Association of Pro-inflammatory Dietary Intake and Non-Alcoholic Fatty Liver Disease: Findings from Iranian case-control study

Dietary inflammatory index and the risks of non-alcoholic fatty liver disease: a systematic review and meta-analysis

Background

Previous studies have suggested a correlation between dietary inflammatory potential and non-alcoholic fatty liver disease (NAFLD). Therefore, the study aimed to investigate the association between dietary inflammatory potential, measured by the dietary inflammation index (DII), and NAFLD.

Methods

From establishing the database to June 2023, a systematic search of PubMed, Web of Science, Embase and Cochrane Library were performed to identify relevant observational studies. These studies reported a correlation between DII and NAFLD. The meta-analysis used odds ratio (OR) with 95% confidence intervals (CI) to evaluate the relationship between DII and NAFLD.

Results

Eight studies were included in this meta-analysis after excluding irrelevant records. A summary of the results from the included studies showed that the risk of NAFLD was higher in those exposed to higher DII (OR = 1.26, 95%CI 1.12 to 1.40, p < 0.001), with a high degree of heterogeneity (I2 = 85.7%, p < 0.001). When DII was divided into 3 tertiles from low to high for comparison, the results showed that the risk of NAFLD was higher in Tertile 2 (T2) population compared to the Tertile 1 (T1) population (OR = 1.75, 95%CI 1.20 to 2.54, p < 0.005). The risk of NAFLD was significantly higher in Tertile 3 (T3) compared to the T1 population (OR = 3.07, 95%CI 1.63 to 5.77, p = 0.001).

Conclusion

The results suggest that high DII is associated with an increased risk of NAFLD, and conversely, low DII is associated with a decreased risk of NAFLD.

Systematic Review Registration

The study complies with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and is registered on PROSPERO (CRD42023455013).

Dietary inflammatory index in relation to the progression of hepatic steatosis and liver fibrosis: evaluation by elastography/Fibroscan

One of the proposed mechanisms by which nutrition influences the progression of hepatic steatosis to fibrosis is inflammation. The study investigated how the inflammatory potential of the diet affects the risk of liver damage in patients with nonalcoholic fatty liver disease (NAFLD), a condition where fat accumulates in the liver. This cross-sectional study included 170 outpatients with newly diagnosed NAFLD. This study used a device called Fibroscan® to measure the degree of liver fibrosis, which is the scarring of the liver tissue due to chronic inflammation. The study also used a tool called the Dietary Inflammatory Index (DII) to measure the inflammatory potential of the diet based on the intake of different foods and nutrients. In the findings of the study, patients with more severe fat accumulation in the liver (hepatic steatosis) had higher DII scores, meaning they had more inflammatory diets. The study also found that higher DII scores were associated with higher weight and body mass index (BMI). One standard deviation (SD) increase in DII scores was associated with a 0.29 kilopascal (95% CI: 0.10-0.44; P-value 0.001) increase in the mean liver stiffness, an indicator of liver fibrosis. The study concluded that patients with higher DII scores had a higher risk of developing liver fibrosis than those with lower DII scores, even after adjusting for confounding factors (odds ratio: 5.89; P-value: 0.001). The study suggested that eating less inflammatory foods may help prevent or slow down the progression of hepatic steatosis and liver in patients with NAFLD.

Association between dietary inflammatory index and risk of fatty liver disease: A systematic review and meta-analysis

AIMS

This meta-analysis aimed to investigate the correlation between dietary inflammatory index (DII) and risks of fatty liver disease.

METHODS

A comprehensive systematic literature search was conducted to select studies published from database inception to 6 September 2023 from five databases. Observational studies examining the association between elevated DII levels and the prevalence of fatty liver disease/liver fibrosis were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using either random-effects or fixed-effect models.

RESULTS

In total, 10 studies comprising 242,006 participants were included in the meta-analysis. Individuals with higher DII had a significantly increased risk of fatty liver disease (OR 1.63; 95% CI 1.08-2.45) and liver fibrosis (OR 1.15; 95% CI 1.09-1.21) compared to those with lower DII.

CONCLUSIONS

This meta-analysis demonstrated an association between higher DII and increased odds of fatty liver disease. However, additional prospective studies are required to further address this question.

