-
1.
The potential prolonged effect at one-year follow-up after 18-month randomized controlled trial of a 90 g/day low-carbohydrate diet in patients with type 2 diabetes.
Chen, CY, Huang, WS, Ho, MH, Chang, CH, Lee, LT, Chen, HS, Kang, YD, Chie, WC, Jan, CF, Wang, WD, et al
Nutrition & diabetes. 2022;12(1):17
-
-
-
Free full text
Plain language summary
A low carbohydrate diet (LCD) could be an effective dietary strategy for managing Type 2 Diabetes and body weight. This follow-up of a randomised controlled study evaluated the effect of moderate LCD after 18 months of 90 g/day LCD in 85 poorly controlled Type 2 Diabetic patients and compared it with Traditional Diabetic Diet (TDD). Those who followed the LCD diet ate significantly fewer carbohydrates and more protein and fat at the follow up between 18 and 30 months compared to those who followed the TDD group. The LCD group also showed significant improvements in serum HbA1C, two-hour serum glucose, serum alanine aminotransferase and Medication Effect Score in comparison with the TDD group. However, the level of triglycerides increased, and HDL levels decreased significantly in the LCD group from 18 to 30 months. There was however no significant difference between the groups in the improvement of HbA1C, fasting serum glucose, 2 h serum glucose, as well as serum cholesterol, triglycerides, low-density lipoprotein, ALT, creatinine, and urine microalbumin. To confirm the benefits of LCD on glycaemic control, further robust studies are needed. Results of this study can help healthcare professionals gain a better understanding of the prolonged effects of LCD on glycaemic control, liver function, and medication effect scores.
Abstract
OBJECTIVES To evaluate the effect at a one-year follow-up after an 18-month randomized controlled trial (RCT) of 90 gm/day low-carbohydrate diet (LCD) in type 2 diabetes. RESEARCH DESIGN AND METHODS Eighty-five poorly controlled type 2 diabetic patients with an initial HbA1c ≥ 7.5% who have completed an 18-month randomized controlled trial (RCT) on 90 g/day low-carbohydrate diet (LCD) were recruited and followed for one year. A three-day weighted food record, relevant laboratory tests, and medication effect score (MES) were obtained at the end of the previous trial and one year after for a total of 30 months period on specific diet. RESULTS 71 (83.5%) patients completed the study, 35 were in TDD group and 36 were in LCD group. Although the mean of percentage changes in daily carbohydrate intake was significantly lower for those in TDD group than those in LCD group (30.51 ± 11.06% vs. 55.16 ± 21.79%, p = 0.0455) in the period between 18 months and 30 months, patients in LCD group consumed significantly less amount of daily carbohydrate than patients in TDD group (131.8 ± 53.9 g vs. 195.1 ± 50.2 g, p < 0.001). The serum HbA1C, two-hour serum glucose, serum alanine aminotransferase (ALT), and MES were also significantly lower for the LCD group patients than those in the TDD group (p = 0.017, p < 0.001, p = 0.017, and p = 0.008 respectively). The mean of percentage changes of HbA1C, fasting serum glucose, 2 h serum glucose, as well as serum cholesterol, triglyceride, low-density lipoprotein, ALT, creatinine, and urine microalbumin, however, were not significantly different between the two groups (p > 0.05). CONCLUSIONS The one-year follow-up for patients on 90 g/d LCD showed potential prolonged and better outcome on glycaemic control, liver function and MES than those on TDD for poorly controlled diabetic patients.
-
2.
The benefits and risks of beetroot juice consumption: a systematic review.
