Introduction: Micronutrient malnutrition has been identified as a serious health problem globally and is on the rise in South Africa. This is evident from the escalating burden of vitamin A deficiency (VAD) in South Africa. Rural infants are the most affected, as their diets often lack micronutrients. Food fortification, vitamin A supplementation and dietary diversity are the strategies that have been employed in South Africa to alleviate VAD. However, these strategies have not been effective, for various reasons. Biofortification is the production of micronutrient dense staple crops to alleviate micronutrient deficiencies. This strategy could complement existing strategies in the alleviation of VAD in South Africa and in other countries, especially in sub-Saharan Africa (SSA), where VAD is prevalent. Aim: The aim of this study was to investigate the nutritional composition and acceptance of a complementary food (soft porridge) made with provitamin A-biofortified maize by female infant caregivers from the rural areas of Umgungundlovu District of KwaZulu-Natal, South Africa. Objectives: (i) To evaluate the nutritional composition of soft porridge made with provitamin A-biofortified maize compared to non-biofortified white maize porridge; (ii) To assess the sensory acceptability of soft porridge made with the biofortified maize by black African female infant caregivers of varying age; and (iii) To determine the perceptions of the black African infant caregivers about the biofortified maize relative to the non-biofortified white maize. Methods: A cross-sectional study was conducted. Grains of two provitamin A-biofortified maize varieties and one white variety (control) were used. Grain and soft porridge of each variety of maize were analysed for their nutritional composition. The sensory acceptability of the porridges were evaluated by black African female infant caregivers, using a five-point facial hedonic scale. Focus group discussions were conducted, using some of the study subjects, to determine their perceptions about the provitamin A-biofortified maize. Results: The results showed that the grains of the provitamin A-biofortified maize varieties and their soft porridges were more nutritious than the control white variety in terms of energy, fibre, fat, protein, iron, zinc and phosphorus content. The results of the sensory evaluation indicated that there was no significant difference in the sensory acceptability of the biofortified soft porridges and the white maize soft porridge, irrespective of the age of the sensory evaluation panellists. The female caregivers perceived the biofortified maize as nutritious and health-beneficial and thought that infants would like its unique yellow colour and taste. However, the black African female caregivers perceived the provitamin A-biofortified maize as an animal feed or food for the poor. Nevertheless, the female caregivers expressed a willingness to give their infants porridge made with provitamin A-biofortified maize if it was cheap, readily available and health-beneficial. Conclusion: This study suggests that provitamin A-biofortified maize has the potential to be used as a complementary food item. Biofortification of maize with provitamin A could be used as a possible complementary strategy to assist in the alleviation of VAD in SSA. Furthermore, the relatively higher energy, fibre, fat, protein, iron, zinc and phosphorus content of the biofortified maize could contribute to the alleviation of protein-energy malnutrition and mineral deficiencies, respectively, which are prevalent in children of SSA. Although the findings of this study, like other previous studies, indicate that there are some negative perceptions about the provitamin A-biofortified maize, this study shows that provitamin A-biofortified maize soft porridge is as acceptable as white maize soft porridge to female infant caregivers from the rural areas of Umgungundlovu District of KwaZulu-Natal, South Africa. The female caregivers are thus likely to accept the biofortified maize for use as an infant complementary food in the form of soft porridge. Further research is recommended to expand the study area and consumer sample size in order to increase the confidence of inferring these results for large rural populations. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2014.

Thesis (M.Sc.)--Memorial University of Newfoundland, Division of Community Health, 2000. / Typescript. Bibliography: leaves 111-118. Also available online.

