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Item A 0.8 fructose:maltodextrin ratio enhances endurance performance and exogenous carbohydrate oxidation : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Exercise and Sport Science at Massey University, Wellington, New Zealand(Massey University, 2011) O'Brien, Wendy JeanIntroduction: A ratio of fructose to glucose/maltodextrin of approximately 0.8 in a carbohydrateelectrolyte solution ingested during endurance exercise was recently seen to substantially increase exogenous-carbohydrate oxidation, gut comfort and performance. However, it remains to be determined if the apparent fructose:glucose ratio optima is robust when the possible confounders of differences in solution osmolality and carbohydrate concentration are removed from consideration via clamping, and if the 0.8 ratio also promotes faster fluid absorption. Methods: In a randomised double-blind crossover, 12 male cyclists rode 2 h at 57.5% peak power, then performed 10 repeated-maximal-sprints, while ingesting artificially sweetened water or one of three isomotic 11.25% carbohydrate-salt solutions at 800 mL·h-1, comprising fructose and, maltodextrin/glucose, at the respective mean rates (g·min-1): 1.0, 0.5 (0.5-Ratio); 0.67, 0.83 (0.8- Ratio); 0.83, 0.67 (1.25-Ratio). Each solution was also spiked with 5 g D2O at 30 min into the 2-h preload. 14C-enriched fructose and naturally 13C-enriched maltodextrin/glucose permitted fructose and glucose oxidation rate evaluation by liquid scintillation and mass spectrometry, respectively, and indirect calorimetry. Results: Mean exogenous-fructose and mean exogenous-glucose oxidation rates were 0.27 (SD%, 46), 0.39 (56) and 0.46 g·min-1 (53), and 0.65 (30), 0.71(14) and 0.58 (28) g·min-1 in 0.5-, 0.8- and 1.25-Ratio, respectively; representing oxidation efficiencies (%) for fructose of 56 (12), 60 (7) and 56 (10), for glucose of 67 (16), 86 (11) and 89 (21), and for total exogenous-carbohydrate of 70 (9), 74 (6) and 64 (9), respectively. Relative to 0.5- and 1.25-Ratios, total exogenous-carbohydrate oxidation rate with 0.8-Ratio was very likely 6.4% (90% confidence limits; ±3.1%) and almost certainly 12.7% (±2.6%) higher, respectively, while respective differences in total-exogenous carbohydrate oxidation efficiency was 4.1±1.8% and 8.8 ±1.9%. Endogenous-carbohydrate oxidation with 1.25-Ratio was very likely higher relative to 0.5- and 0.8-Ratio conditions (31.3%; ±26.6% and 37.3%; ±27.8%, respectively) but comparisons of fat and total-carbohydrate oxidation rates were unclear among carbohydrate solutions. Mean sprint power with 0.8-Ratio was moderately higher than 0.5-Ratio (2.9%; 99% confidence limits ±2.8%) and 1.25-Ratio (3.1%; ±2.7%), and almost certainly higher than Water (11.9%; ±3.0%); repeated-sprint fatigue (slope) was possibly attenuated with 0.8-Ratio compared to 0.5- and 1.25-Ratio (2.1%; ±5.7% and 1.7%; ±5.5%, respectively). Blood D2O enrichment differences were possibly small or inconclusive among all solutions. Differences in gastrointestinal comfort during the 2-h ride were trivial/unclear among the carbohydrate conditions, however, increases in abdominal cramping were likely greater with 0.8-Ratio during the performance test. CHO ratio on CHO metabolism and performance Conclusions: Substantial enhancement of endurance performance results from ingestion of 0.8 ratio fructose:maltodextrin/glucose solutions, which is associated with increased exogenous-carbohydrate oxidation efficiency driven largely by a greater contribution from exogenous-fructose oxidation. Further research is required to determine the effect on fluid absorption and the physiological site responsible for the 0.8 ratio effect.Item Prediction of cellular ATP generation from foods in the adult human : application to developing specialist weight-loss foods : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Palmerston North, New Zealand(Massey University, 2010) Coles, Leah TheresaFor the accurate prediction of the potential ‘available energy’ of a food at the cellular level (i.e. ATP generation from food) it is necessary to be able to predict both the quantity and location of uptake (upper-tract or colon) for each energy-yielding nutrient. The objective was to develop a valid model (‘Combined Model’) for predicting the (potential) ATP available to the body from absorbed nutrients across the total digestive tract. The model was intended for the adult human under conditions where energy intake ≤ energy expenditure and all absorbed nutrients are catabolised. The development of the model involved two parts: (i) the experimental development of a dual in vivo – in vitro digestibility assay (‘dual digestibility assay’) to predict human upper-tract nutrient digestibility, as modelled