Associations between diet, lifestyle factors, and telomere length in women

Linoleic acid exhibits anti-proliferative and anti-invasive activities in endometrial cancer cells and a transgenic model of endometrial cancer

Emerging evidence has provided considerable insights into the integral function of reprogramming fatty acid metabolism in the carcinogenesis and progression of endometrial cancer. Linoleic acid, an essential fatty acid with the highest consumption in the Western diet regimen, has shown pro-tumorigenic or anti-tumorigenic effects on tumor cell growth and invasion in multiple types of cancer. However, the biological role of linoleic acid in endometrial cancer remains unclear. In the present study, we aimed to investigate the functional impact of linoleic acid on cell proliferation, invasion, and tumor growth in endometrial cancer cells and in a transgenic mouse model of endometrial cancer. The results showed that Linoleic acid significantly inhibited the proliferation of endometrial cancer cells in a dose-dependent manner. The treatment of HEC-1A and KLE cells with linoleic acid effectively increased intracellular reactive oxygen species (ROS) production, decreased mitochondrial membrane potential, caused cell cycle G1 arrest, and induced intrinsic and extrinsic apoptosis pathways. The anti-invasive ability of linoleic acid was found to be associated with the epithelial-mesenchymal transition process in both cell lines, including the decreased expression of N-cadherin, snail, and vimentin. Furthermore, treatment of Lkb1fl/flp53fl/fl transgenic mice with linoleic acid for four weeks significantly reduced the growth of endometrial tumors and decreased the expression of VEGF, vimentin, Ki67, and cyclin D1 in tumor tissues. Our findings demonstrate that linoleic acid exhibits anti-proliferative and anti-invasive activities in endometrial cancer cell lines and the Lkb1fl/flp53fl/fl mouse model of endometrial cancer, thus providing a pre-clinical basis for future dietary interventions with linoleic acid in endometrial cancer.

Micronutrient intake and telomere length: findings from the UK Biobank

PURPOSE

To investigate whether micronutrient intake from food as well as the regular uptake of specific vitamins and/or minerals are associated with leucocyte telomere length (LTL).

METHODS

This is a cross-sectional study using data from 422,693 UK Biobank participants aged from 40 to 69 years old, during 2006-2010. LTL was measured as the ratio of telomere repeat number to a single-copy gene and was loge-transformed and z-standardized (z-LTL). Information concerning supplement use was collected at baseline through the touchscreen assessment, while micronutrient intake from food were self-reported through multiple web-based 24 h recall diaries. The association between micronutrient intake or supplement use and z-LTL was assessed using multivariable linear regression models adjusting for demographic, lifestyle and clinical characteristics.

RESULTS

About 50% (n = 131,810) of the participants, with complete data on all covariates, self-reported regular supplement intake. Whilst overall supplement intake was not associated with z-LTL, trends toward shorter z-LTL with regular vitamin B (-0.019 (95% CI: -0.041; 0.002)) and vitamin B9 (-0.027 (-0.054; 0.000)) supplement intake were observed. z-LTL was associated with food intake of pantothenic acid (-0.020 (-0.033; -0.007)), vitamin B6 (-0.015 (-0.027; -0.003)), biotin (0.010 (0.002; 0.018)) and folate (0.016 (0.003; 0.030)). Associations of z-LTL with these micronutrients were differentiated according to supplement intake.

CONCLUSION

Negative associations equivalent to a year or less of age-related change in LTL between micronutrient intake and LTL were observed. Due to this small effect, the clinical importance of the associations and any relevance to the effects of vitamin and micronutrient intake toward chronic disease prevention remains uncertain.

Connecting the Dots: Telomere Shortening and Rheumatic Diseases

Telomeres, repetitive sequences located at the extremities of chromosomes, play a pivotal role in sustaining chromosomal stability. Telomerase is a complex enzyme that can elongate telomeres by appending telomeric repeats to chromosome ends and acts as a critical factor in telomere dynamics. The gradual shortening of telomeres over time is a hallmark of cellular senescence and cellular death. Notably, telomere shortening appears to result from the complex interplay of two primary mechanisms: telomere shelterin complexes and telomerase activity. The intricate interplay of genetic, environmental, and lifestyle influences can perturb telomere replication, incite oxidative stress damage, and modulate telomerase activity, collectively resulting in shifts in telomere length. This age-related process of telomere shortening plays a considerable role in various chronic inflammatory and oxidative stress conditions, including cancer, cardiovascular disease, and rheumatic disease. Existing evidence has shown that abnormal telomere shortening or telomerase activity abnormalities are present in the pathophysiological processes of most rheumatic diseases, including different disease stages and cell types. The impact of telomere shortening on rheumatic diseases is multifaceted. This review summarizes the current understanding of the link between telomere length and rheumatic diseases in clinical patients and examines probable telomere shortening in peripheral blood mononuclear cells and histiocytes. Therefore, understanding the intricate interaction between telomere shortening and various rheumatic diseases will help in designing personalized treatment and control measures for rheumatic disease.

Association Between Ultra-Processed Food Consumption and Leucocyte Telomere Length: A cross-sectional study of UK Biobank

OBJECTIVE

This study aimed to investigate the association between consumption of ultra-processed foods (UPFs) and leucocyte telomere length (LTL).

METHODS

This cross-sectional study utilized data from the UK Biobank, including a total of 64,690 participants. LTL was measured using Q-PCR with natural logarithmic conversion and Z-score normalization. Dietary data were collected through a 24-hour recall questionnaire from 2009 to 2010. UPFs were identified using the Nova food classification and analyzed as either a continuous or categorical variable respectively. Multiple linear regression models were employed to analyze the association between UPF consumption and LTL.

RESULTS

The included participants had an average age of 56.26 years, of whom 55.2% were female. After adjusting for sociodemographic, lifestyle-related and anthropometric variables, LTL exhibited a decrease of 0.005 (95% CI: -0.007, -0.002) with one UPF serving/day increase. Compared to participants consuming ≤ 3.5 servings/day, those consuming 3.5 to < 6, 6 to ≤ 8 and > 8 servings/day showed a shortening of LTL by 0.025 (95% CI: -0.047, -0.004), 0.034 (95% CI: -0.055, -0.012) and 0.038 (95% CI: -0.062, -0.015), respectively (P for trend = 0.001). Subgroup analyses by UPF subclasses revealed that consumption of ready-to-eat/heated food (β = -0.008, 95% CI: -0.014, -0.002), beans and potatoes (β = -0.024, 95% CI: -0.039, -0.009), animal-based products (β = -0.011, 95% CI: -0.019, -0.004), artificial sugar (β = -0.014, 95% CI: -0.025, -0.004), and beverages (β = -0.005, 95% CI: -0.009, -0.001) showed negative associations with LTL. Conversely, breakfast cereals (β = 0.020, 95% CI: 0.004, 0.036) and vegetarian alternatives (β = 0.057, 95% CI: 0.027, 0.086) showed positive correlations with LTL.

CONCLUSIONS

Our study found that a higher consumption of total UPFs was associated with a shorter LTL. However, some subclass UPFs may be associated with longer LTL, depending on their nutritional composition.

Does Adulthood Socioeconomic Status Predict Subsequent Telomere Length in Racially and Ethnically Diverse Women?

Background

Telomere length is a critical biomarker of cellular aging and overall health. While childhood socioeconomic status (SES) indicators such as education and poverty can have long-lasting effects on biological aging, research has shown contradictory results regarding the impact of adulthood SES on future telomere length, particularly in racially and ethnically diverse individuals. This study investigates the effects of baseline adulthood SES indicators such as education and poverty on telomere length nine years later in women, using data from the Future of Families and Child Wellbeing Study (FFCWS).

Methods

We analyzed data from the FFCWS, a longitudinal cohort study. The sample included baseline adulthood SES and follow-up telomere length measure of women (n = 2,421) with varying socioeconomic conditions. Telomere length was measured from saliva samples nine years after the baseline measure of adulthood SES. Education, poverty, and marital status at baseline were assessed. Multivariate linear regression models were used to examine the association between adulthood SES indicators at baseline and future telomere length, controlling for potential confounders.

Results

From the total 2,421 women, 675 were Latino White, 1,158 were non-Latino Black, and 588 were non-Latino White. Our findings indicate that for non-Latino White women poverty at certain level, and childbirth weight, and for non-Latino Black maternal age were predictors of telomere lengths nine years later.

Conclusion

Poverty at a specific level, maternal age and childbirth weight serve as predictors of telomere lengths nine years later in some women. These findings underscore the importance of socioeconomic factors and early-life influences in understanding telomere dynamics and aging processes among women from varied racial and ethnic backgrounds.

Physical Performance and Telomere Length in Older Adults

BACKGROUND

The aging population prompts studying risk factors and markers to predict healthy aging. Telomere length is a promising candidate for assessing various age-related traits.

AIM OF THE STUDY

To investigate the association between physical performance and telomere length.

METHODS

We enrolled 323 older Mexican adults from the "Cohort of Obesity, Sarcopenia, and Frailty of Older Mexican Adults" affiliated with the Instituto Mexicano del Seguro Social and assessed their physical performance using the Short Physical Performance Battery, dividing participants into low (≤7) and high (>7) groups. Absolute telomere length was determined by qPCR, and individuals were classified into short (≤4.22 kb) and long (>4.22 kb) groups. We calculated the mean and adjusted mean, considering sex and age, among others, with 95% CI. We estimated the effect size between physical performance and telomere length using Cohen's d for unequal group sizes and calculated the odds ratio for physical performance based on telomere length.

