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Nutrients May 2020Rheumatoid arthritis (RA) is a systemic, autoimmune disease characterized by joint involvement, with progressive cartilage and bone destruction. Genetic and... (Review)
Review
Rheumatoid arthritis (RA) is a systemic, autoimmune disease characterized by joint involvement, with progressive cartilage and bone destruction. Genetic and environmental factors determine RA susceptibility. In recent years, an increasing number of studies suggested that diet has a central role in disease risk and progression. Several nutrients, such as polyunsaturated fatty acids, present anti-inflammatory and antioxidant properties, featuring a protective role for RA development, while others such as red meat and salt have a harmful effect. Gut microbiota alteration and body composition modifications are indirect mechanisms of how diet influences RA onset and progression. Possible protective effects of some dietary patterns and supplements, such as the Mediterranean Diet (MD), vitamin D and probiotics, could be a possible future adjunctive therapy to standard RA treatment. Therefore, a healthy lifestyle and nutrition have to be encouraged in patients with RA.
Topics: Adult; Arthritis, Rheumatoid; Diet; Diet, Mediterranean; Dietary Supplements; Disease Progression; Feeding Behavior; Female; Gastrointestinal Microbiome; Humans; Male; Middle Aged; Nutritional Status; Probiotics; Risk Factors; Vitamin D
PubMed: 32443535
DOI: 10.3390/nu12051456 -
BMJ (Clinical Research Ed.) Apr 2020To determine the relative effectiveness of dietary macronutrient patterns and popular named diet programmes for weight loss and cardiovascular risk factor improvement... (Meta-Analysis)
Meta-Analysis
Comparison of dietary macronutrient patterns of 14 popular named dietary programmes for weight and cardiovascular risk factor reduction in adults: systematic review and network meta-analysis of randomised trials.
OBJECTIVE
To determine the relative effectiveness of dietary macronutrient patterns and popular named diet programmes for weight loss and cardiovascular risk factor improvement among adults who are overweight or obese.
DESIGN
Systematic review and network meta-analysis of randomised trials.
DATA SOURCES
Medline, Embase, CINAHL, AMED, and CENTRAL from database inception until September 2018, reference lists of eligible trials, and related reviews.
STUDY SELECTION
Randomised trials that enrolled adults (≥18 years) who were overweight (body mass index 25-29) or obese (≥30) to a popular named diet or an alternative diet.
OUTCOMES AND MEASURES
Change in body weight, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, systolic blood pressure, diastolic blood pressure, and C reactive protein at the six and 12 month follow-up.
REVIEW METHODS
Two reviewers independently extracted data on study participants, interventions, and outcomes and assessed risk of bias, and the certainty of evidence using the GRADE (grading of recommendations, assessment, development, and evaluation) approach. A bayesian framework informed a series of random effects network meta-analyses to estimate the relative effectiveness of the diets.
RESULTS
121 eligible trials with 21 942 patients were included and reported on 14 named diets and three control diets. Compared with usual diet, low carbohydrate and low fat diets had a similar effect at six months on weight loss (4.63 4.37 kg, both moderate certainty) and reduction in systolic blood pressure (5.14 mm Hg, moderate certainty 5.05 mm Hg, low certainty) and diastolic blood pressure (3.21 2.85 mm Hg, both low certainty). Moderate macronutrient diets resulted in slightly less weight loss and blood pressure reductions. Low carbohydrate diets had less effect than low fat diets and moderate macronutrient diets on reduction in LDL cholesterol (1.01 mg/dL, low certainty 7.08 mg/dL, moderate certainty 5.22 mg/dL, moderate certainty, respectively) but an increase in HDL cholesterol (2.31 mg/dL, low certainty), whereas low fat (-1.88 mg/dL, moderate certainty) and moderate macronutrient (-0.89 mg/dL, moderate certainty) did not. Among popular named diets, those with the largest effect on weight reduction and blood pressure in comparison with usual diet were Atkins (weight 5.5 kg, systolic blood pressure 5.1 mm Hg, diastolic blood pressure 3.3 mm Hg), DASH (3.6 kg, 4.7 mm Hg, 2.9 mm Hg, respectively), and Zone (4.1 kg, 3.5 mm Hg, 2.3 mm Hg, respectively) at six months (all moderate certainty). No diets significantly improved levels of HDL cholesterol or C reactive protein at six months. Overall, weight loss diminished at 12 months among all macronutrient patterns and popular named diets, while the benefits for cardiovascular risk factors of all interventions, except the Mediterranean diet, essentially disappeared.