Thesis (Mnutr)--Stellenbosch Univresity, 2004. / ENGLISH ABSTRACT: INTRODUCTION: The aim of this study was to investigate post-immigration BMI changes in a South African immigrant population and how dietary intake and habitual physical activity reflect these changes. The study was designed as a cross-sectional, observational survey. Thirty-six volunteers aged 20 - 50 years were included in the sample. Volunteers were South African immigrants in the Atlanta area, USA, who have lived in the USA for more than 6 months but less than 5 years. METHOD: Subjects were required to complete four questionnaires including a selfadministered socia-demographic, physical activity and food frequency questionnaire. The weight history questionnaire containing measurements including height, weight and waist circumference was completed by the investigator. RESULTS: A significant increase in BMI was indicated for both male (p=0.036) and female (p=0.0009) subjects. The increase in BMI for two age categories, 20-29 years (p = 0.018) and 30-39 years (p = 0.006), was also significant. Forty five percent of females reported an energy intake above the Estimated Energy Requirement (EER) for active individuals. Reported saturated fatty acid intake (13% of TE) exceeded the Acceptable Macronutrient Distribution Range (AMOR). The prevalence of inadequate n-3 and n-6 PUFA as well as fibre intake was high, especially in men. Sixty four percent of the population had a 'low active' physical activity level (PAL). CONCLUSION: The observed increase in post-immigration BMI implies that the South African immigrant population, similar to other immigrant populations, has adopted to some extent, the lifestyle and dietary habits of the general US population. As a result, the South African immigrant population may also be subject to increased chronic disease risk. / AFRIKAANSE OPSOMMING: INLEIDING: Die doel van hierdie studie was om die veranderinge in liggaamsmassa index (LMI) wat met immigrasie gepaard gaan in In Suid-Afrikaanse immigrant populasie te ondersoek, asook hoe die populasie se dieet en fisieke aktiwiteit hierdie veranderinge reflekteer. Die studie was In dwarssnit, observasie opname. Die steekproef het bestaan uit 36 vrywilligers (20 - 50 jaar oud). Respondente was deel van In Suid-Afrikaanse immigrant populasie in die Atlanta area, VSA, wat vir langer as 6 maande en korter as 5 jaar in die VSA woonagtig was. METODE: Respondente is versoek om vier vraelyste te voltooi insluitende In sosiodemografiese, fisieke aktiwiteit, -en voedsel frekwensie vraelys. Antropometriese metings, insluitende massa, lengte en middelomtrek is deur die navorser op die massa geskiedenis vraelys aangeteken. RESULTATE: In Betekenisvolle toename in LMI vir beide mans (p=0.036) en vroue (p=0.0009) is gevind. Die toename in LMI vir respondente 20-29 jaar (p = 0.018) en 30- 39 jaar (p = 0.006) was ook betekenisvol. Vyf-en-veertig persent vroue se energie inname was hoër as die aanbevole daaglikse inname vir aktiewe individue. Die populasie se versadigde vetsuur inname (13% van totale energie) was hoër as die aanvaarbare makronutriënt verspreiding. Die prevalensie vir onvoldoende innname van n-3 en n-6 poli-onversadigde vetsure, asook vesel inname was hoog, veralonder mans. Vier-en-sestig persent van die populasie se fisieke aktiwiteit vlak is geklassifiseer as 'lae aktiwiteit' . GEVOLGTREKKING: Die waargenome toename in LMI impliseer dat die studie populasie, soortgelyk aan ander immigrant populasies, die lewensstyl en dieet gewoontes van die algemene Amerikaanse populasie tot In sekere mate aangeneem het en is dus ook onderhewig aan die gevolglike toename in risiko vir kroniese siekte van lewensstyl.

Thesis (MNutr)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Objectives: The objectives of this study were to determine the nutritional content/ contribution of intravenous (IV) fluid and electrolyte administration on the total feeding prescription of intensive care unit (ICU) patients. Methods: Retrospective review of ICU charts of consecutive patients (>18 years) with APACHE II scores ≥10 and on ≥72 hours nutrition therapy (NT) admitted to a medical/surgical ICU. Total fluid, electrolyte, energy and macronutrient intake from nutritional and non-nutritional sources were reviewed from ICU admission until discharge, discontinuation of NT or death for ≤7 days. Energy and