Healthy Middle-aged Participants Research Articles

Cranberry capsule ingestion and bacterial anti‐adhesion activity of urine

Clinical, epidemiological and mechanistic studies support the role of cranberry in maintaining urinary tract health. Current studies suggest cranberry proanthocyanidins (PACs) may prevent urinary tract infections by interfering with adhesion of certain pathogenic E. coli to uroepithelial cells. The current study measured bacterial anti-adhesion activity in human urine after consumption of TheraCran™ cranberry capsules. One 650-mg capsule (equivalent to 16.5 mg oligomeric PACs/capsule) was administered BID to six healthy middle-aged participants over a 2-day period, followed by urine collection over an 8- hr period. An average of 3 hrs following capsule consumption, 67% of urines exhibited bacterial anti-adhesion activity. Activity persisted for at least 8 hrs, suggesting potential protection against bacterial attachment in the uroepithelium over this period. Urinary pH averaged 6.5, eliminating a bacteriostatic effect. No anti-adhesion activity was detected in urines prior to capsule consumption. The threshold for in vitro anti-adhesion activity of the capsules was determined to be 3.5 mg/ml utilizing a mannose-resistant human red blood cell hemagglutination assay specific for P-fimbriated E. coli bacteria. Results suggest that consumption of cranberry capsules may be an effective means of preventing bacterial adhesion in human urine, which could potentially reduce the incidence of urinary tract infections. This work was supported by Theralogix, LLC.

Cortisol responses to mild psychological stress are inversely associated with proinflammatory cytokines

Glucocorticoids can down-regulate immune activity, but acute stress has been reported to increase both cortisol and levels of plasma cytokines. We investigated individual differences in cortisol responses and their associations with proinflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1ra), cardiovascular activity, and mental health. Saliva samples and blood were taken from 199 healthy middle-aged participants of the Whitehall II cohort at baseline, immediately after stress and 45 min later. We defined the 40% of participants with the highest cortisol response to stress as the cortisol responder group and 40% with the lowest response as the cortisol non-responder group. Plasma IL-6 was higher and the IL-1ra response to stress was greater in the cortisol non-responder group. The cortisol non-responders showed lower heart rate variability than the cortisol responders. The cortisol responder group experienced more subjective stress during the tasks and reported more impaired mental health than the non-responders. We conclude that individual variations in neuroendocrine stress responsivity may have an impact on proinflammatory cytokines, and that both high and low cortisol stress responsiveness has potentially adverse effects.

Perception of Postural Limits During Reaching

The relationship between perceived and actual postural limits in reaching by healthy young and middle-aged participants was assessed. Subjects (N = 51) first estimated their expected performance and then executed maximum reaches along a tape measure mounted at shoulder height. Measures of standing and bending reaches were obtained. Subjects estimated their reach limits reasonably accurately but significantly underestimated bending reach and overestimated standing reach. That finding suggests that individuals scale perceived abilities with perceived risk in attempting a given action. The accuracy of a participant's perceived bending reach was unrelated to his or her height, weight, age, and gender, and was only weakly correlated with actual reach excursion (bending - standing reach). The accuracy was strongly correlated with the accuracy of subjects' perceived standing reach; individuals who underestimated standing reach underestimated bending reach much more. That result and the observed lack of correlation between the magnitudes of estimated bending reach and estimated standing reach suggest a serial strategy of estimating bending reach by considering and summing perceived arm's length and perceived reach excursion.