by the rat upper digestive tract, and colonic digestibility, as predicted by fermenting rat ileal digesta in an in vitro digestion system containing human faecal bacteria; and (ii) the development of a series of mathematical equations to predict the net ATP yielded during the post-absorptive catabolism of each absorbed nutrient at the cellular level. A strong correlation (r=0.953, P=0.047) was found between total tract organic matter digestibility (OMD), as predicted with the newly developed dual in vivo – in vitro digestibility assay and with that determined in a metabolic study with humans for four mixed diets ranging considerably in nutrient content. There were no statistically significant (P>0.05) differences for mean OMD between the predicted and determined values for any of the diets. The Combined Model (dual in vivo – in vitro digestibility assay + stoichiometric predictive equations) was applied to three meal replacement formulations and was successfully able to differentiate between the diets in terms of both energy digestibility and predicted ATP yields. When the energy content of each diet was compared to that of a baseline food (dextrin), some metabolisable energy (ME) models gave considerably different ratios compared to that predicted by the Combined Model. By way of example, for Diet C a ratio of 0.96 (Atwater and FDA models) was found ii versus 0.75 (Combined Model). Thus, the model has practical application for predicting dietary available energy content, particularly in the research and development of specialised weight-loss foods, where it may be more accurate than some current ME models. Uniquely, the Combined Model is able to define a food in terms of ATP content (mol ATP / g food) using recent estimates of cellular P/O ratios and therefore, directly relates dietary energy intake to the quantity and form (ATP) of energy ultimately delivered at the cellular level.Item The effect of consuming farmed salmon compared to salmon oil capsules on long chain omega 3 fatty acid and selenium status in humans : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Human Nutrition, Institute of Food, Nutrition and Human Health at Massey University, Auckland, New Zealand(Massey University, 2009) Pauga, MelanieSalmon is a good source of long chain (LC) omega 3 fatty acids and selenium; these are well recognised for their health benefits. Recommendations for LC omega 3 fatty acid intakes presume equivalence between fish and fish oil. The aim of this research was to compare the effects of consuming salmon with salmon oil capsules on LC omega 3 fatty acid and selenium status. Forty four healthy subjects were randomly assigned to consume either two servings of 120 g farmed New Zealand King (FNZK) salmon/week or 2, 4 or 6 capsules of salmon oil/day for 8 weeks. Fasting blood samples, anthropometric measures, food consumption habits information and blood pressure (BP) measurements were obtained at the study commencement and ending. Each subject’s intake of LC omega 3 fatty acids and selenium was determined by analysing the fatty acid and selenium content of duplicate portions of cooked salmon and capsules. The amount of salmon consumed was then calculated by subtracting unconsumed amounts of salmon and then calculating the intake of LC omega 3 fatty acids as grams of LC omega 3 fatty acids consumed per day. Percentage of compliance to capsule intake, based on counts of unconsumed capsules, was calculated to determine the amount of LC omega 3 fatty acids consumed per day from capsules. Change in red blood cells (RBC) LC omega 3 fatty acid levels from equivalent amounts of LC omega 3 fatty acids consumed from capsules and salmon were compared using linear regression analysis predictive models fitted to the capsule data. Omega 3 index was calculated. LC omega 3 fatty acid intakes from salmon and 2, 4 and 6 capsules were 0.82, 0.24, 0.47 and 0.68 g/day, respectively. Equal amounts of LC omega 3 fatty acids consumed from salmon and capsules resulted in similar increases in RBC LC omega 3 fatty acids and omega 3 index (RBC eicosapentaenoic acid (EPA): 0.80 [0.58 – 1.02] vs. 1.00 [0.71 – 1.27] %; RBC docosahexaenoic acid (DHA): 0.93 [0.58 – 1.29] vs. 0.99 [0.68 – 1.31] %; omega 3 index: 1.92 [1.46 – 2.38] vs. 2.25 [1.65 – 2.83] %). The capsules did not contain selenium, but the salmon provided 6.84 µg selenium/day. Plasma selenium concentrations increased significantly in the salmon group compared to the capsuleItem Comparison of rice bran oil margarine with Flora margarine and Flora pro-activ margarine for lowering cholesterol : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Human Nutrition at Massey University, Turitea Campus, Palmerston North, New Zealand(Massey University, 2008) Eady, Sarah LouisePhytosterols have