Proposal for a dietary “phytochemical index”

Dietary acid load as well as dietary phytochemical index, and association with multiple sclerosis: results from a case-control study

INTRODUCTION

Multiple sclerosis (MS) is a chronic inflammatory disease characterized by central nervous system (CNS) lesions. Although the etiology and pathogenesis of MS remains unclear, nutrition is among the environmental factors that may be involved in developing MS. Currently, no specific diet has been associated with MS. This study aimed to investigate the relationship between the dietary phytochemical index (DPI), dietary acid load (DAL), and the risk of developing MS.

METHODS

This case‒control study was conducted on 174 patients with MS and 171 healthy individuals in Mashhad, Iran. Data were collected using a 160-item semiquantitative food frequency questionnaire (FFQ). The study investigated the association between DPI, DAL, and MS, considering anthropometric measures, dietary intake, smoking habits, and sex. DPI, potential renal acid load (PRAL), and net endogenous acid production (NEAP), as indicators of DAL, were calculated based on the FFQ.

RESULTS

The study analyzed 345 participants, comprising 174 (50.4%) MS patients and 171 (49.6%) healthy individuals. The mean age of the participants was 32.45 ± 8.66 years. The DPI score was significantly lower among MS patients, while the NEAP and PRAL scores were significantly higher among MS patients compared to the healthy group. There was no relationship between NEAP (OR 1.001; 95% CI 0.959-1.044; P = 0.974) and PRAL (OR 1.019; 95% CI 0.979-1.061; P = 0.356) and MS incidence.

CONCLUSIONS

The study found higher smoking and obesity rates in MS patients, with a reduced DPI score and increased DAL. Further studies are needed before recommending plant-based foods and dietary acid-base balance evaluation as therapeutic approach.

The potential causal effect of the pre-pregnancy dietary phytochemical index on gestational diabetes mellitus: a prospective cohort study

BACKGROUND

Phytochemicals are non-nutritive bioactive compounds with beneficial effects on the metabolism of glucose. This study aimed to clarify the possible causal effect of the pre-pregnancy dietary phytochemical index (DPI) on gestational diabetes mellitus (GDM).

METHODS

In this prospective cohort study 1,856 pregnant women aged 18-45 years who were in their first trimester, were recruited and followed up until delivery. The dietary intakes of participants were examined using an interviewer-administered validated 168-item semi-quantitative food frequency questionnaire (FFQ). Inverse probability weighting (IPW) of propensity scores (PS), estimated from the generalized boosted model (GBM) were used to obtain a adjusted risk ratio (aRR) for potential confounders.

RESULTS

During the follow-up period, 369 (19.88%) women were diagnosed with GDM. DPI scores ranged from 6.09 to 89.45. There was no association between DPI scores and GDM (aRR: 1.01, 95% confidence interval [CI]: 0.92, 1.08; p trend = 0.922). When comparing DPI quartile 4 (most pro-phytochemical content) to quartile 1 (few phytochemical contents), there was no significant difference between them (aRR: 0.97; 95% CI: 0.75, 1.25; p = 0.852). Also, there was no significant difference between DPI quartile 3 and quartile 1 (aRR: 1.04; 95% CI: 0.81, 1.34; p = 0.741) as well as DPI quartile 2 and quartile 1 (aRR: 0.92; 95% CI: 0.71, 1.21; p = 0.593).

CONCLUSIONS

Although this data did not support the association between pre-pregnancy DPI scores and GDM, further cohort studies to ascertain the causal association between them are warranted.

