Nutrients

1392 KiB

Open AccessReview

Benefits of Docosahexaenoic Acid, Folic Acid, Vitamin D and Iodine on Foetal and Infant Brain Development and Function Following Maternal Supplementation during Pregnancy and Lactation

by Nancy L. Morse

Nutrients 2012, 4(7), 799-840; https://doi.org/10.3390/nu4070799 - 24 Jul 2012

Cited by 105 | Viewed by 36868

Abstract

Scientific literature is increasingly reporting on dietary deficiencies in many populations of some nutrients critical for foetal and infant brain development and function. Purpose: To highlight the potential benefits of maternal supplementation with docosahexaenoic acid (DHA) and other important complimentary nutrients, including vitamin [...] Read more.

Scientific literature is increasingly reporting on dietary deficiencies in many populations of some nutrients critical for foetal and infant brain development and function. Purpose: To highlight the potential benefits of maternal supplementation with docosahexaenoic acid (DHA) and other important complimentary nutrients, including vitamin D, folic acid and iodine during pregnancy and/or breast feeding for foetal and/or infant brain development and/or function. Methods: English language systematic reviews, meta-analyses, randomised controlled trials, cohort studies, cross-sectional and case-control studies were obtained through searches on MEDLINE and the Cochrane Register of Controlled Trials from January 2000 through to February 2012 and reference lists of retrieved articles. Reports were selected if they included benefits and harms of maternal supplementation of DHA, vitamin D, folic acid or iodine supplementation during pregnancy and/or lactation. Results: Maternal DHA intake during pregnancy and/or lactation can prolong high risk pregnancies, increase birth weight, head circumference and birth length, and can enhance visual acuity, hand and eye co-ordination, attention, problem solving and information processing. Vitamin D helps maintain pregnancy and promotes normal skeletal and brain development. Folic acid is necessary for normal foetal spine, brain and skull development. Iodine is essential for thyroid hormone production necessary for normal brain and nervous system development during gestation that impacts childhood function. Conclusion: Maternal supplementation within recommended safe intakes in populations with dietary deficiencies may prevent many brain and central nervous system malfunctions and even enhance brain development and function in their offspring. Full article

(This article belongs to the Special Issue Dietary Lipids: Sources, Function and Metabolism)

► Show Figures

Graphical abstract

224 KiB

Open AccessReview

Maternal Zinc Intakes and Homeostatic Adjustments during Pregnancy and Lactation

by Carmen Marino Donangelo and Janet C. King

Nutrients 2012, 4(7), 782-798; https://doi.org/10.3390/nu4070782 - 24 Jul 2012

Cited by 98 | Viewed by 12353

Abstract

Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include [...] Read more.

Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating effects, systematic reviews and meta-analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit. We hypothesize, therefore, that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and, therefore, mitigate immediate detrimental effects due to a low zinc intake. The specific questions addressed are the following: How is zinc utilization altered during pregnancy and lactation? Are those homeostatic adjustments influenced by maternal zinc status, dietary zinc, or zinc supplementation? These questions are addressed by critically reviewing results from published human studies on zinc homeostasis during pregnancy and lactation carried out in different populations worldwide. Full article

(This article belongs to the Special Issue Zinc in Health and Disease)

► Show Figures

Figure 1

245 KiB

Open AccessReview

Wine, Beer, Alcohol and Polyphenols on Cardiovascular Disease and Cancer

by Sara Arranz, Gemma Chiva-Blanch, Palmira Valderas-Martínez, Alex Medina-Remón, Rosa M. Lamuela-Raventós and Ramón Estruch

Nutrients 2012, 4(7), 759-781; https://doi.org/10.3390/nu4070759 - 10 Jul 2012

Cited by 411 | Viewed by 40312

Abstract

Since ancient times, people have attributed a variety of health benefits to moderate consumption of fermented beverages such as wine and beer, often without any scientific basis. There is evidence that excessive or binge alcohol consumption is associated with increased morbidity and mortality, [...] Read more.

