It has been suggested that cellular damage from oxygen radicals is one of the processes leading to cardio-vascular disease and cancer. Natural antioxidants prevent uncontrolled oxidative reactions by decreasing molecular oxygen levels, scavenging chain-initiating and chain-propagating free radicals, chelating metals, or decomposing peroxides. Beer is rich in antioxidants, derived both from malt and hops, consisting mostly of flavanoids and phenolic secondary plant metabolites. Much research has been conducted concerning antioxidant activity of beer in relationship to flavor stability. Yeast cells possess both enzymatic and non-enzymatic antioxidant systems to defend against oxygen radicals, in addition to scavenging and absorbing molecular oxygen for cell synthesis. It is well known that bottle-conditioned beer has a longer shelf life than conventional beer in terms of flavor stability and freshness. This is likely due to a complex relationship between the yeasts inherent ability to scavenge oxygen species, produce SO₂, chelate transition metals and employ other methods to defend against molecular oxygen. The objective of this research was to determine whether bottle-conditioned beer (which contains live yeast) has a higher antioxidant activity compared to that of conventional beer. Initial experiments were conducted to establish a baseline of antioxidant potentials. The first experiment consisted of determining the antioxidant potential of commercially available beers and how those values compared to common foods and drinks. Next, live yeast was added to commercially available artificially carbonated beer, to determine whether the presence of live yeast alone had an impact on antioxidant potential. Lastly, in the first set of beer trials wort was prepared, brewers yeast added, and then allowed to complete primary fermentation. The beer was bottle-conditioned (naturally carbonated) by the addition of a second yeast strain and either a 'high' or 'low' level of sugar, or artificially carbonated. Treatments consisted of using three different yeasts. A control was prepared by artificially carbonating beer without live yeast. Antioxidant potentials were determined using Ferric Reducing Antioxidant Potential (FRAP) analysis. Results indicated that there was an increase in the level of antioxidant activities between the bottle-conditioned beers compared to the control beer, whether or not the high or low level of yeast was present. In the second set of beer trials wort was prepared, brewers yeast added, and then allowed to complete primary fermentation, as in the first set of beer trials. The beer was bottle-conditioned by the addition of a second yeast strain and sugar, or artificially carbonated followed by the addition of a second yeast but no sugar. Treatments consisted of using three different yeasts. A control was prepared by artificially carbonating beer without live yeast. Dissolved oxygen, free and total sulfite, yeast viability, and antioxidant capacities were again determined. Results indicated that there was an increase in the level of sulfite, a decrease in dissolved oxygen, yeast remained viable for a longer period of time, and antioxidant activities were higher in the bottle-conditioned beers when compared to the control beer. Furthermore, while the differences were not as great, the same trends were observed for all parameters when comparing the artificially carbonated beers containing live yeast to the control beer. The elevation in antioxidant activities of beer with live yeast present (live beer) was significant. The third and final phase of experiments focused on the contribution of antioxidant potential specifically from the yeast. Yeast cells for each strain were cultivated in beer wort, harvested, washed, and cell extracts prepared. The crude yeast extracts were subjected to heat treatment, size fractionation followed by heat and protease treatments, glutathione determination, and lipid extraction, and then analyzed for antioxidant activity. Results indicated a complex interaction between many different yeast components that contributed to the total antioxidant activity provided specifically from yeast. Rather than one single compound, the yeast contributed heat stable components, consisting of proteins and enzymes, molecules with high, medium, and low molecular weights, and active lipid portions. The overall results suggest, that while the malt and hops components likely play the major role in antioxidant activity of beer, beer containing live yeast has a significant increase on that antioxidant activity. Consequently, the flavor stability and health benefits from beer containing live yeast would be increased. / Graduation date: 2003