RESULTS

Participants with low physical performance had significantly shorter telomeres (mean 4.14.44.7 kb, adjusted mean 3.54.04.5 kb, p <0.001), while those with high physical performance exhibited longer telomeres (mean 5.55.75.9 kb, adjusted mean 4.75.35.8 kb, p <0.001), with a medium-to-high telomere length effect size (d = 0.762). The odds of low physical activity increased 2.13.66.1-fold per kb of telomere attrition (adjOR 1.73.36.3, p <0.001).

CONCLUSION

Decreased physical function is associated with shorter telomere length. Absolute telomere length presents a promising biomarker for distinguishing between healthy and unhealthy aging, warranting further investigation.

Telomere Length in a South African Population Co-Infected with HIV and Helminths

Biological ageing refers to the gradual decrease in physiological functions, resulting in immune senescence, cellular damage and apoptosis. Telomere length is a biomarker of biological ageing. Limited studies have associated shorter telomere length with HIV and parasite single infections, with no studies reporting the association of HIV and parasite co-infection with telomere length. The study aimed to investigate whether telomere length shortening is accelerated in a South African population co-infected with HIV and helminths compared to participants singly infected with either HIV or helminths. Additionally, telomere length data were compared with participants' biochemical and full blood count parameters. A total of 200 participants were in groups of uninfected control, HIV single infection, helminth single infection and HIV and helminth co-infection groups. Relative telomere length (RTL) was determined using Real-Time PCR and associated with biochemical and full blood count parameters using multivariate regression analysis models that were adjusted for confounders. The uninfected control group was used as a reference group. The uninfected control group had the highest mean RTL (1.21 ± 0.53) while the HIV-infected (0.96 ± 0.42) and co-infected (0.93 ± 0.41) groups had similar RTLs, and lastly, the helminth-infected group (0.83 ± 0.33) had the lowest RTL (p = 0.0002). When compared to the uninfected control group, a significant association between RTL and biochemical parameters, including blood iron (β = -0.48), ferritin (β = -0.48), transferrin saturation (β = -0.57), transferrin (β = -0.57), phosphate (β = -0.47), vitamin A (β = -0.49) and C-reactive protein (β = -0.52) were noted in the co-infected group (p < 0.05). In addition, a significant association between RTL and full blood count, including (β = -0.47), haematocrit (β = -0.46), mean corpuscular volume (β = -0.47), lymphocytes (β = -0.45), mean corpuscular haemoglobin concentration (β = -0.45), red cell distribution width (β = -0.47), monocytes (β = -0.45), eosinophils (β = -0.45), basophils (β = -0.44) and transferrin saturation (β = -0.57) were also noted in the co-infected group (p < 0.05). Accelerated biological ageing, as indicated by telomere length shortening, is associated with HIV and helminth co-infections.

Aging Processes Are Affected by Energy Balance: Focused on the Effects of Nutrition and Physical Activity on Telomere Length

PURPOSE OF REVIEW

The number and proportion of individuals aged 60 and over are increasing globally. The increase in the elderly population has important social and economic effects. Telomere length is an important marker for healthy aging. Here, we review the relevance between telomere length and energy balance by determining the effects of physical activity, nutrients, dietary patterns, and foods on healthy aging and telomere length with related studies.

RECENT FINDINGS

Evidence emphasizes the importance of telomere length and integrity for healthy aging. It also focuses on the importance of potential interventions such as physical activity and a healthy diet to improve this process. We suggest that ensuring energy balance with regular physical activity and healthy diets can contribute to the aging process by protecting telomere length. In addition, different methods in studies, short and inconsistent durations, different types of exercise, different diet patterns, and non-standard foods have led to conflicting results. More studies are needed to elucidate molecular-based mechanisms.

Identifying the relation between food groups and biological ageing: a data-driven approach

BACKGROUND

Heterogeneity in ageing rates drives the need for research into lifestyle secrets of successful agers. Biological age, predicted by epigenetic clocks, has been shown to be a more reliable measure of ageing than chronological age. Dietary habits are known to affect the ageing process. However, much remains to be learnt about specific dietary habits that may directly affect the biological process of ageing.

OBJECTIVE

To identify food groups that are directly related to biological ageing, using Copula Graphical Models.

METHODS

We performed a preregistered analysis of 3,990 postmenopausal women from the Women's Health Initiative, based in North America. Biological age acceleration was calculated by the epigenetic clock PhenoAge using whole-blood DNA methylation. Copula Graphical Modelling, a powerful data-driven exploratory tool, was used to examine relations between food groups and biological ageing whilst adjusting for an extensive amount of confounders. Two food group-age acceleration networks were established: one based on the MyPyramid food grouping system and another based on item-level food group data.

RESULTS

Intake of eggs, organ meat, sausages, cheese, legumes, starchy vegetables, added sugar and lunch meat was associated with biological age acceleration, whereas intake of peaches/nectarines/plums, poultry, nuts, discretionary oil and solid fat was associated with decelerated ageing.

CONCLUSION

We identified several associations between specific food groups and biological ageing. These findings pave the way for subsequent studies to ascertain causality and magnitude of these relationships, thereby improving the understanding of biological mechanisms underlying the interplay between food groups and biological ageing.

Chronic and Latent Viral Infections and Leukocyte Telomere Length across the Lifespan of Female and Male Individuals Living with or without HIV

BACKGROUND

Chronic/latent viral infections may accelerate immunological aging, particularly among people living with HIV (PLWH). We characterized chronic/latent virus infections across their lifespan and investigated their associations with leukocyte telomere length (LTL).

METHODS

Participants enrolled in the CARMA cohort study were randomly selected to include n = 15 for each decade of age between 0 and >60 y, for each sex, and each HIV status. Cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus 8 (HHV-8), herpes simplex virus 1 (HSV-1), and HSV-2 infection were determined serologically; HIV, hepatitis C (HCV), and hepatitis B (HBV) were self-reported. LTLs were measured using monochrome multiplex qPCR. Associations between the number of viruses, LTL, and sociodemographic factors were assessed using ordinal logistic and linear regression modeling.

RESULTS

The study included 187 PLWH (105 female/82 male) and 190 HIV-negative participants (105 female/84 male), ranging in age from 0.7 to 76.1 years. Living with HIV, being older, and being female were associated with harbouring a greater number of chronic/latent non-HIV viruses. Having more infections was in turn bivariately associated with a shorter LTL. In multivariable analyses, older age, living with HIV, and the female sex remained independently associated with having more infections, while having 3-4 viruses (vs. 0-2) was associated with a shorter LTL.

CONCLUSIONS

Our results suggest that persistent viral infections are more prevalent in PLWH and females, and that these may contribute to immunological aging. Whether this is associated with comorbidities later in life remains an important question.

Plant Foods Intake and Risk of Premature Aging in Adult Survivors of Childhood Cancer in the St Jude Lifetime Cohort (SJLIFE)

PURPOSE

To identify dietary factors that are related to premature aging in adult survivors of childhood cancer, we examined the associations between plant food intakes and age-related deficit accumulation.

METHODS

A total of 3,322 childhood cancer survivors (age 18-65 years, mean = 31, standard deviation = 8.4) in the St Jude Lifetime Cohort had total fruit, total vegetables and subgroups, whole grains, refined grains, nuts/seeds, and nutrients intake assessed using a food frequency questionnaire. Premature aging at baseline was assessed by the deficit accumulation index (DAI) and categorized as low, medium, and high risk. Multinomial logistic regressions (reference: low risk) adjusting for confounders estimated odds ratios (ORs) and 95% CIs. Multivariable linear regression of a continuous intake against a continuous DAI was also performed.

RESULTS

Dark green vegetable (ORhigh v low = 0.47 [95% CI, 0.28 to 0.78] per 1/2 cup/1,000 kcal increment) and nuts/seeds intakes (ORhigh v low = 0.71 [95% CI, 0.47 to 1.08] per 1 oz/1,000 kcal increment; coefficientlinear = -0.0115, P = .02) were associated with a lower risk of premature aging. Conversely, refined grain intake was related to an increased risk of premature aging (ORhigh v low = 1.33 [95% CI, 0.99 to 1.78], per 1 oz/1,000 kcal increment; coefficientlinear = 0.0093, P = .005). Fruit and whole grain intakes were not associated with premature aging risk. Among nutrients abundant in plant foods, dietary folate intake was associated with a lower risk of premature aging (ORhigh v low = 0.89 [95% CI, 0.80 to 0.99] per 50 mcg/1,000 kcal increase). Beta-carotene, lutein/zeaxanthin, and vitamin E intakes from foods were also related to a modestly lower, but not statistically significant, risk of premature aging.

CONCLUSION

Specific plant foods are associated with lower risk of premature aging, providing targets for the interventions to promote healthy aging in childhood cancer survivors.