Since ancient times, people have attributed a variety of health benefits to moderate consumption of fermented beverages such as wine and beer, often without any scientific basis. There is evidence that excessive or binge alcohol consumption is associated with increased morbidity and mortality, as well as with work related and traffic accidents. On the contrary, at the moment, several epidemiological studies have suggested that moderate consumption of alcohol reduces overall mortality, mainly from coronary diseases. However, there are discrepancies regarding the specific effects of different types of beverages (wine, beer and spirits) on the cardiovascular system and cancer, and also whether the possible protective effects of alcoholic beverages are due to their alcoholic content (ethanol) or to their non-alcoholic components (mainly polyphenols). Epidemiological and clinical studies have pointed out that regular and moderate wine consumption (one to two glasses a day) is associated with decreased incidence of cardiovascular disease (CVD), hypertension, diabetes, and certain types of cancer, including colon, basal cell, ovarian, and prostate carcinoma. Moderate beer consumption has also been associated with these effects, but to a lesser degree, probably because of beer’s lower phenolic content. These health benefits have mainly been attributed to an increase in antioxidant capacity, changes in lipid profiles, and the anti-inflammatory effects produced by these alcoholic beverages. This review summarizes the main protective effects on the cardiovascular system and cancer resulting from moderate wine and beer intake due mainly to their common components, alcohol and polyphenols. Full article

(This article belongs to the Special Issue Alcohol and Health)

455 KiB

Open AccessReview

Exercise and Amino Acid Anabolic Cell Signaling and the Regulation of Skeletal Muscle Mass

by Stefan M. Pasiakos

Nutrients 2012, 4(7), 740-758; https://doi.org/10.3390/nu4070740 - 10 Jul 2012

Cited by 34 | Viewed by 16219

Abstract

A series of complex intracellular networks influence the regulation of skeletal muscle protein turnover. In recent years, studies have examined how cellular regulators of muscle protein turnover modulate metabolic mechanisms contributing to the loss, gain, or conservation of skeletal muscle mass. Exercise and [...] Read more.

A series of complex intracellular networks influence the regulation of skeletal muscle protein turnover. In recent years, studies have examined how cellular regulators of muscle protein turnover modulate metabolic mechanisms contributing to the loss, gain, or conservation of skeletal muscle mass. Exercise and amino acids both stimulate anabolic signaling potentially through several intracellular pathways including the mammalian target of rapamycin complex 1 and the mitogen activated protein kinase cell signaling cascades. As novel molecular regulators of muscle integrity continue to be explored, a contemporary analysis of the literature is required to understand the metabolic mechanisms by which contractile forces and amino acids affect cellular process that contribute to long-term adaptations and preservation of muscle mass. This article reviews the literature related to how exercise and amino acid availability affect cellular regulators of skeletal muscle mass, especially highlighting recent investigations that have identified mechanisms by which contractile forces and amino acids modulate muscle health. Furthermore, this review will explore integrated exercise and nutrition strategies that promote the maintenance of muscle health by optimizing exercise, and amino acid-induced cell signaling in aging adults susceptible to muscle loss. Full article

(This article belongs to the Special Issue Interaction of Amino Acids and Dietary Proteins and Exercise on Muscle Health)

► Show Figures

Figure 1

444 KiB

Open AccessArticle

Selected Vitamins and Essential Elements in Meat from Semi-Domesticated Reindeer (Rangifer tarandus tarandus L.) in Mid- and Northern Norway: Geographical Variations and Effect of Animal Population Density

by Ammar Ali Hassan, Torkjel M. Sandanger and Magritt Brustad

Nutrients 2012, 4(7), 724-739; https://doi.org/10.3390/nu4070724 - 10 Jul 2012

Cited by 19 | Viewed by 9079

Abstract

Meat samples (n = 100) were collected from semi-domesticated reindeer originating from 10 grazing districts in Norway. We aimed at studying concentrations, correlations, geographical variations and the effect of animal population density on vitamins A, B3, B7, B12 and E, and calcium, [...] Read more.

