title: Assessing the effects of a short-term green tea intervention in skin microvascular function and oxygen tension in older and younger adults.
abstract: Green tea consumption has been associated with a reduction in cardiovascular disease risk factors. However, there is little evidence examining its potential differing effect between younger and older populations, whilst little is known on its effect on the circulatory system when oxygen demand is higher. Therefore the aim of this study was to evaluate the short-term effects of green tea consumption on microvascular functioning in both an older and younger population. Fifteen young [24 (4.0)] and fifteen older [61 (4.0)] participants, consumed two cups of green tea daily for 14days. We used Laser Doppler Flowmetry (LDF) to assess cutaneous microvascular function and Transcutaneous Oxygen monitoring (TcPO2) to assess skin oxygen tension. Systolic and diastolic blood pressure were also assessed on both visits. We observed significant improvements in axon-mediated microvascular vasodilation for the younger group [1.6 (0.59) vs 2.05 (0.72), p<0.05] and the older group [1.25 (0.58) vs 1.65 (0.5) p<0.05]. Improvements in skin oxygen tension were also noted for both groups in both noted TcPO2 measures (i.e. 1.25 (0.58) vs 1.65 (0.5) (p<0.05), for ΔTcPO2max for the older group, between visits) respectively. Improvements were also observed for systolic blood pressure in both the younger [120 (10) vs 112 (10), p<0.05] and older group [129 (12) v 124 (11), p<0.001]. In conclusion, we observed statistically-significant improvements in microvascular function and skin oxygen tension. Our results suggest that green tea may prove beneficial as a dietary element in lifestyle interventions aiming to lower cardiovascular disease risk, in both older and younger populations.
authors.affiliation: Human Nutrition Unit, The Medical School, The University of Sheffield, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Wasilewski
authors.affiliation: Human Nutrition Unit, The Medical School, The University of Sheffield, UK.
authors.forename: Emmanuel O
authors.initials: EO
authors.lastname: Ubara
authors.affiliation: Centre for Sport and Exercise Science, Sheffield Hallam University, UK. Electronic address: m.klonizakis@shu.ac.uk.
authors.forename: Markos
authors.initials: M
authors.lastname: Klonizakis
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001783:Blood Flow Velocity; D001785:Blood Gas Monitoring, Transcutaneous; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000187:drug effects*; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage* / Q000302:isolation & purification; D010946:Plants, Medicinal; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply* / Q000378:metabolism; D013662:Tea / Q000737:chemistry; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D010936:Plant Extracts; D013662:Tea; D014665:Vasodilator Agents; D010100:Oxygen
keywords: Green tea; Laser Doppler Flowmetry; Oxygen tension