The association between dietary intakes of zinc, vitamin C and COVID-19 severity and related symptoms: A cross-sectional study.

BACKGROUND: The Coronavirus disease 2019 (COVID-19) pandemic has had a devastating impact on health systems, food supplies, and population health. This is the first study to examine the association between zinc and vitamin C intakes and the risk of disease severity and symptoms among COVID-19 patients. METHODS: This cross-sectional study included 250 recovered COVID-19 patients aged 18-65 years from June to September 2021. Data on demographics, anthropometrics, medical history, and disease severity and symptoms were collected. Dietary intake was evaluated using a web-based, 168-item food frequency questionnaire (FFQ). The severity of the disease was determined using the most recent version of the NIH COVID-19 Treatment Guidelines. Using multivariable binary logistic regression, the association between zinc and vitamin C intakes and the risk of disease severity and symptoms in COVID-19 patients was evaluated. RESULTS: The mean age of participants in this study was 44.1 ± 12.1, 52.4% of them were female, and 46% had a severe form of the disease. Participants with higher zinc intakes had lower levels of inflammatory cytokines, such as C-reactive protein (CRP) (13.6 vs. 25.8 mg/l) and erythrocyte sedimentation rate (ESR) (15.9 vs. 29.3). In a fully adjusted model, a higher zinc intake was also associated with a lower risk of severe disease (OR: 0.43; 95% CI: 0.21, 0.90, P-trend = 0.03). Similarly, participants with higher vitamin C intakes had lower CRP (10.3 vs. 31.5 mg/l) and ESR serum concentrations (15.6 Vs. 35.6) and lower odds of severe disease after controlling for potential covariates (OR: 0.31; 95% CI: 0.14, 0.65, P-trend = <0.01). Furthermore, an inverse association was found between dietary zinc intake and COVID-19 symptoms, such as dyspnea, cough, weakness, nausea and vomiting, and sore throat. Higher vitamin C intake was associated with a lower risk of dyspnea, cough, fever, chills, weakness, myalgia, nausea and vomiting, and sore throat. CONCLUSION: In the current study, higher zinc and vitamin C intakes were associated with decreased odds of developing severe COVID-19 and its common symptoms.

Egg Consumption and Risk of All-Cause and Cause-Specific Mortality: A Systematic Review and Dose-Response Meta-analysis of Prospective Studies.

The association between egg consumption and mortality is extremely debatable. This study aimed to investigate the potential dose-response association of egg consumption with risk of mortality from all causes and cause-specific in the general population. The primary comprehensive literature search was conducted in PubMed/Medline, Scopus, ISI Web of Science, and Embase up to March 2021, as well as reference lists of relevant original papers and key journals. We calculated summary RRs and their 95% CIs for the highest and lowest categories, as well as the linear trend estimation of egg intake, using the random-effects model. Thirty-three (32 publications) cohort studies were included. These studies enrolled 2,216,720 participants and recorded 232,408 deaths from all causes. Comparing highest versus lowest egg intake categories was not associated with the risk of mortality from all causes (RR: 1.02; 95% CI: 0.94, 1.11; n = 25), cardiovascular disease (CVD) (RR: 1.04; 95% CI: 0.87, 1.23, n = 11), coronary heart disease (CHD) (RR: 0.98; 95% CI: 0.84, 1.16; n = 10), stroke (RR: 0.81; 95% CI: 0.64, 1.02; n = 9), and respiratory disease (RR: 0.96; 95% CI: 0.53, 1.71; n = 3); however, it was associated with a higher risk of cancer mortality (RR: 1.20; 95% CI: 1.04, 1.39; n = 13). In the linear dose-response analysis, an additional intake of 1 egg per week was associated with a 2% and 4% increased risk of all-cause and cancer mortality, respectively, and a 4% decreased risk of stroke mortality. The certainty of the evidence was rated as low to moderate. Higher egg consumption was not associated with an increased risk of mortality from all causes, CVD, CHD, stroke, or respiratory disease, whereas an elevated risk was observed for cancer mortality. These findings suggest that eggs be consumed in low to moderate amounts (≤1 egg/d) as part of a healthy diet.

Does saffron supplementation have favorable effects on liver function indicators? A systematic review and meta-analysis of randomized controlled trials.

