Effect of lean system 7 on metabolic rate and body composition

A review of citrus plants as functional foods and dietary supplements for human health, with an emphasis on meta-analyses, clinical trials, and their chemical composition

Fruits, flowers, leaves, essential oils, hydrosols, and juices of citrus spp. Are utilized to prepare various forms of food products. Along with their nutritional values, in the health industry, different parts of the plants of the citrus genus have been used as supplements or remedies to prevent or control diseases. This review focused on reported meta-analyses and clinical trials on the health benefits of citrus plants as functional foods. Also, chemical compounds of various citrus species were reviewed. The following information sources were used for data collection: Google Scholar, the Web of Science, Scopus, and PubMed. Various keywords, including "citrus AND chemical compounds," "citrus AND phytochemicals," "citrus species," "citrus AND meta-analysis," "nutritional and therapeutical values of citrus spp.," "clinical trials AND citrus," "clinical trials AND Rutaceae," "health benefits of citrus spp.," "citrus edible or non-edible applications," and scientific names of the citrus plants were utilized to collect data for the review. The scientific name and common name of all twenty-eight citrus species, along with any of the above keywords, were also searched in the mentioned databases. Scientific papers and data sources were sought to review and discuss the citrus plant's nutritional and therapeutic importance. Several meta-analyses and clinical trials have reported beneficial effects of citrus spices on a variety of cancer risks, cardiovascular risk factors, neurologic disorders, urinary tract conditions, and gastrointestinal tract conditions. They have shown anxiolytic, antimicrobial, and pain-alleviating effects. Some of them can be helpful in managing obesity and cardiovascular risk factors.

A systematic review of the impact of 7-keto-DHEA on body weight

7-Keto-DHEA has been commercially advertised as a dietary supplement to support weight loss. The objective of the present systematic review it to summarize the evidence supporting the use of 7-keto-DHEA in overweight and obese population. The systematic search was conducted in Medline, Embase, Cochrane Library, CINAHL, Web of Science, Scopus, ICTRP, and ClinicalTrials.gov. Additionally, reference lists of eligible studies were considered, and authors of relevant studies were contacted. Two authors independently screened the studies against the inclusion criteria and assessed their risk of bias. In total, 4 out of 686 studies were included in the review. They all held a low risk of bias. Half of them showed a significant reduction in body weight. One study found a decrease in body fat percentage and another one reported a decrease in BMI. Two studies stated an increase in resting metabolic rate. No serious adverse effects were reported. Various possible mechanisms in favor of weight loss are discussed; however, with the evidence currently available, no clear answer can be given regarding 7-keto-DHEA and weight loss. Further studies need to be conducted to clarify the efficacy and safety of this drug before it can be recommended for therapeutic use.

Periconceptional care and offspring health at birth and long term, from the perspective of Avicenna

Periconceptional care such as lifestyle plays an important impact role in offspring health. The aim of the present study was to clarify the perspective of Avicenna on periconceptional care. Avicenna (980-1037 A.D.) was one of the outstanding Persian physicians, who made great contributions to the field of medical sciences, in particular, obstetrics. In advance, Avicenna's book, Canon of Medicine, was considered to find his perspectives on periconceptional care. Then, his ideas and theories were compared to the current findings by searching the keywords in main indexing systems including PubMed/MEDLINE, Scopus and Institute for Scientific Information Web of Science as well as the search engine of Google Scholar. Current investigations show that gamete quality, pregnancy outcome, and offspring health at birth and long term depend on both parents' lifestyle in pre- and periconceptional period, as well as the intrauterine environment. Avicenna believed that seminal fluid, sperm, ovum, and developing conditions in utero were influenced by the stages of food digestion and the function of some organs. On the other hand, food digestion and function of the organs also depend on each parent's lifestyle and environmental factors. He mentioned 6 principles of healthy lifestyle: exercise, nutrition, sleep and awareness, excretion of body wastes and retention of necessary materials, psychic features, as well as air and climate. Thus, a multicomponent healthy lifestyle should be considered by parents of child-bearing age in an appropriate period before and in early pregnancy as well as elimination of any disorders in parents, to give birth to more healthy offspring.