Background: Unhealthy lifestyle are important contributors to chronic illness in Hong Kong and worldwide. Lifestyle modification, particularly improving healthy diet and physical activity, can prevent the development of various chronic illnesses, improve disease conditions, reduce the risk of complications and enhance the quality of life. Many behavioural models have been applied to achieve lifestyle modification, but the major limitation was that they mainly treated human behaviours as individual behaviours that were subsequent to rational thinking. Nudge theory, an advanced behavioral concept, proposed to change individual’s motivation, incentives and decision making through non-direct suggestion and non-forced reinforcement. However, the application of Nudge theory has been challenged on the lack of evidence to prove its effectiveness, and its controversial framework for ethical analysis. Objectives: This review was to synthesize the empirical findings about the effectiveness of using nudge theory for lifestyle modification including healthy diet and physical activity. Methodology: Interventional and experimental studies that were conducted based on Nudge theory to change diet or physical activity was identified from the published literature. The studies were divided into two large groups according to outcome measured: healthy diet and physical activity, and they were systematically synthesized. The “nudges” used in these studies were categorized as six types of “nudges” summarized by “nudge unit” as “MINDSPACE” for further discussion. The type of “nudges” that were used in the studies and their effectiveness on changing diet and physical activity was abstracted. Results: Totally, nine articles that met the inclusion criteria were included. Five nudges were identified from the included studies, including Priming (P), Default (D), Salience & Affect (SA), Incentives (I) and Messenger & Norms (MN). It is found that the strategies and methods applied on the same nudge may have different effectiveness. Seven studies applied Priming (P) as nudge to motivate change in diet, which used two major strategies: “availability” and “accessibility”. The evidence was strong that altering the availability of food presence could be effective to change food selection. The results of studies using accessibility were heterogeneous and contradictive with each other. Another three studies used different nudges including Default, Salience & Affect and Incentive. The effectiveness of Default (D) as nudge seemed to be blurry, and the sustainability remained questionable. The ethical consideration is always the primary pillar for applying nudging theory. As long as the applications are stick to necessary ethical concerns, the nudging model can be beneficial through mild “manipulation” rather than harmful. Conclusion: It has potential opportunity to carry out “libertarian paternalism” in Hong Kong. However, it is still a long way to take application of nudging model into regulation, legislation and daily practice. The evidences for each type of nudge were not consistent and enough. Besides, the monitoring and evaluation are not available yet. Future research can be focused on transferring these applications into real practice with an effective monitoring and evaluation system. / published_or_final_version / Public Health / Master / Master of Public Health

published_or_final_version / Community Medicine / Master / Master of Public Health

No description available.

Objective: Since short-term weight loss is often achievable in overweight individuals but long-term weight maintenance is generally poor, this thesis examines the effect of the nature of support programmes and macronutrient composition on weight maintenance following weight loss. Research design and methods: A 2x2 multifactorial design was used to compare two support programmes and two diets differing in macronutrient composition on maintenance of weight loss over a 2-year period. Two hundred women who had recently lost at least 5% of initial body weight were randomised into one of two support programmes. One provided intensive expert, health professional support with regular circuit training classes. The other provided brief and frequent �weigh-ins� and support facilitated by a nurse. Participants were also randomised with regard to recommended diet composition. One eating plan was high in carbohydrate and dietary fibre, emphasising low glycemic index foods. The second eating plan was relatively high in monounsaturated fat and protein and had a low overall glycaemic load. At baseline, 1 and 2-years, weight, waist circumference and blood pressure were measured and body composition was estimated using bioelectrical impedance. Three-day weighed diet records were collected to estimate dietary intake. A fasting blood sample was used to measure glucose, insulin and lipids. Results: At 2-years weight was measured for 87% of participants. On average those randomised to the Expert Support Programme reduced weight by 2.5kg while those on the Nurse Support Programme reduced weight by 3.6kg (difference between support programmes, P=0.976). On the High Carbohydrate Diet average weight loss was 2.4kg compared with a loss of 3.8kg on the High Monounsaturated fat Diet (difference between diets, P=0.419). At follow-up, there were no signficant differences between the support programmes with regards to body composition, systolic and diastolic blood pressures, blood lipid levels, glucose, insulin, and predicted insulin sensitivity. From a health system perspective and relative to the Nurse Support Programme, the Expert Support Programme cost $NZ 928, 970 per QALY gained (or $9, 290 per person). At follow-up, there were no signficant differences between the dietary prescriptions with regard to body composition, systolic and diastolic blood pressures, triglycerides, HDL-cholesterol, glucose, insulin and predicted insulin sensitivity. However, total and LDL cholesterol were significantly lower on the High Carbohydrate Diet compared with the High Monounsaturated fat Diet (total cholesterol 0.2mmol/l, P=0.044, LDL cholesterol 0.2mmol/l, P=0.042). At follow-up those on the High Monounsaturated fat Diet reported significantly higher intakes of saturated fat (1.5%TE), total fat (5%TE), monounsaturated fat (2.4%), and a significantly lower intake of carbohydrate (-5%TE) than those on the High Carbohydrate Diet. Conclusion: A relatively inexpensive nurse led programme appears to be as effective as a more costly expert health professional led programme in achieving weight maintenance over a 2-year period. This inexpensive and successful weight maintenance programme offers a feasible option for implementation in primary health care in New Zealand. Similarly, both dietary approaches produced comparable beneficial effects in terms of weight loss maintenance. However the High Carbohydrate Diet was associated with lower levels of total and LDL cholesterol, possibly due to a lower intake of saturated fat.