protein delivery were compared to calculated targets of 25.4 – 28.6kCal/kg and 1.3 – 1.5g/kg respectively. Summary statistics, correlation coefficients and appropriate analysis of variance were used to describe and analyse the data. Results: A total of 71 patients (49% male), average age 49.2 ± 17.1, average APACHE II score 21.0 ± 6.1, 68% medical and 32% surgical, were included. Fluid and nutrient intake were reviewed over a mean of 5.7 ± 1.1 days. Mean daily fluid delivery was 3.2 ± 0.6L. IV fluid therapy (IVFT) contributed 32.0 ± 12.0% to total fluid delivery (TFD), whereas IV drug administration, including fluids used for reconstitution and dilution purposes, contributed 20.7 ± 8.1% to TFD. Balanced electrolyte solutions (BES) were the crystalloid of choice, prescribed in 91.5% of patients with a mean daily volume (MDV) of 0.5 ± 0.4L. Hypertonic low molecular weight (LMW) 130/0.4kD hydroxyethyl starch (HES) was the colloid of choice, prescribed in 78.9% of patients with a MDV of 0.2 ± 0.1L. Potassium salts were the most frequently prescribed IV electrolyte supplement (IVES), prescribed in 91% of patients (±20 – 60mmol per administration). NT was initiated within 14.5 ± 14.1 hours. The majority (80%) received enteral nutrition (EN). The mean daily energy delivered was 1613 ± 380kCal (25.1kCal/kg), meeting 93.6 ± 17.7% of mean target range (MTR). Mean daily protein delivery (PD) was 72 ± 22g (1.1g/kg), meeting 82.8 ± 19.9% of MTR. Non-nutritional energy sources (NNES), mostly derived from carbohydrate-containing IV fluids, contributed 10.1 ± 7.5% to total energy delivered (156kCal/d). Mean cumulative energy and protein balance was -674.0 ± 1866.1kCal and -86.0 ± 106.9g respectively. The majority (73%) received >90% of the minimum energy target but only 49% >90% of minimum protein target; 59% of those with energy intake 90-110% of target had adequate protein intake. A significant negative correlation was found between cumulative energy/protein balance and the time to initiation of NT (energy: r=-0.28, p=0.02; protein: r=-0.32, p=0.01). Conclusion: In this ICU BES are the crystalloid of choice and hypertonic LMW 130/0.4kD HES the colloid of choice for IVFT. Potassium salts are the most frequently prescribed IVES. NNES added significantly to energy delivery and should be included in the calculation of feeding prescriptions to avoid the harmful effects of overfeeding. Early initiation of EN with conventional products which are energy rich is insufficient to achieve adequate PD. EN formulae with a more favorable nitrogen to non-protein energy ratio could help to optimise PD during the first week of ICU care. / AFRIKAANSE OPSOMMING: Doelwitte: Die doelwit van hierdie studie was om die voedingswaarde/ bydrae van intraveneuse (IV) vog en elektroliet toediening tot die totale voedings voorskrif van pasiënte in ‘n intensiewe sorg eenheid (ISE) te bepaal. Metodes: Retrospektiewe bestudering van die ISE kaarte van agtereenvolgende pasiënte (>18 jaar) opgeneem in ‘n mediese/chirurgie ISE en met APACHE II tellings ≥10 en ≥72 ure voedingsterapie (VT). Totale vog, elektroliet, energie en makronutriënt inname vanaf voedingsverwante en nie-voedingsverwante bronne is vanaf ISE opname tot en met ontslag, staking van VT of sterfte, vir ≤7 dae hersien. Energie en proteiën inname is vergelyk met berekende doelwitte van 25.4 – 28.6kKal/kg en 1.3 – 1.5g/kg onderskeidelik. Beskrywende statisitiek, korrelasie koeffisiënte en toepaslike analises van variansie is gebruik vir data analise. Resultate: 71 pasiënte (49% mans), gemiddelde ouderdom 49.2 ± 17.1, gemiddelde APACHE II telling 21.0 ± 6.1, 68% medies en 32% chirurgie, is ingesluit. Vog en voedingstof inname is hersien oor ‘n gemiddelde tydperk van 5.7 ± 1.1 dae. Gemiddelde vog inname was 3.2 ± 0.6L/dag. IV vog terapie (IVVT) het 32.0 ± 12.0% bygedra tot totale vog inname (TVI). IV medikasie toediening, insluitende die herkonstruksie en verwatering van medikasie, het 20.7 ± 8.1% bygedra tot TVI. Die mees voorgeskrewe kristalloiëd en kolloiëd vir IVVT was gebalanseerde elektroliet oplossings (GEO), voorgeskryf in 91.5% van pasiënte (gemiddeld 0.5 ± 0.4L/dag), en hipertoniese lae molekulêre gewig (LMG) 130/0.4kD hidroksie-etiel stysel (HES), voorgeskryf in 78.9% van pasiënte (gemiddeld 0.2 ± 0.1L/dag), onderskeidelik. Die mees voorgeskrewe IV elektroliet supplement was kalium