Does the timing of intake matter? Association between caffeine intake and depression: Evidence from the National Health and Nutrition Examination Survey

Mediation role of telomere length in the relationship between physical activity and PhenoAge: A population-based study

Background

The relationship between physical activity (PA), telomere length, and phenotypic age (PhenoAge) represents a pivotal area of investigation in aging research.

Methods

The study encompassed a cohort of 6200 participants aged 20 years and above, sourced from the National Health and Nutrition Examination Survey (NHANES). Physical activity (PA) levels were assessed employing the Global Physical Activity Questionnaire, while DNA samples were collected to determine telomere length, measured in base pairs. PhenoAge, an emerging aging index relying on nine distinct chemical biomarkers, was computed.

Results

Incorporating a fully adjusted model, our analysis showed significant correlations between PA engagement and PhenoAge [Low PA, β (95 % CI): 0.039(-0.071,-0.008), p = 0.021; Moderate PA, β (95 % CI): 0.058(-0.082,-0.034), p < 0.001; High PA, β (95 % CI): 0.069(-0.096,-0.042), p < 0.001]. Furthermore, a positive link emerged between elevated PA levels and telomere length, with a β (95 % CI) of 0.011(0.001, 0.022), p = 0.034. A mediation analysis was performed, demonstrating that telomere length mediated the connection between PA and PhenoAge, with a proportion mediated calculated at 3.57 %.

Conclusions

Our findings suggest that PA may play a key role in mitigating aging processes by preserving telomere length, highlighting the potential of PA as a target for interventions aimed at promoting healthy aging and longevity.

Association of 24-h Energy Intake Behavior With Depressive Symptoms: Findings From the National Health and Nutrition Examination Survey

Objective: Appetite changes are a significant clinical feature of depression, with circadian rhythms disruption being a crucial mechanism in depression. However, the specific role of eating rhythms in depression remains unclear. This study aimed to assess the relationship between energy intake rhythmicity and depressive symptoms. Methods: A total of 34,974 noninstitutionalized individuals were recruited from the National Health and Nutrition Examination Survey. To investigate the relationship between 24-h energy intake and depressive symptoms, covariate-adjusted sample-weighted regressions were employed. The study analyzed various aspects of energy intake rhythmicity, including the proportion of energy intake from non-meals and meal times, as well as the proportion of energy intake across meals and various time periods (morning, midday, afternoon, evening, night, and overnight). Results: A high proportion of energy intake from non-meals (adjusted odds ratio [OR] = 1.11, 95% confidence interval [CI]: 1.08-1.15) was associated with higher depressive symptoms. The proportion of breakfast energy intake in total daily energy intake was nonlinearly associated with depressive symptoms. In participants with a breakfast energy intake below 20%, the prevalence of depressive symptoms decreased by 15% (adjusted OR = 0.85, 95% CI: 0.75-0.96) per each 10% increment in the proportion of breakfast energy intake. A U-shaped relationship was identified between the timing of the day's last energy intake and depressive symptoms, with the lowest prevalence occurring at 7:48 PM (before 7:48 PM: adjusted [OR = 0.96, 95% CI: 0.94-0.98]; after 7:48 PM: adjusted [OR = 1.11, 95% CI: 1.03-1.20]). Conclusions: Among adults in the United States, the proportion of energy consumed from non-meals was associated with higher depressive symptoms. Adequate energy intake at breakfast and moderate end-times of energy intake were linked to reduced depressive symptoms. These results may contribute to designing of future studies on dietary rhythm interventions for managing depression.

Longitudinal Effects of Lifetime Caffeine Consumption on Levels of Depression, Anxiety, and Stress: A Comprehensive Review

PURPOSE OF REVIEW

Caffeine has high bioavailability and a purine-like alkaloid structure. It exerts wide-ranging physiological effects by binding to adenosine receptors throughout the human body. Through the activation of those receptors, it can regulate many physiological events in the body. The impact of caffeine consumption on depression, anxiety, stress, and human health remains unclear, constituting an important knowledge gap. This review was conducted to examine the effects of caffeine consumption on depression, anxiety, and stress levels and to offer some recommendations for its future use.