Heart Toxicity Related to Herbs and Dietary Supplements: Online Table of Case Reports. Part 4 of 5

BACKGROUND

The purpose of this review was to create an online research summary table of heart toxicity case reports related to dietary supplements (DS; includes herbs).

METHODS

Documented PubMed case reports of DS appearing to contribute to heart-related problems were used to create a "Toxic Table" that summarized the research (1966 to April, 2016, and cross-referencing). Keywords included "herb," "dietary supplement," and cardiac terms. Case reports were excluded if they were herb combinations (some exceptions), Chinese herb mixtures, teas of mixed herb contents, mushrooms, poisonous plants, self-harm (e.g. suicide), excess dose (except vitamins/minerals), drugs or illegal drugs, drug-herbal interactions, and confounders of drugs or diseases. The spectrum of heart toxicities included hypertension, hypotension, hypokalemia, bradycardia, tachycardia, arrhythmia, ventricular fibrillation, heart attack, cardiac arrest, heart failure, and death.

RESULTS

Heart related problems were associated with approximately seven herbs: Four traditional Chinese medicine herbs - Don quai (Angelica sinensis), Jin bu huan (Lycopodium serratum), Thundergod vine or lei gong teng (Tripterygium wilfordii Hook F), and Ting kung teng (Erycibe henryi prain); one an Ayruvedic herb - Aswagandha, (Withania somnifera); and two North American herbs - blue cohosh (Caulophyllum thalictroides), and Yohimbe (Pausinystalia johimbe). Aconitum and Ephedra species are no longer sold in the United States. The DS included, but are not limited to five DS - bitter orange, caffeine, certain energy drinks, nitric oxide products, and a calming product. Six additional DS are no longer sold. Licorice was the food related to heart problems.

CONCLUSION

The online "Toxic Table" forewarns clinicians, consumers and the DS industry by listing DS with case reports related to heart toxicity. It may also contribute to Phase IV post marketing surveillance to diminish adverse events that Government officials use to regulate DS.

Acute p-synephrine ingestion increases fat oxidation rate during exercise

AIMS

p-Synephrine is a protoalkaloid widely used in dietary supplements for weight management because of its purported thermogenic effects. However, there is a lack of scientific information about its effectiveness to increase fat metabolism during exercise. The purpose of this investigation was to determine the effects of an acute ingestion of p-synephrine on fat oxidation at rest and during exercise.

METHODS

In a double-blind, randomized and counterbalanced experimental design, 18 healthy subjects performed two acute experimental trials after the ingestion of p-synephrine (3 mg kg(-1) ) or after the ingestion of a placebo (cellulose). Energy expenditure and fat oxidation rates were measured by indirect calorimetry at rest and during a cycle ergometer ramp exercise test (increases of 25 W every 3 min) until volitional fatigue.

RESULTS

In comparison with the placebo, the ingestion of p-synephrine did not change energy consumption (1.6 ± 0.3 vs. 1.6 ± 0.3 kcal min(-1) ; P = 0.69) or fat oxidation rate at rest (0.08 ± 0.02 vs. 0.10 ± 0.04 g min(-1) ; P = 0.15). However, the intake of p-synephrine moved the fat oxidation-exercise intensity curve upwards during the incremental exercise (P < 0.05) without affecting energy expenditure. Moreover, p-synephrine increased maximal fat oxidation rate (0.29 ± 0.15 vs. 0.40 ± 0.18 g min(-1) ; P = 0.01) during exercise although it did not affect the intensity at which maximal fat oxidation was achieved (55.8 ± 7.7 vs. 56.7 ± 8.2% VO2peak ; P = 0.51).

CONCLUSIONS

The acute ingestion of p-synephrine increased the fat oxidation rate while it reduced the carbohydrate oxidation rate when exercising at low-to-moderate exercise intensities.

