Browsing by Person "Farhat, Grace"

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A need to reconsider the definition of 'healthy participants' in epidemiological studies and clinical trials
(Nature, 2014-06) Farhat, Grace
Health is defined as the absence of disease with a state of physical, mental and social welfare.1 Overweight and obesity describe weight ranges that are above the healthy limits, and are frequently assessed by body mass index (BMI) and also by waist circumference (WC) and body fat percentage.2 BMI provides a rough estimate of the body fat percentage for most people, with few exceptions as in the case of athletes (it overestimates fat mass) and older people (it underestimates fat mass). Central body fat distribution has been regarded as an important predictor of chronic disorders such as cardiovascular diseases and type 2 diabetes.
Comparison of the Effects of High versus Low-Polyphenol Dark Chocolate on Body Weight and Biochemical Markers: A Randomized Trial
(E-Cronicon, 2015-09-12) Farhat, Grace; Drummond, Sandra; Fyfe, Lorna; McDougall, G.; Al-Dujaili, Emad A. S.
Background: Dark chocolate (DC) has amongst the highest content of polyphenols in foods, but the chocolate processing methods may greatly reduce this amount. Few studies addressed the possible detrimental effects of low polyphenol DC on body weight, glucose metabolism and lipid levels, and the potential role of cocoa flavanols in body weight control. Therefore, this study aimed to determine the effect of DC rich and DC low in polyphenols on BMI, fasting blood glucose, high sensitivity C-reactive protein (hs-CRP) and lipid levels in adults. Methods: Sixty-one participants took part in a randomized parallel trial. Volunteers randomly received 20g daily of either PRDC (polyphenol-rich DC) or of low polyphenol DC (LPDC) for four weeks. Anthropometric measures and blood samples were collected at baseline and after 4 weeks. Results: A significant net increase in BMI (0.17 0.32 kg/m2, p = 0.007), fasting blood glucose (0.44 1.08 mmol/l, p = 0.041) and triglycerides levels (0.13 0.23 mmol/l, p = 0.008) was observed in the low polyphenol DC group following the 4 weeks intervention, while the levels of these parameters did not significantly change in the polyphenol-rich DC group. There was no significant change in hs-CRP levels in both groups. Conclusions: Results show that the intake of PRDC seems to be more metabolically healthy than LPDC intake, and this highlights the potential role of polyphenols in counteracting the negative effects of fat and energy intake in chocolate. The outcomes raise concerns about the polyphenol content and quality of DC products in the market. Further studies are needed to fully investigate the health benefits of dark chocolate intake, compare the effects of different types of chocolate and establish the necessary guidelines of the type and content of polyphenols in the chocolate preparations to ensure their favourable effect on health.
Dark Chocolate: An Obesity Paradox or a Culprit for Weight Gain?
(John Wiley & Sons, Ltd, 2014-06-02) Farhat, Grace; Drummond, Sandra; Fyfe, Lorna; Al-Dujaili, Emad A. S.
Obesity remains a major public health challenge, and its prevalence is dramatically increasing. Diet and exercise are typically recommended to prevent and manage obesity; however, the results are often conflicting. Polyphenols, a class of phytochemicals that have been shown to reduce the risk factors for diabetes type II and cardiovascular diseases, are recently suggested as complementary agents in the management of obesity through several mechanisms such as decreasing fat absorption and/or fat synthesis. Dark chocolate, a high source of polyphenols, and flavanols in particular, has lately received attention for its possible role in modulating obesity because of its potential effect on fat and carbohydrate metabolism, as well as on satiety. This outcome was investigated in animal models of obesity, cell cultures and few human observational and clinical studies. The research undertaken to date has shown promising results, with the possible implication of cocoa/dark chocolate in the modulation of obesity and body weight through several mechanisms including decreasing the expression of genes involved in fatty acid synthesis, reducing the digestion and absorption of fats and carbohydrates and increasing satiety. 2013 John Wiley & Sons, Ltd.
Effect of polyphenol-rich dark chocolate on anthropometric, nutritional, biochemical and physiological markers in normal weight and overweight adults
(Queen Margaret University, Edinburgh, 2014) Farhat, Grace
Polyphenols are phytochemicals widely available in plants. Dark chocolate (DC) is a high source of polyphenols, particularly flavanols. Studies previously reported a beneficial effect of polyphenol-rich dark chocolate (PRDC) on insulin sensitivity and oxidative stress, while its effects on blood pressure, serum lipid levels and inflammation remain unclear. In addition, a research area regarding the effect of PRDC on body weight control emerged recently. Two investigations were carried out. Study I (61 participants) looked at the effect of PRDC on insulin sensitivity in normal weight and overweight adults, while Study II (14 participants) investigated the effect of PRDC on body weight in overweight individuals. Volunteers received 20g of either PRDC (500mg of polyphenols) or placebo DC (low in polyphenols) daily for 4 weeks (Study I) or 12 weeks (Study II). Anthropometric measures and blood, saliva and urine samples were taken. Results showed that 4 weeks of PRDC supplementation decreased insulin levels (p<0.001) and HOMA-IR (p=0.003), and increased QUICKI (p<0.001), but had no significant impact on glucose levels (p=0.16). However, participants administered placebo DC showed an increase in insulin (p=0.014), HOMA-IR (p=0.003), TG (p= 0.008), glucose (p=0.041) and BMI (p=0.007) levels and a decrease in QUICKI (p=0.013). No significant changes in blood pressure, other serum lipid levels or glucocorticoid hormones were noted in both groups. In study II, there was an increase in BMI in the whole study population (p=0.046) with no significant difference between groups. Results indicate a potential implication of PRDC in the prevention of risk factors for cardiovascular diseases. Findings also highlight the detrimental effects of placebo DC, and propose the analysis of polyphenol content of different DC brands in the market. The increase in BMI and other markers only in the placebo group after four weeks, suggests that PRDC may counteract the adverse effects of fat and energy in the diet. However, the increase in BMI in both groups after 12 weeks implies further investigations to test the counteracting effect of PRDC over the long term.