RECENT FINDINGS

We performed a comprehensive literature search using PubMed, Web of Science and Google Scholar databases for original articles published in recent years on "caffeine metabolism", "caffeine mechanism", "anxiety", "depression", "stress". Caffeine, which has an antagonistic effect on adenosine, can reduce the risk and symptoms of depression and improve general mental health by modulating the central nervous system and neurotransmitter systems. However, increases in anxiety and stress levels, which are often seen together with depression, are observed due to high-dose caffeine consumption. Caffeine's effects on depression, anxiety, and stress may vary depending on different factors, but the level of consumption is particularly important and attention should be paid to upper limits and reference values while evaluating consumption amounts.

Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show?

Caffeine is a popular ergogenic aid that has a plethora of evidence highlighting its positive effects. A Google Scholar search using the keywords "caffeine" and "exercise" yields over 200,000 results, emphasizing the extensive research on this topic. However, despite the vast amount of available data, it is intriguing that uncertainties persist regarding the effectiveness and safety of caffeine. These include but are not limited to: 1. Does caffeine dehydrate you at rest? 2. Does caffeine dehydrate you during exercise? 3. Does caffeine promote the loss of body fat? 4. Does habitual caffeine consumption influence the performance response to acute caffeine supplementation? 5. Does caffeine affect upper vs. lower body performance/strength differently? 6. Is there a relationship between caffeine and depression? 7. Can too much caffeine kill you? 8. Are there sex differences regarding caffeine's effects? 9. Does caffeine work for everyone? 10. Does caffeine cause heart problems? 11. Does caffeine promote the loss of bone mineral? 12. Should pregnant women avoid caffeine? 13. Is caffeine addictive? 14. Does waiting 1.5-2.0 hours after waking to consume caffeine help you avoid the afternoon "crash?" To answer these questions, we performed an evidence-based scientific evaluation of the literature regarding caffeine supplementation.

The role of education attainment on 24-hour movement behavior in emerging adults: evidence from a population-based study

PURPOSE

The purpose of this study was to explore the relationship between education level and health behavior including sleep, work activity, exercise activity, and sedentary behavior among emerging adults.

METHODS

This study utilized data from the National Health and Nutrition Examination Survey (NHANES) collected between 2007 and 2018. The study sample included 4,484 emerging adults aged 18-25 years and the weighted participants were 30,057,813. Weighted multivariable regression analysis was performed to investigate the association between education level and the aforementioned health behavior, adjusting for age, gender, race/ethnicity, marital status, poverty-income ratio, BMI, smoking, and alcohol drinking status.

RESULTS

This study revealed that higher education level was associated with shorter sleep duration [Fully adjusted model, β (95% CI): -0.588 (-0.929, -0.246), p < 0.001]. Additionally, those with higher education levels were more likely to allocate time in sedentary behavior [β (95% CI): 90.162 (41.087, 139.238), p < 0.001]. Moreover, higher education level was related to less work activity [β (95% CI): -806.991 (-1,500.280, -113.703), p = 0.023] and more exercise activity time [β (95% CI): 118.196 (-21.992, 258.385), p = 0.097]. Subgroup analysis further verified this trend and detected that males with higher education level tended to participate in less work activity [β (95% CI): -1,139.972 (-2,136.707, -143.237), p = 0.026] while females with higher education level tended to engage in more exercise activity [Fully adjusted model, β (95% CI): 141.709 (45.468, 237.950), p = 0.004].

CONCLUSION

This study highlighted the importance of education level as a significant factor in promoting healthy behavior among emerging adults. The findings underscored the need for the Ministry of Education to prioritize educating this demographic about the significance of maintaining adequate sleep patterns and reducing sedentary habits. Encouraging them to allocate more time for work and physical activities can significantly contribute to their overall wellbeing and success, ultimately fostering a healthier next generation.