Association between dietary inflammatory index and mental disorders using multilevel modeling with GLIMMIX

Introduction

The Dietary Inflammatory Index (DII) is a composite nutritional index that has gained significant attention in the past decade due to its association with physical and mental well-being. To accurately assess the precise effects of DII on health outcomes, the effects of nutrients and foods need to be adjusted. This study aimed to investigate the association between DII and mental disorders (depression, anxiety, and stress) using multilevel modeling to minimize the bias of the previous methods.

Methods

This cross-sectional analytical study was conducted using data from the initial phase of the Tehran University of Medical Sciences Employees' Cohort Study (TEC). Nutritional information was obtained through a dish-based semi-quantitative food frequency questionnaire (DFQ), while psychological data were collected using the depression, anxiety and stress scale (DASS-42). The acquired data were analyzed using multilevel modeling in three levels (foods, nutrients, and DII, respectively) through GLIMMIX in the SAS software.

Results

A total of 3,501 individuals participated in this study. The results of the multilevel model demonstrated a significant statistical association between DII and mental disorders after adjusting for baseline characteristics, nutrients and foods. For each unit increase in DII, the mean scores for stress, anxiety, and depression increased by 3.55, 4.26, and 3.02, respectively (p < 0.001).

Conclusion

Based on the multilevel model's findings, it is recommended to minimize the use of pro-inflammatory nutrients and foods to increase the mental health. Multilevel data analysis has also been recommended in nutritional studies involving nested data to obtain more accurate and plausible estimates.

Dietary inflammatory potential is associated with higher odds of hepatic steatosis in US adults: a cross-sectional study

OBJECTIVE

Inflammation plays a critical role in the progression of chronic liver diseases, and diet can modulate inflammation. Whether an inflammatory dietary pattern is associated with higher risk of hepatic steatosis or fibrosis remains unclear. We aimed to investigate the associations between inflammatory dietary pattern and the odds of hepatic steatosis and fibrosis.

DESIGN

In this nationwide cross-sectional study, diet was measured using two 24-h dietary recalls. Empirical dietary inflammatory pattern (EDIP) score was derived to assess the inflammatory potential of usual diet, which has been validated to highly predict inflammation markers in the study population. Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were derived from FibroScan to define steatosis and fibrosis, respectively.

SETTING

US National Health and Nutrition Examination Survey.

PARTICIPANTS

4171 participants aged ≥18 years.

RESULTS

A total of 1436 participants were diagnosed with S1 steatosis (CAP ≥ 274 dB/m), 255 with advanced fibrosis (LSM ≥ 9·7 kPa). Compared with those in the lowest tertile of EDIP-adherence scores, participants in the highest tertile had 74 % higher odds of steatosis (OR: 1·74, 95 % CI (1·26, 2·41)). Such positive association persisted among never drinkers, or participants who were free of hepatitis B and/or C. Similarly, EDIP was positively associated with CAP in multivariate linear model (P < 0·001). We found a non-significant association of EDIP score with advanced fibrosis or LSM (P = 0·837).

CONCLUSIONS

Our findings suggest that a diet score that is associated with inflammatory markers is associated with hepatic steatosis. Reducing or avoiding pro-inflammatory diets intake might be an attractive strategy for fatty liver disease prevention.

Diets with Higher Anti-inflammatory Potential Associated with Lower Risk of Development of Nonalcoholic Fatty Liver Disease and Early-Stage of Fibrosis Among US Adults

BACKGROUND

There is limited evidence of how dietary inflammatory potential influences nonalcoholic fatty liver disease (NAFLD) progression.

AIMS

Our study aims to evaluate the association of dietary inflammatory index (DII) with liver fibrosis, a hallmark feature of NAFLD, among US adults.

METHODS

Cross-sectional data consisting of 5,506 participants in the National Health and Nutrition Examination Survey from 2011 to 2018 were used. Energy adjusted-DII (E-DII) scores were calculated using 2 days of 24-h dietary recall data. We used a partial proportional odds model to determine risk at each stage of fibrosis according to the E-DII score.