Association Between Dietary Phytochemical Index and Neonatal Thyroid Function

Background: Thyroid hormones regulate fetal growth and differentiation of several tissues. Maternal dietary patterns may be correlated with changes in the level of neonatal thyroid-stimulating hormone (TSH). We hypothesized that since maternal nutrition affects birth weight and offspring growth, it may also impact endocrine patterns in offspring. This study is aimed at assessing the relationship between maternal dietary phytochemical index (DPI) in the first trimester of pregnancy and neonatal cord blood thyroid hormone levels. Methods: This cross-sectional study is a substudy of a birth cohort. Overall, 216 mothers, aged 16-45 years, were recruited in their first trimester of pregnancy. To calculate DPI, the daily energy percentage of phytochemical-rich foods was divided by the total daily energy intake. At delivery time, TSH and free thyroxine (FT4) levels were measured in cord blood samples using chemiluminescence immunoassay. Results: The mean (standard deviation (SD)) age of mothers was 29.56 (5.50) years, and 47% of newborns were girls. The mean (SD) of DPI in the first, second, third, and fourth quartiles was 25.03 ± 4.67, 33.87 ± 2.18, 40.64 ± 2.10, and 51.17 ± 4.98, respectively. There was not any significant correlation between DPI score with cord serum TSH and FT4 levels in crude and adjusted analysis. Conclusion: No significant relationship between maternal DPI with cord serum TSH and FT4 levels was shown. Limited experience exists about the effect of maternal diet quality indices on neonatal thyroid function, and further studies are needed in this regard.

Dietary Total Polyphenol, Flavonoid, and Lignan Intakes Are Associated with Obesity and Diabetes-Related Traits: A Case-Control Study

Purpose: Dietary phytochemicals have been under examination as adjuvants for the prevention and treatment of obesity and diabetes. This study aimed at examining the potential associations of dietary "Phytochemical Index" (PI) and polyphenol intake with obesity and diabetes-related parameters. Materials and Methods: The case-control study involved 331 participants (156 overweight/obese and 175 normal weight), aged 18-50 years. Dietary intake was assessed using the 24-hr dietary recall method, and the PI score was calculated as the percentage of energy intake provided by phytochemical-rich foods. Polyphenol intakes were calculated using Phenol-Explorer and U.S. Department of Agriculture databases. Anthropometrical measurements were taken, serum glucose, insulin, and lipid profiles were analyzed, homeostatic model assessment for insulin resistance (HOMA-IR) was calculated, and blood pressure was measured. Linear regression analyses were used to examine the potential associations. Results: Participants with higher PI scores had higher total and some sub-classes polyphenol intakes compared with lower ones (P < 0.05, for each). Dietary PI score was not associated with any of the anthropometrical measurements; however, total polyphenol and flavonoids intakes were inversely associated with body mass index (β = -0.269, P = 0.049; β = -0.262, P = 0.048; respectively), waist circumference (β = -0.127, P = 0.021; β = -0.130, P = 0.016; respectively), and waist-to-hip ratio (β = -20.724, P = 0.032; β = -22.199, P = 0.018; respectively) after adjusting for potential confounders. Either dietary PI score or total and sub-class polyphenol intakes were not associated with a better metabolic profile, except for the lignan intake, which was inversely associated with HOMA-IR (β = -0.048, P = 0.011). Conclusions: Higher dietary polyphenol intake may have potential in the prevention of obesity and diabetes, and validated practical tools are essential for the assessment of polyphenol intake in clinical practice.

The predictive role of the dietary phytochemical index in relation to the clinical and psychological traits of migraine headaches