Association of Obesity with Telomere Length in Human Sperm

Background: Telomere attrition and mitochondrial dysfunction are two fundamental aspects of aging. Calorie restriction (CR) is the best strategy to postpone aging since it can enhance telomere attrition, boost antioxidant capacity, and lower the generation of reactive oxygen species (ROS). Since ROS is produced by mitochondria and can readily travel to cell nuclei, it is thought to be a crucial molecule for information transfer between mitochondria and cell nuclei. Important variables that affect the quality and functionality of sperm and may affect male reproductive health and fertility include telomere length, mitochondrial content, and the ratio of mitochondrial DNA (mtDNA) to nuclear DNA (nDNA). Telomere damage results from mitochondrial failure, whereas nuclear DNA remains unaffected. This research aims to investigate potential associations between these three variables and how they might relate to body mass index. Methods: Data were collected from 82 men who underwent IVF/ICSI at the University Hospital of Ioannina's IVF Unit in the Obstetrics and Gynecology Department. Evaluations included sperm morphology, sperm count, sperm motility, and participant history. To address this, male participants who were categorized into three body mass index (ΒΜΙ) groups-normal, overweight, and obese-had their sperm samples tested. Results: For both the normal and overweight groups, our results show a negative connection between relative telomere length and ΒΜI. As an illustration of a potential connection between mitochondrial health and telomere maintenance, a positive correlation was found for the obese group. Only the obese group's results were statistically significant (p < 0.05). More evidence that longer telomeres are associated with lower mitochondrial content can be found in the negative connection between telomere length and mitochondrial content in both the normal and overweight groups. However, the obese group showed a positive association. The data did not reach statistical significance for any of the three groups. These associations may affect sperm quality since telomere length and mitochondrial concentration are indicators of cellular integrity and health. Moreover, the ratio of mtDNA to nDNA was positively correlated with the relative telomere lengths of the obese group, but negatively correlated with the normal and overweight groups. In every group that was studied, the results were not statistically significant. According to this, male fertility may be negatively impacted by an imbalance in the copy number of the mitochondrial genome compared to the nuclear DNA in sperm. Conclusions: Essentially, the goal of our work is to determine whether mitochondria and telomere length in human sperm interact. Understanding these connections may aid in the explanation of some male infertility causes and possibly contribute to the creation of new treatment modalities for problems pertaining to reproductive health. The functional implications of these connections and their applications in therapeutic settings require further investigation.

The Relationship between Dietary Macronutrient Composition and Telomere Length Among US Adults

The role of dietary macronutrients and energy intake in the aging process has been well-established. However, previous research has mainly focused on the association between leukocyte telomere length (LTL) and individual macronutrients, while the effects of macronutrient composition on LTL remain unclear. This cross-sectional analysis involved 4130 US adults (44.8 ± 17.0 years; 51% female) from the National Health and Nutrition Examination Survey during 1999-2002. A single 24-h dietary recall is used to collect dietary data. The relationship between dietary macronutrient composition and LTL is examined using three-dimensional generalized additive models. After adjustment for age, sex, ethnicity, education, physical activity, BMI, and dietary quality, a three-dimensional association of macronutrient composition with LTL (P = 0.02) is revealed. Diets lower in protein (5-10%), higher in carbohydrates (75%), and lower in fat (15-20%) are associated with the longest LTL corresponding to 7.7 years of slower biological aging. Diets lowest in protein (5%) and carbohydrate (40%), while highest in dietary fat (55%) are associated with the shortest LTL, corresponding to accelerated biological aging of 4.4 years. The associations appeared magnified with higher energy intake. These findings support a complex relationship between dietary macronutrients and biological aging independent of diet quality.

Association between modifiable lifestyle factors and telomere length: a univariable and multivariable Mendelian randomization study

BACKGROUND

Telomere length has long been recognized as a valuable biomarker of aging and is inversely correlated with chronological age. Various lifestyle factors have been implicated in telomere shortening or preservation; however, the association between lifestyle factors and telomere length remains controversial. To address this issue, we conducted a Mendelian randomization (MR) analysis to investigate the potential causal associations between multiple lifestyle factors and telomere length.

METHODS

Independent genetic variants strongly associated with lifestyle factors (tobacco smoking, sleep duration, insomnia, and physical activity) were selected as instrumental variables from corresponding genome-wide association studies (GWASs). Summary-level data for telomere length was obtained from a GWAS comprising 472,174 European ancestries. Univariable and multivariable MR analyses were performed to assess the relationships.

RESULTS

The genetic liability to lifetime smoking was robustly associated with shorter telomere length (odd ratio [OR]: 0.882; 95% confidence interval [CI]: 0.847-0.918). Genetically predicted insomnia was also linked to shorter telomere length (OR: 0.972; 95% CI: 0.959-0.985), while no significant association was observed between sleep duration and telomere length. Furthermore, a suggestive association was found between moderate-to-vigorous physical activity and longer telomere length (OR: 1.680; 95% CI: 1.115-2.531). In multivariable MR analyses, adjusting for potential mediators such as body mass index, type 2 diabetes, alcohol consumption, and alcohol use disorder, the associations of lifetime smoking and insomnia with telomere length remained robust.

CONCLUSION

Our findings suggest that smoking and insomnia may contribute to telomere shortening, while physical activity may play a role in telomere length maintenance. These findings underscore the importance of managing positive risk factors and adopting a healthy lifestyle to promote telomere health.

Telomerase activity and telomere length in women with breast cancer or without malignancy: A systematic review and meta-analysis

AIM

We performed a systematic review and meta-analysis to assess whether telomerase activity and telomere length are associated with breast cancer.

METHODS

PubMed, Web of Science, Embase, LILACS, Scielo, Embase, and CNKI databases were searched to obtain relevant articles published through May 10, 2023, following PRISMA guidelines and a registered PROSPERO protocol (CRD42022335402). We included observational studies reporting telomerase activity or telomere length in patients with breast cancer compared with women with benign lesions or normal tissue (control women). The Newcastle-Ottawa Scale was used to evaluate the quality of studies. Data were expressed as odds ratios (OR) and 95 % confidence intervals (CI). Random effects and inverse variance methods were used to meta-analyze associations. The I2 test was used to assess heterogeneity.

RESULTS

The meta-analysis of telomerase shows significantly greater activity in patients with breast cancer than in those without malignancies (OR = 23.46, 95 % CI 14.07-39.11, p < 0.00001, I2 = 72 %). There were non-significant differences in relative telomere length (OR = 1.16, 95 % CI = 0.90-1.49, p = 0.26, I2 = 86 %) and leukocyte telomere length (OR = 2.32, 95 % CI = 0.89-6.08, p = 0.09, I2 = 98 %) between women with and without breast cancer. In subgroup analyses by world regions of studies, both telomerase activity and telomere length displayed the same trends as in their respective meta-analyses. In sensitivity analyses, variables showed their respective same trends.

CONCLUSION

Telomerase activity is higher in patients with breast cancer than in women without malignancies. There were no significant differences in either relative telomere length or leukocyte telomere length in women with and without breast cancer. PROSPERO protocol CRD42022335402.

Relationship between dietary macronutrients intake and biological aging: a cross-sectional analysis of NHANES data

PURPOSE

This study aimed to investigate the association between macronutrient intake and biological age.

METHODS

Data were collected from 26,381 adults who participated in the United States National Health and Nutrition Examination Survey (NHANES). Two biological ages were estimated using the Klemera-Doubal method (KDM) and PhenoAge algorithms. Biological age acceleration (AA) was computed as the difference between biological age and chronological age. The associations between macronutrient intakes and AA were investigated.

RESULTS

After fully adjusting for confounding factors, negative associations were observed between AA and fiber intake (KDM-AA: β - 0.53, 95% CI - 0.62, - 0.43, P < 0.05; PhenoAge acceleration: β - 0.30, 95% CI - 0.35, - 0.25, P < 0.05). High-quality carbohydrate intake was associated with decreased AA (KDM-AA: β - 0.57, 95% CI - 0.67, - 0.47, P < 0.05; PhenoAge acceleration: β - 0.32, 95% CI - 0.37, - 0.26, P < 0.05), while low-quality carbohydrate was associated with increased AA (KDM-AA: β 0.30, 95% CI 0.21, 0.38, P < 0.05; PhenoAge acceleration: β 0.16, 95% CI 0.11, 0.21, P < 0.05). Plant protein was associated with decreased AA (KDM-AA: β - 0.39, 95% CI - 0.51, - 0.27, P < 0.05; PhenoAge acceleration: β - 0.21, 95% CI - 0.26, - 0.15, P < 0.05). Long-chain SFA intake increased AA (KDM-AA: β 0.16, 95% CI 0.08, 0.24, P < 0.05; PhenoAge acceleration: β 0.11, 95% CI 0.07, 0.15, P < 0.05). ω-3 PUFA was associated with decreased KDM-AA (β - 0.18, 95% CI - 0.27, - 0.08, P < 0.05) and PhenoAge acceleration (β - 0.09, 95% CI - 0.13, - 0.04, P < 0.05).

CONCLUSION

Our findings suggest that dietary fiber, high-quality carbohydrate, plant protein, and ω-3 PUFA intake may have a protective effect against AA, while low-quality carbohydrate and long-chain SFA intake may increase AA. Therefore, dietary interventions aimed at modifying macronutrient intakes may be useful in preventing or delaying age-related disease and improving overall health.