soute, voorgeskryf in 91% van pasiënte (±20 – 60 mmol per toediening). VT is binne 14.5 ± 14.1 ure geinisieër. Die meerderheid (80%) het enterale voeding (EV) ontvang. Die gemiddelde daaglikse energie inname van 1613 ± 380kCal (25.1kKal/kg) het 93.6 ± 17.7% van die gemiddelde doelwit rykwydte (GDR) bereik. Die gemiddelde daaglikse proteiën inname van 72 ± 22g (1.1g/kg) het 82.8 ± 19.9% van die GDR bereik. Nie voedings-verwante energie bronne (NVEB), meestal vanaf koolhidraat-bevattende IV vloeistowwe, het 10.1 ± 7.5% tot totale energie inname (TEI) bygedra (156kKal/d). Die gemiddelde kumulatiewe energie en proteiën balans was -674.0 ± 1866.1kKal en -86.0 ± 106.9g onderskeidelik. Die meerderheid (73%) het >90% van die minimum energie doelwit (ED) bereik. Slegs 49% het >90% van die minimum proteiën doelwit (PD) bereik. Opsomming: Die kristalloiëd en kolloiëd van keuse vir IVT is GEO en hipertoniese LMG 130/0.4kD HES onderskeidelik. Kalium soute word mees algemeen voorgeskryf. NVEB dra beduidend by tot TEI en moet inaggeneem word tydens die berekening van voedingsvoorskrifte ten einde oorvoeding te voorkom. Vroeë inisiëring van EV met konvensionele energie-ryke EV produkte is onvoldoende om genoegsame proteiën inname te verseker. EV produkte met ‘n gunstiger stikstof tot nie-proteiën energie verhouding sal help om proteiën inname gedurende die eerste week van intensiewe sorg te optimaliseer.Slegs 59% van pasiënte met genoegsame energie inname (90-110% van ED) het hul minimum PD bereik. Daar was ‘n beduidende negatiewe korrelasie tussen kumulatiewe energie/proteiën balans en die tyd tot inisiëring van VT (energie: r=-0.28, p=0.02; proteiën: r=-0.32, p= 0.01).

Thesis (MNutr)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Introduction: Intensive lifestyle intervention in people with Type 2 Diabetes Mellitus (T2DM) is associated with weight loss, significant reductions in HbA1c% and a reduction in cardiovascular disease risk factors. Small towns unfortunately experience a deficit of dieticians, thus limiting access to lifestyle intervention. Furthermore, a limited number of South African studies have evaluated the effect of dietary habits, anthropometric status, activity level (AL) and dietician-led medical nutrition therapy (MNT) on glycaemic control in patients with T2DM. This study thus aimed to identify the association between glycaemic control and lifestyle habits in adults with T2DM living in Thabazimbi. The role of the dietician with regard to optimal glycaemic control was also investigated with great interest. Methods: Individuals (>18 years) with T2DM who had a recent HbA1c test result and no acute infection/illness were included in the study over a 7 month recruitment period. Weight, height and waist circumference were measured, AL and dietetic contact evaluated, and dietary habits assessed by means of a structured questionnaire. Six home-measured post-prandial glucose (PPG) measurements and HbA1c% were used to evaluate glycaemic control. Results: A total of 62 (59.7% males) patients were included. The mean age was 60.13 ±10.85 years and mean T2DM disease duration was 121 ±96.56 months. Only 6.45% of participants had a normal Body Mass Index classification. Most (90.32%) participants had a substantially increased waist circumference (WC). Half of the participants had a sedentary/low AL, whilst 48.39% had an active/moderately active AL. Almost all (95%) participants indicated it was necessary for persons with DM to consult a dietician for MNT, however only 63% of participants actually consulted one. Mean dietary compliance was 74.53 ±10.93%. The average HbA1c% and PPG of participants were respectively 7.50 ±1.62% and 8.90 ±3.21mmol/l. A significant negative association (r=-0.31; p=0.02) was found between HbA1c% and percentage dietary compliance. The number of dietetic sessions completed and average PPG were also significantly [(r=0.40; p=0.001), (r=-0.34; p=0.01)] associated with percentage dietary compliance. In turn PPG had a significant positive (r=0.30; p=0.02) association with DM disease duration. Both the good HbA1c and good PPG control groups had significantly (p=0.01, p=0.04) better dietary habits than the poor HbA1c and PPG control groups. When compared to the poor PPG group, the good PPG group made significantly (p=0.04) better dietary decisions with regard to the main meal’s carbohydrate quality and