We investigated the relationship between dietary phytochemical index (DPI) and migraine headaches in Iranian patients, analyzing both clinical and psychological traits. A cross-sectional study was conducted using non-obese adults aged 20-50 years who were diagnosed with migraine. The study used a validated 168-item food frequency questionnaire to assess the usual dietary intake of participants. The DPI was calculated using the following formula: [daily energy derived from phytochemical-rich foods (in kJ)/total daily energy intake (in kJ)] × 100. Clinical outcomes of migraine including frequency, duration, and severity of headaches, as well as migraine-related disability were obtained using relevant questionnaires. Moreover, the mental health profile of patients including depression, anxiety, and stress, as well as serum levels of nitric oxide (NO) were measured. A Poisson regression was used for headache frequency. Linear regression analyzed migraine-related outcomes including duration, severity, migraine-related disability, and serum NO levels. In addition, psychological traits were analyzed via logistic regression. A total of 262 individuals (85.5% females) with a mean age of 36.1 years were included in the analysis. The frequency of migraine attacks was lower in patients in the last DPI tertile compared to those in the first DPI tertile both in the crude [incidence rate ratio (IRR) = 0.70, 95% confidence interval (CI) 0.63, 0.78, Ptrend < 0.001] and fully-adjusted models (IRR = 0.84, 95% CI 0.74, 0.96, Ptrend = 0.009). After controlling for potential confounders, an inverse relationship was observed between higher adherence to DPI and migraine-related disability (β = - 2.48, 95% CI - 4.86, - 0.10, P trend = 0.046). After controlling for potential confounders, no significant relationship was observed between DPI and depression (OR = 0.79, 95% CI 0.42, 1.47, Ptrend = 0.480), anxiety (OR = 1.14, 95% CI 0.61, 2.14, Ptrend = 0.655), and stress (OR = 1.04, 95% CI 0.57, 1.90, Ptrend = 0.876). Higher intakes of phytochemical-rich foods may be associated with lower migraine frequency and improved daily activities among patients. Further studies should confirm our observations and delineate the biological pathways linking phytochemicals and migraine headaches.

Association between dietary phytochemical index and risk of benign prostatic hyperplasia: a case-control study

BACKGROUND

Dietary intake of phytochemicals has been associated with a reduced risk of chronic diseases, but research on their relationship with benign prostatic hyperplasia (BPH) is limited. This case-control study aimed to investigate the association between a Dietary Phytochemical Index (DPI) and BPH risk in a Middle-Eastern population.

METHODS

The study recruited 112 BPH patients and 112 age-matched healthy controls (40-75 years) from Al-Zahra Hospital Clinic in Isfahan, Iran between 2021 and 2022. Dietary intake was assessed using a validated food-frequency questionnaire, and DPI was calculated as the ratio of energy intake from phytochemical-rich foods to total daily energy intake. Logistic regression analysis was performed, adjusting for potential confounders.

RESULTS

In the crude model, participants in the highest DPI tertile had a 70% lower odds of BPH compared to those in the lowest tertile (OR:0.3, 95% CI 0.15-0.61, P-trend = 0.001). After adjusting for confounders, this inverse association remained significant (OR:0.23, 95% CI 0.15-0.63, P-trend = 0.001). Participants with higher DPI consumed more whole grains (p = 0.02), nuts (p < 0.001), legumes (p = 0.02), fruits (p < 0.001), vegetables (p < 0.001), olives and oilve products (p = 0.02), and tomato and its products (p < 0.001) in their diet compared to the lowest tertile. However, red meat (p = 0.03) and refined grains (p < 0.001) were consumed in higher amounts in the lowest tertile compared to the highest DPI tertile.

CONCLUSIONS

This study demonstrates a protective association between DPI and BPH risk in the Middle-Eastern population. Encouraging higher intake of phytochemical-rich foods may help reduce the risk of BPH, highlighting the relevance of nutritional science in promoting prostate health.

Dietary Phytochemical Index in Relation to Metabolic Health Status, Serum Adropin, and Brain-Derived Neurotrophic Factor Levels in Adults

Background

Little is known about the relationship between dietary intake of phytochemicals with metabolic health status and underlying mechanisms.

Objectives

Little is known about the relationship between dietary intake of phytochemicals with metabolic health status and underlying mechanisms. We hypothesized that dietary phytochemical index (DPI) improves metabolic health status by ameliorating serum concentrations of brain-derived neurotrophic factor (BDNF) and adropin.

Methods

A cross-sectional study was performed in 527 adults (286 males and 241 females). The dietary intakes of participants were collected by a 168-item food frequency questionnaire, and DPI was estimated as a percentage of energy intake derived from phytochemical-rich foods. Anthropometric variables, blood pressure, glycemic and lipid profiles, and biochemical variables were assessed. The metabolically unhealthy (MU) phenotype was determined based on the definition presented by Wildman et al.