RESULTS

The weighted prevalence of NAFLD (assessed by US fatty liver index) was 34.5%, with 23.2% (assessed by NAFLD Fibrosis Score) having mild fibrosis, 10.4% intermediate fibrosis, and 0.9% advanced fibrosis. When comparing the most pro-inflammatory diets to the most anti-inflammatory diets (AIDs) in the multivariable model, the marginal probability effect (MPE) of NAFLD, mild fibrosis and intermediate fibrosis increased by 11.7% (95% CI 6.6%, 16.9%), 7.0% (95% CI 3.5%, 10.4%) and 4.0% (95% CI 0.3%, 7.5%), respectively. The MPE of advanced fibrosis was not significant (MPE = 0.7%; 95% CI - 1.1%, 2.8%). Similar associations were observed when applying Fibrosis-4 and transient elastography as fibrosis diagnostic measurements.

CONCLUSIONS

An AID was associated with lower risk of development of NAFLD and early-stage of fibrosis among US adults. But the associations became attenuated and dissipated as the fibrogenesis became severe. Further studies are needed to re-confirm our observations.

Role of BMI in the relationship between dietary inflammatory index and non-alcoholic fatty liver disease: an intermediary analysis

OBJECTIVE

Previous studies have indicated that a pro-inflammatory diet is associated with non-alcoholic fatty liver disease (NAFLD), but the role of BMI remains ambiguous. We aim to study the intermediary effect of BMI on the relationship between dietary inflammatory properties and NAFLD.

METHODS

A total of 19536 adult participants from the National Health and Nutrition Examination Surveys (NHANES) were included. Dietary inflammatory index (DII) was used to evaluate the dietary inflammatory properties and NAFLD was diagnosed by non-invasive biomarkers. Weighted multivariable logistic regression models estimated ORs and 95% CIs between DII and incidence of NAFLD. Interaction effect between DII and BMI on NAFLD was tested and the mediation analysis of BMI was performed.

RESULTS

Higher DII scores, representing higher inflammatory potential of diet, were positively associated with a higher risk of NAFLD. Compared with the first quartile of DII, people from the second quartile (OR: 1.23 [95% CI: 1.04, 1.46]) to the fourth quartile (OR: 1.59 [95% CI: 1.31, 1.94]) have a higher risk of NAFLD before adjustment for BMI. The overall association was completely mediated by BMI (89.19%).

CONCLUSIONS

Our findings suggested that a higher pro-inflammatory potential diet was associated with a higher prevalence of NAFLD, and this association might be mediated by BMI.

Pro- and Antioxidant Effect of Food Items and Matrices during Simulated In Vitro Digestion

The digestive tract can be considered a bioreactor. High levels of reactive oxygen species (ROS) during digestion may predispose for local and/or systemic oxidative stress and inflammation, e.g., inflammatory bowel diseases. Food items rich in antioxidants may prevent such aggravation. This investigation analyzed pro-and antioxidant patterns of food matrices/items following in vitro digestion. Gastrointestinal digestion reflecting typically consumed quantities was performed on nine food items (orange and tomato juice, soda, coffee, white chocolate, sausage, vitamin C and E, and curcumin) and their combinations (n = 24), using the INFOGEST model. Antioxidant potential was measured by FRAP, DPPH, and ABTS, and pro-oxidant aspects by MDA (malondialdehyde) and peroxide formation. An anti-pro-oxidant score was developed, combining the five assays. Liquid food items showed moderately high antioxidant values, except for coffee and orange juice, which exhibited a high antioxidant potential. Solid matrices, e.g., white chocolate and sausage, showed both high pro-oxidant (up to 22 mg/L MDA) and high antioxidant potential (up to 336 mg/L vitamin C equivalents) at the same time. Individual vitamins (C and E) at physiological levels (achievable from food items) showed a moderate antioxidant potential (<220 mg/L vitamin C equivalents). Overall, both antioxidant and pro-oxidant assays correlated well, with correlation coefficients of up to 0.894. The effects of food combinations were generally additive, i.e., non-synergistic, except for combinations with sausage, where strong quenching effects for MDA were observed, e.g., with orange juice. In conclusion, as especially highlighted by complex matrices demonstrating both pro- and antioxidant potential, only measuring one aspect would result in physiological misinterpretations. Therefore, it is imperative to employ a combination of assays to evaluate both pro- and antioxidant properties of food digesta to ensure physiological relevance.

Association of diet quality indices with serum and metabolic biomarkers in participants of the ORISCAV-LUX-2 study

PURPOSE

Diet quality is a critical modifiable factor related to health, including the risk of cardiometabolic complications. Rather than assessing the intake of individual food items, it is more meaningful to examine overall dietary patterns. This study investigated the adherence to common dietary indices and their association with serum/metabolic parameters of disease risk.