CONCLUSIONS
Moderate certainty evidence shows that most macronutrient diets, over six months, result in modest weight loss and substantial improvements in cardiovascular risk factors, particularly blood pressure. At 12 months the effects on weight reduction and improvements in cardiovascular risk factors largely disappear.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42015027929.
Topics: Blood Pressure; Body Mass Index; Body Weight; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Diet, Carbohydrate-Restricted; Diet, Fat-Restricted; Diet, Mediterranean; Humans; Network Meta-Analysis; Nutrients; Obesity; Randomized Controlled Trials as Topic; Risk Reduction Behavior; Weight Loss
PubMed: 32238384
DOI: 10.1136/bmj.m696 -
Endocrine Practice : Official Journal... Dec 2020Cholesterol is an important molecule in humans and both its excess and its deficiency cause disease. Most clinicians appreciate its role in stabilizing cellular plasma... (Review)
Review
OBJECTIVE
Cholesterol is an important molecule in humans and both its excess and its deficiency cause disease. Most clinicians appreciate its role in stabilizing cellular plasma membranes but are unaware of its myriad other functions.
METHODS
This review highlights cholesterol's newly recognized important roles in human physiology and pathophysiology.
RESULTS
The basis for cholesterol's ubiquitous presence in eukaryote organisms is its three part structure involving hydrophilic, hydrophobic, and rigid domains. This structure permits cholesterol to regulate multiple cellular processes ranging from membrane fluidity and permeability to gene transcription. Cholesterol not only serves as a molecule of regulation itself, but also forms the backbone of all steroid hormones and vitamin D analogs. Cholesterol is responsible for growth and development throughout life and may be useful as an anticancer facilitator. Because humans have a limited ability to catabolize cholesterol, it readily accumulates in the body when an excess from the diet or a genetic abnormality occurs. This accumulation results in the foremost cause of death and disease (atherosclerosis) in the Western world. Identification of cholesterol's disease-producing capabilities dates back 5,000 years to the Tyrolean iceman and more recently to ancient mummies from many cultures throughout the world. In contrast, a deficiency of cholesterol in the circulation may result in an inability to distribute vitamins K and E to vital organs with serious consequences.
CONCLUSION
Understanding the benefits and hazards of cholesterol in the clinical setting will improve the endocrinologist's ability to control diseases associated with this unique molecule.
ABBREVIATIONS
CVD = cardiovascular disease; HDL = high-density lipoprotein; LDL = low-density lipoprotein; NPC1L1 = Niemann-Pick C-1-like-1 protein; U.S. = United States; USDA = U.S. Department of Agriculture.