Several pharmaceutical and non-pharmaceutical approaches have been suggested to improve liver health. There is a large discrepancy in the effects of saffron supplementation on liver function in adults. To fill this knowledge gap, this systematic review and meta-analysis of randomized controlled trials (RCTs) assess the effects of saffron supplementation on liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). A systematic search current to August 2020 was performed in PubMed/Medline, Scopus, Web of Science, and Google Scholar using relevant keywords to detect eligible articles. A random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence (95% CI). Nine eligible trials were included in the final analysis. The pooled analysis revealed that serum ALT concentrations were significantly reduced using saffron compared to placebo (WMD: -2.39 U/L; 95% CI: -4.57 to -0.22; P = 0.03, I2= 87.9%, P < 0.001). However, saffron supplementation did not affect levels of serum AST (WMD: 1.12 U/L; 95% CI: -1.42 to 3.65; P = 0.39) or ALP (WMD: 4.32 U/L; 95% CI: -6.91 to 15.54; P = 0.78). In the dose-response analysis, we did not find a significant dose-response relationship between dosage and duration of saffron supplementation on serum levels of ALT, AST, and ALP. We found that saffron supplementation can reduce ALT serum concentrations without significant effects on other liver function indicators, including AST and ALP. Nevertheless, future large RCTs on diverse populations are needed to understand better the effects of saffron and its constituents on these enzymes.

Refined grains consumption is associated with a greater odds of glioma.

Objective: Grain consumption has been associated with brain carcinogenesis in earlier studies, however, no data are available examining the association between refined grains consumption and risk of glioma. The current study was done to investigate the association between refined grains consumption and risk of glioma in Iranian adults.Methods: This hospital-based case-control study was performed on 128 pathologically confirmed cases with glioma and 256 age- and sex-matched controls in Tehran, Iran. Dietary intakes of participants including refined grains consumption were collected using a validated Block-format 123-item detailed food frequency questionnaire (FFQ). Refined grains were considered as the sum of white breads, pasta, rice, boiled and fried potato, sweets, and cookies.Results: A significant positive association was found between refined grains consumption and glioma (OR: 3.51, 95% CI: 1.97-6.26, Ptrend < 0.001). This association did not change after adjustment for energy intake (OR: 4.30, 95% CI: 2.27-8.15, Ptrend < 0.001). After controlling for potential confounders, those in the top tertile of refined grains consumption were significantly more likely to have glioma than those in the bottom tertile (OR: 2.92, 95% CI: 1.38-6.17, Ptrend = 0.007). This significant association remained unchanged, even after further adjustment for other dietary variables (OR: 2.54, 95% CI: 1.15-5.63, Ptrend = 0.02) and BMI (OR: 2.49, 95% CI: 1.12-5.53, Ptrend = 0.03).Conclusion: We found a significant positive association between refined grains consumption and odds of glioma. Further prospective cohort studies are needed to confirm these findings.

Dietary glycaemic index and glycaemic load in relation to risk of breast cancer.

OBJECTIVE: Previous studies on the association between glycaemic index (GI) and glycaemic load (GL) in relation to breast cancer risk are contradictory. The aim of this study was to examine the association between dietary GI and GL and risk of breast cancer in Iranian women. DESIGN: Population-based case-control study. Dietary GI and GL were assessed using a validated Willett-format 106-item semi-quantitative FFQ. SETTING: Isfahan, Iran. PARTICIPANTS: Cases were 350 patients with newly diagnosed stage I-IV breast cancer, for whom the status of breast cancer was confirmed by physical examination and mammography. Controls were 700 age-matched apparently healthy individuals who were randomly selected from general population. RESULTS: After controlling for potential confounders, individuals in the highest tertile of dietary GI had 47 % higher odds of breast cancer than women in the lowest tertile (OR: 1·47; (95 % CI 1·02, 2·12)). Stratified analysis by menopausal status showed such association among postmenopausal women (OR: 1·51; (95 % CI 1·02, 2·23)). We found no significant association between dietary GL and odds of breast cancer either before (OR: 1·35; (95 % CI 0·99, 1·84)) or after adjustment for potential confounders (OR: 1·24; (95 % CI 0·86, 1·79)). In addition, stratified analysis by menopausal status revealed no significant association between dietary GL and odds of breast cancer. CONCLUSIONS: Our findings showed a significant positive association between dietary GI and odds of breast cancer. However, we observed no significant association between dietary GL and odds of breast cancer.

Dietary phytochemical index in relation to risk of stroke: a case-control study.