Meat samples (n = 100) were collected from semi-domesticated reindeer originating from 10 grazing districts in Norway. We aimed at studying concentrations, correlations, geographical variations and the effect of animal population density on vitamins A, B3, B7, B12 and E, and calcium, iron, zinc, selenium, chromium and cobalt. Mean concentrations of vitamins A, B3, B7; B12 and E were < 5 µg, 6.6 mg, < 0.5 µg, 4.7 µg and 0.5 mg/100 g wet weight, respectively. Concentrations of calcium, iron, zinc, selenium, chromium and cobalt were 4.7 mg, 2.8 mg, 6.4 mg, 19.4 µg, 1.7 µg and 0.5 µg/100 g wet weight, respectively. Vitamin E and selenium were the nutrients that exhibited the largest geographical variations (p < 0.05), although no geographical gradient was observed for any of the studied nutrients. Age had a significant effect on zinc and selenium concentrations. Iron was significantly positive correlated with calcium (r = 0.3416, p < 0.01) and vitamin B12 with zinc (r = 0.35, p < 0.05). Reindeer from districts with low animal population density had significantly higher selenium concentration than those from districts with medium and high population densities (p < 0.01). Reindeer meat contained higher vitamin B12, iron, zinc and selenium concentrations when compared to Norwegian beef, lamb, mutton, pork and chicken meat. Full article

► Show Figures

Figure 1

188 KiB

Open AccessArticle

Effects of Eating Fresh Lean Pork on Cardiometabolic Health Parameters

by Karen J. Murphy, Rebecca L. Thomson, Alison M. Coates, Jonathan D. Buckley and Peter R. C. Howe

Nutrients 2012, 4(7), 711-723; https://doi.org/10.3390/nu4070711 - 5 Jul 2012

Cited by 45 | Viewed by 19175

Abstract

High protein meat-based diets are commonly promoted for weight loss, supposedly by increasing satiety and energy expenditure. Pork is a good source of protein however little information on the metabolic effects of pork consumption exists. This pilot study aimed to examine whether regular [...] Read more.

High protein meat-based diets are commonly promoted for weight loss, supposedly by increasing satiety and energy expenditure. Pork is a good source of protein however little information on the metabolic effects of pork consumption exists. This pilot study aimed to examine whether regular consumption of fresh lean pork could improve body composition and cardiovascular risk factors in a 6 month parallel intervention trial. 164 overweight adults (mean BMI 32) were randomly assigned to incorporate up to 1 kg pork/week by substituting for other foods or maintain their habitual diet (control). Plasma levels of lipids, glucose and insulin, BMI, waist/hip circumference, blood pressure, heart rate and arterial compliance were measured at baseline and 3 and 6 months. Body composition was determined using dual energy X-ray absorptiometry. A total of 144 volunteers completed and volunteers in the pork group increased their intake 10 fold by substituting pork for mainly beef and chicken. After 3 months, there were significant (p ≤ 0.01) reductions in weight, BMI, waist circumference, % body fat, fat mass and abdominal fat in the pork group relative to controls, which persisted for 6 months. There was no change in lean mass, indicating that the reduction in weight was due to loss of fat mass. There were no significant effects on other metabolic parameters. Regular consumption of lean fresh pork may improve body composition. Full article

► Show Figures

Figure 1

1545 KiB

Open AccessArticle

Alcohol Exposure Alters Mouse Lung Inflammation in Response to Inhaled Dust

by Michael L. McCaskill, Debra J. Romberger, Jane DeVasure, Jessica Boten, Joseph H. Sisson, Kristina L. Bailey, Jill A. Poole and Todd A. Wyatt

Nutrients 2012, 4(7), 695-710; https://doi.org/10.3390/nu4070695 - 4 Jul 2012

Cited by 15 | Viewed by 8433

Abstract

Alcohol exposure is associated with increased lung infections and decreased mucociliary clearance. Occupational workers exposed to dusts from concentrated animal feeding operations (CAFOs) are at risk for developing chronic inflammatory lung diseases. Agricultural worker co-exposure to alcohol and organic dust has been established, [...] Read more.