A sex-specific association of leukocyte telomere length with thigh muscle mass

OBJECTIVES

Telomeres are DNA-protein complexes at the ends of linear chromosomes that protect against DNA degradation. Telomeres shorten during normal cell divisions and therefore, telomere length is an indicator of mitotic-cell age. In humans, telomere shortening is a potential biomarker for disease risk, progression and premature death. Physical activity has been associated with longer leukocyte telomere length (LTL) in some studies. In the current study the relationship between LTL, thigh muscle mass and adipose tissue distribution was explored.

METHODS

We performed anthropometric measurements and magnetic resonance imaging (MRI) measurements of the thigh in 149 healthy subjects (77 male, 72 female). LTL was measured using qPCR. Additionally, the subjects answered a questionnaire concerning their training behaviour.

RESULTS

In male subjects, LTL was significantly associated with thigh muscle mass, independent of age and body mass index (p=0.006). In addition, a slight association of LTL with weekly endurance units in the male group was found. These relations could not be observed in females.

CONCLUSIONS

In conclusion, we observed a sex-specific association of LTL and thigh muscle mass in healthy males. The reason of this sex-specific association is currently unclear, but could be related to different training effects and/or hormonal pathways in men and women.

Diet and Aging: The Role of Polyphenol-Rich Diets in Slow Down the Shortening of Telomeres: A Review

The ends of human chromosomes are defended by DNA-protein complexes named telomeres, which inhibit the chromosomes from fusing with each other and from being known as a double-strand break by DNA reparation proteins. Telomere length is a marker of biological aging, and disfunction of telomeres is related to age-related syndromes. Telomere attrition has been shown to be accelerated by oxidative stress and inflammation. Telomere length has been proven to be positively linked with nutritional status in human and animal scientific research as several nutrients influence it through mechanisms that imitate their function in cellular roles including oxidative stress and inflammation. Data reported in this article support the idea that following a low-in-fat and rich-plant polyphenols food diet seems to be able to slow down the shortening of telomeres.

Association between Lipids, Apolipoproteins and Telomere Length: A Mendelian Randomization Study

(1) Background: The relationship between lipids, apolipoproteins, and telomere length (TL) has been explored in previous studies; however, the causal relationship between the two remains unclear. This study aims to assess the causal relationship between lipids, apolipoproteins, and TL using the two-sample Mendelian randomization (MR) approach; (2) Methods: This study comprehensively employed both univariate MR (uvMR) and multivariate MR (mvMR) methods to genetically evaluate the associations between 21 exposures related to lipids and apolipoproteins and the outcome of TL. During the analysis process, we utilized various statistical methods, including Inverse Variance Weighting (IVW), Weighted Median, MR-Egger regression, MR-PRESSO, and outlier tests. Furthermore, to confirm the robustness of the results, we conducted several sensitivity analyses to explore potential heterogeneity; (3) Results: The uvMR analysis indicated that an increase in MUFA, MUFA/FA ratio, LDL-C, VLDL-C, total cholesterol, ApoB, and triglycerides (TG) was associated with an increase in TL. However, this relationship did not manifest in the mvMR analysis, suggesting that this association may be based on preliminary evidence; (4) Conclusions: MR analysis results suggest potential suggestive positive causal relationships between genetically predicted MUFA, MUFA/FA ratio, LDL-C, VLDL-C, total cholesterol, ApoB, and TG with TL.

Are pregnancy and parity associated with telomere length? A systematic review

BACKGROUND

Women's reproduction requires increased energy demands, which consequently may lead to cellular damage and aging. Hence, Telomere Length (TL), a biomarker of biological aging and health status may possibly serve as a biomarker of reproductive effort. The aim of this systematic review is to evaluate telomere dynamics throughout pregnancy and the association between parity and TL.

METHODS

A systematic search was conducted across seven databases including CINAHL, Cochrane, PsycINFO, Proquest, PubMed; Scopus; and Web of Science, using keywords and MeSH descriptors of parity and TL. Predefined inclusion and exclusion criteria were used to screen abstracts and titles. After the removal of duplicates, 3431 articles were included in the primary screening, narrowed to 194 articles included in the full-text screening. Consensus was reached for the 14 studies that were included in the final review, and the Newcastle-Ottawa scale (NOS) was utilized to assess the quality of the selected studies. A mini meta-analysis utilized JASP 0.17.3 software and included 4 applicable studies, comprising a total of 2564 participants to quantitatively assess the estimated effect size of parity on TL.

RESULTS

Of the 11 studies reviewed on parity and TL, four demonstrated a negative correlation; one - a positive correlation and six -found no correlation. Studies demonstrating a negative correlation encompassed rigorous methodological practices possibly suggesting having more children is associated with enhanced telomere attrition. Of the four longitudinal studies assessing telomere dynamics throughout pregnancy, most found no change in TL from early pregnancy to postpartum suggesting pregnancy does not affect TL from early pregnancy to early postpartum. The meta-analysis revealed a negative, yet, non-significant effect, of the estimated effect size of parity on TL(ES = -0.009, p = 0.126, CI -0.021, 0.03).

CONCLUSIONS

Studies assessing pregnancy, parity and TL yielded mixed results, most likely due to the different research methods utilized in each study. Improvements in study design to better understand the short-term effects of pregnancy on TL and the effect of parity on TL over time, include precise definitions of parity, comparisons of different age groups, inclusion of reproductive lifespan and statistically adjusting for potential confounders in the parity and TL relationship.

Central obesity and its association with retinal age gap: insights from the UK Biobank study

BACKGROUND

Conflicting evidence exists on the association between ageing and obesity. Retinal age derived from fundus images has been validated as a novel biomarker of ageing. In this study, we aim to investigate the association between different anthropometric phenotypes based on body mass index (BMI) and waist circumference (WC) and the retinal age gap (retinal age minus chronological age).

METHODS

A total of 35,550 participants with BMI, WC and qualified retinal imaging data available were included to investigate the association between anthropometric groups and retinal ageing. Participants were stratified into 7 different body composition groups based on BMI and WC (Normal-weight/Normal WC, Overweight/Normal WC, Mild obesity/Normal WC, Normal-weight/High WC, Overweight/High WC, Mild obesity/High WC, and Severe obesity/High WC). Linear regression and logistic regression models were fitted to investigate the association between the seven anthropometric groups and retinal age gap as continuous and categorical outcomes, respectively.

RESULTS

A total of 35,550 participants (55.6% females) with a mean age 56.8 ± 8.04 years were included in the study. Individuals in the Overweight/High WC, Mild obesity/High WC and Severe obesity/High WC groups were associated with an increase in the retinal age gap, compared with those in the Normal Weight/Normal WC group (β = 0.264, 95% CI: 0.105-0.424, P =0.001; β = 0.226, 95% CI: 0.082-0.371, P = 0.002; β = 0.273, 95% CI: 0.081-0.465, P = 0.005; respectively) in fully adjusted models. Similar findings were noted in the association between the anthropometric groups and retinal ageing process as a categorical outcome.

CONCLUSION

A significant positive association exists between central obesity and accelerated ageing indexed by retinal age gaps, highlighting the significance of maintaining a healthy body shape.

Cell Survival, Death, and Proliferation in Senescent and Cancer Cells: the Role of (Poly)phenols

Cellular senescence has long been considered a permanent state of cell cycle arrest occurring in proliferating cells subject to different stressors, used as a cellular defense mechanism from acquiring potentially harmful genetic faults. However, recent studies highlight that senescent cells might also alter the local tissue environment and concur to chronic inflammation and cancer risk by secreting inflammatory and matrix remodeling factors, acquiring a senescence-associated secretory phenotype (SASP). Indeed, during aging and age-related diseases, senescent cells amass in mammalian tissues, likely contributing to the inevitable loss of tissue function as we age. Cellular senescence has thus become one potential target to tackle age-associated diseases as well as cancer development. One important aspect characterizing senescent cells is their telomere length. Telomeres shorten as a consequence of multiple cellular replications, gradually leading to permanent cell cycle arrest, known as replicative senescence. Interestingly, in the large majority of cancer cells, a senescence escape strategy is used and telomere length is maintained by telomerase, thus favoring cancer initiation and tumor survival. There is growing evidence showing how (poly)phenols can impact telomere maintenance through different molecular mechanisms depending on dose and cell phenotypes. Although normally, (poly)phenols maintain telomere length and support telomerase activity, in cancer cells this activity is negatively modulated, thus accelerating telomere attrition and promoting cancer cell death. Some (poly)phenols have also been shown to exert senolytic activity, thus suggesting both antiaging (directly eliminating senescent cells) and anticancer (indirectly, via SASP inhibition) potentials. In this review, we analyze selective (poly)phenol mechanisms in senescent and cancer cells to discriminate between in vitro and in vivo evidence and human applications considering (poly)phenol bioavailability, the influence of the gut microbiota, and their dose-response effects.

