Dietary proteins are sources of some amino acid precursors of two neurotransmitters relevant for biological rhythms, serotonin and melatonin, which are involved in sleep and alertness. Meat is the main source of proteins in many countries. Furthermore, meat consumption is of special interest because it provides high-quality protein as well as saturated and trans fatty acids. However, its effect on sleep patterns is unclear. Thereby, the aim was to examine the association of habitual meat consumption with changes in sleep duration and with sleep quality in older adults. We used data from 1,341 participants in the Seniors-ENRICA cohort aged ≥60 years, followed from 2012 through 2015. Habitual meat consumption was assessed at baseline with a validated diet history. Sleep duration and quality were ascertained both in 2012 and 2015. Analyses were performed with logistic regression and adjusted for socio-demographic variables, lifestyle, morbidity, sleep duration and poor sleep indicators at baseline. During follow-up, 9.0% of individuals increased and 7.9% decreased their sleep duration by ≥2 hours/night. Compared with individuals in the lowest tertile of meat consumption (<87 g/d), those in the highest tertile (≥128 g/d) showed increased incidence of a large decrease (≥2 h) in sleep duration (OR: 1.93; 95% CI:1.01-3.72; p-trend:0.04). Higher consumption of meat was also associated with incidence of snoring (OR:2.06; 95% CI:1.17-3.60; p-trend:0.01) and poor general sleep quality (OR:1.71; 95% CI:1.04-2.82; p-trend:0.03). Each 100 g/d increment in meat intake was associated with a 60% higher risk of both large sleep duration changes and poor sleep quality (OR:1.60; 95% CI:1.07-2.40). Results were in the same direction for red and processed meat and for white meat separately, and among individuals with physical impairment. Higher meat consumption (≥128 g/d) was associated with changes in sleep duration and with poor sleep in older adults.

Background Sleep disturbances may contribute to physical function impairment among older adults. Objective To examine the associations between sleep quality and duration and impaired physical function among older adults. Methods Cross-sectional study involving 392 non-institutionalized adults aged ≥65 years, who were recruited from primary health care centres in Spain. Sleep quality and duration were assessed with the Pittsburgh Sleep Quality Index (PSQI). The FRAIL scale was used to identify physical frailty, the short physical performance battery to assess lower extremity functional impairment (LEFI) and grip strength was measured using a hand-held dynamometer to assess muscle weakness. Statistical analyses were performed with logistic regression models adjusted for potential confounders. Results Participants with poor sleep quality (PSQI global score ≥10) were more likely to have functional limitations; the odds ratio (95% confidence interval) was 2.90 (1.10–7.64) for physical frailty, 2.73 (1.34–5.58) for LEFI and 2.32 (1.14–4.75) for muscle weakness. Sleep quality components associated with frailty were sleep disturbances, use of sleeping medication and daytime dysfunction. The only quality component associated with LEFI was poor sleep efficiency, while subjective poor sleep quality and daytime dysfunction were linked to muscle weakness. No associations were observed between night-time sleep duration and physical function indicators. Conclusions Poor self-reported sleep quality, but not sleep duration, was associated with an increased frequency of physical frailty, LEFI and muscle weakness. Interventions to improve sleep quality could contribute to healthy ageing.

Background Zinc could be a target nutrient in the prevention of physical impairment and frailty in older adults due to its anti-inflammatory/antioxidant properties. However, prospective studies evaluating this inquiry are scarce. Thus, we aimed to assess the association between zinc intake and impaired lower-extremity function (ILEF) and frailty among community-dwelling older adults. Methods We examined 2,963 adults aged ≥60 years from the Seniors-ENRICA cohort. At baseline (2008–2010) and subsequent follow-up (2012), zinc intake (mg/d) was estimated with a validated computerized face-to-face diet history and adjusted for total energy intake. From 2012 to 2017, the occurrence of ILEF was ascertained with the Short Physical Performance Battery, and of frailty according to the Fried phenotype criteria. Analyses were conducted using Cox proportional hazard models adjusted for relevant confounders, including lifestyle, comorbidity, and dietary factors. Results During follow-up, we identified 515 incident cases of ILEF and 241 of frailty. Compared to participants in the lowest tertile of zinc intake (3.99–8.36 mg/d), those in the highest tertile (9.51–21.2 mg/d) had a lower risk of ILEF [fully-adjusted hazard ratio (95% confidence interval): 0.75 (0.58–0.97); p for trend: 0.03] and of frailty [0.63 (0.44–0.92); p for trend: 0.02]. No differences in the association were seen by strata of socio-demographic and lifestyle factors. Conclusions Higher zinc intake was prospectively associated with a lower risk of ILEF and frailty among older adults, suggesting that adequate zinc intake, that can be achieved through a healthy diet, may help preserve physical function and reduce the progression to frailty.

Nut consumption was associated with half the risk of impaired agility and mobility in men and with lower risk of overall physical function impairment in women. The suggested protective effect of nut consumption on physical functioning merits further examination.