A Cross-Sectional Comparison of the Whole Blood Fatty Acid Profile and Omega-3 Index of Male Vegan and Omnivorous Endurance Athletes

Athletes Can Benefit from Increased Intake of EPA and DHA-Evaluating the Evidence

Fatty fish, which include mackerel, herring, salmon and sardines, and certain species of algae (e.g., Schizochytrium sp., Crytthecodiniumcohnii and Phaeodactylumtricornutum) are the only naturally rich sources of the omega-3 polyunsaturated fatty acids (n-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA are the most biologically active members of the n-3 PUFA family. Limited dietary sources and fluctuating content of EPA and DHA in fish raise concerns about the status of EPA and DHA among athletes, as confirmed in a number of studies. The beneficial effects of EPA and DHA include controlling inflammation, supporting nervous system function, maintaining muscle mass after injury and improving training adaptation. Due to their inadequate intake and beneficial health-promoting effects, athletes might wish to consider using supplements that provide EPA and DHA. Here, we provide an overview of the effects of EPA and DHA that are relevant to athletes and discuss the pros and cons of supplements as a source of EPA and DHA for athletes.

Vegan nutrition: a preliminary guide for health professionals

Since the beginning of the 21st century, interest in vegan diets has been rapidly increasing in most countries. Misconceptions about vegan diets are widespread among the general population and health professionals. Vegan diets can be health-promoting and may offer certain important advantages compared to typical Western (and other mainstream) eating patterns. However, adequate dietary sources/supplements of nutrients of focus specific to vegan diets should be identified and communicated. Without supplements/fortified foods, severe vitamin B12 deficiency may occur. Other potential nutrients of focus are calcium, vitamin D, iodine, omega-3 fatty acids, iron, zinc, selenium, vitamin A, and protein. Ensuring adequate nutrient status is particularly important during pregnancy, lactation, infancy, and childhood. Health professionals are often expected to be able to provide advice on the topic of vegan nutrition, but a precise and practical vegan nutrition guide for health professionals is lacking. Consequently, it is important and urgent to provide such a set of dietary recommendations. It is the aim of this article to provide vegan nutrition guidelines, based on current evidence, which can easily be communicated to vegan patients/clients, with the goal of ensuring adequate nutrient status in vegans.

The influence of a basic military training diet on whole blood fatty acid profile and the Omega-3 Index of Australian Army recruits

This study described the whole blood fatty acid profile and Omega-3 Index (O3I) of Australian Army recruits at the commencement and completion of basic military training (BMT). Eighty (80) males (17-34 y, 77.4±13.0 kg, 43.5±4.3 mL/kg/min) and 37 females (17-45 y, 64.3±8.8 kg, 39.3±2.7 mL/kg/min) volunteered to participate (N=117). Whole blood samples of each recruit were collected using a finger prick in weeks 1 and 11 (n=82) and analysed via gas chromatography for the relative proportions of each fatty acid (mean [95% CI]). The macronutrient characteristics of the diet offerings was also determined. At commencement there was a low omega-3 status (sum of omega-3; 4.95% [4.82-5.07]) and O3I (5.03% [4.90-5.16]) and no recruit recorded an O3I >8% (desirable). The omega-6/omega-3 (7.04 [6.85-7.23]) and arachidonic acid / eicosapentaenoic acid (AA/EPA) (18.70 [17.86-19.53]) ratios for the cohort were also undesirable. The BMT mess menu provided a maximum of 190 mg/day of eicosapentaenoic acid (EPA) and 260 mg/day of docosahexaenoic acid (DHA). The O3I of the recruits was lower by week 11 (4.62% [4.51-4.78], p<0.05), the omega-6/omega-3 increased (7.27 [7.07-7.47] p<0.05) and the AA/EPA remained elevated (17.85 [16.89-18.81]). In conclusion, Australian Army recruits' omega-3 status remained undesirable during BMT and deserves nutritional attention. Novelty Bullets • Australian Army recruits' Omega-3 Index, at the commencement of BMT, was reflective of the Western-style diet. • The BMT diet offered minimum opportunity for daily EPA and DHA consumption. • Every recruit experienced a further reduction of their Omega-3 Index during BMT.

Scaling the peak and steady-state aerobic power of running and walking humans

PURPOSE

The first aim of this experiment was to evaluate the appropriateness of linear and non-linear (allometric) models to scale peak aerobic power (oxygen consumption) against body mass. The possibilities that oxygen consumption would scale allometrically across the complete metabolic range, and that the scaling exponents would differ significantly between basal and maximal-exercise states, were then evaluated. It was further hypothesised that the scaling exponent would increase in a stepwise manner with elevations in exercise intensity. Finally, the utility of applying the scaling exponent derived for peak aerobic power to another population sample was evaluated.

METHODS

Basal, steady-state walking and peak (treadmill) oxygen-consumption data were measured using 60 relatively homogeneous men (18-40 year; 56.0-117.1 kg), recruited across five mass classes. Linear and allometric regressions were applied, with the utility of each scaling method evaluated.

RESULTS

Oxygen consumption scaled allometrically with body mass across the complete metabolic range, and was always superior to both ratiometric analysis and linear regression. The scaling exponent increased significantly from rest (mass^0.57) to maximal exercise (mass^0.75; P < 0.05), but not between steady-state walking (mass^0.87) and maximal exercise (P > 0.05). When used with an historical database, the maximal-exercise exponent successfully removed the mass bias.

CONCLUSION

It has been demonstrated that the oxygen consumption of healthy humans scales allometrically with body mass across the entire metabolic range. Moreover, only two scaling exponents (rest and exercise) were required to produce mass-independent outcomes from those data. Accordingly, ratiometric and linear regression analyses are not recommended as scaling methods.