METHODS

Dietary intakes of the general adult population (n = 1404, 25-79 years) were assessed by a validated food-frequency questionnaire (174 items). The French ANSES-Ciqual food composition database was used to compute nutrient intakes. Seven indicators were calculated to investigate participants' diet quality: the Alternative Healthy Eating Index (AHEI), Dietary Approaches to Stop Hypertension Score (DASH-S), Mediterranean Diet Score (MDS), Diet Quality Index-International (DQI-I), Dietary Inflammatory Index (DII), Dietary Antioxidant Index (DAI), and Naturally Nutrient-Rich Score (NNRS). Various serum/metabolic parameters were used in the validity and association analyses, including markers of inflammation, blood glucose, and blood lipid status.

RESULTS

Following linear regression models adjusted for confounders, the DASH-S was significantly associated with most metabolic parameters (14, e.g., inversely with blood pressure, triglycerides, urinary sodium, uric acid, and positively with serum vitamin D), followed by the DQI-I (13, e.g., total cholesterol, apo-A/B, uric acid, and blood pressure) and the AHEI (11, e.g., apo-A, uric acid, serum vitamin D, diastolic blood pressure and vascular age).

CONCLUSION

Food-group-based indices, including DASH-S, DQI-I, and AHEI, were good predictors for serum/metabolic parameters, while nutrient-based indices, such as the DAI or NNRS, were less related to biological markers and, thus, less suitable to reflect diet quality in a general population.

Validation and Comparison of Two Dietary Indexes for Predicting Nonalcoholic Fatty Liver Disease in US Adults

BACKGROUND

Two indexes have been used to describe dietary inflammatory potential: the experiment-based dietary total antioxidant capacity (TAC) and the literature-derived dietary inflammatory index (DII). How robustly each index represents dietary inflammatory potential and the risk of nonalcoholic fatty liver disease (NAFLD) has not yet been established.

OBJECTIVES

We investigated the relation between dietary inflammatory potential and NAFLD, and compared the abilities of the TAC and DII scores to predict NAFLD in US adults.

METHODS

Cross-sectional data from 12,410 participants aged 20-80 y in the NHANES from 2011 to 2018 were identified. TAC and DII scores were calculated using 2 d of 24-h dietary recall data. We examined the association between dietary index and risk of NAFLD using linear and logistic regression models.

RESULTS

Higher energy-adjusted TAC (E-TAC) and inversely energy-adjusted DII (IE-DII) scores (both representing more anti-inflammatory diets) were associated with lower hepatic steatosis index (HSI) and US fatty liver index (USFLI) values after adjusting for potential covariates, and the association for each SD increase in the IE-DII was stronger than the E-TAC (β estimates for HSI: -0.39 compared with -0.25; P-difference = 0.036). In modeling the risk of NAFLD, we observed that participants with IE-DII scores in the highest quartile had the lowest ORs for NAFLD as assessed by either the HSI (OR: 0.77; 95% CI: 0.62, 0.96; P-trend = 0.023) or USFLI (OR: 0.48; 95% CI: 0.35, 0.68; P-trend <0.0001). TAC scores were also associated with NAFLD as assessed by the USFLI.

CONCLUSIONS

An anti-inflammatory diet is beneficial for reducing the risk of NAFLD in US adults. The DII is a stronger predictor of hepatic measures than the TAC, and we recommend that future hepatic health studies use the DII to estimate dietary inflammatory potential.

The association between dietary inflammation scores and non-alcoholic fatty liver diseases in Iranian adults

BACKGROUND

Potential dietary inflammation can precursor chronic diseases such as hepatic disorders. We aimed to examine the association of empirical dietary inflammatory patterns (EDIP) and dietary inflammation scores (DIS) with the risk of nonalcoholic fatty liver diseases (NAFLD) in Iranian adults.

METHODS

This case-control study was conducted on 225 newly diagnosed NAFLD cases and 450 controls aged 20-60 years. The individuals' dietary data were collected using a validated food frequency questionnaire. The detection of NAFLD in subjects was done using the ultrasonography scan of the liver and confirmation of gastroenterologists. To calculate of EDIP score, the average daily intakes of each item (15 food items) were multiplied by the proposed weights, and then all the weighted values were summed. Also, to calculate the DIS score, each food item (18 food items) is multiplied by its specific weight to obtain the weighted values of each item. The weighted values were then standardized using the Z-score. Finally, the standardized weighted values of all the items were summed to get the overall DIS score for the individuals. Logistic regression models, adjusted for potential confounders, were used to estimate the odds ratios and 95% confidence interval (CI) of NAFLD across tertiles of EDIP and DIS.