quantity. Body Mass Index, WC, AL and extent of dietetic contact didn’t play a significant role in the glycaemic classification (good vs. poor) of participants. Conclusion: The longer T2DM is present, the worse PPG control becomes. Optimal dietary habits play a significant positive role in both the long- and short term glycaemic control of people with T2DM in Thabazimbi. The choice and portion size of the main meal’s carbohydrates has been identified to be the most important dietary role-player in the glycaemic control of this study population. This study also shows that if individuals with DM spend enough time with a dietician, it could potentially contribute to better dietary compliance and subsequent better glycaemic control. / AFRIKAANSE OPSOMMING: Inleiding: Intensiewe leefstyl intervensie onder diegene met Tipe 2 Diabetes Mellitus (T2DM) word geassosieer met gewigsverlies, beduidende verlaging in HbA1c% asook ’n vermindering in verskeie kardiovaskulêre-siekte risiko faktore. Plattelandse dorpies beleef egter ’n tekort aan dieetkundiges, wat gevolglik toegang tot leefstyl intervensie beperk. Daar is ook ’n beperkte hoeveelheid Suid-Afrikaanse studies wat die impak van eetgewoontes, antropometriese status, aktiwiteitsvlak en dieetkundige-begeleide dieetterapie op glisemiese beheer in T2DM pasiënte evalueer. Die doel van die studie was dus om die verband tussen glisemiese beheer en leefstyl gewoontes in volwassenes met T2DM in Thabazimbi te bepaal. Die rol van die dieetkundige met betrekking tot optimale glisemiese beheer was ook met groot belangstelling nagevors. Metodes: Diegene (>18 jaar) met T2DM wat oor ’n onlangse HbA1c toets uitslag beskik het en nie enige akute siektes/infeksie gehad het nie, is oor ’n 7 maande werwingsperiode ingesluit. Gewig, lengte en middel-omtrek was gemeet, aktiwiteitsvlak en dieetkundig-kontak bepaal, en eetgewoontes geassesseer m.b.v. ’n gestruktueerde vraelys. Ses tuis-bepaalde na-ete bloedsuiker lesings en HbA1c% was gebruik om glisemiese beheer te evalueer. Resultate: Twee-en-sestig (59.7% mans) pasiënte het aan die studie deelgeneem. Die gemiddelde ouderdom was 60.13 ±10.85 jaar en die gemiddelde T2DM duurte 121 ±96.56 maande. Slegs 6.45% van die deelnemers het ’n gesonde Liggaam-Massa-Indeks gehad. Meeste (90.32%) deelnemers se middel-omtrek was ook ruimskoots verhoog. Die helfte van die deelnemers het ’n passiewe/lae aktiwiteitsvlak gehad, terwyl 48.39% ’n aktief/matig-aktiewe aktiwiteitsvlak gerapporteer het. Amper al (95%) die deelnemers het aangedui dat mense met T2DM ’n dieetkundige moet raadpleeg vir dieetterapie. Slegs 63% van die deelnemers het egter werklik ’n dieetkundige vir diabetes dieetterapie geraadpleeg. Gemiddelde dieet-gehoorsaamheid was 74.53 ±10.93% en die gemiddelde HbA1c % en na-ete bloedsuiker vlakke van deelnemers was onderskeidelik 7.50 ±1.62% en 8.90 ±3.21mmol/l. Daar was ’n beduidende negatiewe verband (r=-0.31; p=0.02) tussen HbA1c % en persentasie dieet-gehoorsaamheid. ’n Beduidende verband was ook tussen persentasie dieet-gehoorsaamheid en die hoeveelheid voltooide dieetterapie sessies (r=0.40; p=0.001) asook die gemiddelde na-ete bloedglukose vlak (r=-0.34; p=0.01) geïdentifiseer. Na-ete bloedglukose het ook ’n beduidende positiewe (r=0.30; p=0.02) verband met die duurte van diabetes getoon. Beide die goeie HbA1c en goeie na-ete glukose groepe het beduidend (p=0.01, p=0.04) beter eetgewoontes as die swak HbA1c en swak na-ete glukose groepe gehad. Die goeie na-ete glukose groep het veral beduidend (p=0.04) beter dieet keuses m.b.t die hoofmaal se koolhidraat kwaliteit en kwantiteit gemaak. Lengte-Massa-Indeks, middel-omtrek, aktiwiteitsvlak en die mate van dieetkundige kontak het nie ’n beduidende rol in die glisemiese klassifikasie (goed teenoor swak) van deelnemers gespeel nie. Gevolgtrekking: Na-ete bloedsuiker beheer word al hoe slegter hoe langer T2DM teenwoordig is. Optimale eetgewoontes speel ’n beduidende positiewe rol in beide die lang- en kort-termyn glisemiese beheer van mense met T2DM in Thabazimbi. Die keuse en porsie grootte van die hoofmaal se koolhidrate blyk die belangrikste dieet rolspeler in die glisemiese beheer van die studie populasie te wees. Die studie dui ook aan dat as mense met T2DM genoeg tyd saam met ’n dieetkundige deurbring, dit moontlik kan bydra tot beter dieet-gehoorsaamheid en gevolglik beter glisemiese beheer.

