Context Serum 25-hydroxyvitamin D [25(OH)D], dietary and supplemental vitamin D may influence cognitive outcomes. Objectives Sex/age-specific and race-specific associations of vitamin D status and intake were examined with longitudinal change in various cognitive domains in a large sample of ethnically and socio-economically diverse US urban adults. Design Two prospective waves of data from Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study were used. Setting: Baltimore City, MD, 2004-2013. Participants U.S. adults aged 30-64y at baseline visit, length of follow-up between visits 1 (2004-2009) and 2 (2009-2013) with mean follow-up time±SD: 4.64±0.93y. Final analytic sample sizes ranged from 1,231-1,803 participants with 1.5-2.0 visits/participant. Main outcome and exposure measures Cognitive performance was assessed using 11 test scores covering domains of global cognition, attention, learning/memory, executive function, visuo-spatial/visuo-construction ability, psychomotor speed and language/verbal. Serum 25(OH)D, vitamin D intake and use of supplements containing vitamin D were the key exposures. Results Based on multiple mixed-effects linear regression models, there was a consistent relationship between vitamin D status (overall) and supplemental intake (older women and African-Americans) with a slower rate of decline in the domain of verbal fluency. Higher dietary intake of vitamin D was linked to slower rate of decline in verbal memory among younger women, and a slower rate of decline in visual memory/visuo-constructive abilities among Whites. All other associations were inconsistent. Conclusions Vitamin D status and intakes were inversely related to domain-specific cognitive decline in US urban adults. Larger population studies are needed to replicate our findings.
This secondary analysis of survey data examined mediating-moderating effects of allostatic load score (calculated using the Rodriquez method) on the association between nutrient-based Dietary Approaches to Stop Hypertension (DASH) diet score (Mellen Index) and the all-cause and cause-specific mortality risks among 11,630 adults ≥ 30 years of age from the 2001–2010 National Health and Nutrition Examination Surveys with no history of cardiovascular disease or cancer at baseline, and who were followed-up for ~9.35 years. Multivariable models were adjusted for demographic, socioeconomic, lifestyle, and health characteristics. All-cause, cardiovascular disease, and cancer-specific mortality rates were estimated at 6.5%, 1.1%, and 1.9%, respectively. The median DASH total score was 3.0 (range: 1–8) (with 78.3% scoring < 4.5), whereas the median allostatic load score was 3 (range: 0–9). The DASH diet, fiber, and magnesium were negatively correlated with allostatic load, whereas allostatic load predicted higher all-cause mortality, irrespective of the DASH diet. Whereas protein was protective, potassium increased all-cause mortality risk, irrespective of allostatic load. Potassium was protective against cardiovascular disease-specific mortality but was a risk factor for cancer-specific mortality. Although no moderating effects were observed, mediation by the allostatic load on cardiovascular disease-specific mortality was observed for DASH total score and selected component scores. Direct (but not indirect) effects of DASH through the allostatic load were observed for all-cause mortality, and no direct or indirect effects were observed for cancer-specific mortality. From a public health standpoint, the allostatic load may be a surrogate for the preventive effects of the DASH diet and its components on cardiovascular disease-specific mortality risk.
Complex processes appear to link sleep duration and quality with dietary patterns. Numerous studies show healthful benefits of the Dietary Approaches to Stop Hypertension (DASH) diet, but few have examined its association with sleep duration or quality. The current study tested cross-sectional associations of DASH diet quality score with sleep quality among adults. Analyses of participants were from the 2005–2008 wave of the National Health and Nutrition Examination Surveys (n = 3941 adults ≥30 years of age, complete data). We performed sex- and age group-stratified multiple OLS regression analyses with DASH total score and components as main predictors and sleep quality as main outcomes, adjusting sequentially for socio-demographic, behavioral and health-related factors. Sex and age differences in associations of DASH with sleep quality, adjusting for covariates, were also examined by incorporating two-way interaction terms between sex/age and the DASH score in each unstratified model. We found that the DASH diet score was inversely related to poor sleep-related daytime dysfunction adjusted by age, sex, demographic and socio-economic factors. Some sex-specific associations were detected between DASH diet component scores and sleep quality. Notably, the potassium DASH component was inversely associated with Factor 1 (“sleepiness and sleep disturbance”) among women. The fiber DASH component was associated with better sleep quality and inversely related to Factor 2 (“sleep-related daytime dysfunction”) in younger subjects. This study indicates health benefits of the DASH diet for sleep duration and quality. Future longitudinal studies and randomized placebo-controlled trials are required to ascertain protective effects.