Dietetics, Nutrition and Biological Sciences
Permanent URI for this collectionhttps://eresearch.qmu.ac.uk/handle/20.500.12289/23
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Item Effect of Polyphenol Supplementation on Memory Functioning in Overweight and Obese Adults: A Systematic Review and Meta-Analysis(MDPI, 2024-02-06) Farag, Sara; Tsang, Catherine; Al-Dujaili, Emad A. S.; Murphy, Philip N.Negative health consequences of obesity include impaired neuronal functioning and cell death, thus bringing the risk of impaired cognitive functioning. Antioxidant properties of polyphenols offer a possible intervention for overweight people, but evidence for their effectiveness in supporting cognitive functioning is mixed. This review examined evidence from randomized controlled trials concerning the effect of polyphenols on tasks requiring either immediate or delayed retrieval of learned information, respectively, thus controlling for differences in cognitive processes and related neural substrates supporting respective task demands. Searches of the PubMed/Medline, PsycInfo, and Scopus databases identified 24 relevant primary studies with N = 2336 participants having a BMI ≥ 25.0 kg/m2. The participants’ mean age for the 24 studies exceeded 60 years. Respective meta-analyses produced a significant summary effect for immediate retrieval but not for delayed retrieval. The present findings support a potential positive effect of chronic supplementation with polyphenols, most notably flavonoids, on immediate retrieval in participants aged over 60 years with obesity being a risk factor for cognitive impairment. We recommend further investigation of this potential positive effect in participants with such risk factors. Future research on all populations should report the phenolic content of the supplementation administered and be specific regarding the cognitive processes tested.Item Antioxidant Properties and Beneficial Cardiovascular Effects of a Natural Extract of Pomegranate in Healthy Volunteers: A Randomized Preliminary Single-Blind Controlled Study(MDPI, 2022-10-28) Al-Dujaili, Emad A. S.; Casey, Ciara; Stockton, AngelaPomegranates are known to possess anti-hypertensive, anti-atherogenic and cardioprotective effects mainly due to their pleiotropic effects on various cellular pathways, especially those triggered by oxidative stress. The aim of this study was to investigate the effect of natural standardized pomegranate (PE) extract on cardiovascular risk factors in 24 healthy volunteers who participated in a randomized, single-blind placebo-controlled study. There were 12 subjects in the PE group and 12 in the placebo group. Variables were measured at baseline and after 14 and 28 days of supplementation are anthropometry, BP, pulse wave velocity, fat and lean body mass, salivary and urinary cortisol, and cortisone, total phenolics, antioxidant capacity and lipid peroxidation. Urinary total phenolics excretion and antioxidant capacity were significantly increased after 14 and 28 days of PE intake. At day 28, there were also statistically significant decreases in systolic and diastolic blood pressure (BP), pulse wave velocity, body fat and fat mass, as well as an increase in lean body mass. Significant changes in the placebo group were not found. Glucocorticoid levels showed a significant decrease in saliva cortisol at day 28 (morning) in the PE group, and cortisol/cortisone ratio was significantly decreased following 28 days of PE intake at morning, noon, and evening. Urine free cortisol was significantly reduced at day 14. These findings suggest that pomegranate extract intake may improve antioxidant and oxidative stress status and play a beneficial role in the attenuation of some cardiovascular risk factors. Future studies should concentrate on overweight and older people.Item Effect of Pomegranate Extract Consumption on Satiety Parameters in Healthy Volunteers: A Preliminary Randomized Study(MDPI, 2022-08-31) Stockton, Angela; Al-Dujaili, Emad A. S.There has been an increasing interest in nutraceuticals and functional foods in reducing appetite and to lose weight. We assessed the effect of oral pomegranate extract (PE) and PE juice (PJ) intake vs. placebo on satiety parameters in healthy volunteers. Twenty-eight subjects (mean age 34.5 ± 13.7 years, body mass index [BMI] 25.05 ± 3.91 kg/m2) were randomized to 3-week priming supplementation with PE (Pomanox®) or placebo. On week 3, satiety parameters were determined on 1 testing day after participants ingested a breakfast and a lunch meal with PJ juice, using 100-mm visual acuity scales (VAS) for hunger, desire to eat, fullness and satisfaction. Meal quality and palatability were also tested. The desire to eat was less at all time points in the PJ juice with PE priming group and participants were also less hungry (p = 0.044) than those who consumed placebo. There was an overall significant difference between the groups (p 0.001). Participants in the PJ juice with PE priming group experienced significantly greater satisfaction (p = 0.036) and feeling of fullness (p = 0.02) than those in the placebo group. These findings suggest that consumption of PE could have the potential to modulate satiety indicators.Item Effects of ginseng ingestion on salivary testosterone and DHEA levels in healthy females: An exploratory study(MDPI, 2020-05-28) Al-Dujaili, Emad A. S.; Abu Hajleh, Maha N.; Chalmers, RuthGinseng is a traditional herbal adaptogen that has been historically used in China and the Far East. Ginsenosides are the active component of ginseng known to exert several actions by targeting “multi-receptor systems”, both extracellular and intracellular. In humans, ginseng effects remain unclear. This study aimed to investigate whether ginseng can influence salivary androgen levels (testosterone and dehydroepiandrosterone (DHEA)) in females. The study followed a parallel partially controlled design. Healthy women (n = 24) were recruited and divided into two groups (A = 20−32 and B = 38−50 years). Volunteers were asked to maintain a food diary pre and post ginseng consumption and collected four salivary samples (7 a.m., 9 a.m., 12 p.m., and 5 p.m.) before and after ingesting 75 mg red Korean ginseng extract per day for seven days. Testosterone and DHEA were then assayed by ELISA methods. Group A’s mean daily salivary testosterone pre ginseng ingestion increased from 76.3 ± 16.6 to 98.4 ± 21.1 pg/mL post ginseng (p 0.01) with significant difference at all time points, and mean daily salivary DHEA increased from 1.53 ± 0.63 to 1.98 ± 0.89 ng/mL post ginseng (p = 0.02). Group B’s mean daily salivary testosterone pre ginseng ingestion was 61.2 ± 16.9 and post ginseng 68.1 ± 11.5 pg/mL (p = 0.132), and daily salivary DHEA increased from 0.91 ± 0.32 to 1.62 ± 0.49 ng/mL post ginseng (p = 0.014) with significant difference at all time points. In conclusion, it appears that ginseng intake significantly increased salivary testosterone levels in the younger women group, but only slightly in the older group. However, DHEA levels in the older women showed a marked and significant increase. These results suggest a potential role for ginseng in modulating salivary androgen levels and that such effect may be more evident in older women where the levels of androgens (DHEA) start to decline. However, it has to be stressed that our results are preliminary and further properly controlled trials are justified.