Topics: Atherosclerosis; Cholesterol; Cholesterol, HDL; Diet; Humans
PubMed: 33471744
DOI: 10.4158/EP-2020-0347 -
Nutrition and Health Dec 2022Low-carbohydrate diets may have endocrine effects, although individual studies are conflicting. Therefore, a review was conducted on the effects of low- versus... (Meta-Analysis)
Meta-Analysis Review
Low-carbohydrate diets may have endocrine effects, although individual studies are conflicting. Therefore, a review was conducted on the effects of low- versus high-carbohydrate diets on men's testosterone and cortisol. The review was registered on PROSPERO (CRD42021255957). The inclusion criteria were: intervention study, healthy adult males, and low-carbohydrate diet: ≤35% carbohydrate. Eight databases were searched from conception to May 2021. Cochrane's risk of bias tool was used for quality assessment. Random-effects, meta-analyses using standardized mean differences and 95% confidence intervals, were performed with Review Manager. Subgroup analyses were conducted for diet duration, protein intake, and exercise duration. Twenty-seven studies were included, with a total of 309 participants. Short-term (<3 weeks), low- versus high-carbohydrate diets moderately increased resting cortisol (0.41 [0.16, 0.66], < 0.01). Whereas, long-term (≥3 weeks), low-carbohydrate diets had no consistent effect on resting cortisol. Low- versus high-carbohydrate diets resulted in much higher post-exercise cortisol, after long-duration exercise (≥20 min): 0 h (0.78 [0.47, 1.1], < 0.01), 1 h (0.81 [0.31, 1.31], < 0.01), and 2 h (0.82 [0.33, 1.3], < 0.01). Moderate-protein (<35%), low-carbohydrate diets had no consistent effect on resting total testosterone, however high-protein (≥35%), low-carbohydrate diets greatly decreased resting (-1.08 [-1.67, -0.48], < 0.01) and post-exercise total testosterone (-1.01 [-2, -0.01] = 0.05). Resting and post-exercise cortisol increase during the first 3 weeks of a low-carbohydrate diet. Afterwards, resting cortisol appears to return to baseline, whilst post-exercise cortisol remains elevated. High-protein diets cause a large decrease in resting total testosterone (∼5.23 nmol/L).
Topics: Adult; Male; Humans; Hydrocortisone; Testosterone; Diet, Carbohydrate-Restricted; Exercise; Carbohydrates
PubMed: 35254136
DOI: 10.1177/02601060221083079 -
Nutrients Jul 2020Osteoporosis is a common chronic disease characterized by a decrease in bone mineral density, impaired bone strength, and an increased risk of fragility fractures.... (Review)
Review
Osteoporosis is a common chronic disease characterized by a decrease in bone mineral density, impaired bone strength, and an increased risk of fragility fractures. Fragility fractures are associated with significant morbidity, mortality and disability and are a major public health problem worldwide. The influence of nutritional factors on the development and progression of this disease can be significant and is not yet well established. Calcium intake and vitamin D status are considered to be essential for bone metabolism homeostasis. However, some recent studies have questioned the usefulness of calcium and vitamin D supplements in decreasing the risk of fractures. The adequate intake of protein, vegetables and other nutrients is also of interest, and recommendations have been established by expert consensus and clinical practice guidelines. It is important to understand the influence of nutrients not only in isolation but also in the context of a dietary pattern, which is a complex mixture of nutrients. In this review, we evaluate the available scientific evidence for the effects of the main dietary patterns on bone health. Although some dietary patterns seem to have beneficial effects, more studies are needed to fully elucidate the true influence of diet on bone fragility.
Topics: Bone Density; Bone and Bones; Calcium, Dietary; Chronic Disease; Diet; Diet, Healthy; Dietary Supplements; Humans; Nutritional Status; Osteoporosis; Osteoporotic Fractures; Vitamin D
PubMed: 32635394
DOI: 10.3390/nu12071986 -
JAMA Network Open Nov 2023Increasing evidence suggests that, compared with an omnivorous diet, a vegan diet confers potential cardiovascular benefits from improved diet quality (ie, higher... (Randomized Controlled Trial)
Randomized Controlled Trial
IMPORTANCE
Increasing evidence suggests that, compared with an omnivorous diet, a vegan diet confers potential cardiovascular benefits from improved diet quality (ie, higher consumption of vegetables, legumes, fruits, whole grains, nuts, and seeds).
OBJECTIVE
To compare the effects of a healthy vegan vs healthy omnivorous diet on cardiometabolic measures during an 8-week intervention.
DESIGN, SETTING, AND PARTICIPANTS
This single-center, population-based randomized clinical trial of 22 pairs of twins (N = 44) randomized participants to a vegan or omnivorous diet (1 twin per diet). Participant enrollment began March 28, 2022, and continued through May 5, 2022. The date of final follow-up data collection was July 20, 2022. This 8-week, open-label, parallel, dietary randomized clinical trial compared the health impact of a vegan diet vs an omnivorous diet in identical twins. Primary analysis included all available data.
