receiving non-insulin medications. One hundred participants were stratified by age and sex (1:1) and randomized to control (n = 50) or intervention (n = 50) groups. The control received standard care only, while the intervention received 500 mg quercetin daily for 12 weeks, followed by an 8-week washout and a final consecutive 12-week supplementation period (total: 32 weeks), as adjunct to their usual care. Comprehensive health assessments, including blood analyses, were conducted at baseline and study termination. Quality of life and anxiety were assessed using the 36-item Short Form Health Survey (SF-36) and Short Anxiety Screening Test (SAST-10). Results: Eighty-eight patients with T2DM concluded the trial. Compared with the control, glycated hemoglobin (HbA1c) levels showed a significant decrease (Δ%-change: −4.0% vs. 0.1%, p = 0.011). Quercetin also significantly improved PiKo-6 readings (FEV₁: 5.6% vs. −1.5%, p = 0.002), systolic blood pressure (−5.0% vs. −0.2%, p = 0.029), night-time sleep (11.6% vs. −7.3%, p < 0.001), anxiety levels (SAST-10) (−26.2% vs. 3.3%, p < 0.001), and quality of life (SF-36) (both physical and mental components, p < 0.001). Conclusions: Based on the current open-label study, quercetin appears to be a promising supplement for T2DM, providing lifestyle and care support. Further research is warranted to shift this potential from clinical usefulness and feasibility to multidisciplinary evidence.

Ageing is a complex and unavoidable physiological process which, in simple terms, consists of a progressive deterioration in the functionality of cells, tissues and organs, culminating in an increased risk of developing chronic pathologies. Telomeres, the repetitive nucleotide structures at the end of chromosomes, ensure genomic integrity and modulate cellular senescence. The progressive shortening of telomere length with each cell division directly correlates with an increased susceptibility to developing chronic pathologies. However, this shortening, normally physiological and inevitable, can be markedly accelerated in the presence of chronic infections, such as HIV-1 infection, by sustained and continuous activation of the immune system, chronic inflammation, generation of oxidative stress, or direct alterations produced by viral proteins. Thus, in this narrative review, we discuss the 12 hallmarks of ageing in the context of HIV-1 infection, as understanding the molecular changes induced by HIV-1 through these well-established pillars could provide a holistic approach to the management of HIV-positive patients. At the same time, considering that telomeres are at the centre of all these changes, an assessment of the impact of antiretroviral therapy on telomere length is necessary to guide clinical decisions. The ultimate goal of this research is to develop personalised therapies to increase the quality of life and health outcomes of HIV patients.