The effect of dietary glycemic index and glycemic load on inflammatory biomarkers: a systematic review and meta-analysis of randomized clinical trials

Low-Grade Inflammation and Ultra-Processed Foods Consumption: A Review

Low-grade inflammation alters the homeostasis of the organism and favors the onset of many chronic diseases. The global growth in the prevalence of noncommunicable diseases in recent years has been accompanied by an increase in the consumption of ultra-processed foods (UPF). Known to be hyperpalatable, economic and ready-to-eat, increased consumption of UPF has already been recognized as a risk factor for several chronic diseases. Different research groups have tried to investigate whether UPF consumption could promote low-grade inflammation and thus favor the development of noncommunicable diseases. Current evidence highlights the adverse health effects of UPF characteristics, not only due to the nutrients provided by a diet rich in UPF, but also due to the non-nutritive components present in UPF and the effect they may have on gut health. This review aims to summarize the available evidence on the possible relationship between excessive UPF consumption and modulation of low-grade inflammation, as potential promoters of chronic disease.

The Impact of Diet and Physical Activity on Psoriasis: A Narrative Review of the Current Evidence

Psoriasis is an inflammatory disease with strong genetic links and numerous features of autoimmunity that are also influenced by environment and lifestyle, including nutritional factors and physical activity (PA), with regards to the condition of patients. Recent reports in the field of nutrigenomics indicate a significant impact of nutrients in modulating microRNAs. However, few studies have evaluated the effect of nutritional systems and PA on treating psoriasis. This narrative review updates information regarding the current dietary recommendations for individuals with psoriasis and discusses the role of diet and PA in psoriasis prevention and treatment. Application of nutrigenetics in psoriasis therapy is also discussed. The PubMed and Google Scholar databases were searched using the MeSH terms for "nutrigenomics", "dietetics", "diet therapy", "diet", "physical activity", and "exercise" in conjunction with the MeSH terms for "psoriasis" and "dermatology". Evidence has shown that patients with psoriasis should have a personalized anti-inflammatory diet. Psoriasis patients are less physically active; most performed exercises of low-to-moderate intensity and were less likely to undertake regular exercise. Identifying nutrigenomic discoveries and the current lifestyle interventions associated with psoriasis can help physicians and physical therapists develop educational programs to manage and protect against the disease.

Combined association of depressive symptoms and sugar-sweetened beverages consumption with low cognitive performance

BACKGROUND

The combined association of depressive symptoms and sugar-sweetened beverages (SSB) consumption with low cognitive performance is poorly understood so far.

METHODS

Data from the National Health and Nutrition Examination Survey 2011-2014 and Food Patterns Equivalents Database was used. Depressive symptoms were identified using the Patient Health Questionnaire-9. The combinations of depressive symptoms/SSB were defined as a categorical variable comprising no depressive symptoms/low SSB, no depressive symptoms/high SSB, mild-to-severe depressive symptoms/low SSB and mild-to-severe depressive symptoms/high SSB. Cognitive function was measured by three tests. People whose score were lower than the gender group stratified lowest quartile were defined as low cognitive performance. Logistic regression model was applied to examine the combined association with low cognitive performance. Interaction analysis was conducted to verify the interaction with gender.

RESULTS

The combined associations of depressive symptoms and SSB consumption with low cognitive performance were significant. For the Consortium to Establish a Registry for Alzheimer's Disease test, the combinations of mild-to-severe depressive symptoms/low SSB (ORs (95 % CI): 1.59 (1.01, 2.52)), no depressive symptoms/high SSB (ORs (95 % CI): 1.48 (0.96, 2.26)) and mild-to-severe depressive symptoms/high SSB (ORs (95 % CI): 1.74 (1.21, 2.53)) had significant or marginally significant associations with low cognitive performance to those with no depressive symptoms and low SSB consumption.

LIMITATION

This is a cross-sectional study.

CONCLUSIONS

The combination of depressive symptoms and SSB consumption might be associated with low cognitive performance, which had gender differences. These evidences could help guide interventions that focus on dietary nutrition patterns or mood for low cognitive performance.

