Citrus Aurantium and caffeine complex versus placebo on biomarkers of metabolism: a double blind crossover design

Nitrate-rich beet juice intake on cardiovascular performance in response to exercise in postmenopausal women with arterial hypertension: study protocol for a randomized controlled trial

BACKGROUND

There is no evidence of the use of beetroot juice with a previously recommended dose of nitrate (NO3) (> 300 mg) on the cardiovascular performance during and recovery following exercise in postmenopausal women with systemic arterial hypertension (SAH).

METHODS

We will investigate the effects of beetroot juice rich in NO3 acutely (800 mg) and during a week with daily doses (400 mg) on blood pressure, heart rate (HR), cardiac autonomic control, endothelial function, inflammatory, hormonal, and stress biomarkers oxidative stress and enzymes involved in nitric oxide synthesis and mitochondrial regulation, under resting conditions, as well as mediated by submaximal aerobic exercise sessions. Through a randomized, crossover, triple-blind, placebo-controlled clinical trial, 25 physically inactive women with SAH will undergo an acute and 1-week trial, each with two intervention protocols: (1) placebo and (2) beetroot, in which will ingest beet juice with or without NO3 in its composition with a 7-day washout interval. On collection days, exercise will be performed on a treadmill for 40 min at a speed corresponding to 65-70% of VO2peak. The collection of variables (cardiovascular, autonomic, and blood samples for molecular analyses) of the study will take place at rest (135 min after ingestion of the intervention), during exercise (40 min), and in the effort recovery stage (during 60 min) based on previously validated protocols. The collections were arranged so that the measurement of one variable does not interfere with the other and that they have adequate intervals between them.

DISCUSSION

The results of this research may help in the real understanding of the nutritional compounds capable of generating safety to the cardiovascular system during physical exercise, especially for women who are aging and who have cardiovascular limitations (e.g., arterial hypertension) to perform physical exercise. Therefore, our results will be able to help specific nutritional recommendations to optimize cardiovascular health.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05384340. Registered on May 20, 2022.

Bitter Orange (Citrus aurantium L.) Intake Before Submaximal Aerobic Exercise Is Safe for Cardiovascular and Autonomic Systems in Healthy Males: A Randomized Trial

Background

There are still no studies of the cardiovascular safety of the isolated use of Citrus aurantium in aerobic submaximal exercise.

Objective

To evaluate the effect of C. aurantium supplementation on the recovery of cardiorespiratory and autonomic parameters following a session of submaximal aerobic exercise.

Methods

Twelve healthy male adults achieved a crossover, randomized, double-blind, and placebo-controlled trial. C. aurantium (600 mg, p-synephrine at 30% amount [180 mg]) or placebo (600 mg of starch) were ingested 90 min before evaluation in randomized days. We evaluated systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), mean arterial pressure (MAP), heart rate (HR) and, HR variability indexes at Rest and during 60 min of recovery from exercise.

Results

Citrus aurantium ingestion accelerated the reduction in SBP after exercise, anticipated the return of vagal modulation of the heart after exercise via the HF (ms2), pNN50 (%), and 2 UV% indices. Moreover, rushed the output of sympathetic modulation after exercise via the 0V% index. No unfavorable cardiovascular effects were achieved for HR, DBP, PP, and MAP parameters.

Conclusions

Citrus aurantium was shown to be safe for the cardiovascular and autonomic systems alongside submaximal aerobic exercise in healthy males.

Effects of Functional Phenolics Dietary Supplementation on Athletes' Performance and Recovery: A Review

In recent years, many efforts have been made to identify micronutrients or nutritional strategies capable of preventing, or at least, attenuating, exercise-induced muscle damage and oxidative stress, and improving athlete performance. The reason is that most exercises induce various changes in mitochondria and cellular cytosol that lead to the generation of reactive species and free radicals whose accumulation can be harmful to human health. Among them, supplementation with phenolic compounds seems to be a promising approach since their chemical structure, composed of catechol, pyrogallol, and methoxy groups, gives them remarkable health-promoting properties, such as the ability to suppress inflammatory processes, counteract oxidative damage, boost the immune system, and thus, reduce muscle soreness and accelerate recovery. Phenolic compounds have also already been shown to be effective in improving temporal performance and reducing psychological stress and fatigue. Therefore, the aim of this review is to summarize and discuss the current knowledge on the effects of dietary phenolics on physical performance and recovery in athletes and sports practitioners. Overall, the reports show that phenolics exert important benefits on exercise-induced muscle damage as well as play a biological/physiological role in improving physical performance.

Involvement of serotonergic pathways in gastric dysmotility induced by fat burning nutritional supplements in mice

Fat burners are a category of nutritional supplements that are claimed to increase the metabolism and promote greater energy expenditure, leading to weight loss. However, little is known about the side effects on gastrointestinal motility. In this study, we evaluated the effect of ingestion with a fat burner named Thermbuterol® (THERM) on the gastric motility and food behavior of mice. THERM compounds were identified using nuclear magnetic resonance (NMR). Mice received variable doses of THERM (10, 50, 100 or 300 ​mg/kg, p.o.) or NaCl 0.15 ​M (control). Gastric emptying (GE) was assessed using the phenol red technique. Another set of mice was pretreated with intraperitoneal administration of hexamethonium (HEXA, 10 ​mg/kg), prazosin (PRAZ, 0.25 ​mg/kg), propranolol (PROP, 2 ​mg/kg), parachlorophenylalanine (PCPA, 300 ​mg/kg) or ondansetron (ONDA, 50 ​μg/kg) 30 ​min before THERM treatment for evaluation of GE. We assessed the gastrointestinal responsiveness in vitro as well as THERM's effects on food behavior. Caffeine was the major compound of THERM, identified by NMR. THERM 100 and 300 ​mg/kg decreased GE compared to the respective controls. Pretreatment with PRAZ or PROP did not prevent gastric dysmotility induced by THERM 100 ​mg/kg. However, the pretreatment with HEXA, ONDA or PCPA prevented GE delay induced by THERM. In vitro, THERM relaxed contractions in strips of longitudinal gastric fundus and duodenum. THERM also increased food intake, which was prevented by PCPA and ONDA treatments. THERM decreased GE of a liquid and increased food intake in mice, a phenomenon mediated by the autonomic nicotinic receptors and serotoninergic receptor.

A Critical Review on the Role of Food and Nutrition in the Energy Balance

The mass media has increasingly frequently suggested to the general population that specific foods or nutritional schemes are able to affect both human metabolism and energy expenditure, thus facilitating weight loss. This critical review is aimed at assessing available evidence on the roles of nutrients, food and dietary regimens in energy intake and energy expenditure. We queried the National Library of Medicine, the Cochrane Library, Excerpta Medica dataBASEand the Cumulative Index to Nursing and Allied Health Literature database, and a search strategy was performed by using database-specific subject headings and keywords. We found that available scientific evidence on these topics is scarce, and that the limited number of available studies often have poor methodological quality. Only a few foods show beneficial effects on metabolism and energy expenditure, as the human energy balance is complex and multifactorial. Finally, microbiota may interfere with the intake, use and expenditure of energy in the human body. Conclusive evidence is still lacking, and, at present, it is not possible to identify a food or a diet with a significant impact on human energy expenditure.