been shown to be effective in reducing serum cholesterol levels in numerous human clinical studies and regular consumption is recommended as part of therapeutic lifestyle changes aimed at reducing low density lipoprotein (LDL-C) in the treatment of hyperlipidaemia, a risk factor for cardiovascular disease. Fat based spreads have been shown to be a very successful vehicle for delivery of plant sterols, readily accepted by consumers and efficacious in reducing cholesterol levels. Alfa One™ Rice Bran Oil (RBO) spread is a new product entering into the market place. It is derived from rice bran oil and contains high levels of unsaponifiable material rich in phytosterols, triterpene alcohols, ferulic acid esters ([gamma]-oryzanol) and vitamin E isomers. As such it may have the potential to lower serum cholesterol levels when consumed on a daily basis. In order to establish the effectiveness of Alfa One™ Rice Bran Oil (RBO) spread compared with Flora pro-activ® margarine, a well established brand of plant sterol margarine already proven to lower cholesterol, a randomised double blind cross-over human clinical trial over 12 weeks was conducted. The study was divided into two treatment arms. The first arm of the study was to determine whether Alfa One™ RBO spread (containing 1.5% plant sterols) could lower total and LDL cholesterol levels to a greater extent than standard Flora margarine (containing no plant sterols) or Flora Pro-activ® margarine (containing 8% plant sterols). The second study arm tested the proposition that daily consumption of Alfa One™ Rice Bran Oil (RBO) spread in conjunction with rice bran oil (containing 0.5% plant sterols) would lower total and LDL cholesterol to a greater extent than Alfa One™ RBO spread in isolation and more than Flora margarine in conjunction with sunflower oil. Eighty mildly hypercholesterolaemic individuals (total cholesterol [greater than or equal to] 5 mmol/L and [less than or equal to] 7.5 mmol/L) were recruited and randomised into two groups of forty. Participants were asked to continue with their normal dietary pattern but to replace any margarine/butter/fat consumption with the trial products. One group of 40 were then assigned to the first treatment arm of the study (margarine-only group) and were randomised to consume 20 g (4 teaspoons) Alfa One™ RBO spread daily for 4 weeks, or 20 g Flora margarine daily for 4 weeks, or 20 Flora pro-activ® daily for 4 weeks. Phytosterol levels delivered in these amounts were: RBO margarine: 118mg phytosterol and 14 mg [gamma]-oryzanol; Flora proactiv® 1600 mg phytosterol; Flora margarine 0mg phytosterol. The second group of 40 were allocated to the second arm of the trial (margarine and oil group) and consumed 20 g Alfa One™ RBO spread and 30 ml rice bran oil (RBO) daily for 4 weeks, or 20 g Flora margarine and 30 ml sunflower oil daily for 4 weeks, or 20 g Alfa One™ RBO spread daily for 4 weeks, changing treatment at the end of each 4-week period. Phytosterol amounts delivered in these amounts were: RBO margarine: 118 mg phytosterol and 14 mg [gamma] oryzanol; RBO 222mg mg phytosterol, 150 mg [gamma] oryzanol. Each participant consumed all three treatments in a random order over a 12 week period. At baseline and following each 4 week intervention period, measurements were made of weight and blood pressure. Venous blood samples were collected for analysis of total cholesterol, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), total cholesterol: HDL-C, triglycerides and plasma phytosterols. Three-day diet records from each individual were also collected for analysis of normal dietary intake. Results showed that compared to a standard Flora margarine, Alfa One™ RBO spread significantly reduced total cholesterol by 2.2% (P=0.045), total cholesterol:HDL by 4.1% (P=0.005) and LDL-C by 3.5% (P=0.016), but was not as effective overall as Flora Pro-activ® which reduced total cholesterol by 4.4% (P=0.001), total cholesterol:HDL by 3.4% (P=0.014) and LDL-C by 5.6% (P=0.001). Consumption of Flora margarine alone produced no significant decrease from baseline figures in any of the cholesterol parameters measured. Surprisingly, in group two, the addition of rice bran oil to the Alfa One™ RBO spread produced no differences in cholesterol levels. The reason for this unexpected result is being explored further. These results confirm that Alfa One™ RBO spread is effective in lowering serum cholesterol levels when consumed as part of a normal diet. Studies have shown that a 1% reduction in LDL-C can equate to a 2% decrease in coronary heart disease (CHD) risk thus suggesting that the 3.5% reduction demonstrated by Alfa One™ RBO spread in this study could be effective in reducing CHD risk as much as 6% in a mildly hypercholesterolaemic population.