Taxa metabólica basal de homens residentes na cidade de Goiânia

INTRODUÇÃO: A Taxa Metabólica Basal (TMB) é a quantidade de energia necessária para o corpo humano manter os processos fisiológicos normais e a homeostase. Atualmente, a TMB é calculada a partir de equações baseadas na população norte-americana e/ou europeia. OBJETIVO: Comparar as equações de Harris-Benedict, Food and Agriculture Organization e Institute of Medicine com a calorimetria indireta em indivíduos do sexo masculino residentes na cidade de Goiânia. MÉTODOS: A determinação da TMB foi feita pela análise direta de gases, utilizando o analisador VO2000. Foram avaliados 44 voluntários do sexo masculino, com média de idade 29,8 anos (Desvio padrão - DP = 6,21), estatura 1,79 m (DP = 0,06), peso 77,79 kg (DP = 8,49), IMC 24,30 kg/m2 (DP = 1,96), gordura corporal 15,84% (DP = 4,49), circunferência da cintura 80,48 cm (DP = 5,89). RESULTADOS: Foi observada diferença significante (p < 0,05) para os valores da TMB estimada pelas equações de Harris-Benedict (1.824,7, DP = 138,2 kcal/dia) e Food and Agriculture Organization (1.821,8, DP = 115,4 kcal/dia), quando comparado ao valor obtido pela calorimetria indireta (1.709,8, DP = 329,7 kcal/dia). Esse valor não foi significantemente diferente do obtido pela equação do Institute of Medicine (1.791, DP = 329 kcal/dia). CONCLUSÃO: As equações Harris-Benedict e Food and Agriculture Organization podem superestimar a TMB de homens jovens, sadios, com características semelhantes as do presente estudo. As equações do Institute of Medicine, por sua vez, resultam em valores estimados de TMB mais próximos aos mensurados.

A review of the human clinical studies involving Citrus aurantium (bitter orange) extract and its primary protoalkaloid p-synephrine

This review summarizes the published as well as unpublished human studies involving Citrus aurantium (bitter orange) extract and its primary protoalkaloid p-synephrine, providing information and an assessment of the safety and efficacy of these widely used products. The results of over 20 studies involving a total of approximately 360 subjects that consumed p-synephrine alone or in combination with other ingredients are reviewed and critiqued. Over 50 % of the subjects involved in these studies were overweight/obese, and approximately two-thirds of these overweight/obese subjects consumed caffeine (132-528 mg/day) in conjunction with p-synephrine (10-53 mg/day). Bitter orange/p-synephrine containing products were consumed for up to 12 weeks. Approximately 44 % of the subjects consumed a bitter orange/p-synephrine only product, while the remainder consumed a complex product that contained multiple ingredients in addition to p-synephrine. In general, bitter orange extract alone (p-synephrine) or in combination with other herbal ingredients did not produce significant adverse events as an increase in heart rate or blood pressure, or alter electrocardiographic data, serum chemistry, blood cell counts or urinalysis. p-Synephrine alone as well as in combination products were shown to increase resting metabolic rate and energy expenditure, and modest increases in weight loss were observed with bitter orange extract/p-synephrine-containing products when given for six to 12 weeks. Longer term studies are needed to further assess the efficacy of these products and affirm their safety under these conditions.

A review of the receptor-binding properties of p-synephrine as related to its pharmacological effects

Bitter orange (Citrus aurantium) extract and its primary protoalkaloid p-synephrine are used widely in weight loss/weight management and sports performance products. Because of structural similarities, the pharmacological effects of p-synephrine are widely assumed to be similar to those of ephedrine, m-synephrine (phenylephrine), and endogenous amine neurotransmitters as norepinephrine and epinephrine. However, small structural changes result in the receptor binding characteristics of these amines that are markedly different, providing a plausible explanation for the paucity of adverse effects associated with the wide-spread consumption of p-synephrine in the form of dietary supplements as well as in various Citrus foods and juices. This paper summarizes the adrenoreceptor binding characteristics of p-synephrine relative to m-synephrine, norepinephrine, and other amines as related to the observed pharmacological effects.