Alcohol exposure is associated with increased lung infections and decreased mucociliary clearance. Occupational workers exposed to dusts from concentrated animal feeding operations (CAFOs) are at risk for developing chronic inflammatory lung diseases. Agricultural worker co-exposure to alcohol and organic dust has been established, although little research has been conducted on the combination effects of alcohol and organic dusts on the lung. Previously, we have shown in a mouse model that exposure to hog dust extract (HDE) collected from a CAFO results in the activation of protein kinase C (PKC), elevated lavage fluid cytokines/chemokines including interleukin-6 (IL-6), and the development of significant lung pathology. Because alcohol blocks airway epithelial cell release of IL-6 in vitro, we hypothesized that alcohol exposure would alter mouse lung inflammatory responses to HDE. To test this hypothesis, C57BL/6 mice were fed 20% alcohol or water ad libitum for 6 weeks and treated with 12.5% HDE by intranasal inhalation method daily during the final three weeks. Bronchoalveolar lavage fluid (BALF), tracheas and lungs were collected. HDE stimulated a 2–4 fold increase in lung and tracheal PKCε (epsilon) activity in mice, but no such increase in PKCε activity was observed in dust-exposed mice fed alcohol. Similarly, alcohol-fed mice demonstrated significantly less IL-6 in lung lavage in response to dust than that observed in control mice instilled with HDE. TNFα levels were also inhibited in the alcohol and HDE-exposed mouse lung tissue as compared to the HDE only exposed group. HDE-induced lung inflammatory aggregates clearly present in the tissue from HDE only exposed animals were not visually detectable in the HDE/alcohol co-exposure group. Statistically significant weight reductions and 20% mortality were also observed in the mice co-exposed to HDE and alcohol. These data suggest that alcohol exposure depresses the ability of the lung to activate PKCε-dependent inflammatory pathways to environmental dust exposure. These data also define alcohol as an important co-exposure agent to consider in the study of inhalation injury responses. Full article

(This article belongs to the Special Issue Alcohol and Health)

► Show Figures

Figure 1

270 KiB

Open AccessReview

Zinc and Regulation of Inflammatory Cytokines: Implications for Cardiometabolic Disease

by Meika Foster and Samir Samman

Nutrients 2012, 4(7), 676-694; https://doi.org/10.3390/nu4070676 - 4 Jul 2012

Cited by 221 | Viewed by 17924

Abstract

In atherosclerosis and diabetes mellitus, the concomitant presence of low-grade systemic inflammation and mild zinc deficiency highlights a role for zinc nutrition in the management of chronic disease. This review aims to evaluate the literature that reports on the interactions of zinc and [...] Read more.

In atherosclerosis and diabetes mellitus, the concomitant presence of low-grade systemic inflammation and mild zinc deficiency highlights a role for zinc nutrition in the management of chronic disease. This review aims to evaluate the literature that reports on the interactions of zinc and cytokines. In humans, inflammatory cytokines have been shown both to up- and down-regulate the expression of specific cellular zinc transporters in response to an increased demand for zinc in inflammatory conditions. The acute phase response includes a rapid decline in the plasma zinc concentration as a result of the redistribution of zinc into cellular compartments. Zinc deficiency influences the generation of cytokines, including IL-1β, IL-2, IL-6, and TNF-α, and in response to zinc supplementation plasma cytokines exhibit a dose-dependent response. The mechanism of action may reflect the ability of zinc to either induce or inhibit the activation of NF-κB. Confounders in understanding the zinc-cytokine relationship on the basis of in vitro experimentation include methodological issues such as the cell type and the means of activating cells in culture. Impaired zinc homeostasis and chronic inflammation feature prominently in a number of cardiometabolic diseases. Given the high prevalence of zinc deficiency and chronic disease globally, the interplay of zinc and inflammation warrants further examination. Full article

(This article belongs to the Special Issue Zinc in Health and Disease)

► Show Figures

Figure 1

240 KiB

Open AccessReview

Zinc and Cancer: Implications for LIV-1 in Breast Cancer

by Bruce J. Grattan and Hedley C. Freake

Nutrients 2012, 4(7), 648-675; https://doi.org/10.3390/nu4070648 - 4 Jul 2012

Cited by 104 | Viewed by 12367

Abstract

Zinc is a trace mineral which is vital for the functioning of numerous cellular processes, is critical for growth, and may play an important role in cancer etiology and outcome. The intracellular levels of this mineral are regulated through the coordinated expression of [...] Read more.