RESULTS

The mean (SD) age and BMI of the study population (53% male) were 38.1 (8.8) years and 26.8 (4.3) kg/m2, respectively. The median (IQR) of EDIP and DIS scores in individuals were 0.52 (0.34, 0.73), and 0.04 (- 0.55, 0.59), respectively. Based on the multivariable-adjusted model, after controlling for age, sex, physical activity, smoking, marital status, waist-to-hip ratio, and dietary energy intake, individuals in the second (OR 2.01, 95% CI 1.07-3.76) and third tertiles of DIS (OR 2.54, 95% CI 1.39-4.63) had a higher odds of NAFLD compared to the lowest tertile of DIS (Ptrend = 0.003). Also, in the final model, there is a significant direct association between EDIP score and odds of NAFLD [(OR T2 vs. T1 = 0.88, 95% CI 0.50-1.57) and (OR T3 vs. T1 = 1.82, 95% CI 1.02-3.23)], (Ptrend = 0.031).

CONCLUSION

Our results suggested that higher scores of EDIP and DIS, indicating the high inflammatory potential of dietary pattern, are associated with increased odds of NAFLD in Iranian adults.

Antioxidant potential of diet – Association between dietary antioxidant index and odds of coronary heart disease: A case-control study

BACKGROUND: Oxidative stress and chronic inflammation are among the leading causes of coronary heart disease (CHD). Studies investigated the relationship between dietary antioxidants and the risk/odds of CHD, and contradictory results have been reported. Dietary antioxidant index (DAI) is a novel and reliable nutritional tool that examines the diet’s overall antioxidant capacity. Its validity was examined using serum total antioxidant capacity and malondialdehyde. OBJECTIVE: This study aimed to investigate the relationship between DAI score and odds of CHD. METHODS: In this incidence case-control study, 320 individuals with a definitive diagnosis of CHD and 320 participants without CHD or related risk factors attending the same hospitals/polyclinics were selected as the case and control groups. We estimated the DAI by summing up six standardized intakes of major dietary antioxidants, including manganese, vitamin E, A, C, selenium, and zinc. RESULTS: Modeling DAI categorized according to the median (–0.38), in multi-adjusted model showed a significant protective association with the odd of CHD (OR = 0.72; 95%CI:0.51–0.99, p-value = 0.05). Also, modeling DAI as a continuous variable in multi-adjusted models (OR = 0.94;95%CI:0.90–0.95; p-value = 0.01) showed significant results. CONCLUSION: Using the DAI to investigate the relationship between dietary antioxidants and CHD can show more realistic results than a single study of antioxidants.

The association between an energy-adjusted dietary inflammatory index and inflammation in rural and urban Black South Africans

OBJECTIVE

To quantify the inflammatory potential of the diet of rural and urban Black South Africans using an adapted energy-adjusted dietary inflammatory index (AE-DII) and to investigate its relationship with inflammatory and cardio-metabolic disease risk markers. Dietary inflammatory potential has not been investigated in African populations.

DESIGN

Cross-sectional investigation.

SETTING

Rural and urban sites in the North West province of South Africa.

PARTICIPANTS

1885 randomly selected, apparently healthy Black South Africans older than 30 years.

RESULTS

AE-DII scores ranged from -3·71 to +5·08 with a mean of +0·37. AE-DII scores were significantly higher in men (0·47 ± 1·19) than in women (0·32 ± 1·29), and in rural (0·55 ± 1·29) than urban participants (0·21 ± 1·19). Apart from its dietary constituents, AE-DII scores are primarily associated with age, rural-urban status and education. Contrary to the literature, alcohol consumption was positively associated with AE-DII scores. Of the four tested inflammatory and thirteen cardio-metabolic biomarkers, the AE-DII was only significantly negatively associated with albumin and HDL cholesterol, and positively with waist circumference and fasting glucose, upon full adjustment.