INTERVENTION
Twin pairs were randomized to follow a healthy vegan diet or a healthy omnivorous diet for 8 weeks. Diet-specific meals were provided via a meal delivery service from baseline through week 4, and from weeks 5 to 8 participants prepared their own diet-appropriate meals and snacks.
MAIN OUTCOMES AND MEASURES
The primary outcome was difference in low-density lipoprotein cholesterol concentration from baseline to end point (week 8). Secondary outcome measures were changes in cardiometabolic factors (plasma lipids, glucose, and insulin levels and serum trimethylamine N-oxide level), plasma vitamin B12 level, and body weight. Exploratory measures were adherence to study diets, ease or difficulty in following the diets, participant energy levels, and sense of well-being.
RESULTS
A total of 22 pairs (N = 44) of twins (34 [77.3%] female; mean [SD] age, 39.6 [12.7] years; mean [SD] body mass index, 25.9 [4.7]) were enrolled in the study. After 8 weeks, compared with twins randomized to an omnivorous diet, the twins randomized to the vegan diet experienced significant mean (SD) decreases in low-density lipoprotein cholesterol concentration (-13.9 [5.8] mg/dL; 95% CI, -25.3 to -2.4 mg/dL), fasting insulin level (-2.9 [1.3] μIU/mL; 95% CI, -5.3 to -0.4 μIU/mL), and body weight (-1.9 [0.7] kg; 95% CI, -3.3 to -0.6 kg).
CONCLUSIONS AND RELEVANCE
In this randomized clinical trial of the cardiometabolic effects of omnivorous vs vegan diets in identical twins, the healthy vegan diet led to improved cardiometabolic outcomes compared with a healthy omnivorous diet. Clinicians can consider this dietary approach as a healthy alternative for their patients.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT05297825.
Topics: Adult; Female; Humans; Male; Body Weight; Cardiovascular Diseases; Cholesterol, LDL; Diet, Vegan; Insulins; Twins, Monozygotic; Vegetables; Middle Aged; Diet, Healthy
PubMed: 38032644
DOI: 10.1001/jamanetworkopen.2023.44457 -
Current Opinion in Gastroenterology Nov 2022Several recent studies have corroborated a strong association between diet and gastric cancer risk; investigators have also identified dietary factors that protect... (Review)
Review
PURPOSE OF REVIEW
Several recent studies have corroborated a strong association between diet and gastric cancer risk; investigators have also identified dietary factors that protect against gastric cancer. This review summarizes the literature on this topic and guides future research directions.
RECENT FINDINGS
High-salt intake disrupts the gastric mucosal defense barrier, promoting Helicobacter pylori colonization and penetration of other carcinogenic compounds. Processed foods, processed meats, red meat, alcohol, foods with high dietary fat, and dietary cholesterol increase the risk of gastric carcinogenesis. On the other hand, increased consumption of fruits, vegetables, whole grains, nuts, and a low-salt diet may offer a protective effect.
SUMMARY
Despite decreases in gastric cancer incidence because of increased identification and treatment of H. pylori , gastric cancer remains one of the most common cancers worldwide with a high mortality rate. This disturbing statistic highlights the importance of reducing and eliminating other risk factors for gastric cancer. There is a strong body of evidence that alcohol, processed foods, high salt intake, high fat intake, and foods with animal products (meats, eggs, and dairy) increase the risk of gastric cancer. A diet that is high in whole grains, fruits, vegetables, nuts and is low in salt may reduce the risk of gastric cancer.
Topics: Animals; Carcinogenesis; Cholesterol, Dietary; Diet; Dietary Fats; Helicobacter pylori; Humans; Risk Factors; Sodium Chloride, Dietary; Stomach Neoplasms; Vegetables
PubMed: 36165035
DOI: 10.1097/MOG.0000000000000875 -
Applied Physiology, Nutrition, and... Jul 2023In January 2022, a group of experts came together to discuss current perspectives and future directions in nutritional immunology as part of a symposium organized by the... (Review)
Review
In January 2022, a group of experts came together to discuss current perspectives and future directions in nutritional immunology as part of a symposium organized by the Canadian Nutrition Society. Objectives included (1) creating an understanding of the complex interplay between diet and the immune system from infants through to older adults, (2) illustrating the role of micronutrients that are vital to the immune system, (3) learning about current research comparing the impact of various dietary patterns and novel approaches to reduce inflammation, autoimmune conditions, allergies, and infections, and (4) discussing select dietary recommendations aimed at improving disease-specific immune function. The aims of this review are to summarize the symposium and to identify key areas of research that require additional exploration to better understand the dynamic relationship between nutrition and immune function.