The time course of this increase in muscle n-3 PUFA composition and anabolic protein expression is currently unknown. In Chapter 2 of this thesis ten healthy male participants consumed 5g.d-1 of n-3 PUFA-enriched fish oil for 4 weeks. Muscle biopsies samples were collected in the fasted, rested state 2 weeks prior, immediately before (Week 0), at Week 1, Week 2 and Week 4 after initiation of fish oil supplementation for assessment of changes in lipid composition and expression of anabolic signalling proteins over time. Muscle lipid profile, (% total n-3 PUFA/total fatty acids) increased from W0 to W2 (3.8 ± 0.2 to 5.1 ± 0.3 %) and continued to rise at W4 (6.7 ± 0.4 %). Total protein content of FAK increased from W0 to W4 (3.9 ± 1.5 fold) whereas total mTOR was increased from W0 at W1 (2.4 ± 0.6 fold) with no further significant increases at W2 and W4. For the first time this study demonstrates that oral fish oil consumption results in an increase of n-3 PUFA levels in human skeletal muscle that is associated with increases in the expression of anabolic signalling proteins. Our understanding of the anabolic signalling process that underpins muscle protein synthesis has been advanced by the application of the WB technique. However, the semi-quantitative nature and poor dynamic range associated with the WB technique may lead to incongruence regarding the molecular response of skeletal muscle to anabolic stimulation. Chapter 3 of this thesis developed and applied a quantitative in vitro [γ-32P] ATP kinase assay (KA) alongside a traditional WB methodology to assess p70S6K1 signalling responses in human skeletal muscle to RE and protein feeding. Following validation in tissue culture with rapamycin and optimization of the assay in human skeletal muscle, this methodology was tested in a physiologically relevant context. In this regard, six males performed unilateral resistance exercise (RE) followed by the consumption of 20 g of protein. Skeletal muscle biopsies were obtained at pre-RE, at 1 h and 3 h post-RE. In response to RE and protein consumption, p70S6K1 activity was significantly increased from pre-RE at 1 h and 3 h post-RE (8.84 ± 0.78 to 17.18 ± 2.62 and 15.62 ± 3.12 µU/mg). However, phosphorylated p70S6K1thr389 was not significantly elevated. To assess if a combined stimulus of RE and feeding can influence AMPK activity we directly measured AMPK activity. AMPK activity was suppressed from pre-RE at 3 h post-RE (24.15 ± 1.6 to 15.64 ± 1.07 mU/mg), whereas phosphorylated ACCser79 was unchanged. These data therefore highlight the utility of the KA to study skeletal muscle plasticity. Previous studies have shown that ingestion of n-3 PUFA potentiates the phosphorylation of mTORC1 and associated kinases in response to nutrition. However, no study has identified whether n-3 PUFA supplementation potentiates anabolic kinase activity when RE is performed prior to nutrient provision. In Chapter 4 of this thesis, twenty healthy males consumed 5g.d-1 of either fish oil (FO) or coconut oil (CO) capsules for 8 weeks. Muscle biopsy samples were collected in the fasted, rested state before and after 8 weeks of supplementation for assessment of changes in lipid composition. Following 8 weeks of supplementation muscle samples also were obtained at rest (Rest), post RE in both the exercise leg (Post-RE) and the rested leg (Pre-FED) and also at 3 h post RE and protein feeding from both the exercise leg (3 h post-REF) and rested leg (3 h post-FED). There was a 2-fold increase in muscle (5.53 ± 0.3 to 11.16 ± 0.45 % of total fatty acids) n-3 PUFA composition after supplementation in the FO group but no change in the CO group. Following supplementation there was an increase in p70S6K1 activity at 3 h post-REF from Rest in the CO group (5.6 ± 1.4 to 12.2 ± 2.1 µU/mg) but no change in the FO group. In the CO group, AMPKα2 was significantly increased at Post-RE from Rest (3.7 ± 0.7 to 9.9 ± 2.0 mU/mg). These data show that 8 weeks of n-3 PUFA enriched fish oil supplementation suppresses the activity of p70S6K1 in response to RE and protein feeding.