Zinc is a trace mineral which is vital for the functioning of numerous cellular processes, is critical for growth, and may play an important role in cancer etiology and outcome. The intracellular levels of this mineral are regulated through the coordinated expression of zinc transporters, which modulate both zinc influx as well as efflux. LIV-1 (ZIP6) was first described in 1988 as an estrogen regulated gene with later work suggesting a role for this transporter in cancer growth and metastasis. Despite evidence of its potential utility as a target gene for cancer prognosis and treatment, LIV-1 has received relatively little attention, with only three prior reviews being published on this topic. Herein, the physiological effects of zinc are reviewed in light of this mineral’s role in cancer growth with specific attention being given to LIV-1 and the potential importance of this transporter to breast cancer etiology. Full article

(This article belongs to the Special Issue Zinc in Health and Disease)

175 KiB

Open AccessArticle

Effect of Levan Supplement in Orange Juice on Weight, Gastrointestinal Symptoms and Metabolic Profile of Healthy Subjects: Results of an 8-Week Clinical Trial

by Eva Niv, Yami Shapira, Ira Akiva, Evgenia Rokhkind, Etty Naor, Mira Arbiv and Nachum Vaisman

Nutrients 2012, 4(7), 638-647; https://doi.org/10.3390/nu4070638 - 4 Jul 2012

Cited by 15 | Viewed by 7245

Abstract

Levan is a commonly used dietary fiber of the fructans group. Its impact on health remains undetermined. This double blind controlled study aimed to investigate the effect of 8 weeks’ daily consumption of 500 mL of natural orange juice enriched with 11.25 g [...] Read more.

Levan is a commonly used dietary fiber of the fructans group. Its impact on health remains undetermined. This double blind controlled study aimed to investigate the effect of 8 weeks’ daily consumption of 500 mL of natural orange juice enriched with 11.25 g of levan compared to the same amount of natural orange juice without levan on weight, gastrointestinal symptoms and metabolic profiles of 48 healthy volunteers. The statistical analyses compared between- and within-group findings at baseline, 4 weeks and study closure. The compared parameters were: weight, blood pressure, blood laboratory tests, daily number of defecations, scores of stool consistency, abdominal pain, bloating, gas, dyspepsia, vomiting and heartburn. Despite a higher fiber level recorded in the study group, there was no significant difference in the effect of the two kinds of juices on the studied parameters. Both juices decreased systolic and diastolic pressures, increased sodium level (within normal range), stool number, and bloating scores, and decreased gas scores. In conclusion, levan itself had no effect on weight, gastrointestinal symptoms or metabolic profile of healthy volunteers. Its possible effect on obese, hypertensive or hyperlipidemic patients should be investigated in further studies. Full article

440 KiB

Open AccessArticle

Significant Effect of a Pre-Exercise High-Fat Meal after a 3-Day High-Carbohydrate Diet on Endurance Performance

by Ikuma Murakami, Takayuki Sakuragi, Hiroshi Uemura, Hajime Menda, Munehiro Shindo and Hiroaki Tanaka

Nutrients 2012, 4(7), 625-637; https://doi.org/10.3390/nu4070625 - 27 Jun 2012

Cited by 17 | Viewed by 19418

Abstract

We investigated the effect of macronutrient composition of pre-exercise meals on endurance performance. Subjects consumed a high-carbohydrate diet at each meal for 3 days, followed by a high-fat meal (HFM; 1007 ± 21 kcal, 30% CHO, 55% F and 15% P) or high-carbohydrate [...] Read more.

We investigated the effect of macronutrient composition of pre-exercise meals on endurance performance. Subjects consumed a high-carbohydrate diet at each meal for 3 days, followed by a high-fat meal (HFM; 1007 ± 21 kcal, 30% CHO, 55% F and 15% P) or high-carbohydrate meal (HCM; 1007 ± 21 kcal, 71% CHO, 20% F and 9% P) 4 h before exercise. Furthermore, just prior to the test, subjects in the HFM group ingested either maltodextrin jelly (M) or a placebo jelly (P), while subjects in the HCM ingested a placebo jelly. Endurance performance was measured as running time until exhaustion at a speed between lactate threshold and the onset of blood lactate accumulation. All subjects participated in each trial, randomly assigned at weekly intervals. We observed that the time until exhaustion was significantly longer in the HFM + M (p < 0.05) than in HFM + P and HCM + P conditions. Furthermore, the total amount of fat oxidation during exercise was significantly higher in HFM + M and HFM + P than in HCM + P (p < 0.05). These results suggest that ingestion of a HFM prior to exercise is more favorable for endurance performance than HCM. In addition, HFM and maltodextrin ingestion following 3 days of carbohydrate loading enhances endurance running performance. Full article