published_or_final_version / Public Health / Master / Master of Public Health

Introduction: Dementia refers to impairments of memory and other cognitive functions with consequent decline in activities of daily living. Besides cognitive symptoms, demented patients can also exhibit behavioral and psychological symptoms of dementia (BPSD), which are stressors leading to family caregivers’ burden. Physical activity may give rise to benefits in cognitive function, and may reduce behavioral symptoms and caregivers’ burden. However, most previous studies were reported from Caucasian populations. There was no previous report on the relationship of physical activity in dementia patients on family caregiver’s burden in Hong Kong Chinese older adults. Objectives: The objective of this study was to investigate the associations of physical activity level with cognitive function, behavioral and psychological symptoms and caregivers’ burden in dementia patients in Hong Kong Chinese population. Method: This was a cross-sectional study. 201 dementia patients who were screened by the inclusion and exclusion criteria were recruited from the Geriatric Clinic in Queen Mary Hospital, Hong Kong, from May 2013 to August 2013. Social demographic information and comorbid diseases information were collected from all subjects. Subjects were then assessed with the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Alzheimer’s Disease Cooperative Study Activities of Daily Living Inventory (ADCS-ADL), Physical Activity Scale for the Elderly (PASE), as well as Neuropsychiatric Inventory (NPI). Subjects’ family caregivers were assessed with Zarit Burden Interview (ZBI). Main outcome measures: The outcome measures for the cognitive function were the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). The outcome measures for BPSD and caregiver’s burden were the Neuropsychiatric Inventory (NPI) and Zarit Burden Interview (ZBI), respectively. Results: We screened a total of 239 subjects in the Geriatric Clinic of Queen Mary Hospital. 201 subjects (70 males and 131 females) were recruited. 38 participants were excluded according to the exclusion criteria. The score means (SD) of the recruited were: PASE =27.5 (23.9); ADCS-ADL=45.3 (14.5); MMSE=17.3 (5.4); MoCA=9.9 (5.3); NPI=9.5 (9.7); ZBI=33.3 (14.8). In bivariate analysis, the PASE score was significantly associated with the MMSE score (rho=0.259, p<0.001), the MoCA score (rho=0.311, p<0.001), the NPI score (rho=-0.225, p=0.001), and the ZBI score (rho=-0.253, p<0.001). In multivariate analyses, using general linear models, the PASE score was independently associated with the MMSE (F=5.57, p=0.001) and MoCA (F=7.10, p<0.001) scores, after adjusting for significant confounders in bivariate analyses (i.e. age, education and gender). The PASE was also independently associated with the NPI score (F=2.89, p=0.037). The PASE score was not an independent predictor of the ZBI score. However, the subjects’ ADCS-ADL score (F=15.65, p<0.001), and the NPI score (F=8.55, p=0.004) were independent predictors of the caregiver’s ZBI score. / published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Introduction Depression can lead to long term health burden; while alcohol is now also one of the global burdens of diseases. This review is trying to investigate how healthy population can be at risk when the trends of alcohol consumption are increasing. Methods and Results This review studied 11 journals out of 1096 literature in PubMed / Medline / PsyInfo for alcohol and depression association via prospective cohort or longitudinal study. Results varied in outcomes measured and no conclusion on developed causality with alcohol and depression. Discussions Some significant associations may be observed at heavy use of alcohol or binge drinking groups. Young adolescents association was not as significant as adult studies results. Some stratification on gender difference is also non-conclusive. Population on heavy drinking and dependency are at risk of developing depression. Conclusions Future perspectives in research like the need of developing high quality research and more on population approach studies focusing on alcohol and depression should be carried. Prevention of alcohol-related problems especially in young people or population as a whole should include policies reducing overall alcohol consumption, or reducing the rates of high-risk drinking. / published_or_final_version / Public Health / Master / Master of Public Health