Zamani, H, de Joode, MEJR, Hossein, IJ, Henckens, NFT, Guggeis, MA, Berends, JE, de Kok, TMCM, van Breda, SGJ
Critical reviews in food science and nutrition. 2021;61(5):788-804
-
-
-
Plain language summary
This review examined the health benefits and risks associated with beetroot juice (BRJ) from 86 studies. The nitrate contained in high amounts in BRJ increases nitric oxide (NO) levels in the body. NO has vasodilatory effects and thus reduces blood pressure and helps oxygen- and nutrient delivery to organs and muscles. Hence there has been an interest in BRJ for sports performance improvement and the prevention and treatment of cardiovascular disease. The review collected evidence of the effect of BRJ on the cardiovascular system and sports performance according to gender, trained and untrained individuals. Whilst the authors also briefly mention other health benefits of BRJ. From wider research, it is known that excess nitrate can form carcinogenic N-nitroso compounds (NOCs) in the body. Yet little is known whether this could also be a potential risk with BRJ consumption since vegetable consumption and many plant compounds generally appear to reduce the risk of cancers and can block the formation of NOCs. Hence the authors concluded that more research is needed to ensure that currently suggested dosages for BRJ do not aid NOCs production. In summary, BRJ has a beneficial effect on nitric oxide levels, oxygen consumption, blood flow, platelet aggregation, heart rate, cardiac output, blood pressure, improves sports performance and endurance and could be valuable for the management of cardiovascular disease. Yet high levels of consumption may not come without risks and more studies are needed to assess safety.
Abstract
Beetroot juice (BRJ) has become increasingly popular amongst athletes aiming to improve sport performances. BRJ contains high concentrations of nitrate, which can be converted into nitric oxide (NO) after consumption. NO has various functions in the human body, including a vasodilatory effect, which reduces blood pressure and increases oxygen- and nutrient delivery to various organs. These effects indicate that BRJ may have relevant applications in prevention and treatment of cardiovascular disease. Furthermore, the consumption of BRJ also has an impact on oxygen delivery to skeletal muscles, muscle efficiency, tolerance and endurance and may thus have a positive impact on sports performances. Aside from the beneficial aspects of BRJ consumption, there may also be potential health risks. Drinking BRJ may easily increase nitrate intake above the acceptable daily intake, which is known to stimulate the endogenous formation of N-nitroso compounds (NOC's), a class of compounds that is known to be carcinogenic and that may also induce several other adverse effects. Compared to studies on the beneficial effects, the amount of data and literature on the negative effects of BRJ is rather limited, and should be increased in order to perform a balanced risk assessment.
-
3.
Coronavirus disease 2019 (COVID-19) and obesity. Impact of obesity and its main comorbidities in the evolution of the disease.
Cornejo-Pareja, IM, Gómez-Pérez, AM, Fernández-García, JC, Barahona San Millan, R, Aguilera Luque, A, de Hollanda, A, Jiménez, A, Jimenez-Murcia, S, Munguia, L, Ortega, E, et al
European eating disorders review : the journal of the Eating Disorders Association. 2020;28(6):799-815
-
-
-
Plain language summary
The Covid-19 pandemic has caused thousands of deaths worldwide. Being obese is associated with worse outcomes following infection with Covid-19. This review aimed to summarise the data available on the relationship between Covid-19 and obesity, and explored some of the possible reasons for this relationship. The researchers found that obesity is an independent and strong risk factor for severe infection, Intensive Care Unit (ICU) admission and death. The impact of obesity might be of particular relevance in males and in younger individuals. Long‐term complications of Covid‐19 could also be more frequent and severe in obese subjects. There are many potential mechanisms that could explain this relationship. These include the effects of obesity and related diseases such as diabetes, high blood pressure and heart disease on the immune system, lung function, vitamin D deficiency and male hormones. The researchers also discussed the possibility of fat cells acting as a possible reservoir for Covid-19 infection. Research into Covid-19 is still at a very early stage and more studies are needed.
Abstract
The COVID-19 pandemic is posing a great challenge worldwide. Its rapid progression has caused thousands of deaths worldwide. Although multiple aspects remain to be clarified, some risk factors associated with a worse prognosis have been identified. These include obesity and some of its main complications, such as diabetes and high blood pressure. Furthermore, although the possible long-term complications and psychological effects that may appear in survivors of COVID-19 are not well known yet, there is a concern that those complications may be greater in obese patients. In this manuscript, we review some of the data published so far and the main points that remain to be elucidated are emphasized.
