Browsing by Subject "Hydroxytyrosol"
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Item Chronic and acute effects of hydroxytyrosol on antioxidant status and inflammation at rest and during exercise(2012-05) Simpson, Ashlee Danielle; Ivy, John, 1945-; Farrar, Roger P.Evidence shows that consumption of a Mediterranean diet can lower the risk of all-cause and cause-specific mortality suggesting that this diet has an overall effect on health. Antioxidants found within olive oil, the primary source of fat in the Mediterranean diet, may be leading contributors to the decreased disease risk. More specifically, hydroxytyrosol (HT), one of the most active and powerful antioxidants found in olive oil, has the ability to increase total antioxidant status and lower levels of lipid peroxidation. In addition to a healthy diet, physical activity decreases the risk of cardiovascular morbidity and mortality; however, aerobic exercise of sufficient intensity or duration can induce oxidative stress. Therefore, the purpose of this study was to investigate the effects of 6 weeks of HT supplementation on antioxidant status and markers of inflammation in healthy, recreationally active males before and throughout acute aerobic exercise bouts. Using a randomized, double-blind, repeated-measures, placebo-controlled design, sixty-one (n=61) participants were randomly assigned to consume a placebo (PLA), low dose of HT (LHT, 50 mg/day), or high dose of HT (HHT, 150 mg/day). Throughout the course of the study, the participants performed four time trial rides (TT1-TT4) on cycle ergometers. TT1 occurred before supplementation, TT2 halfway through the supplementation period, and TT3 and TT4 occurred in the sixth week and final two days of supplementation. Blood was drawn prior to (pre) and just before termination (end) of each time trial to measure markers of antioxidant status and inflammation during exercise. We did not observe significant main effects for treatment on any of the markers for antioxidant status (TEAC) or for markers of inflammation (oxLDL, CRP, 8IP, TNFα, IL-6, IL-10, IL-1β, or IL-1ra). Significant treatment-by-time interactions occurred for CRP, 8IP, and IL-6 although significant treatment differences in these measures were not detected. We conclude that chronic and acute HT supplementation does not improve antioxidant status nor decrease markers of inflammation in this population at rest, during, or following exercise.Item Effect of hydroxytyrosol supplementation on mitochondrial biogenesis, aerobic capactiy, and endurance exercise performance in healthy men(2011-08) Healy, Marin Elise; Ivy, John, 1945-; Farrar, Roger P.The purpose of this study was to investigate the effects of hydroxytyrosol (HT) supplementation on markers of mitochondrial biogenesis, aerobic capacity, and endurance exercise performance in recreationally active men. Sixty-one (n = 61) subjects (21.46 ± 0.22 yrs, 179.46 ± 0.79 cm, 78.91 ± 1.19 kg) consumed either a high dose (HI) HT supplement (150 mg HT), a low dose (LO) HT supplement (50 mg HT), or a placebo (PLA) every day for 6 weeks. Muscle biopsies from the vastus lateralis were obtained at baseline and after 6 weeks of supplement consumption and analyzed for markers of mitochondrial biogenesis: succinate dehydrogenase (SDH), citrate synthase (CS), and peroxisome proliferator-activated receptor ɣ coactivator (PGC)-1α. Subjects completed exercise testing on a bicycle ergometer at baseline and after 3 and 6 weeks of supplement consumption to measure changes in maximal aerobic power (VO2MAX), lactate threshold, respiratory exchange ratio (RER), substrate utilization, and endurance exercise performance on a 20 km time trial course. The primary findings were that HT supplementation increased muscle oxidative enzyme activity suggesting increased oxidative capacity. HT also increased time trial performance at midpoint and endpoint and this corresponded with an improvement in lactate threshold and a lower RER for the LO HT treatment. Time trial performance was also improved at endpoint for PLA, however, unlike LO an HI HT, this was accompanied by a significant increase in rating of perceived exercise (RPE) and not associated with improvements in muscle oxidative capacity. Our results indicate that HT ranging from 50 to 150 mg/day for 6 weeks can improve muscle oxidative capacity and aerobic performance, and suggests that HT may be used chronically to improve mitochondrial function. HT may be used as an effective means to increase mitochondria to improve exercise performance, and