BACKGROUND & AIM: No study explores the association of dietary phytochemical index (DPI) with stroke. This study was undertaken to obtain the required insight in this regard in Iranian adults. METHODS: This hospital-based case-control study was carried out on 195 stroke patients (diagnosed based on clinical and brained CT findings) and 195 control subjects with no history of cerebrovascular diseases or neurologic disorders). Data collection on dietary intakes was done using a 168-item validated FFQ. DPI was calculated using the McCarty equation. Logistic regression model in different models was used to evaluate the association between DPI and stroke. RESULTS: Mean age of study participants was 64.8 years, and 53.4% of them were male. Individuals in the highest tertile of DPI were younger (63 ± 11 vs. 67.4 ± 13 y, P = 0.01) and less likely to be physically active (2804 ± 5714 vs. 4772 ± 11912 M, P = 0.03). After adjustment for potential confounders, no significant relationship was observed between DPI and stroke risk (OR: 0.76; 95% CI: 0.39-1.49). However, when we considered the effect of dietary intakes, subjects in the top tertile of DPI were 61% less likely to have a stroke than those in the bottom tertile (OR: 0.39; 95% CI: 0.16-0.95). When BMI was controlled, the association between DPI and stroke became strengthened (OR: 0.32; 95% CI: 0.12-0.86). CONCLUSION: We found evidence indicating a significant inverse association between DPI and odds of stroke in adults. Further prospective studies are warranted to confirm this association.

Adherence to plant-based dietary patterns in relation to glioma: a case-control study.

Available evidence suggests a favorable association between adherence to a plant-based diet and disease prevention, but data on the link between such dietary intakes and cancer are scarce. We examined the association between the overall plant-based diet (PDI), healthy plant-based diet (hPDI), and unhealthy plant-based diet (uPDI) and risk of glioma. This case-control study was conducted on 128 newly diagnosed glioma patients, and 256 hospital-based controls. Cases were diagnosed by pathological test and controls were selected from hospitalized people in orthopedic and surgical wards. Dietary intakes were assessed using a validated Block-format 123-items food frequency questionnaire. Scores of plant-based dietary patterns were calculated using the method suggested by Satija et al. After controlling for potential confounders, individuals with higher scores of PDI (OR: 0.54, 95% CI: 0.32-0.91, P-trend < 0.001) and hPDI (OR: 0.32, 95% CI: 0.18-0.57, P-trend < 0.001) had significantly lower odds of glioma compared with those with the lowest scores. This association did not change in the fully adjusted model; such that subjects in the highest tertile of PDI and hPDI were 69% and 71% less likely to have glioma compared with those in the lowest tertile. In contrast, higher scores of uPDI was significantly associated with a greater odds of glioma (OR: 2.85, 95% CI: 1.26-6.47, P-trend = 0.02). Adherence to PDI and hPDI was associated with a lower odds of glioma, while greater adherence to uPDI was directly associated with the likelihood of glioma. Further prospective cohort studies are needed to examine our findings.

Dietary phytochemical index in relation to risk of glioma: a case-control study in Iranian adults.

BACKGROUND & AIM: No study is available that explores the association of dietary phytochemical index (DPI) with glioma. The objective of the current study was to assess this association in Iranian adults. METHODS: This hospital-based case-control study included 128 newly-diagnosed cases of glioma and 256 age- and sex-matched controls. Data collection on dietary intakes was done using a 123-item validated food frequency questionnaire. Calculation of DPI was done as (dietary energy derived from phytochemical-rich foods (kcal)/total daily energy intake (kcal)) × 100. Logistic regression models were used to examine the association between DPI and glioma. RESULTS: Individuals in the top tertile of DPI were more likely to be older and female. Before taking potential confounders into account, subjects in the top tertile of DPI tended to have a 40% reduced chance of glioma than those in the bottom tertile (OR: 0.60; 95% CI: 0.35-1.02, P = 0.06). After controlling for age, sex, energy intake, several demographic variables and dietary intakes, the association between DPI and glioma became strengthened (OR: 0.43; 95% CI: 0.19-0.97, P = 0.04). CONCLUSION: High intakes of phytochemical-rich foods were associated with a lower risk of glioma in adults. High consumption of phytochemical-rich foods might be recommended to prevent glioma. However, further studies with a prospective design are needed to confirm our findings.

The association between plant-based dietary patterns and risk of breast cancer: a case-control study.