Two studies were conducted to determine the effect of varying vitamin B-6 (B- 6) status on lymphocyte mitogenic response and pyridoxal 5'-phosphate (PLP) concentration in peripheral blood mononuclear cells (PBMC) in young women. In the first study, women were fed 1 mg/d for the first week and 1.5, 2.1 and 2.7 mg/d during 2 weeks of each of the subsequent 3 experimental periods. Plasma PLP and urinary 4: pyridoxic acid (4-PA) were increased with increasing B-6 intake. B-6 intake > 2.1 mg significantly enhanced lymphocyte proliferation, and non-significantly increased plasma interleukin-2 concentration. Lymphocyte proliferation was significantly correlated with B-6 intake, erythrocyte aminotransferase activity coefficients and plasma PLP. PBMC PLP tended to increase after 2 weeks of 2.7 mg B-6 intake, and was significantly correlated with plasma PLP. In the second study, women consumed their normal diets whose estimated mean dietary B-6 intake was 0.9 mg for 27 d. For the last 20 d, all subjects were given a multivitamin supplement containing 1.8 mg B- 6, and half of the subjects were given an additional 50 mg of B-6 supplement. Plasma PLP and urinary 4-PA were significantly higher in the group with 50 mg B-6, but lymphocyte proliferation did not significantly differ between the groups. After 10 d of supplementation, lymphocyte proliferation was significantly higher than the other time points. A significant increase in PBMC PLP was observed after 3 days and 20 days following 50 mg and multivitamin supplementation only, respectively. After 20 days of supplementation, there was no significant difference of mean PBMC PLP between the groups. PBMC PLP was significantly correlated with plasma PLP, PL and 4-PA. In both studies, no strong relationship was found between PBMC PLP and lymphocyte proliferation. The findings from these studies demonstrate no further benefit of a higher B-6 intake than 2.1 mg on lymphocyte mitogenic response, once the response was significantly enhanced with B-6 intake 0.8 mg higher than the current recommendation. Finally, results from two studies suggest that the current recommendation of vitamin B-6 for young women may not be adequate to maximize lymphocyte mitogenic response and PLP concentration in PBMC. / Graduation date: 2002

This study examined the effect of vitamin B-6 supplementation and exhaustive submaximal exercise on plasma catecholamine concentrations, and the relationship between plasma catecholamines and fuel use, heart rate and oxygen consumption. Five trained men (age= 18-35 years; V0₂max=53 ml 0₂/kg/min.) participated in two controlled dietary periods that were identical except for the addition of 20 mg/d pyridoxine (PN) supplementation during the second period. On the seventh morning of each period, fasted subjects exercised to exhaustion on a cycle ergometer at 74.5% ± 7.8 V0₂max. Blood was drawn pre-exercise (twice), 60 minutes into exercise, immediately post-exercise and 60 minutes post-exercise. Plasma was analyzed for norepinephrine, epinephrine, glucose, pyridoxal 5'-phosphate (PLP), lactic acid, glycerol and free fatty acids (FFA). Heart rate and oxygen consumption were measured pre-exercise and at 10-minute intervals during exercise. Mean plasma PLP concentration was significantly higher during the supplemented versus the nonsupplemented trial at all time points. There were no statistically significant differences in mean plasma catecholamine concentrations or mean plasma fuel concentrations between the nonsupplemented and supplemented trials at any of the time points examined. There were significant changes in the mean plasma concentrations of norepinephrine, lactic acid, glycerol and FFA over time in both trials. Respiratory exchange ratios (R) were higher during the supplemented trial compared to the nonsupplemented trial, but the differences did not attain statistical significance. There were no significant differences in mean exercise times to exhaustion or mean heart rates between the trials. The overall mean oxygen consumption during exercise was consistently higher during the supplemented versus the nonsupplemented trial and the difference attained significance (p=0.016) at one time point (10 min.). The mean oxygen consumption during rest was lower during supplementation versus nonsupplementation, but the difference was not statistically significant. The percent plasma volume change (PVC) was significantly greater at post-exercise, relative to pre-exercise, during the supplemented versus the nonsupplemented trial. The percent PVC also increased significantly over time during the supplemented but not the nonsupplemented trial. These results suggest that 20 mg/d of vitamin B-6 supplementation does not effect plasma catecholamine concentrations, fuel utilization or heart rate at rest or during submaximal exercise to exhaustion. The results may suggest a higher oxygen consumption during exhaustive exercise after PN supplementation. / Graduation date: 1996