High-Fat Diet Impairs Muscle Function and Increases the Risk of Environmental Heatstroke in Mice

Environmental heat-stroke (HS) is a life-threatening response often triggered by hot and humid weather. Several lines of evidence indicate that HS is caused by excessive heat production in skeletal muscle, which in turn is the result of abnormal Ca2+ leak from the sarcoplasmic reticulum (SR) and excessive production of oxidative species of oxygen and nitrogen. As a high fat diet is known to increase oxidative stress, the objective of the present study was to investigate the effects of 3 months of high-fat diet (HFD) on the HS susceptibility of wild type (WT) mice. HS susceptibility was tested in an environmental chamber where 4 months old WT mice were exposed to heat stress (41 °C for 1 h). In comparison with mice fed with a regular diet, mice fed with HFD showed: (a) increased body weight and accumulation of adipose tissue; (b) elevated oxidative stress in skeletal muscles; (c) increased heat generation and oxygen consumption during exposure to heat stress; and finally, (d) enhanced sensitivity to both temperature and caffeine of isolated muscles during in-vitro contracture test. These data (a) suggest that HFD predisposes WT mice to heat stress and (b) could have implications for guidelines regarding food intake during periods of intense environmental heat.

Effect of low glycaemic index or load dietary patterns on glycaemic control and cardiometabolic risk factors in diabetes: systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To inform the update of the European Association for the Study of Diabetes clinical practice guidelines for nutrition therapy.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, and the Cochrane Library searched up to 13 May 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials of three or more weeks investigating the effect of diets with low glycaemic index (GI)/glycaemic load (GL) in diabetes.

OUTCOME AND MEASURES

The primary outcome was glycated haemoglobin (HbA1c). Secondary outcomes included other markers of glycaemic control (fasting glucose, fasting insulin); blood lipids (low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), non-HDL-C, apo B, triglycerides); adiposity (body weight, BMI (body mass index), waist circumference), blood pressure (systolic blood pressure (SBP) and diastolic blood pressure (DBP)), and inflammation (C reactive protein (CRP)).

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and assessed risk of bias. Data were pooled by random effects models. GRADE (grading of recommendations assessment, development, and evaluation) was used to assess the certainty of evidence.

RESULTS

29 trial comparisons were identified in 1617 participants with type 1 and 2 diabetes who were predominantly middle aged, overweight, or obese with moderately controlled type 2 diabetes treated by hyperglycaemia drugs or insulin. Low GI/GL dietary patterns reduced HbA1c in comparison with higher GI/GL control diets (mean difference −0.31% (95% confidence interval −0.42 to −0.19%), P<0.001; substantial heterogeneity, I2=75%, P<0.001). Reductions occurred also in fasting glucose, LDL-C, non-HDL-C, apo B, triglycerides, body weight, BMI, systolic blood pressure (dose-response), and CRP (P<0.05), but not blood insulin, HDL-C, waist circumference, or diastolic blood pressure. A positive dose-response gradient was seen for the difference in GL and HbA1c and for absolute dietary GI and SBP (P<0.05). The certainty of evidence was high for the reduction in HbA1c and moderate for most secondary outcomes, with downgrades due mainly to imprecision.

CONCLUSIONS

This synthesis suggests that low GI/GL dietary patterns result in small important improvements in established targets of glycaemic control, blood lipids, adiposity, blood pressure, and inflammation beyond concurrent treatment with hyperglycaemia drugs or insulin, predominantly in adults with moderately controlled type 1 and type 2 diabetes. The available evidence provides a good indication of the likely benefit in this population.

STUDY REGISTRATION

ClinicalTrials.gov NCT04045938.

A systematic review and meta-analysis of prospective studies on obesity and risk of inflammatory bowel disease

CONTEXT

There are only a few systematic reviews on the association of obesity with risk of inflammatory bowel disease (IBD) to date.

OBJECTIVE

The current study was undertaken to systematically review prospective cohort studies on the association between body mass index (BMI) and risk of IBD. It was carried out according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

DATA SOURCES

Relevant prospective cohort studies published from 1969 to July 2020 were searched through PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar, using suitable keywords.

DATA EXTRACTION

Hazard ratios (HRs) or relative risks (RRs) and 95% confidence intervals (CIs) for IBD or its subtypes across categories of BMI were extracted.

DATA ANALYSIS

The log HRs/RRs, including standard errors, were calculated based on reported HRs or RRs and their 95% CIs, and overall effect size was calculated using a fixed-effects model. All statistical analyses were done using STATA version 14.0 (Stata Corp LP, College Station, TX, USA).