Limited data are available, linking the plant-based diets to breast cancer (BC). We examined the association of overall plant-based diet index (PDI), hypothesized healthful (hPDI) and unhealthful versions of a plant-based diet index (uPDI) with BC in Iranian women. This population-based case-control study included 350 cases with newly diagnosed BC and 700 age-matched apparently healthy controls. We collected dietary data using a validated, Willett-format semi-quantitative food frequency questionnaire. Using these data, we generated a PDI by dedicating positive scores to plant foods, and reverse scores to animal foods, hPDI by assigning positive scores to healthy plant foods and reverse scores to less healthy plant foods and animal foods, and finally uPDI in which positive scores were assigned to less healthy plant foods and reverse scores to healthy plant foods and animal foods. After controlling for potential confounders, individuals in the highest quartile of PDI had 67% lower odds of BC than those in the lowest quartile (OR 0.33; 95% CI 0.22-0.50). Individuals with the greatest adherence to hPDI were 36% less likely to have BC than those with the lowest adherence, in the fully adjusted model (OR 0.64; 95% CI 0.43-0.94). In terms of uPDI, women in the top quartile had a 2.23 times greater chance of BC than those in the bottom quartile (OR 2.23; 95% CI 1.48-3.36). Greater adherence to PDI and hPDI was inversely associated with the risk of BC, whereas uPDI was associated with an increased risk.

Effects of saffron (Crocus sativus L.) supplementation on inflammatory biomarkers: A systematic review and meta-analysis.

The effect of saffron supplementation on subclinical inflammation remains inconclusive. We performed a systematic review and meta-analysis to summarize available findings on the effect of saffron supplementation on inflammatory biomarkers (C-reactive protein [CRP], tumor necrosis factor-α [TNF-α], and interleukin-6 [IL-6]) in adults. We searched PubMed/Medline, Scopus, Web of Science, and Google Scholar databases up to November 2019 using relevant keywords to identify eligible trials. All randomized controlled trials (RCTs) that examined the effect of oral saffron supplementation on plasma concentrations of CRP, TNF-α, and IL-6 were included. For each outcome, mean differences and SDs were pooled using a random-effects model. Overall, eight RCTs were included in this meta-analysis. The pooled results showed that saffron supplementation did not result in significant changes in serum CRP (weighted mean difference [WMD]: -0.43 mg/L; 95% confidence interval [CI]: -1.04 to 0.17; p = .16), serum TNF-α (WMD: -1.29 pg/mL; 95% CI: -4.13 to 1.55; p = .37), and IL-6 concentrations (WMD: 0.11 pg/mL; 95% CI: -0.79 to 1.00; p = .81). Subgroup analysis indicated a significant reduction in serum CRP levels in studies with baseline CRP of ≥3 mg/L, saffron dosage of ≤30 mg/day, and intervention duration of <12 weeks, as well as trials that used crocin. Similarly, saffron was found to decrease TNF-α in studies that recruited non-diabetic subjects, subjects with baseline levels of ≥15 pg/mL, and participants with <50 years old, as well as trials that administered saffron at the dosage of ≤30 mg/day. We also found a significant non-linear effect of saffron dosage on serum CRP concentrations (pnon-linearity = .03). The overall results indicated that saffron supplementation did not affect inflammatory cytokines. Further high-quality studies are needed to firmly establish the clinical efficacy of supplemental saffron on inflammatory biomarkers.

Adherence to the Mediterranean dietary pattern in relation to glioma: A case-control study.

BACKGROUND: Although Mediterranean diet (MD) was associated with a lower risk of mortality and cancer, no data are available investigating the association between adherence to the MD and risk of glioma. METHODS: In this case-control study, we enrolled a total of 128 newly diagnosed patients with glioma, confirmed by pathological assessment, and 256 hospital-based controls from 2009 to 2011 in Tehran, Iran. A valid and reliable Block-format food frequency questionnaire (FFQ) was used to assess dietary intakes. Adherence to the MD was examined using the scoring method suggested by Trichopoulou et al. Logistic regression was used to examine the associations of interest. RESULTS: After controlling for age, sex, and energy intake, participants in the highest tertile of MD score had not significantly lower odds of glioma than those in the lowest tertile (OR: 0.58, 95% CI: 0.32-1.03, Ptrend = 0.06). However, after taking other potential confounders into account, individuals with the greatest adherence to the MD score were 74% less likely to have glioma than those with the lowest adherence (OR: 0.26, 95% CI: 0.12-0.55, Ptrend < 0.001). Additional adjustments for dietary intakes and BMI did not significantly alter this association (OR: 0.36, 95% CI: 0.16-0.78, Ptrend = 0.009; OR: 0.36, 95% CI: 0.16-0.78, Ptrend = 0.01, respectively). CONCLUSION: We found that adherence to the MD was associated with a lower likelihood of having glioma. Prospective cohort studies are needed to further examine these findings.