Trained male cyclists (6 in study 1, 5 in study 2) cycled to exhaustion (EXH) at 75% of VO₂ max twice; once in the non-supplemented (NS) state and once in the vitamin B-6 (B-6)(20 mg PN) supplemented (S) state. The diet contained 2.3 mg B-6 in study 1 and 1.9 mg B-6 in study 2. Urine was collected during each dietary period. During each exercise (EX) test, blood was drawn prior to (PRE), one hour during (DX), immediately after (POST) and one hour after (POST 60) EX and sweat was collected. Compared to baseline (PRE) levels, plasma pyridoxal 5'-phosphate (PLP) and vitamin B-6 (PB-6) concentrations increased at DX, decreased at POST, and decreased below PRE at POST 60 in the NS and S states. EX to EXH in the S state resulted in a greater increase in PLP DX in study 1 (31% increase vs. 16%) and PB-6 in study 2 (25% increase vs. 11%) as compared to the NS state. Red blood cell (RBC) PLP significantly increased from POST to POST 60 in the S state in study 2. The excretion of urinary 4-pyridoxic acid (4-PA) and urinary B-6 (UB-6) was not significantly altered by EX to EXH. The mean excretion of 4-PA was significantly greater in the NS state in study 2 (7.98 ±1.83 mmol/d) as compared to the excretion in study 1 (6.20 ±0.93 mmol/d), whereas the excretion was significantly greater in the S state in study 1 (92.2 ±8.69 mmol/d) compared to the excretion in study 2 (82.7 ±6.16 mmol/d). The percent of B-6 intake excreted as UB-6 (6% in study 1 and 10% in study 2) was significantly different between the studies in the NS state. Vitamin B-6 supplementation did not significantly alter the rise in growth hormone (hGH) concentration seen with EX to EXH. The loss of B-6 in sweat with EX to EXH was not altered by B-6 supplementation. The loss of B-6 in sweat ranged from 0.0011 mmol to 0.0039 mmol. Therefore, EX to EXH in the B-6 S state resulted in a greater increase in plasma PLP and PB-6 DX as compared to the NS state. The decrease in PB-6 and PLP at POST 60 in the S state coincided with a significant increase in RBC PLP, suggesting the movement of B-6 from the plasma into the RBC at POST 60. EX to EXH and B-6 supplementation did not alter the excretion of 4-PA or UB-6 suggesting that B-6 metabolism was unchanged. The loss of B-6 in sweat was comparable to previously reported values and was not altered by B-6 supplementation. B-6 supplementation did not alter the changes in hGH resulting from EX to EXH alone. / Graduation date: 1995

Current dietary recommendations have placed increasing emphasis on dietary fat as an important element to decrease risk of cardiovascular disease (CVD). Although total fat and the fatty acid composition of diets influence the risk of CVD, the optimal amounts of different fatty acids are not well defined, especially if n-6 and n-3 fatty acids are considered. Despite the fact that postmenopausal women are at increased risk of CVD, few studies have investigated the influence of dietary fatty acids on this risk. Therefore, this study was designed to determine the effect of supplementation with different fatty acids on risk factors of CVD in postmenopausal women. Sixteen healthy, postmenopausal women were randomly assigned in a three-period crossover trial to treatments of 15 g/d supplements of oleic acid-rich sunflower oil (TS), linoleic acid-rich safflower oil (SO), and eicosapentaenoic acid- and docosahexaenoic acid-rich fish oil (FO). Each treatment period lasted 5 weeks followed by a 7-week washout interval. When the women were supplemented with FO compared to supplementation with either TS or SO, the concentration of high density lipoprotein cholesterol tended to increase (p=0.07 and 0.05, respectively) as did the size of the low density lipoprotein (LDL) particle (P=0.03 in both instances) while the concentration of triacylglycerol (p=0.0001 and 0.02, respectively) and apolipoprotein B (apo B) (P=0.005 and P=0.01, respectively) decreased. The concentration , i.e., total cholesterol, cholesterol ester, free cholesterol, phospholipids, α- and γ-tocopherol, of the two LDL subfractions was not influenced by any of the oil supplements but was greater in the large (L) subfraction than the small (S). When the oxidation of the two subfractions was measured by monitoring the formation of conjugated dienes, the lag time was shorter in both fractions after supplementation with FO compared to supplementation with SO (P=0.0001) or TS (P=0.0001) but the effect was greater in the L subfraction. The rate of formation of conjugated dienes, which was slower after FO supplementation than supplementation with either TS (P=0.02) or SO (P=0.001), was faster in the L compared to the S subfraction. When oxidation was measured by monitoring the increase in negative charge on apo B over 23 hr, only the 1 hr time point differed. The increase was greater in the FO-supplemented group than either the TS- or SO-supplemented groups (P=0.001 in both instances). The change was greater in S LDL (P=0.007). These findings demonstrate a greater potential antiatherogenic property of dietary n-3-rich oil than n-6- or n-9-rich ones as indicated by changes to plasma lipids, lipoproteins, apo B, and particle size but the influence of the oxidative susceptibility of L and S subfractions is less conclusive. / Graduation date: 2000