Effects of Almond Consumption on Vascular Health, Functional Performance, and Sleep in Active Older Adults Who Are Overweight

Cardiovascular disease (CVD) is the leading cause of death, with age being the strongest predictor of cardiovascular health. Age-related changes to the vasculature such as endothelial dysfunction and arterial stiffening are believed to be two of the major phenotype changes associated with this increased CVD risk. Increased oxidative stress and inflammation are major contributors to endothelial dysfunction, arterial stiffening, and other age-related poor health outcomes such as decreased functional performance and poorer sleep quality. Almonds are rich in antioxidants and anti-inflammatory nutrients that may combat age-related health decline, but more research is needed to better understand the potential benefits. Purpose: The purpose of this study was to determine the effects of almond consumption on vascular health, physical function, and sleep in active adults who were overweight and obese. Methods: Ten (females = 5) active, older adults (57 ± 4 years) who were overweight or obese (body mass index (BMI): 27.6 ± 2.6 kg/m2) were included in this randomized, cross-over study. Participants consumed almonds (64 g/day; 384 kcal) or an isocaloric control snack (84 g/day of granola bars; 380 kcal) for 12 weeks, separated by a 4-week washout. Vascular health was assessed through flow mediated dilation (FMD) to determine endothelial function, pulse-wave velocity (PWV) and pulse wave analysis (PWA) to determine arterial stiffness, and blood draws to determine a circulating oxidative stress biomarker (total antioxidant capacity (TAC)). Functional performance was assessed by the Continuous Scale Physical Functional Performance 10 item scale (CS-PFP-10) test and a treadmill submaximal oxygen consumption (VO2) test. Sleep was determined objectively through ActiGraph accelerometry and subjectively through the Pittsburgh Sleep Quality Index (PSQI). A two-way (treatment x time) repeated measures analysis of variance (ANOVA) was used to assess the effects of intervention (almond, control) and time (baseline, post) on outcomes. Significance was accepted at p < 0.05. Results: Self-reported compliance was not significantly different between treatments (93% for the almond regimen and 96% for the isocaloric control snack regimen). There were no significant differences between baseline measurements for any of the variables, indicating the washout period was sufficient. There was a significant treatment x time interaction on FMD%, F(1,9) = 13.69, p = 0.005, η2 = 0.603, with FMD% being greater after the almond regimen compared to control (almond: 9.05 ± 2.87 %; control: 6.61 ± 2.04 %, F(1,9) = 7.960, p = 0.020, η2 = 0.469), with a mean difference of 2.445%. However, there were no significant treatment x time interactions found in normalized FMD% or any other vascular health measurements, including the biomarker for oxidative stress (TAC). Additionally, there were no significant treatment x time interaction on functional performance assessments. There was a significant treatment x time interaction on sleep efficiency, F(1,7) = 8.231, p = 0.024, η2 = 0.540 with sleep efficiency being greater after the almond regimen compared to the control (almond: 92 ± 2 %; control: 88 ± 6 %, F(1,7) = 5.784, p = 0.047, η2 = 0.452), with a mean difference of 4%. There was also a significant treatment x time interaction on wake after sleep onset (WASO), F(1,7) = 7.325, p = 0.030, η2 = 0.511 with WASO being greater after the almond regimen compared to the control (almond: 37 ± 13 minutes; control: 56 ± 32 minutes F(1,7) = 4.707, p = 0.067, η2 = 0.402) with a mean difference of 19 minutes. However, there were no significant treatment x time interaction found in any other sleep measurements. Conclusion: Our findings indicate that 12 weeks of almond consumption may benefit some aspects of vascular health and sleep but may not benefit functional performance, in comparison to an isocaloric control snack. While there are endless snack options, almonds may be a good snack alternative for people who want to improve their vascular health and sleep better.