-
4.
Dietary flavanols improve cerebral cortical oxygenation and cognition in healthy adults.
Gratton, G, Weaver, SR, Burley, CV, Low, KA, Maclin, EL, Johns, PW, Pham, QS, Lucas, SJE, Fabiani, M, Rendeiro, C
Scientific reports. 2020;10(1):19409
-
-
-
Free full text
Plain language summary
Fruits and vegetables contain flavonoids that can protect against vascular diseases and cognitive ageing. Studies have shown that cocoa flavonoids can enhance the function of endothelial cells and blood vessels in peripheral arteries. This randomised, double-blinded, placebo-controlled crossover study assessed the effects of cocoa flavanols on cerebral and peripheral vascular and cognitive function. The healthy young subjects showed greater tissue oxygenation and cerebrovascular reactivity in the frontal parts of the brain during the carbon dioxide challenge after high cocoa flavonoid intervention. Furthermore, the cocoa flavonoid intervention improved cognitive and peripheral endothelial functions in healthy young subjects. Even though the mechanistic link behind the beneficial effects of flavonoids is not understood completely, the positive effects could be due to the ability of flavanols to enhance the bioavailability of circulation Nitric Oxide (NO). The study also found that flavonoids improved cognitive function in healthy individuals only when there was a high cognitive demand. Further robust studies are required to evaluate the mechanisms behind the benefits associated with acute flavonoid intake. Healthcare professionals can utilise the findings from this study to gain insight into the advantages of consuming a flavonoid-rich diet. Additionally, they can learn about the differing responses to flavanol intake between individuals.
Abstract
Cocoa flavanols protect humans against vascular disease, as evidenced by improvements in peripheral endothelial function, likely through nitric oxide signalling. Emerging evidence also suggests that flavanol-rich diets protect against cognitive aging, but mechanisms remain elusive. In a randomized double-blind within-subject acute study in healthy young adults, we link these two lines of research by showing, for the first time, that flavanol intake leads to faster and greater brain oxygenation responses to hypercapnia, as well as higher performance only when cognitive demand is high. Individual difference analyses further show that participants who benefit from flavanols intake during hypercapnia are also those who do so in the cognitive challenge. These data support the hypothesis that similar vascular mechanisms underlie both the peripheral and cerebral effects of flavanols. They further show the importance of studies combining physiological and graded cognitive challenges in young adults to investigate the actions of dietary flavanols on brain function.
-
5.
PROFAST: A Randomized Trial Assessing the Effects of Intermittent Fasting and Lacticaseibacillus rhamnosus Probiotic among People with Prediabetes.
Tay, A, Pringle, H, Penning, E, Plank, LD, Murphy, R
Nutrients. 2020;12(11)
-
-
-
Free full text
Plain language summary
The prevalence of diabetes is increasing worldwide, and with it, the risk of cardiovascular disease is also increasing. Intermittent fasting has been shown to reduce weight and improve glycaemic control. Weight control and glycaemic control were also improved with probiotic Lacticaseibacillus rhamnosus HN001 supplementation. This pilot, 12-week, double-blinded, two-armed, randomized 1:1 study aimed to investigate the combined effects of intermittent fasting with daily probiotic Lacticaseibacillus rhamnosus HN001 supplementation on glycaemic management in participants with prediabetes. For two days, participants restricted their calorie intake to 600-650 kcal, followed by five days of ad libitum consumption (5:2). Intermittent fasting for 12 weeks improved glycaemic control (reduced HbA1c) and reduced body weight by 5%. The supplementation with Lacticaseibacillus rhamnosus HN001 did not significantly improve these outcomes. Probiotic supplementation significantly improved mental health and social functioning in participants. There is a need for further large, robust studies to assess the effects of intermittent fasting alone and when it is combined with different exercise forms and different prebiotic and probiotic supplements on cardiometabolic markers and mental health. The findings of this study may be useful to healthcare professionals in understanding the effects of fasting on metabolism as well as the psychological benefits of Lacticaseibacillus rhamnosus HN001 supplementation.