limit diseases associated with mitochondrial dysfunction such as cardiovascular disease, type II diabetes, and some cancers.Item Effect of hydroxytyrosol supplementation on muscle damage in healthy human following an acute bout of exercise(2013-05) Kim, Heon Tae; Farrar, Roger P.; Ivy, John, 1945-The purpose of this study was to investigate the effects of 6 weeks of hydroxytyrosol (HT) supplementation on markers of muscle damage in healthy, recreationally active men before and throughout acute aerobic exercise bouts. Using a randomized, double-blind, repeated-measures, placebo-controlled design, sixty-one (n = 61) subjects (21.46 ± 0.22 yrs, 179.46 ± 0.79 cm, 78.91 ± 1.19 kg) consumed either a high dose (HI) HT supplement (150 mg HT), a low dose (LO) HT supplement (50 mg HT), or a placebo (PLA) every day for 6 weeks. Throughout the course of the study, the subjects performed four time trial rides (TT1-TT4) on a cycle ergometer. TT1 occurred before supplementation, TT2 halfway through the supplementation period, and TT3 and TT4 occurred in the sixth week and final two days of supplementation. Blood was drawn prior to (pre) and just before termination (end) of each time trial to measure markers of muscle damage during exercise. We observed that endurance exercise increased indicators of muscle damage, CPK and myoglobin, but an association between HT treatment and reduced muscle damage indicators during exercise were not demonstrated. However, the HT supplementation for 6 weeks in recreationally-active males improved time trial performance in the HT treatment groups over the course of the study and this improvement was accompanied by a lower increase in myoglobin concentration in blood in the HI treatment group than in the LO treatment group. Also, performance was improved after 6 weeks in the PLA group. This improvement was associated with an increase in rating of perceived exertion (RPE). RPE was not increased in either the LO and HI treatment groups, although time trial performance was significantly improved. It is possible that HT can improve performance by altering perception of effort. We conclude that chronic and acute HT supplementation did not reduce markers of muscle damage in this population at rest, during, or following exercise, but improved aerobic performance.Item Effect of hydroxytyrosol supplementation on the lipid profile and metabolic disease risk markers in healthy men(2012-05) Burns, James Dorsey; Ivy, John, 1945-Hydroxytyrosol (HT) has been found to be a potent antioxidant and hypocholesterolemic agent in various animal models of disease including dyslipidemia, atherosclerosis, and diabetes. Therefore, the purpose of this study was to examine the effects of hydroxytyrosol (HT) supplementation on the lipid profile and metabolic risk markers in recreationally active men. Sixty-one (n = 61) subjects (21.46 ± 0.22 yrs, 179.46 ± 0.79 cm, 78.91 ± 1.19 kg) consumed HT in either a high dose (HI, 150 mg HT; n = 22), a low dose (LO, 50 mg HT; n = 20), or a placebo (PLA; n = 19) every day for 6 weeks. Blood draws were obtained at baseline, 14, 28, and 39 days under fasting conditions. Analyzed were the components of the plasma lipid profile: total cholesterol (TC), high density lipoprotein cholesterol (HDLc), the TC:HDLc fraction, low density lipoprotein cholesterol (LDLc), very low density lipoprotein cholesterol (VLDLc), and triglycerides (Tg); and markers of metabolic risk: uric acid, lipase, hemoglobin (Hb), glycated hemoglobin (HbA1c), and blood glucose (BG). The primary finding was that HT, in either HI or LO dosages did not cause clinically meaningful changes in the blood lipid profile or markers of metabolic risk. Subjects in the HI group experienced a small big significant increase in fasting blood glucose, while those in the PLA group experienced a significant increase in VLDLc concentration. In both cases, however, the mean values remained within their respective healthy reference ranges. Whether these changes would persist beyond the 6-week course of this study is not known. While no improvements were seen in any of our selected measures, these results indicate that HT supplementation, ranging from 50 to 150 mg/day, is safe to consume for durations up to 6 weeks in healthy young men. By maintaining the lipid profile and metabolic risk markers within a healthy range, it is possible that HT may impart a degree of protection against cardiovascular and metabolic disease risk, but such an effect may only be apparent when the plasma lipid and/or metabolic risk profile is abnormal.