Crosstalk between G-quadruplex and ROS

The excessive production of reactive oxygen species (ROS) can lead to single nucleic acid base damage, DNA strand breakage, inter- and intra-strand cross-linking of nucleic acids, and protein-DNA cross-linking involved in the pathogenesis of cancer, neurodegenerative diseases, and aging. G-quadruplex (G4) is a stacked nucleic acid structure that is ubiquitous across regulatory regions of multiple genes. Abnormal formation and destruction of G4s due to multiple factors, including cations, helicases, transcription factors (TFs), G4-binding proteins, and epigenetic modifications, affect gene replication, transcription, translation, and epigenetic regulation. Due to the lower redox potential of G-rich sequences and unique structural characteristics, G4s are highly susceptible to oxidative damage. Additionally, the formation, stability, and biological regulatory role of G4s are affected by ROS. G4s are involved in regulating gene transcription, translation, and telomere length maintenance, and are therefore key players in age-related degeneration. Furthermore, G4s also mediate the antioxidant process by forming stress granules and activating Nrf2, which is suggestive of their involvement in developing ROS-related diseases. In this review, we have summarized the crosstalk between ROS and G4s, and the possible regulatory mechanisms through which G4s play roles in aging and age-related diseases.

Functional association between telomeres, oxidation and mitochondria

Prior research has substantiated the vital role of telomeres in human fertility. Telomeres are prerequisites for maintaining the integrity of chromosomes by preventing the loss of genetic material following replication events. Little is known about the association between sperm telomere length and mitochondrial capacity involving its structure and functions. Mitochondria are structurally and functionally distinct organelles that are located on the spermatozoon's midpiece. Mitochondria produce adenosine triphosphate (ATP) through oxidative phosphorylation (OXPHOS), which is necessary for sperm motility and generate reactive oxygen species (ROS). While a moderate concentration of ROS is critical for egg-sperm fusion, and fertilization, excessive ROS generation is primarily related to telomere shortening, sperm DNA fragmentation, and alterations in the methylation pattern leading to male infertility. This review aims to highlight the functional connection between mitochondria biogenesis and telomere length in male infertility, as mitochondrial lesions have a damaging impact on telomere length, leading both to telomere lengthening and reprogramming of mitochondrial biosynthesis. Furthermore, it aims to shed light on how both inositol and antioxidants can positively affect male fertility.

Therapeutic Antiaging Strategies

Aging constitutes progressive physiological changes in an organism. These changes alter the normal biological functions, such as the ability to manage metabolic stress, and eventually lead to cellular senescence. The process itself is characterized by nine hallmarks: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. These hallmarks are risk factors for pathologies, such as cardiovascular diseases, neurodegenerative diseases, and cancer. Emerging evidence has been focused on examining the genetic pathways and biological processes in organisms surrounding these nine hallmarks. From here, the therapeutic approaches can be addressed in hopes of slowing the progression of aging. In this review, data have been collected on the hallmarks and their relative contributions to aging and supplemented with in vitro and in vivo antiaging research experiments. It is the intention of this article to highlight the most important antiaging strategies that researchers have proposed, including preventive measures, systemic therapeutic agents, and invasive procedures, that will promote healthy aging and increase human life expectancy with decreased side effects.

A multi-exposure approach to study telomere dynamics in childhood: A role for residential green space and waist circumference

BACKGROUND

Telomeres are vulnerable to various environmental exposures and lifestyle factors, encompassed in the exposome. Recent research shows that telomere length is substantially determined early in life and that exposures in childhood may have important consequences in setting later life telomere length.

OBJECTIVES

We explore in a child population the associations of 17 exposures with telomere length and longitudinal telomere change.

METHODS

Children (2.8-10.3y at baseline, 51.3% boys) were followed-up for five to seven years. Relative telomere length was measured at baseline and follow-up using quantitative real-time PCR. Exposures and lifestyle factors included: body composition (body mass index and waist circumference), dietary habits (sugar- and fat-rich food intake, vegetables and fruit intake), psychosocial stress (events, emotions, behaviour), sleep duration, physical activity, and residential environmental quality (longterm black carbon, particulate matter exposure, and residential green space). Cross-sectional (n=182) and longitudinal (n=150) analyses were assessed using linear regression models, adjusting for age, sex, socioeconomic status and multiple testing.

RESULTS

Our longitudinal analyses showed that higher residential green space at baseline was associated with (β=0.261, p=0.002) lower telomere attrition and that children with a higher waist circumference at baseline showed a higher telomere attrition (β=-0.287, p=0.001). These two predictors were confirmed via LASSO variable selection and correction for multiple testing. In addition, children with more unhealthy exposures at baseline had a significantly higher telomere attrition over the follow-up period compared to children with more healthy exposures (β=-0.200, p=0.017).

DISCUSSION

Waist circumference and residential green space were identified as predictors associated with telomere attrition in childhood. These results further support the advantages of a healthy lifestyle from early age onwards and the importance of a green environment to promote molecular longevity from childhood onwards.

The Impact of Foods, Nutrients, or Dietary Patterns on Telomere Length in Childhood and Adolescence: A Systematic Review

Environmental factors such as diet can affect telomere length (TL) dynamics. However, the role that children’s and adolescents’ diets play in maintaining TL is not well understood. Thus, we conducted a systematic review to examine the association between the intake of nutrients, foods, food groups, and/or dietary patterns and TL in childhood and adolescence. Following the PRISMA guidelines, we searched MEDLINE via PubMed, Embase, and Cochrane databases and additional registers and methods. The five selected studies were cross-sectional and conducted in children and adolescents aged 2 to 18 years. The main results suggest that a higher consumption of fish, nuts and seeds, fruits and vegetables, green leafy and cruciferous vegetables, olives, legumes, polyunsaturated fatty acids, and an antioxidant-rich diet might positively affect TL. On the contrary, a higher intake of dairy products, simple sugar, sugar-sweetened beverages, cereals, especially white bread, and a diet high in glycaemic load were factors associated with TL shortening. To our knowledge, this is the first systematic review examining the impact of dietary intake factors on TL in childhood and adolescence. Although limited, these results are consistent with previous studies in different adult populations. Further research is needed to ascertain potential nutritional determinants of TL in childhood and adolescence.

Effect of Omega-3 Fatty Acids on Telomeres-Are They the Elixir of Youth?

Telomeres are complexes consisting of tandem repeat DNA combined with associated proteins that play a key role in protecting the ends of chromosomes and maintaining genome stability. They are considered a biological clock, as they shorten in parallel with aging. Furthermore, short telomeres are associated with several age-related diseases. However, the variability in telomere shortening independent of chronological age suggests that it is a modifiable factor. In fact, it is regulated inter alia by genetic damage, cell division, aging, oxidative stress, and inflammation. A key question remains: how can we prevent accelerated telomere attrition and subsequent premature replicative senescence? A number of studies have explored the possible impact of omega-3 fatty acids on telomere shortening. This review summarizes published cross-sectional studies, randomized controlled trials, and rodent studies investigating the role of omega-3 fatty acids in telomere biology. It also covers a broad overview of the mechanism, currently favored in the field, that explains the impact of omega-3 fatty acids on telomeres—the food compound’s ability to modulate oxidative stress and inflammation. Although the results of the studies performed to date are not consistent, the vast majority indicate a beneficial effect of omega-3 fatty acids on telomere length.

Essential Factors for a Healthy Microbiome: A Scoping Review

Recent discoveries of the purpose and potential of microbial interactions with humans have broad implications for our understanding of metabolism, immunity, the host−microbe genetic interactions. Bioavailability and bioaccessibility of phytonutrients in foods not only enrich microbial diversity in the lower human gastrointestinal tract (GIT) but also direct the functioning of the metagenome of the microbiota. Thus, healthy choices must include foods that contain nutrients that satisfy both the needs of humans and their microbes. Physical activity interventions at a moderate level of intensity have shown positive effects on metabolism and the microbiome, while intense training (>70% VO2max) reduces diversity in the short term. The microbiome of elite endurance athletes is a robust producer of short-chain fatty acids. A lifestyle lacking activity is associated with the development of chronic disease, and experimental conditions simulating weightlessness in humans demonstrate loss of muscle mass occurring in conjunction with a decline in gut short-chain fatty acid (SCFA) production and the microbes that produce them. This review summarizes evidence addressing the relationship between the intestinal microbiome, diet, and physical activity. Data from the studies reviewed suggest that food choices and physical fitness in developed countries promote a resource “curse” dilemma for the microbiome and our health.

Associations of the Gut Microbiota Composition and Fecal Short-Chain Fatty Acids with Leukocyte Telomere Length in Children Aged 6 to 9 Years in Guangzhou, China: A Cross-sectional Study

BACKGROUND

Telomere length (TL) serves as a marker of cellular senescence and appears to plateau between the age of 4 y and young adulthood, after which the gut microbiota are supposed to be established. However, scarce data are available regarding the correlation between gut microbiota composition and TL in the pediatric population.

OBJECTIVES

We aimed to investigate whether the gut microbiota and the concentrations of SCFAs in feces are associated with leukocyte TL in children.

METHODS

In total, 401 children aged 6-9 y from Guangzhou were enrolled in this cross-sectional study. qPCR was used to determine relative TL in peripheral blood leukocytes. The gut microbiota was characterized by 16S ribosomal RNA amplicon sequencing and the fecal concentrations of total SCFAs and SCFA subtypes were determined using HPLC. The multivariate methods with an unbiased variable selection (MUVR) algorithm and partial least square models were used to select predictable operational taxonomic units (OTUs). Further correlation analyses were performed based on multiple linear regression models with adjustment for covariates and false discovery rate.