Effect of Polyphenol-Rich Dark Chocolate on Salivary Cortisol and Mood in Adults
(MDPI, 2019-05-29) Tsang, Catherine; Hodgson, Lindsay; Bussu, Anna; Farhat, Grace; Al-Dujaili, Emad
The aim of the present study was to investigate whether ingestion of polyphenol-rich dark chocolate improved salivary cortisol levels and subjective mood states in adults recruited from a health and social care setting. Twenty-six participants ingested 25 g/day of a high polyphenol dark chocolate (containing 500 mg of total flavonoids) or a similar amount of a control dark chocolate containing negligible flavonoids for four weeks. Twenty-four-hour salivary glucocorticoid levels (cortisol and cortisone) were measured by an enzyme-linked immunosorbent assay, and subjective mood was assessed using a validated Positive Affect and Negative Affect Schedule. Total daily cortisol, morning cortisol, and the cortisol/cortisone ratio were significantly reduced (p < 0.001) after ingestion of only the high polyphenol dark chocolate. There were no significant differences between groups for overall scores for positive affect and negative affect. No changes were observed after the control dark chocolate, or any other parameter measured. In conclusion, the findings from this small-scale study indicate lowering of salivary cortisol levels following polyphenol-rich dark chocolate in adults recruited from a health and social care setting. Such changes may be attributable to their ability to inhibit 11β-hydroxysteroid dehydrogenase type 1 activity and warrant further investigation.
Effect of pomegranate extract on blood pressure and anthropometry in adults: a double-blind placebo-controlled randomised clinical trial
(CUP, 2017-08-09) Stockton, Angela; Farhat, Grace; McDougall, Gordon J.; Al-Dujaili, E. A. S.
Pomegranate (Punica granatum), a polyphenol-rich fruit, has been suggested to reduce cardiovascular risk due to its antioxidant properties. Hypertension and obesity are the most preventable cardiovascular risk factors. Few studies on blood pressure and/or body-weight status have been conducted in human subjects. Previous investigations have tended to focus on pomegranate juice. The aim of the present study was to investigate the effect of pomegranate extract (PE) on blood pressure and anthropometric measures in adults with no symptomatic disease. A total of fifty-five participants enrolled in a randomised double-blinded placebo-controlled clinical trial where they were assigned to either PE capsules or placebo capsules for 8 weeks. Blood pressure, body weight, waist circumference, waist:hip ratio (WHR) and body composition (lean body mass, body fat) were measured at baseline, week 4 and week 8. Results showed a significant decrease in diastolic blood pressure after 8 weeks (by 279 (sd 532) mmHg; P < 005), while the decrease in systolic blood pressure did not reach statistical significance (257 (sd 74) mmHg; P > 005). Body fat percentage, lean body mass, waist circumference and WHR did not significantly differ between groups at the end of the intervention. Results suggest that PE may reduce blood pressure and possibly prevent hypertension in the normotensive population. Further large trials are required to elucidate this effect.
Polyphenols and Their Role in Obesity Management: A Systematic Review of Randomized Clinical Trials
(Wiley, 2017-05-11) Farhat, Grace; Drummond, Sandra; Al-Dujaili, Emad A. S.
Polyphenols have been suggested to reduce body weight and modify body composition through different mechanisms. These effects have been extensively studied in animals and in vitro and to a lesser extent in humans. The aim of this review is to consider the association between polyphenols and body weight status by focusing on human intervention studies. We conducted a systematic literature search in MEDLINE (via EBSCOhost), ProQuest CENTRAL, and Cochrane CENTRAL without time restrictions. Randomized controlled trials assessing the effect of polyphenols on weight and/or body composition in the overweight and/or obese population were included. Nineteen studies met our inclusion criteria. Results suggest that further research is required before supporting a potential role of polyphenols in reducing weight in overweight and obese individuals (nine studies showed a significant decrease in weight by a mean of 1.47 0.58 kg). Nevertheless, several studies indicated that polyphenols might be effective in preventing small increases in weight during periods of overfeeding rather than reducing weight as such. The outcomes noted do not yet support polyphenol supplementation as a complementary approach in weight loss diets. Further larger trials with a duration of 12 months or more are needed to elucidate the effect of polyphenols on body weight status. Copyright 2017 John Wiley & Sons, Ltd. Copyright 2017 John Wiley & Sons, Ltd.