(This article belongs to the Special Issue Advances in Sports Nutrition)

► Show Figures

Figure 1

222 KiB

Open AccessArticle

Zinc Intake and Its Dietary Sources: Results of the 2007 Australian National Children’s Nutrition and Physical Activity Survey

by Anna M. Rangan and Samir Samman

Nutrients 2012, 4(7), 611-624; https://doi.org/10.3390/nu4070611 - 26 Jun 2012

Cited by 33 | Viewed by 9524

Abstract

The current Australian Nutrient Reference Values (NRV) use different Estimated Average Requirements (EAR) for zinc for adolescent boys and girls compared to the previous recommendations. The adequacy of zinc intakes of 2–16 years old children (n = 4834) was examined in the [...] Read more.

The current Australian Nutrient Reference Values (NRV) use different Estimated Average Requirements (EAR) for zinc for adolescent boys and girls compared to the previous recommendations. The adequacy of zinc intakes of 2–16 years old children (n = 4834) was examined in the 2007 Australian National Children’s Nutrition and Physical Activity Survey. Zinc intakes were estimated from two 24-h recalls and compared with age- and gender-specific NRV. Food sources of zinc were assessed and compared with those of the 1995 National Nutrition Survey. The mean (SD) zinc intake was 10.2 (3.0) mg/day for all children. Nearly all children met the EAR for zinc except for 14–16 years old boys (29% did not meet EAR). Children (2–3 years) were at highest risk of excessive zinc intakes with 79% exceeding the Upper Level of Intake. Meat and poultry; milk products; and cereals and cereal products contributed 68% of total zinc intake. The contribution of cereals to total zinc intake has increased significantly since 1995, due to the greater market-availability of zinc-fortified breakfast cereals. We conclude that sub-groups of Australian children are at-risk of inadequate (boys 14–16 years) or excessive (children 2–3 years) zinc intakes, and monitoring of zinc status is required. Full article

(This article belongs to the Special Issue Zinc in Health and Disease)

► Show Figures

Figure 1

171 KiB

Open AccessArticle

Consumption of a Diet Rich in Cottonseed Oil (CSO) Lowers Total and LDL Cholesterol in Normo-Cholesterolemic Subjects

by Kathleen E. Davis, Chandan Prasad and Victorine Imrhan

Nutrients 2012, 4(7), 602-610; https://doi.org/10.3390/nu4070602 - 26 Jun 2012

Cited by 20 | Viewed by 7247

Abstract

Animal data indicates that dietary cottonseed oil (CSO) may lower cholesterol; however, the effects of a CSO-rich diet have not been evaluated in humans. Thirty-eight healthy adults (aged 18–40; 12 males, 26 females) consumed a CSO rich diet (95 g CSO [...] Read more.

Animal data indicates that dietary cottonseed oil (CSO) may lower cholesterol; however, the effects of a CSO-rich diet have not been evaluated in humans. Thirty-eight healthy adults (aged 18–40; 12 males, 26 females) consumed a CSO rich diet (95 g CSO daily) for one week. Anthropometric measurements were obtained, and blood was drawn pre- and post-intervention. Serum lipids (total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL), triglyceride (TG), and free fatty acids (FFA)) were assayed. There was no change in weight or waist circumference among participants. There was no change in HDL (Pre: 1.27 ± 0.4 mmol/L; Post: 1.21 ± 0.3 mmol/L) or TG (Pre: 0.91 ± 0.6 mmol/L; Post: 1.06 ± 1.0 mmol/L). Total cholesterol and LDL were reduced (TC Pre: 4.39 ± 0.9 mmol/L; Post: 4.16 ± 0.8 mmol/L; LDL Pre: 2.70 ± 0.8 mmol/L; Post: 2.47 ± 0.6 mmol/L). When data were grouped by sex, total cholesterol was reduced in female participants (Pre: 4.34 ± 0.9 mmol/L; Post: 4.09 ± 0.8 mmol/L). Consumption of a high fat, CSO-rich diet for one week reduced total cholesterol in female participants without reducing HDL. Full article

251 KiB

Open AccessReview

Ergogenic Effects of β-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy

by John Caruso, Jessica Charles, Kayla Unruh, Rachel Giebel, Lexis Learmonth and William Potter

Nutrients 2012, 4(7), 585-601; https://doi.org/10.3390/nu4070585 - 26 Jun 2012

Cited by 39 | Viewed by 13863

Abstract

β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how [...] Read more.