Topics: Infant; Humans; Aged; Canada; Nutritional Status; Diet; Micronutrients; Vitamin D
PubMed: 36888970
DOI: 10.1139/apnm-2022-0276 -
Journal of Nutritional Science 2023Whilst dietary cholesterol guidelines have waivered through the years with historic restrictions lifted for the majority of the general population, recommendations to... (Review)
Review
Whilst dietary cholesterol guidelines have waivered through the years with historic restrictions lifted for the majority of the general population, recommendations to reduce saturated fat intake have been the mainstay of dietary guidelines since the 1980s and were recently reinforced by the Scientific Advisory Committee on Nutrition (SACN). Cholesterol metabolism is complex, with saturated fat known to have a more significant contribution at raising levels of low-density lipoprotein (LDL) cholesterol, a well-established risk factor for cardiovascular disease (CVD). However, it is clear from metabolic research that hyper-responsiveness to both dietary cholesterol and saturated fat exists; hence, for specific subsets of the population, reductions in both nutrients may be indicated. With this in mind, the current article aims to provide an overview of the mechanisms underlying biological variation in responsiveness and introduces research currently underway which will hopefully identify simple biomarkers that can be used to predict responsiveness and permit tailored, personalised, dietary advice. Eggs are a well-known source of dietary cholesterol whilst being low in saturated fat. A common question encountered in clinical practice is must individuals limit intake to manage blood cholesterol levels. This article summarises key recent papers which confirm that eggs can be enjoyed as part of a healthy balanced diet, whilst highlighting the need for further research in certain population groups, e.g. in individuals with diabetes.
Topics: Humans; Dietary Fats; Cholesterol, Dietary; Cardiovascular Diseases; Cholesterol; Diet
PubMed: 37706071
DOI: 10.1017/jns.2023.82 -
Nutrition and Health Jun 2023A recent meta-analysis found low-carbohydrate, high-protein diets (> 3.4 g/kg of bodyweight/day) (g/kg/day) decreased men's total testosterone (∼5.23 nmol/L)... (Meta-Analysis)
Meta-Analysis
A recent meta-analysis found low-carbohydrate, high-protein diets (> 3.4 g/kg of bodyweight/day) (g/kg/day) decreased men's total testosterone (∼5.23 nmol/L) [Whittaker and Harris (2022) Low-carbohydrate diets and men's cortisol and testosterone: systematic review and meta-analysis. . DOI: 10.1177/02601060221083079]. This finding has generated substantial discussion, however, it has often lacked clarity and context, with the term 'high-protein' being used unqualified. Firstly, diets < 3.4 g/kg/day are not associated with a consistent decrease in testosterone. Secondly, the average protein intake is ∼1.3 g/kg/day, conventional 'high-protein' diets are ∼1.8-3 g/kg/day and the vast majority of athletes are < 3.4 g/kg/day; meaning very few individuals will ever surpass 3.4 g/kg/day. To avoid such confusion in the future, the following definitions are proposed: very high (> 3.4 g/kg/day), high (1.9-3.4 g/kg/day), moderate (1.25-1.9 g/kg/day) and low (<1.25 g/kg/day). Using these, very high-protein diets (> 3.4 g/kg/day) appear to decrease testosterone, however high- and moderate-protein diets (1.25-3.4 g/kg/day) do not.
Topics: Male; Humans; Testosterone; Body Weight; Diet, Carbohydrate-Restricted; Nutritional Status; Diet, High-Protein
PubMed: 36266956
DOI: 10.1177/02601060221132922