Renata Leite Tavares

Potential ergogenic activity of grape juice in runners

Recent studies have indicated that certain food products have ergogenic potential similar to that of sports supplements. The present study aimed to investigate the potential ergogenic effect of integral purple grape juice on the performance of recreational runners. Twenty-eight volunteers of both sexes (age, 39.8 ± 8.5 years; peak oxygen consumption, 43.2 ± 8.5 mL/(kg·min)) were randomized into either a group that received grape juice (grape juice group (GJG), n = 15; 10 mL/(kg·min) for 28 days) or a group that received an isocaloric, isoglycemic, and isovolumetric control beverage (control group (CG), n = 13). A time-to-exhaustion exercise test, anaerobic threshold test, and aerobic capacity test were performed, together with assessments of markers of oxidative stress, inflammation, immune response, and muscle injury, performed at baseline and 48 h after the supplementation protocol. The GJG showed a significant increase (15.3%) in running time-to-exhaustion (p = 0.002) without significant improvements in either anaerobic threshold (3.6%; p = 0.511) or aerobic capacity (2.2%; p = 0.605). In addition, GJG exhibited significant increases in total antioxidant capacity (38.7%; p = 0.009), vitamin A (11.8%; p = 0.016), and uric acid (28.2%; p = 0.005), whereas α-1-acid glycoprotein significantly decreased (20.2%; p = 0.006) and high-sensitivity C-reactive protein levels remained unchanged. In contrast, no significant changes occurred in any of these variables in the CG. In conclusion, supplementation with purple grape juice shows an ergogenic effect in recreational runners by promoting increased time-to-exhaustion, accompanied by increased antioxidant activity and a possible reduction in inflammatory markers.

Chia induces clinically discrete weight loss and improves lipid profile only in altered previous values

INTRODUCTION chia (Salvia hispanica L.) has an elevated concentration of dietary fiber, it has been used to weight loss and enhance blood glucose and lipid profile. However, data in human are still scarce or do not exist, according to the analyzed variable. AIM to evaluate the effect of chia supplementation in body composition, lipid profile and blood glucose in overweight or obese individuals. METHODS men and women were randomly allocated in groups that ingested 35 g of chia flour/day (CHIA; n=19; 48.8±1.8 years) or placebo (PLA; n=7; 51.4±3.1 years) for 12 weeks. Body composition and food intake were evaluated in each four weeks. Lipid profile and blood glucose were measured in the beginning and in the end of the study. RESULTS Chia induced significant intragroup reduction in body weight (-1.1±0.4 kg; p<0.05), with a greater reduction among obese than overweighed individuals (-1.6±0.4 kg; p<0.00), but without difference when compared to PLA. Waist circumference reduced 1.9±0.6 cm in CHIA group (p <0.05), but only intragroup. It was observed a reduction in total cholesterol (p=0.04) and VLDL-c (p=0.03), and an increase in HDL-c (p=0.01) but only in the groups that ingested chia flour and presented abnormal initial values. Triglycerides, blood glucose and LDL-C showed no changes for either group. CONCLUSION consumption of chia for 12 weeks promotes significant but discrete reduction in weight and waist circumference, and enhances lipid profile dependent of initial values.

Effects of Dietary Brazilian Palm Oil (Mauritia flexuosa L.) on Cholesterol Profile and Vitamin A and E Status of Rats

In vitro studies have been carried out to establish the nutritional differences between crude and refined vegetable oils; however, the impact of the consumption of these foods on metabolism, in particular the effect of buriti oil, needs to be further evaluated. The aim of this study was to evaluate the biochemical and murine parameters and the vitamin A and E status in young rats fed with diets supplemented with crude or refined buriti oil. The animals (n = 30) were randomized into three groups receiving diet added of soybean oil (control), crude buriti oil (CBO) and refined buriti oil (RBO) for 28 days. Rats fed with diet added of refined buriti oil (RBO) showed reduced total cholesterol (up to 60.27%), LDL (64.75%), triglycerides (55.47%) and enzyme aspartate transaminase (21.57%) compared to those fed with diet added of crude oil. Serum and hepatic retinol and tocopherol were higher by two to three times in CBO and RBO groups compared to the control group, but no differences were observed for murine parameters. The results indicate that buriti oil is an important source of the antioxidant vitamins A and E, and refined buriti oil is suggested as alternative to improve the lipid profile of healthy rats.

Effect of the consumption on buriti oil on the metabolism of rats induced by iron overload

OBJECTIVES To compare the effect of the consumption of buriti oil and soybean oil on the metabolism of rats under stress induced by iron overload. MATERIALS AND METHODS A total of 28 rats were randomized into control groups who consumed diet added of soybean (CS) or buriti oil (CB) and gavage with saline and two experimental groups who consumed diet added of soybean (ES) or buriti oil (EB) and daily gavage with iron II sulfate as stress inducer. The fatty acid profile of diets was analyzed. Body weight and diet consumption were evaluated every two days. The lipid profile and liver weight of animals were evaluated at the end of the experiment. RESULTS Diet added of soybean oil showed higher percentage of polyunsaturated fatty acids (45.6%) and diet with buriti oil was rich in monounsaturated fatty acids (66.9%). There were no differences in food intake, total cholesterol, HDL-cholesterol and LDL-cholesterol among groups (p > 0.05). However, animals fed with diet supplemented with buriti oil showed intermediate triglyceride levels (CB: 65 mg/dL; EB: 68.7 mg/dL) compared to ES group (102.5 mg/dL). The liver of rats from the CS group had higher weight (2.06 ± 0.2 g) compared to the CB group (1.56 ± 0.1 g). CONCLUSION Buriti oil consumption was able to minimize some changes related to iron overload.

Treinamento de força reduz perfil glicêmico de ratos

Aim: To evaluate the effect of a ten-week strength training on the blood glucose of rats. Methods: Eighteen rats were divided into two groups: sedentary and trained. Trained animals underwent strength training for ten weeks. The animals performed four sets of eight jumps with intervals of 30 seconds during ten weeks with a frequency of 3 times per week. An overload weight was imposed to the animals, using appropriate vests, which increased every two weeks. Body weight and food consumption were evaluated weekly. At the end of the experiment, the animals were euthanized and their blood glucose and weights of visceral fat and carcass were measured. Results: No changes were observed in body weight (359.29±38.56 g vs. 355±15.58 g), food intake (162.1±16.6 g vs 156.57±5.4 g) and weight of carcass (222.5±22.7 g vs 230.7±9.3 g), however, reduction of visceral fat (17.4±3.3 g vs 12.9±1.7 g) and blood glucose (180.0±21.9 mg/dL vs. 151.7±19.6 mg/dL) was observed in the trained animals. Conclusion: The protocol used in this study reduced visceral fat and blood glucose in animals subjected to strength training