Objective: To review in the literature on the association between diabetes and background exposure of dioxins among general population. Method: Systematic review on studies the association of background dioxin exposure and diabetes among general population, published from January 1960 to July 2013 in PubMed, and from January 1979 to July 2013 in China National Knowledge Infrastructure (CNKI). Result: A total of nine articles (including seven cross-sectional studies, one longitudinal study and one cohort study) out of 111 articles from PubMed and 5 articles from CNKI were included in the systematic review. Five out of nine studies found a positive association between background exposure to dioxins or dioxins-like compounds and the risk of diabetes whilst two studies reported an inverse association between dioxins and insulin concentrations or IGF-I serum levels. Two studies reported positive significant relation of dioxins and diabetes in women but not in men. Discussion: Based on this systematic review, the association of background dioxins exposure and diabetes among general population remains unclear. Given the crosssection design of the studies, causal relation between dioxin exposure and diabetic risks cannot be drawn. / published_or_final_version / Public Health / Master / Master of Public Health

Introduction Ill-fitting footwear is one of the well-known risk factors causing foot ulceration in the diabetic population. Current literature for fitness of foot dimensions is insufficient, especially on foot-shoe length and foot-shoe width measurement in absolute numerical differences. The aims of the study were to compare and identify the footwear fitness in diabetic patients with peripheral sensory neuropathy, diabetic patients without peripheral neuropathy and non diabetes. Materials and Method 　　Diabetes patients were assessed for peripheral sensory neuropathy by two sensory tests, 10-g monofilament test using 10-g Semmes-Weinstein monofilament and vibration perception threshold test using neurotheisometer. Abnormal results of both tests indicated diabetes sensory neuropathy. The dimensions of foot length and foot width were determined by the Brannock device while internal shoe length and internal shoe width were measured by an inside caliper. The mean of internal shoe-length difference and shoe-width difference of three groups were calculated and compared. Reference ranges of 10-15mm of shoe-length difference and 0-7mm were selected from past literature. The values of shoe-length and shoe-width differences were dichotomized into correct and incorrect fit category. Footwear fitness of the three groups was compared. Demographics of patients, information on self foot care, shoe size check and footwear habit were collected for correlation analysis. Results Data was collected from 20 diabetes patients with sensory neuropathy, 60 diabetes patients without neuropathy and 40 non diabetes controls. There were significant difference in shoe-length difference among three groups, with larger shoe-length difference in diabetic neuropathy group (left: 21.9mm, / right: 21.7mm), followed by non neuropathy diabetes (left: 15.2mm, / right: 15.5mm) and controls (left: 13.4mm, / right: 14.5mm) (left p=0.002 / right p=0.008). The shoe-length differences of both diabetes groups exceeded the reference range, indicating long footwear. No significant difference was reported related to shoe-width difference. Analysis of shoe fit category showed around 15-17% of diabetes patients were wearing correctly fit shoes in both length and width. A high prevalence of diabetes patient had ill-fitting footwear while nearly half of them wear shoes with correct width but incorrect length. There is nearly no correlations between shoe-length fit, shoe-width fit and frequency of self foot check, frequency of footwear size check and frequency of diabetic footwear education. Discussion Most diabetes patients wear ill-fitting footwear, especially those with peripheral sensory neuropathy when compared to control group. There is significant difference in shoe-length difference among the three groups, with reference to the 10-15mm range as the gap length allowance. Diabetic patients tend to wear long and loose footwear in this study even they had past foot education and practice proper self foot check regularly. These might imply incomprehensive proper diabetic footwear education and self footwear assessment in current diabetes care pathway. These components are essential in diabetes foot care and people with diabetes are highly recommended to select a pair of good fit footwear. Further research is required to standardize the methodologies of measurement in foot dimensions and footwear fitness as well as investigate on relations of additional foot parameters in shoe fitting. / published_or_final_version / Orthopaedics and Traumatology / Master / Master of Medical Sciences