The safety of Citrus aurantium (bitter orange) and its primary protoalkaloid p-synephrine

Citrus aurantium (bitter orange) extract and its principal protoalkaloidal constituent p-synephrine are widely used in weight loss and weight management as well as in sports performance products. However, questions are raised frequently regarding the safety of these ingredients. The potential inherent dangers associated with the use of products containing C. aurantium extract are frequently touted, while conversely, millions of doses of dietary supplements have been consumed by possibly millions of individuals in recent years. Furthermore, millions of people consume on a daily basis various juices and food products from Citrus species that contain p-synephrine. This review summarizes current information regarding the safety of C. aurantium (bitter orange) extract and p-synephrine based on human, animal and in vitro assessments as well as receptor binding and mechanistic studies. The data indicate that based on current knowledge, the use of bitter orange extract and p-synephrine appears to be exceedingly safe with no serious adverse effects being directly attributable to these ingredients.

Effect of acute administration of an herbal preparation on blood pressure and heart rate in humans

Confusion and controversy exist regarding the cardiovascular effects of dietary supplements containing caffeine and Citrus aurantium (bitter orange) extract. The primary protoalkaloidal ingredient in bitter orange extract is p-synephrine which has some structural similarities to ephedrine and nor-epinephrine, but exhibits markedly different pharmacokinetic and receptor binding properties. The goal of this study was to investigate the cardiovascular effects of a product containing caffeine, bitter orange extract (p-synephrine) and green tea extract in mildly overweight individuals. Fourteen female and nine male subjects (age 24.7 ±7.4 yrs, BMI: 26.6 ±3.8) volunteered in this randomized, placebo-controlled, crossover, double-blind designed study. On day one, subjects entered the laboratory following an overnight fast. Heart rate and blood pressure were recorded at 60 min. Expired air was analyzed for the next 10 min of the session. At each of three meals, subjects ingested one capsule that was either a non-caloric placebo or a dietary supplement that contained 13 mg p-synephrine and 176 mg caffeine. On the following day, the subjects returned and repeated the protocol for data collection beginning 60 min after consuming one capsule of the placebo or the dietary supplement. No effects of the dietary supplement on heart rate, systolic and diastolic blood pressure or mean arterial pressure were observed. No between or within group differences were observed when data were analyzed for gender and caffeine usage. A small but significant decrease in resting respiratory exchange ratio was observed for the low caffeine user group in response to the product containing caffeine and p-synephrine. The results of this study indicate that ingestion of a product containing bitter orange extract, caffeine and green tea extract does not lead to increased cardiovascular stress and that fat oxidation may increase in certain populations.

Relative changes in resting energy expenditure during weight loss: a systematic review

A more comprehensive understanding of the effects of weight loss on the changes in resting energy expenditure (EE) is relevant. A MEDLINE search was performed to identify studies with information relevant to this systematic review. From this search, the mean rate of resting EE decrease relative to weight loss was calculated from 90 available publications. A decrease of resting EE relative to weight loss of -15.4 +/- 8.7 kcal kg(-1) was observed from 2977 [corrected] subjects. No sex differences were noted in the overall resting EE decrease relative to weight loss. However, a significant sex differences was seen with pharmacological interventions, which seemed to depress the resting EE relative to weight loss to a greater extent in men than in women (P < 0.05). A greater drop in resting EE relative to weight loss was observed for short interventions (more than 2 but less than 6 weeks) when compared with long interventions (<6 weeks) (-27.7 +/- 6.7 vs. -12.8 +/- 7.1 kcal kg(-1)) (P < 0.001). Men and women have a similar decrease in resting EE relative to weight loss except in the case of pharmacological interventions. Short interventions also produced greater resting EE losses relative to weight loss.

ISSN exercise & sport nutrition review: research & recommendations

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients.