Major Gaps in Understanding Dietary Supplement Use in Health and Disease.

Precise dietary assessment is critical for accurate exposure classification in nutritional research, typically aimed at understanding how diet relates to health. Dietary supplement (DS) use is widespread and represents a considerable source of nutrients. However, few studies have compared the best methods to measure DSs. Our literature review on the relative validity and reproducibility of DS instruments in the United States [e.g., product inventories, questionnaires, and 24-h dietary recalls (24HR)] identified five studies that examined validity (n = 5) and/or reproducibility (n = 4). No gold standard reference method exists for validating DS use; thus, each study's investigators chose the reference instrument used to measure validity. Self-administered questionnaires agreed well with 24HR and inventory methods when comparing the prevalence of commonly used DSs. The inventory method captured nutrient amounts more accurately than the other methods. Reproducibility (over 3 months to 2.4 years) of prevalence of use estimates on the questionnaires was acceptable for common DSs. Given the limited body of research on measurement error in DS assessment, only tentative conclusions on these DS instruments can be drawn at present. Further research is critical to advancing knowledge in DS assessment for research and monitoring purposes.

Feasibility of a yoga intervention to decrease pain in older women: a randomized controlled pilot study.

BACKGROUND: A significant proportion of older women suffer from chronic pain, which can decrease quality of life. The objective of this pilot randomized study was to evaluate the feasibility of a flow-restorative yoga intervention designed to decrease pain and related outcomes among women aged 60 or older. METHODS: Flow-restorative yoga classes were held twice weekly for 1 hour and led by a certified yoga instructor. Participants randomized to the intervention group attended the yoga classes for 12 weeks and received supplemental materials for at-home practice. Those randomized to the control group were asked to maintain their normal daily routine. Feasibility was evaluated using recruitment and retention rates, class and home practice adherence rates, and participant satisfaction surveys. Outcome measures (self-reported pain, inflammatory markers, functional fitness, quality of life, resilience, and self-reported physical activity) were assessed at baseline and post-intervention. Paired t-tests or Wilcoxon signed-rank tests were used to examine changes in outcome measures within treatment groups. RESULTS: Thirty-eight participants were recruited and randomized. Participants were primarily white, college-educated, and higher functioning, despite experiencing various forms of chronic pain. Attendance and retention rates were high (91 and 97%, respectively) and the majority of participants were satisfied with the yoga program (89%) and would recommend it to others (87%). Intervention participants also experienced reductions in pain interference and improvements in energy and social functioning. CONCLUSIONS: This pilot study provides essential data to inform a full scale randomized trial of flow-restorative yoga for older women with chronic pain. Future studies should emphasize strategies to recruit a more diverse study population, particularly older women at higher risk of disability and functional decline. TRIAL REGISTRATION: Clinicaltrials.gov , NCT03790098 . Registered 31 December 2018 - Retrospectively registered.