β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former’s merits as a buffer. Carnosine normally makes a small contribution to a cell’s total buffer capacity; yet β-alanine supplementation raises intracellular carnosine concentrations that in turn improve a muscle’s ability to buffer protons. Numerous studies assessed the impact of oral β-alanine intake on muscle carnosine levels and exercise performance. β-alanine may best act as an ergogenic aid when metabolic acidosis is the primary factor for compromised exercise performance. Blood lactate kinetics, whereby the concentration of the metabolite is measured as it enters and leaves the vasculature over time, affords the best opportunity to assess the merits of β-alanine supplementation’s ergogenic effect. Optimal β-alanine dosages have not been determined for persons of different ages, genders and nutritional/health conditions. Doses as high as 6.4 g day⁻¹, for ten weeks have been administered to healthy subjects. Paraesthesia is to date the only side effect from oral β-alanine ingestion. The severity and duration of paraesthesia episodes are dose-dependent. It may be unwise for persons with a history of paraesthesia to ingest β-alanine. As for any supplement, caution should be exercised with β-alanine supplementation. Full article

(This article belongs to the Special Issue Advances in Sports Nutrition)

► Show Figures

Figure 1

244 KiB

Open AccessArticle

Recovery from Cycling Exercise: Effects of Carbohydrate and Protein Beverages

by Qingnian Goh, Christopher A. Boop, Nicholas D. Luden, Alexia G. Smith, Christopher J. Womack and Michael J. Saunders

Nutrients 2012, 4(7), 568-584; https://doi.org/10.3390/nu4070568 - 25 Jun 2012

Cited by 22 | Viewed by 11554

Abstract

The effects of different carbohydrate-protein (CHO + Pro) beverages were compared during recovery from cycling exercise. Twelve male cyclists (VO_2peak: 65 ± 7 mL/kg/min) completed ~1 h of high-intensity intervals (EX1). Immediately and 120 min following EX1, subjects consumed one of [...] Read more.

The effects of different carbohydrate-protein (CHO + Pro) beverages were compared during recovery from cycling exercise. Twelve male cyclists (VO_2peak: 65 ± 7 mL/kg/min) completed ~1 h of high-intensity intervals (EX1). Immediately and 120 min following EX1, subjects consumed one of three calorically-similar beverages (285–300 kcal) in a cross-over design: carbohydrate-only (CHO; 75 g per beverage), high-carbohydrate/low-protein (HCLP; 45 g CHO, 25 g Pro, 0.5 g fat), or low-carbohydrate/high-protein (LCHP; 8 g CHO, 55 g Pro, 4 g fat). After 4 h of recovery, subjects performed subsequent exercise (EX2; 20 min at 70% VO_2peak + 20 km time-trial). Beverages were also consumed following EX2. Blood glucose levels (30 min after beverage ingestion) differed across all treatments (CHO > HCLP > LCHP; p < 0.05), and serum insulin was higher following CHO and HCLP ingestion versus LCHP. Peak quadriceps force, serum creatine kinase, muscle soreness, and fatigue/energy ratings measured pre- and post-exercise were not different between treatments. EX2 performance was not significantly different between CHO (48.5 ± 1.5 min), HCLP (48.8 ± 2.1 min) and LCHP (50.3 ± 2.7 min). Beverages containing similar caloric content but different proportions of carbohydrate/protein provided similar effects on muscle recovery and subsequent exercise performance in well-trained cyclists. Full article

(This article belongs to the Special Issue Advances in Sports Nutrition)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Nutrients, Volume 4, Issue 7 (July 2012) – 15 articles , Pages 568-840

Further Information

Guidelines

MDPI Initiatives

Follow MDPI