Abstract
Both intermittent fasting and specific probiotics have shown promise in improving glucose tolerance with a potential for synergistic effects through alterations to gut microbiota. In this randomized, double-blinded, two-arm feasibility study, we investigated whether intermittent fasting, supplemented with Lacticaseibacillus rhamnosus HN001 probiotic, reduces HbA1c in individuals with prediabetes. All participants with HbA1c 40-50 mmol/mol commenced intermittent fasting (2 days per week of calorie restriction to 600-650 kcal/day) and were randomized 1:1 to either daily probiotic (Lacticaseibacillus rhamnosus HN001) or placebo for 12 weeks. The primary outcome was a change in HbA1c. Secondary outcomes included changes in anthropometry, body composition, glucoregulatory markers, lipids, hunger hormones, liver enzymes, inflammatory markers, gut hormones, calorie and macronutrient intake, quality of life, hunger, mood and eating behavior. Of 33 participants who commenced the trial, 26 participants (mean age 52 years, body mass index (BMI) 34.7 kg/m2) completed the intervention (n = 11 placebo, n = 15 probiotic). HbA1c decreased from 43 ± 2.7 mmol/mol to 41 ± 2.3 mmol/mol, p < 0.001, with average of 5% weight loss. No significant between-group differences were seen in primary or secondary outcomes except for social functioning (p = 0.050) and mental health (p = 0.007) scores as improvements were seen in the probiotic group, but not in the placebo group. This study shows additional psychological benefits of probiotic supplementation during intermittent fasting to achieve weight loss and glycemic improvement in prediabetes.
-
6.
Endothelial Function is improved by Inducing Microbial Polyamine Production in the Gut: A Randomized Placebo-Controlled Trial.
Matsumoto, M, Kitada, Y, Naito, Y
Nutrients. 2019;11(5)
-
-
-
Free full text
Plain language summary
Endothelial dysfunction is an early warning sign for plaque formation in atherosclerosis. This study explores the Bifidobacterium animalis subsp. Lactis (Bifal) and arginine (Arg) on endothelial function in forty-four healthy subjects. The subjects were randomised to receive 100g daily of natural yoghurt containing Bifal and Arg, or a placebo, for a total of twelve weeks. In a precursor to this study, the authors found that Bifal and Arg increased the production of certain polyamines in the gut, essential to cell proliferation and inhibition of inflammation. They concluded that exogenous polyamines from foods may be of benefit to cardiovascular health. In this follow-up study they measured fecal, blood and urine samples to analyse polyamine concentration, bacterial DNA, serum polyamine, inflammatory cytokines, triglycerides and other biochemical parameters. The reactive hyperemia index (RHI), the primary outcome, was measured using endo-peripheral arterial tone (EndoPAT). The results showed that the participants who received the Bifal and Arg yoghurt saw their RHI increase from 1.50 to 1.81, suggesting that Bifal + Arg YG intake restored endothelial function to normal levels. The other biomarkers measured also suggested an improvement of vascular endothelial function with a reduction in serum platelet and triglyceride levels, two risk factors for atherosclerosis.