RESULTS

With the use of MUVR, 35 relevant and minimal optimal OTUs were finally selected. Multiple linear regression analysis showed that the abundance of several OTUs, including OTU334 (belonging to the genus Family XIII AD3011 group), OTU726 (belonging to the species Lachnoclostridium phocaeense), OTU1441 (belonging to the genus Ruminococcus torques group), OTU2553 (belonging to the genus Lachnospiraceae UCG-010), and OTU3375 (belonging to the family Lachnospiraceae), was negatively associated with leukocyte TL (β: -0.187 to -0.142; false discovery rate (FDR)-corrected P value (PFDR) = 0.009-0.035]. However, neither SCFA subtype nor total SCFA content in feces exhibited significant associations with TL (β: -0.032 to 0.048; PFDR = 0.915-0.969).

CONCLUSIONS

The gut microbiota, but not fecal SCFA concentration, was significantly associated with TL in this pediatric population.

Effect of omega-3 fatty acid supplementation on telomere length and telomerase activity: A systematic review of clinical trials

Evidence suggests antioxidant and anti-inflammatory properties of omega-3 polyunsaturated fatty acids (n-3 PUFA). However, the effect of supplementation of this fatty acid profile on the telomere length and the telomerase enzyme activity was not revised yet. The PubMed and Embase® databases were used to search for clinical trials. A total of six clinical trials were revised. Omega-3 PUFA supplementation did not statistically affect telomere length in three out of three studies but affected telomerase activity in two out of four studies. The supplementation increased telomerase enzyme activity in subjects with first-episode schizophrenia. Besides, it decreased telomerase enzyme activity without modulating the effects of Pro12Ala polymorphism on the PPARγ gene in type 2 diabetes subjects. The methodological differences between the studies and the limited number of studies on the theme suggest that further studies are needed to elucidate the effects of n-3 PUFA supplementation on telomere length and telomerase enzyme activity in humans.

Obesity Accelerates Leukocyte Telomere Length Shortening in Apparently Healthy Adults: A Meta-Analysis

Background

Shorter telomere length is associated with numerous comorbidities. Several studies have investigated the role of obesity in telomere shortening. In the current systematic review and meta-analysis, we summarized the results of studies that evaluated the association between obesity and telomere length.

Methods

A systematic search from Scopus, PubMed, Embase, and ProQuest electronic databases up to 19 March 2021 without language restriction was performed and after data extraction and screening, 19 manuscripts were eligible to be included in the final meta-synthesis.

Results

The highest category of telomere length was associated with an approximate 0.75 kg/m2 reduction in body mass index (BMI; WMD = -0.75 kg/m2; CI = -1.19, -0.31; p < 0.001; I 2 = 99.4%). Moreover, overweight/obese individuals had 0.036 kbp shorter telomere length compared with non-overweight/obese adults (WMD = -0.036; CI = -0.05, -0.02; p = 0.030; I 2 = 100%). According to the results of subgroupings, continent, age, and sample size could be possible sources of heterogeneity.

Conclusion

From the results, it was clear that obesity was associated with shorter telomere length. Because of the observational design of included studies, the causality inference of results should be done with caution; thus, further longitudinal studies are warranted for better inference of causal association.

Effects of dietary interventions on telomere dynamics

Telomeres play a critical role in maintaining cellular fate through tight regulation of cell division and DNA damage or repair. Over the years, it is established that biological ageing is defined by a gradual derangement in functionality, productivity, and robustness of biological processes. The link between telomeres and ageing is highlighted when derangement in telomere biology often leads to premature ageing and concomitant accompaniment of numerous age-associated diseases. Unfortunately, given that ageing is a biologically complicated intricacy, measures to reduce morbidity and improve longevity are still largely in the infancy stage. Recently, it was discovered that dietary habits and interventions might play a role in promoting successful healthy ageing. The intricate relationship between dietary components and its potential to protect the integrity of telomeres may provide unprecedented health benefits and protection against age-related pathologies. However, more focused prospective and follow-up studies with and without interventions are needed to unequivocally link dietary interventions with telomere maintenance in humans. This review aims to summarise recent findings that investigate the roles of nutrition on telomere biology and provide enough evidence for further studies to consider the topic of nutrigenomics and its contributions toward healthy ageing and concomitant strategy against age-associated diseases.

Associations of Maternal Polyunsaturated Fatty Acids With Telomere Length in the Cord Blood and Placenta in Chinese Population

Few studies have investigated the correlation between maternal polyunsaturated fatty acids (PUFAs) and telomeres in offspring, and the underlying influential mechanisms. In this study, we assessed the associations of maternal PUFAs with telomere length (TL) and DNA methylation of the telomerase reverse transcriptase (TERT) promoter in the cord blood and the placenta. A total of 274 pregnant women and their newborn babies were enrolled in this study. Maternal blood before delivery, the cord blood, and the placenta at birth were collected. Fatty acids in maternal erythrocytes and cord blood cells were measured by gas chromatography (GC). TL in the cord blood and the placenta was determined using real-time quantitative PCR (qPCR) by calculating the product ratio of telomeric DNA to the single-copy gene β-globin. The TERT promoter methylation was analyzed by DNA bisulfite sequencing. The associations of maternal fatty acids with TL were analyzed by univariate and multivariate regression. We found that low concentrations of docosapentaenoci acid (DPA, C22: 5n-3) and total n-3 PUFAs, adrenic acid (ADA, C22: 4n-6), and osbond acid (OA, C22: 5n-6) and high concentrations of linoleic acid (LA, C18: 2n-6) in maternal erythrocytes were associated with the shortened TL in cord blood cells (estimated difference in univariate analysis −0.36 to −0.46 for extreme quintile compared with middle quintile), and that low concentrations of cord blood docosahexaenoic acid (DHA, C22: 6n-3) were related to the shortened TL in cord blood cells. Differently, high concentrations of α-linolenic acid (LNA, C18: 3n-3), eicosatrienoic acid (EA, C20: 3n-3), DHA, and γ-linoleic acid (GLA, C18:3n-6) in maternal erythrocytes were associated with the shortened TL in the placenta (estimated difference in univariate analysis −0.36 to −0.45 for higher quintiles compared with the middle quintile). Further examination demonstrated that the concentrations of DHA and total n-3 PUFAs in maternal erythrocytes had positive associations with DNA methylation of the TERT promoter in the cord blood instead of the placenta. These data suggest that maternal PUFAs are closely correlated to infant TL and the TERT promoter methylation, which are differently affected by maternal n-3 PUFAs between the cord blood and the placenta. Therefore, keeping higher levels of maternal n-3 PUFAs during pregnancy may help to maintain TL in the offspring, which is beneficial to long-term health.

The Effect of Nutrition on Aging-A Systematic Review Focusing on Aging-Related Biomarkers

Despite the increasing life expectancy, an individual’s later years tends to be accompanied by a decrease in the quality of life. Though biological changes that occur through the natural process of aging cannot be controlled, the risk factors associated with lifestyle can. Thus, the main goal of this systematic review was to evaluate how nutrition can modulate aging. For this purpose, thirty-six studies were selected on (i) the efficiency of nutrition’s effect on aging, (ii) the evaluation of biomarkers that promote healthy aging, and (iii) how to increase longevity through nutrition, and their quality was assessed. The results showed that choosing low carbohydrate diets or diets rich in vegetables, fruits, nuts, cereals, fish, and unsaturated fats, containing antioxidants, potassium, and omega-3 decreased cardiovascular diseases and obesity risk, protected the brain from aging, reduced the risk of telomere shortening, and promoted an overall healthier life. With this study, the conclusion is that since the biological processes of aging cannot be controlled, changing one’s nutritional patterns is crucial to prevent the emergence and development of diseases, boost longevity, and, mostly, to enhance one’s quality of life and promote healthy aging.

Effect of Physical Activity, Smoking, and Sleep on Telomere Length: A Systematic Review of Observational and Intervention Studies

Aging is a risk factor for several pathologies, restricting one’s health span, and promoting chronic diseases (e.g., cardiovascular and neurodegenerative diseases), as well as cancer. Telomeres are regions of repetitive DNA located at chromosomal ends. Telomere length has been inversely associated with chronological age and has been considered, for a long time, a good biomarker of aging. Several lifestyle factors have been linked with telomere shortening or maintenance. However, the consistency of results is hampered by some methodological issues, including study design, sample size, measurement approaches, and population characteristics, among others. Therefore, we aimed to systematically review the current literature on the effects of three relevant lifestyle factors on telomere length in human adults: physical activity, smoking, and sleep. We conducted a qualitative systematic review of observational and intervention studies using the Preferred Reporting Item for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The systematic literature search covered articles published in MEDLINE and EMBASE databases (from 2010 to 2020). A total of 1400 studies were identified; 83 were included after quality control. Although fewer sedentary activities, optimal sleep habits, and non- or ex-smoker status have been associated with less telomere shortening, several methodological issues were detected, including the need for more targeted interventions and standardized protocols to better understand how physical activity and sleep can impact telomere length and aging. We discuss the main findings and current limitations to gain more insights into the influence of these lifestyle factors on the healthy aging process.