CONCLUSION

Overall, 9 studies were included. Combining findings from 5 studies, a statistically significant 21% lower risk of ulcerative colitis incidence was found in patients with obesity than in those with normal weight (RR, 0.79; 95% CI, 0.68-0.92; I2= 0.0%), but not with risk of ulcerative colitis exacerbation, as found by meta-analysis of 3 studies. Pooling data from 5 studies, no significant differences were seen in the risk of Crohn's disease incidence between patients in the highest range of BMI and those in the normal range. In addition, no significant nonlinear association was found between BMI and risk of Crohn's disease (P=0.94). A significant inverse association was found between obesity and total IBD incidence (RR, 0.76; 95% CI, 0.66-0.88; I2=93.2%), but not between increasing BMI and IBD exacerbation, or between increasing BMI and IBD incidence.

Dietary Carbohydrate Intake Glycemic Index and Glycemic Load and the Risk of Prostate Cancer among Iranian Men: A Case-Control Study

Previous studies have presented a few evidences on the relationship between dietary carbohydrate intake, glycemic index (GI), glycemic load (GL), with the prostate cancer risk. We performed a case-control study to evaluate these associations in 50 men with histologically confirmed prostate cancer and 100 control men. Odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs) were derived using logistic regression. The fully adjusted ORs for the top vs. the bottom quartile were 15.02 (P trend = 0.004), 1.04 (P trend = 0.003), and 10.35 (P trend = 0.002) for carbohydrate intake, GI and GL, respectively. Significant associations with prostate cancer remained only among men with reduced fiber intake for carbohydrate intake, GI and GL and among those had increased fiber intake for GI. These findings support the hypothesis that diet with high carbohydrate, GI and GL enhance risk of prostate cancer.

Insulinemic and Inflammatory Dietary Patterns Show Enhanced Predictive Potential for Type 2 Diabetes Risk in Postmenopausal Women

OBJECTIVE

The empirical dietary index for hyperinsulinemia (EDIH) and empirical dietary inflammatory pattern (EDIP) scores assess the insulinemic and inflammatory potentials of habitual dietary patterns, irrespective of the macronutrient content, and are based on plasma insulin response or inflammatory biomarkers, respectively. The glycemic index (GI) and glycemic load (GL) assess postprandial glycemic potential based on dietary carbohydrate content. We tested the hypothesis that dietary patterns promoting hyperinsulinemia, chronic inflammation, or hyperglycemia may influence type 2 diabetes risk.

RESEARCH DESIGN AND METHODS

We calculated dietary scores from baseline (1993-1998) food frequency questionnaires among 73,495 postmenopausal women in the Women's Health Initiative, followed through March 2019. We used multivariable-adjusted Cox regression to estimate hazard ratios (HRs) and 95% CIs for type 2 diabetes risk. We also estimated multivariable-adjusted absolute risk of type 2 diabetes.

RESULTS

During a median 13.3 years of follow-up, 11,009 incident cases of type 2 diabetes were diagnosed. Participants consuming the most hyperinsulinemic or proinflammatory dietary patterns experienced greater risk of type 2 diabetes; HRs (95% CI) comparing highest to lowest dietary index quintiles were EDIH 1.49 (1.32-1.68; P _trend < 0.0001) and EDIP 1.45 (1.29-1.63; P _trend < 0.0001). The absolute excess incidence for the same comparison was 220 (EDIH) and 271 (EDIP) cases per 100,000 person-years. GI and GL were not associated with type 2 diabetes risk: GI 0.99 (0.88-1.12; P _trend = 0.46) and GL 1.01 (0.89-1.16; P _trend = 0.30).

CONCLUSIONS

Our findings in this diverse cohort of postmenopausal women suggest that lowering the insulinemic and inflammatory potentials of the diet may be more effective in preventing type 2 diabetes than focusing on glycemic foods.

Independent and combined associations of sugar-sweetened beverage consumption, TV viewing, and physical activity with severe depressive symptoms among 59,402 adults

Objective:

Our aim was to analyze the association between sugar-sweetened beverage consumption and depressive symptoms, as well as the extent to which TV viewing and physical activity moderate this association.