CONCLUSION

Rural men consumed the most pro-inflammatory diet, and urban women the least pro-inflammatory diet. The diet of the participants was not overtly pro- or anti-inflammatory and was not associated with measured inflammatory markers. The inflammatory potential of alcohol at different levels of intake requires further research. Understanding dietary inflammatory potential in the context of food insecurity, unhealthy lifestyle practices and lack of dietary variety remains limited.

Metabolic and Hepatic Effects of Energy-Reduced Anti-Inflammatory Diet in Younger Adults with Obesity

BACKGROUND

Associated with epidemics of obesity, nonalcoholic fatty liver disease (NAFLD) is becoming the most prevalent liver disease worldwide. The cornerstone of therapy for NAFLD is lifestyle intervention, mainly focused on weight loss. Significant weight loss results from energy-restricted diets, regardless of macronutrient distribution. An anti-inflammatory diet was related to lower odds of NAFLD among daily alcohol drinkers and individuals with metabolic syndrome. This study aims to evaluate the effect of an energy-reduced anti-inflammatory diet on liver status in younger adults with obesity after a 6-month follow-up.

METHODS

A two-arm randomized controlled trial surveyed 81 participants' (mean age, 43 years) anthropometric and body composition changes. Metabolic status was determined with glycaemic and lipid status, inflammatory status with hs-CRP, IL-6, and TNF-α, and liver status with liver enzymes, NAFLD-FLS, FLI, and FIB-4 indices. The inflammatory potential of the diet was assessed by the Dietary Inflammatory Index, DII®.

RESULTS

Energy-restricted anti-inflammatory diet resulted in significant weight loss (-7.1%, p < 0.001), in reducing the visceral adiposity (-22.3%, p < 0.001), metabolic (HOMA-IR, -15.5%; total cholesterol, -5.3%; LDL-C, -4.6%; triglycerides, -12.2%), and inflammatory biomarkers (hs-CRP, -29.5%; IL-6, -18.2%; TNF-α, -34.2%), with significant improvement of liver parameters (NAFLD-FLS, -143.4%; FLI, -14.3%; FIB-4, -2.5%).

CONCLUSION

The study showed the effectiveness of the anti-inflammatory diet with significant improvement of liver parameters in younger adults with obesity, which may reinforce the effectiveness of nutrition-based lifestyle programs, with an anti-inflammatory dietary approach for the treatment and resolution of NAFLD.

The association between dietary antioxidant index (DAI) and nonalcoholic fatty liver disease (NAFLD) onset; new findings from an incident case-control study

BACKGROUND

Evidence suggests an increasing global trend in non-alcoholic fatty liver disease (NAFLD) prevalence. Researchers have noted the importance of the role of dietary antioxidants in reducing the incidence of NAFLD. The dietary antioxidant index (DAI) is a valid indicator that considers the -diet's total antioxidant properties. The present study was designed and conducted to investigate the relationship between DAI and NAFLD. We hypothesized that there is a link between the DAI and the NAFLD.

METHODS

This case-control study included 295 patients with NAFLD and 704 controls. The patients' dietary intake was assessed through a valid and reliable semi-quantitative food frequency questionnaire. We standardized each of vitamin A, C, E, and selenium, manganese, and zinc by subtracting the global mean and dividing by the global SD to calculate the DAI.

RESULTS

Subjects with DAI score -0.46 < were at higher odds of having NAFLD compared to subjects with DAI -0.46 ≥ (OR_{DAI<-0.46/≥-0.46} = 0.55; 95% CI = 0.41-0.73). After adjustment for age, gender, and total energy intake (model B) a reverse and significant association was seen (OR_{DAI<-0.46/≥-0.46} = 0.57; 95% CI = 0.39-0.82).

CONCLUSION

The role of antioxidants in reducing the odds of NAFLD is fundamental. Taking antioxidants such as vitamins A, E, C, zinc, selenium, and manganese through food can effectively reduce NAFLD odds. On the other hand, studies should examine DAI's sensitivity and specificity in various settings and outcomes to use it in clinical work.

Validation of Dietary Antioxidant Index (DAI) and investigating the relationship between DAI and the odds of gastric cancer

BACKGROUND

Gastric cancer (GC) incidence and mortality are rapidly growing worldwide. It is estimated that more than 1,000,000 new cases are diagnosed each year, and more than 78,000 people lose their lives due to GC. The association between dietary antioxidants and GC has been shown in some studies. However, because of the discrepancy between the findings and the lack of a valid indicator, it seems necessary to design and validate the Dietary Antioxidant Index (DAI) to examine the diet's total antioxidant content. The present study aimed to survey the validity of DAI and its association with the odds of GC.