Fat metabolism is associated with telomere length in six population-based studies

Telomeres are repetitive DNA sequences located at the end of chromosomes, which are associated to biological aging, cardiovascular disease, cancer, and mortality. Lipid and fatty acid metabolism have been associated with telomere shortening. We have conducted an in-depth study investigating the association of metabolic biomarkers with telomere length (LTL). We performed an association analysis of 226 metabolic biomarkers with LTL using data from 11 775 individuals from six independent population-based cohorts (BBMRI-NL consortium). Metabolic biomarkers include lipoprotein lipids and subclasses, fatty acids, amino acids, glycolysis measures and ketone bodies. LTL was measured by quantitative polymerase chain reaction or FlowFISH. Linear regression analysis was performed adjusting for age, sex, lipid-lowering medication and cohort-specific covariates (model 1) and additionally for body mass index (BMI) and smoking (model 2), followed by inverse variance-weighted meta-analyses (significance threshold pmeta = 6.5x10-4). We identified four metabolic biomarkers positively associated with LTL, including two cholesterol to lipid ratios in small VLDL (S-VLDL-C % and S-VLDL-ce %) and two omega-6 fatty acid ratios (FAw6/FA and LA/FA). After additionally adjusting for BMI and smoking, these metabolic biomarkers remained associated with LTL with similar effect estimates. In addition, cholesterol esters in very small VLDL (XS-VLDL-ce) became significantly associated with LTL (p = 3.6x10-4). We replicated the association of FAw6/FA with LTL in an independent dataset of 7845 individuals (p = 1.9x10-4). To conclude, we identified multiple metabolic biomarkers involved in lipid and fatty acid metabolism that may be involved in LTL biology. Longitudinal studies are needed to exclude reversed causation.

The Association between 25-Hydroxyvitamin D Concentration and Telomere Length in the Very-Old: The Newcastle 85+ Study

(1) Introduction: vitamin D may maintain the telomere length, either directly or via the inflammation effect and/or modulating the rate of cell proliferation. Whilst results from cross-sectional studies investigating the association between 25(OH)D concentration and telomere length have been mixed, there is a dearth of data from prospective studies which have assessed these associations. This study aimed to examine the association between 25(OH)D concentration in plasma and telomere length in blood cells in very-old adults (≥85 years old) at baseline, 18 months and 36 months by controlling for related lifestyle factors. (2) Methodology: our prospective cohort study comprised 775 participants from the Newcastle 85+ Study who had 25(OH)D measurements at baseline. Plasma 25(OH)D was stratified as <25 nmol/L (low), 25-50 nmol/L (moderate) and >50 nmol/L (high). Peripheral blood mononuclear cell telomere length was measured by quantitative real-time polymerase chain reaction at baseline, 18 and 36 months from baseline. (3) Results: a positive significant association was found between 25(OH)D concentration and telomere length amongst very-old participants at baseline (95% CI = 12.0-110.3, B = 61.2 ± 5.0, p = 0.015). This association was negative at 18 months (95% CI = -59.9--7.5, B = -33.7 ± 13.3, p = 0.012) but was non-significant at 36 months. (4) Conclusion: Circulating 25(OH)D concentration shows inconsistent relationships with telomere length over time in very-old (85+ year old) adults.

Central obesity accelerates leukocyte telomere length (LTL) shortening in apparently healthy adults: A systematic review and meta-analysis

Shorter telomere length is associated with numerous comorbidities; central obesity might trigger leukocyte telomere shortening; in the current meta-analysis we evaluated the association of central obesity with leukocyte telomere length among adults. A systematic search from Scopus, PubMed, Embase and Proquest electronic databases up to May 2021 was done. The final screening, provided five articles to be included in final meta-analysis. Those in the highest category of telomere length had 3.72 cm lower waist circumference (WC) compared with those in the lowest category (WMD=-3.718; CI=-7.180, -0.257 P = 0.035; I² = 95.4%). Also, those in the highest LTL category had 0.02 lower waist to hip ratio (WHR) compared with those in the lowest category, although this association was not significant (WMD: -0.02; CI=-0.04, 0.01; P = 0.19; I²= 90.7%). In quality assessment of included studies, all of the studies had moderate or high quality score and there was no study with poor quality. Higher leukocyte telomere length was accompanied with lower WC among adults. This association was not significant for difference in WHR. Because of the high heterogeneity values and also because of the observational design of included studies, the inference of causality of these associations needs further investigations.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1971155 .

Telomeres: the role of shortening and senescence in major depressive disorder and its therapeutic implications

Major depressive disorder (MDD) is one of the most prevalent and debilitating psychiatric disorders, with a large number of patients not showing an effective therapeutic response to available treatments. Several biopsychosocial factors, such as stress in childhood and throughout life, and factors related to biological aging, may increase the susceptibility to MDD development. Included in critical biological processes related to aging and underlying biological mechanisms associated with MDD is the shortening of telomeres and changes in telomerase activity. This comprehensive review discusses studies that assessed the length of telomeres or telomerase activity and function in peripheral blood cells and brain tissues of MDD individuals. Also, results from in vitro protocols and animal models of stress and depressive-like behaviors were included. We also expand our discussion to include the role of telomere biology as it relates to other relevant biological mechanisms, such as the hypothalamic-pituitary-adrenal (HPA) axis, oxidative stress, inflammation, genetics, and epigenetic changes. In the text and the discussion, conflicting results in the literature were observed, especially considering the size of telomeres in the central nervous system, on which there are different protocols with divergent results in the literature. Finally, the context of this review is considering cell signaling, transcription factors, and neurotransmission, which are involved in MDD and can be underlying to senescence, telomere shortening, and telomerase functions.

Long- and Short-Term Exposures to PM10 Can Shorten Telomere Length in Individuals Affected by Overweight and Obesity

Reduced telomere length (TL) has been associated with increased risk of age-related diseases, most likely through oxidative stress and inflammation, which have also been claimed as mechanisms underlying health effects of air pollution exposure. We aimed to verify whether exposure to particulate matter with diameter ≤10 µm (PM₁₀) affects TL. We recruited 1792 participants with overweight/obesity in Milan (Italy) in 2010-2015 who completed a structured questionnaire on sociodemographic data, gave a blood sample for TL measurement by real-time PCR, and were assigned air pollution and meteorological data of their residential address. In multivariate mixed-effects linear models (with a random intercept on PCR plate), we observed a -0.51% change in TL (95% confidence interval (CI): -0.98; -0.05)) per 10 µg/m³ increase in PM₁₀ at the day of recruitment. A similar decreasing trend in TL was observed up to two weeks before withdrawal, with percentage changes as low as -1.53% (average exposure of the 12 days before recruitment). Mean annual exposure to PM₁₀ was associated with -2.57% TL reduction (95%CI: -5.06; -0.08). By showing consistent associations between short- and long-term PM₁₀ exposures and reduced TL, our findings shed light on the potential mechanisms responsible for the excess of age-related diseases associated with air pollution exposure.

Telomeres: New players in immune-mediated inflammatory diseases?

Telomeres are repetitive DNA sequences located at the ends of linear chromosomes that preserve the integrity and stability of the genome. Telomere dysfunctions due to short telomeres or altered telomere structures can ultimately lead to replicative cellular senescence and chromosomal instability, both mechanisms being hallmarks of ageing. Chronic inflammation, oxidative stress and finally telomere length (TL) dynamics have been shown to be involved in various age-related non-communicable diseases (NCDs). Immune-mediated inflammatory diseases (IMIDs), including affections such as inflammatory bowel disease, psoriasis, rheumatoid arthritis, spondyloarthritis and uveitis belong to this group of age-related NCDs. Although in recent years, we have witnessed the emergence of studies in the literature linking these IMIDs to TL dynamics, the causality between these diseases and telomere attrition is still unclear and controversial. In this review, we provide an overview of available studies on telomere dynamics and discuss the utility of TL measurements in immune-mediated inflammatory diseases.

Dietary pattern and telomere length in preschool children in a middle-income country

Telomere length (TL) has been associated with lifestyle and dietary pattern. However, the available evidence on this association in children is scarce, especially in low- and middle-income countries (LMICs). Therefore, this study aimed to evaluate the association of dietary pattern and leukocyte TL (LTL) in preschool children, Sabzevar, Iran (2017). This cross-sectional study was based on 187 preschool children (aged 5 to 7) recruited from 27 kindergartens. Nutrition information including amounts of consumed dairy products, meat and processed meat products, nuts and seeds, white bread and refined grains, fruits, vegetables, simple sugars, fats and drinks was obtained through a questionnaire. Linear mixed-effects models were fitted with polymerase chain reaction (PCR) plate ID and kindergartens as random effects to estimate the association of each food group consumption with LTL, controlled for relevant covariates. Higher consumption of dairy products and sugar was associated with shorter LTL (β = -0.180, 95% confidence interval [CI]: -0.276, -0.085, P value <0.001 and β = -0.139, 95% CI: -0.193, -0.086, P value <0.001, respectively). An increase in consumption of fish, nuts and seeds, coloured fruits, green leafy vegetables, cruciferous vegetables and olive was significantly associated with the increase in relative LTL. The associations for the consumption of legumes, other fruits, yellow and orange vegetables, red meat, egg, white bread and refined grains, solid and liquid fats, processed meats, potato chips, carbonated drinks, tea (black) and soft drinks groups were not statistically significant. Our findings showed that there was an association between the consumption of certain food groups with LTL.