Methods:

We used cross-sectional data from the 2013 Brazilian National Survey (Pesquisa Nacional de Saúde) of 59,402 adults (33,482 women, mean age = 42.9 years, 95%CI 42.7-43.2 years). Depressive symptoms (Patient Health Questionnaire-9), physical activity, TV viewing, and sugar-sweetened beverage consumption, as well as potential confounders (chronological age, ethnicity, consumption of candy/sweets and fruit, multimorbidity, education, and employment status) were self-reported. Poisson regression models were used for association analyses.

Results:

The consumption of 16 or more glasses/week of sugar-sweetened beverages was associated with higher levels of severe depressive symptoms among women compared to no consumption (prevalence ratio [PR] 1.71 [95%CI 1.38-2.11]). Consistent interactions were observed between 1-5 glasses and TV viewing (PR 2.09 [95%CI 1.06-4.12]) and between 11-15 glasses and TV viewing (PR 2.90 [95%CI 1.29-6.50]) among men compared to no consumption, given that the co-occurrence of sugar-sweetened beverage consumption and elevated TV viewing was associated with higher odds of severe depressive symptoms. Sugar-sweetened beverage consumption did not interact with physical activity, only presenting an independent association.

Conclusion:

Sugar-sweetened beverage consumption was independently associated with severe depressive symptoms among women and interacted with TV viewing, but not with physical activity among men.

Effects of Dietary Glycemic Index and Glycemic Load on Cardiometabolic and Reproductive Profiles in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Women with polycystic ovary syndrome (PCOS) exhibit cardiometabolic (e.g., insulin resistance) and associated reproductive disruptions. Lifestyle modification (e.g., diet) is recommended as the first-line therapy to manage PCOS; however, a favorable dietary regimen remains unclear beyond energy restriction. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to summarize evidence on impacts of dietary glycemic index (GI) or glycemic load (GL) on cardiometabolic and reproductive profiles to update the International Evidence-based Guideline for the Assessment and Management of PCOS. Databases of MEDLINE, Cochrane, Web of Science, and Scopus were searched through 30 October 2019, and confirmed on 25 March 2020, to identify RCTs (≥8 wk) comparing the effects of diets with lower (LGI/LGL) and higher (HGI/HGL) GI/GL on glucoregulatory outcomes, lipid profile, anthropometrics, and androgen status in PCOS. The primary outcome was HOMA-IR. Data were pooled by random-effects models and expressed as weighted mean differences and 95% CIs. The risk of bias was assessed by the Cochrane tool. Ten RCTs (n = 403) were eligible. Eight evaluated LGI and 2 LGL diets. LGI diets decreased HOMA-IR (-0.78; -1.20, -0.37; I2 = 86.6%), fasting insulin (-2.39; -4.78, 0.00 μIU/mL; I2 = 76.8%), total cholesterol (-11.13; -18.23, -4.04 mg/dL; I2 = 0.0%), LDL cholesterol (-6.27; -12.01, -0.53 mg/dL; I2 = 0.0%), triglycerides (-14.85; -28.75, -0.95 mg/dL; I2 = 31.0%), waist circumference (-2.81; -4.40, -1.23 cm; I2 = 53.9%), and total testosterone (-0.21; -0.32, -0.09 nmol/L; I2 = 8.6%) compared with HGI diets (all: P ≤ 0.05) without affecting fasting glucose, HDL cholesterol, weight, or free androgen index (all: P ≥ 0.07). Some results were contradictory and only described narratively for 2 RCTs that evaluated LGL diets, since inclusion in meta-analyses was not possible. LGI diets improved glucoregulatory outcomes (HOMA-IR, insulin), lipid profiles, abdominal adiposity, and androgen status, conceivably supporting their inclusion for dietary management of PCOS. Further RCTs should confirm these observations and address whether LGI diets improve more patient-pressing complications, including ovulatory cyclicity, infertility, and cardiovascular disease risk in this high-risk population. This review was registered at www.crd.york.ac.uk/PROSPERO as CRD42020175300.

Lifestyle and Food Habits Impact on Chronic Diseases: Roles of PPARs

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that exert important functions in mediating the pleiotropic effects of diverse exogenous factors such as physical exercise and food components. Particularly, PPARs act as transcription factors that control the expression of genes implicated in lipid and glucose metabolism, and cellular proliferation and differentiation. In this review, we aim to summarize the recent advancements reported on the effects of lifestyle and food habits on PPAR transcriptional activity in chronic disease.