METHODS

In this hospital-based case-control study, 82 patients with GC and 95 healthy controls were examined. We used a 168-item food frequency questioner to assess dietary intakes. The DAI was calculated based on the intake of vitamin A, C, E, and selenium, manganese, and zinc. We standardized each of the six vitamins and minerals by subtracting the global mean and dividing by the global standard deviation to calculate DAI. We then calculated the DAI by summing up the standardized intakes of these vitamins and minerals of the individuals with equal weight.

RESULTS

We observed a significant correlation between DAI and total antioxidant capacity (TAC) after controlling for age, body mass index (BMI), energy intake, smoking and fasting blood sugar, education, total fat intake, helicobacter pylori infection, total cholesterol, and saturated fatty acid (SFA) intakes. Results obtained from modeling DAI as a continuous variable in relation to GC showed a negative association after adjustment for age and in the multivariable analysis (OR = 0.64, CI = 0.43-0.95).

CONCLUSION

DAI is a valid indicator of dietary antioxidants assessments, and it can be used as a predictor of antioxidant status due to its correlation with serum antioxidant levels. The results showed that dietary antioxidants have a significant relationship with GC, which indicates the importance of antioxidants in this cancer's etiology.

Dietary Inflammatory Index score and risk of developing endometriosis: A case–control study

The possible relationship between chronic inflammation from dietary exposure and endometriosis has not been investigated. Thus, the aim of this study was to investigate the association between the Dietary Inflammatory Index (DII®) and endometriosis. Women with endometriotic lesions were defined as cases ( n = 59), and controls ( n = 59) had no visible ectopic endometrium sites. Body mass index (BMI=weight(kg)/height(m)2) was calculated from measured height and weight and waist circumference was measured. A validated semi-quantitative food frequency questionnaire was used to calculate the DII score. Women with endometriosis were younger, thinner; and had a more pro-inflammatory diet and more pain (dysmenorrhea, chronic pelvic pain, deep dyspareunia), than controls. Women with higher DII scores (>0.86) were more likely to have endometriosis and to present with dyspareunia. Results obtained from modeling DII as a categorical variable in relation to risk of endometriosis showed a near tripling of risk (OR = 2.77; 95% CI = 1.13–6.77) for women with DII >0.86 versus those with DII ⩽ 0.86, after adjusting for age and BMI. After multivariable adjustment, women with DII > 0.86 were four times more likely to have endometriosis compared to women with DII ⩽ 0.86 (OR = 4.14; 95% CI= 1.50–11.4). In conclusion, a pro-inflammatory diet was significantly associated with endometriosis.

Association Between Index of Nutritional Quality and Nonalcoholic Fatty Liver Disease: The Role of Vitamin D and B Group

BACKGROUND

Numerous studies have revealed that diet has been considered as an important pathogenic factor for nonalcoholic fatty liver disease (NAFLD). The Index of Nutritional Quality (INQ) is a method of quantitative and qualitative evaluation of single foods and diets, which has special significance in recognizing clinical nutritional problems.

MATERIALS AND METHODS

This study included 295 patients with NAFLD and 704 controls. The dietary intake was assessed through a valid and reliable food frequency questionnaire. INQ was calculated from the questionnaire data and was compared between the 2 groups.

RESULTS

The controls had higher INQ of vitamin D, vitamin E, thiamin, riboflavin, niacin, vitamin B12; biotin, pantothenic acid, magnesium and zinc compared to the patients with NAFLD. After controlling for several covariates, positive associations were observed between NAFLD risk and INQs of riboflavin (OR_riboflavin = 0.49, 95% confidence interval [CI]: 0.28-0.78; OR_biotin = 0.35, 95% CI: 0.18-0.76; OR_pantothenic = 0.28, 95% CI: 0.12-0.64; OR_magnesium = 0.28, 95% CI: 0.11-0.75; OR_zinc = 0.15 95% CI: 0.05-0.42).

CONCLUSIONS

Findings of the present study suggest that subjects who follow a more healthy and nutrient-rich diet, especially in terms of vitamins D, B1, B2, B12, B3 and zinc, are at a lower risk of NAFLD compared to those who consume unhealthy and nutrient-poor diet.