Abstract
Recently, it was demonstrated that spermidine-induced autophagy reduces the risk of cardiovascular disease in mice. Intestinal bacteria are a major source of polyamines, including spermidine. We previously reported that the intake of both Bifidobacterium animalis subsp. lactis (Bifal) and arginine (Arg) increases the production of putrescine, a spermidine precursor, in the gut. Here, we investigated the effects of Bifal and Arg consumption on endothelial function in healthy subjects. Healthy individuals with body mass index (BMI) near the maximum value in the "healthy" range (BMI: 25) (n = 44) were provided normal yogurt containing Bifal and Arg (Bifal + Arg YG) or placebo (normal yogurt) for 12 weeks in this randomized, double-blinded, placebo-controlled, parallel-group comparative study. The reactive hyperemia index (RHI), the primary outcome, was measured using endo-peripheral arterial tone (EndoPAT). The change in RHI from week 0 to 12 in the Bifal + Arg YG group was significantly higher than that in the placebo group, indicating that Bifal + Arg YG intake improved endothelial function. At week 12, the concentrations of fecal putrescine and serum putrescine and spermidine in the Bifal + Arg YG group were significantly higher than those in the placebo group. This study suggests that consuming Bifal + Arg YG prevents or reduces the risk of atherosclerosis.
-
7.
A randomised controlled intervention trial evaluating the efficacy of a Mediterranean dietary pattern on cognitive function and psychological wellbeing in healthy older adults: the MedLey study.
Knight, A, Bryan, J, Wilson, C, Hodgson, J, Murphy, K
BMC geriatrics. 2015;15:55
-
-
-
Free full text
Plain language summary
Age-related mental decline is an increasing global health problem. Dementia and Alzheimer’s Disease are progressive conditions currently viewed as incurable with no lasting pharmaceutical options. Recent evidence has indicated that diet and lifestyle may help to delay the onset and progression of mental decline. This randomised controlled trial (RCT) will aim to assess the effect of a six months dietary intervention on several mental outcomes, cardiovascular changes and general well being for subjects aged sixty-five and older. The RCT will compare the Mediterranean diet (MedDiet) with continued habitual diet (HabDiet). The MedDiet subjects will follow the traditional Cretan Mediterranean diet. Compliance will be assessed using food questionnaires and multiple blood markers. This RCT will be one of the first worldwide to provide evidence for the cause-effect relationship between the MedDiet and age-related mental function in a healthy older adults. The RCT has recruited 166 participants so will provide robust evidence. Results have yet to be published.
Abstract
BACKGROUND The incidence of age-related cognitive decline is rising considerably around the world. There is evidence from a number of recent cross-sectional and prospective studies indicating positive associations between the Mediterranean dietary pattern (MedDiet) and improved cognitive outcomes among the elderly including, reduced age-related cognitive decline and enhanced age-related cognitive performance. However, to date no study has validated these associations in healthy older adult populations (≥65 years and above) with randomised evidence. The main aim of the present study is to provide justified evidence regarding the efficacy of a MedDiet approach to safely reduce the onset of cognitive decline, and promote optimal cognitive performance among healthy older adults using rigorous, randomised intervention methodology. METHODS/DESIGN MedLey is a 6-month, randomised controlled 2-cohort parallel group intervention trial, with initial assessment at baseline and repeated every three months. A sample of 166 healthy Australian men and women aged 65 years and above, with normal cognitive function and proficient in English language were recruited from metropolitan Adelaide, South Australia for the study. Participants randomly allocated to the experimental group are required to maintain an intervention dietary pattern based from the traditional Cretan MedDiet (i.e. vegetables, fruits, olive oil, legumes, fish, whole grain cereals, nuts and seeds and low consumption of processed foods, dairy products, red meat and vegetable oils) for six months, while those participants allocated to the control group are asked to maintain their customary lifestyle and diet. The primary outcome of interest is the quantitative difference in age-related cognitive performance, as measured by latent variables (cognitive constructs) sensitive to normal ageing and diet (i.e. speed of processing, memory, attention, executive functions, visual spatial and visuomotor ability). Secondary outcomes include change in biomarkers of inflammation, oxidative stress, lipid metabolism, glucose, insulin, blood flow velocity, and psychological well-being factors (i.e. stress, sleep, anxiety, depression). DISCUSSION To our knowledge this will be one of the first randomised clinical trials worldwide to provide evidence for the cause-effect relationship between the MedDiet and age-related cognitive function in a healthy older adult population (≥65 years and over). TRIAL REGISTRATION Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12613000602729.