Association of Childhood Socioeconomic Status with Leukocyte Telomere Length Among African Americans and the Mediating Role of Behavioral and Psychosocial Factors: Results from the GENE-FORECAST Study

Purpose

We examined if childhood socioeconomic status (SES) was related to adult leucocyte telomere length (TL) using the data of 361 African American (AA) participants from the GENE-FORECAST Study. We also assessed the mediating role of behavioral and psychosocial factors in the association between childhood SES and adult TL.

Methods

Childhood SES was assessed individually by using participant’s mother’s education and occupation, father’s education and occupation, parental home ownership, and family structure. TL was assessed using the quantitative polymerase chain reaction method. Information on potential confounders and mediators were collected. The associations of childhood SES with TL were assessed using multivariable linear regression models. We used path analysis to quantify and test the share of these associations that was statistically explained by each of the mediators (participant’s educational attainment, smoking status, physical activity, dietary habit, perceived stress, and depressive symptoms).

Results

Mother’s education was associated with longer average TL (β: 0.021; 95% CI: 0.001, 0.04, p=0.038) in confounder adjusted models. Once mediators were introduced in the model, the estimates were reduced and remained marginally significant (β: 0.017; 95% CI: −0.003, 0.038, p=0.061). According to path model, approximately 19% of the effect of mother’s education on TL (β: 0.004; 95% CI: −0.001, 0.01, p < 0.10) was mediated through participant’s own education level. No significant mediation effect was observed for any other mediators.

Conclusions

These data provide evidence that participant’s mother’s education was positively linked to adult TL in AA population. Participant’s own educational level partially explained this association.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40615-021-01040-5.

Effects of Randomized Controlled Infancy-Onset Dietary Intervention on Leukocyte Telomere Length-The Special Turku Coronary Risk Factor Intervention Project (STRIP)

Reduced telomere length (TL) is a biological marker of aging. A high inter-individual variation in TL exists already in childhood, which is partly explained by genetics, but also by lifestyle factors. We examined the influence of a 20-year dietary/lifestyle intervention on TL attrition from childhood to early adulthood. The study comprised participants of the longitudinal randomized Special Turku Coronary Risk Factor Intervention Project (STRIP) conducted between 1990 and 2011. Healthy 7-month-old children were randomized to the intervention group (n = 540) receiving dietary counseling mainly focused on dietary fat quality and to the control group (n = 522). Leukocyte TL was measured using the Southern blot method from whole blood samples collected twice: at a mean age of 7.5 and 19.8 years (n = 232; intervention n = 108, control n = 124). Yearly TL attrition rate was calculated. The participants of the intervention group had slower yearly TL attrition rate compared to the controls (intervention: mean = −7.5 bp/year, SD = 24.4 vs. control: mean = −15.0 bp/year, SD = 30.3; age, sex and baseline TL adjusted β = 0.007, SE = 0.004, p = 0.040). The result became stronger after additional adjustments for dietary fat quality and fiber intake, serum lipid and insulin concentrations, systolic blood pressure, physical activity and smoking (β = 0.013, SE = 0.005, p = 0.009). A long-term intervention focused mainly on dietary fat quality may affect the yearly TL attrition rate in healthy children/adolescents.

Association of telomere length and telomerase methylation with n-3 fatty acids in preschool children with obesity

BACKGROUND

Telomeres play a crucial role in cellular survival and its length is a predictor for onset of chronic non-communicable diseases. Studies on association between telomeres and obesity in children have brought discrepant results and the underlying mechanisms and influential factors are to be elucidated. This study aimed to investigate changes in telomere length and telomerase reverse transcriptase (TERT) DNA methylation, and further to determine their correlation with n-3 polyunsaturated fatty acids (PUFAs) in preschool children with obesity.

METHODS

Forty-six preschool children with obesity aged 3 to 4 years were included in the study, with equal numbers of age- and gender-matched children with normal weight as control. Leukocyte telomere length was determined by the ratio of telomeric product and single copy gene obtained using real-time qPCR. DNA methylation of TERT promoter was analyzed by bisulfite sequencing. Fatty acids in erythrocytes were measured by gas chromatography with a total of 15 fatty acids analyzed. The total saturated fatty acids (SFAs), total n-6 PUFAs, total n-3 PUFAs, and the ratio of arachidonic acid (AA) to docosahexaenoic acid (DHA) were calculated. Then the correlation between leukocyte telomere length, TERT promoter methylation and fatty acids was determined.

RESULTS

In preschool children with obesity, leukocyte telomeres were shortened and had a negative association with the body mass index. The methylated fractions in 13 of 25 CpG sites in the TERT promoter were increased by approximately 3 to 35% in the children with obesity compared to the normal weight children. Erythrocyte lauric acid and total SFAs, lenoleic acid and total n-6 PUFAs were higher, and DHA was lower in the children with obesity than those in the children with normal weight. Correlative analysis showed that leukocyte telomere length had a positive association with total SFAs and DHA, and a negative association with the AA/DHA ratio. However, no association between erythrocyte DHA and the TERT promoter methylation was found.

CONCLUSION

These data indicate that the reduced body DHA content and increased AA/DHA ratio may be associated with shortened leukocyte telomeres in child obesity, which is probably not involved in the TERT promoter methylation.

Role of maternal nutrition and oxidative stress in placental telomere attrition in women with preeclampsia

Background:Maternal nutrition influences the growth and development of the fetus and influences pregnancy outcome. We have earlier demonstrated altered maternal nutrition and increased oxidative stress in women with preeclampsia. Oxidative stress is known to be associated with reduced telomere length and short telomere aggregates. Increased telomere attrition leads to increased cellular senescence and tissue ageing. Methods:The present review focuses on the role of maternal nutrition and oxidative stress in telomere attrition in preeclampsia. Results and Conclusion:Future studies need to examine the association between maternal nutritional status in early pregnancy, oxidative stress and telomere attrition in preeclampsia.

Telomere Length in Healthy Adults Is Positively Associated With Polyunsaturated Fatty Acids, Including Arachidonic Acid, and Negatively With Saturated Fatty Acids

Lymphocyte telomere length (LTL) is a biomarker of aging that may be modified by dietary factors including fat. Red blood cell fatty acid status is a well-validated indicator of long-term dietary intake of fat from various sources. Recent findings from epidemiological studies of LTL in relation to fatty acids in red blood cells are not conclusive. The present study was carried out to investigate if red blood cell fatty acid status in 174 healthy older South Australians is associated with LTL. Lymphocyte telomere length was measured by real-time qPCR and fatty acid content in red blood cells was measured by gas chromatography. Our results indicate that the majority of saturated fatty acids and monounsaturated fatty acids are negatively associated with LTL, whereas polyunsaturated fatty acids are positively associated with LTL. Multiple regression analysis revealed that arachidonic acid (C20:4n-6) is significantly, independently, positively correlated with LTL (β = 0.262; p = .000). The significant association of fatty acids, particularly C20:4n-6, with telomere length warrants further research.

The effects of everyday-life exposure to polycyclic aromatic hydrocarbons on biological age indicators

BACKGROUND

Further knowledge on modifiable aging risk factors is required to mitigate the increasing burden of age-related diseases in a rapidly growing global demographic of elderly individuals. We explored the effect of everyday exposure to polycyclic aromatic hydrocarbons (PAHs), which are fundamental constituents of air pollution, on cellular biological aging. This was determined via the analysis of leukocyte telomere length (LTL), mitochondrial DNA copy number (LmtDNAcn), and by the formation of anti-benzo[a]pyrene diolepoxide (B[a]PDE-DNA) adducts.

METHODS

The study population consisted of 585 individuals living in North-East Italy. PAH exposure (diet, indoor activities, outdoor activities, traffic, and residential exposure) and smoking behavior were assessed by questionnaire and anti-B[a]PDE-DNA by high-performance-liquid-chromatography. LTL, LmtDNAcn and genetic polymorphisms [glutathione S-transferase M1 and T1 (GSTM1; GSTT1)] were measured by polymerase chain reaction. Structural equation modelling analysis evaluated these complex relationships.

RESULTS

Anti-B[a]PDE-DNA enhanced with PAH exposure (p = 0.005) and active smoking (p = 0.0001), whereas decreased with detoxifying GSTM1 (p = 0.021) and in females (p = 0.0001). Subsequently, LTL and LmtDNAcn reduced with anti-B[a]PDE-DNA (p = 0.028 and p = 0.018), particularly in males (p = 0.006 and p = 0.0001). Only LTL shortened with age (p = 0.001) while elongated with active smoking (p = 0.0001). Besides this, the most significant determinants of PAH exposure that raised anti-B[a]PDE-DNA were indoor and diet (p = 0.0001), the least was outdoor (p = 0.003).

CONCLUSION

New findings stemming from our study suggest that certain preventable everyday life exposures to PAHs reduce LTL and LmtDNAcn. In particular, the clear association with indoor activities, diet, and gender opens new perspectives for tailored preventive measures in age-related diseases.

CAPSULE

Everyday life exposure to polycyclic aromatic hydrocarbons reduces leukocyte telomere length and mitochondrial DNA copy number through anti-B[a]PDE-DNA adduct formation.