Results

The MU phenotype was identified in 51.4% of male and 32.0% of female participants. Participants in the third tertile of DPI had 59% lower odds of MU than those in the first tertile (OR: 0.41; 95% CI: 0.19, 0.87) after considering potential confounders. Stratified analysis by sex and body mass index indicated that DPI was inversely related to MU phenotype in females (OR: 0.28; 95% CI: 0.08, 0.97) and normal-weight individuals (OR: 0.11; 95% CI: 0.02, 0.62). DPI was also inversely associated with hyperglycemia, hypertriglyceridemia, and chronic inflammation. Nonsignificant reduced odds of low BDNF (OR: 0.87; 95% CI: 0.42, 1.84) and adropin (OR: 0.75; 95% CI: 0.31, 1.79) were observed in individuals in the top tertile of DPI compared with those in the bottom tertile.

Conclusions

This study showed that individuals with higher dietary intake of phytochemicals had lower odds of MU, particularly females and normal-weight individuals. No significant relationship was observed between serum BDNF and adropin with phytochemical intake.

Dietary antioxidant status indices may not interact with CETP Taq1B polymorphism on lipid profile and severity of coronary artery stenosis in patients under coronary angiography

The association of CETP Taq1B polymorphism with some metabolic traits is still controversial. The interaction of adherence to dietary indices with this polymorphism on the severity of coronary artery stenosis and serum lipid parameters needs to be investigated. This study aimed to test this hypothesis. This cross-sectional study included 453 patients who were referred from Afshar Hospital of Yazd and undergoing coronary angiography from 2020 to 2021. Dietary intake was evaluated by a 178-item validated and reliable dietary questionnaire. Dietary indices such as dietary antioxidant index (DAI), dietary antioxidant quality score (DAQS), and dietary phytochemical index (DPI) are determined according to dietary guidelines. The Taq1B variant was genotyped by the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). Two-way ANOVA was used to test the interaction between Taq1B polymorphism and dietary indices. The results of the frequency analysis of Taq1B genotypes showed that 10.4% were B1B1, 72.4% B1B2, and 17.2% B2B2. No significant interaction was found between the Taq1B variant with high adherence to DAQS, DAI, and DPI on total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), triglyceride (TG) levels, and Gensini score (GS) and Syntax score (SS). In high-adherence dietary indices, lipid profile and coronary artery stenosis scores did not differ significantly in Taq1B genotypes. Due to the insignificant results in this research, further studies are needed to investigate the role of Taq1B SNP in modulating dyslipidemia and the severity of the CAD in interaction with dietary indices.

Association of dietary phytochemical index with cardiometabolic risk factors

Objective(s): Cardio-metabolic risk factors are becoming a global health concern. To address this problem, one of the proposed ways is to focus on phytochemical-rich foods consumption. Therefore, we aimed to summarize the results of observational studies (cohorts, case-control, and cross-sectional) that investigated the association between dietary phytochemical index (PI) as a new index for evaluating phytochemical-rich food intake and various risk factors of cardio-metabolic disorders. Methods: We conducted a comprehensive systematic review through PubMed, Scopus, and Web of Science databases. The literature search was performed up to August 2021 with no publication year restriction on observational studies investigating the association between PI and cardiometabolic risk factors on adults and children. A random-effect meta-analysis was used. Results: Overall, 16 articles (cross-sectional, case-control, cohort) were eligible for this systematic review and 8 studies with 99771 participants were included in the meta-analysis. Random effect meta-analysis showed that adherence to higher dietary PI decrease the odds of abdominal obesity (OR: 0.73, 95% CI: 0.58, 0.88, I2: 84.90), generalized obesity (OR: 0.84, 95% CI: 0.69, 0.98, I2: 68.10), hypertriglyceridemia (OR: 0.81, 95% CI: 0.73, 0.89, I2: 0.00), hypertension (OR: 0.86, 95% CI: 0.73, 0.99, I2: 7.02), and MetS (OR: 0.79, 95% CI: 0.69, 0.88, I2: 84.90). However, results considering the associations between dietary PI with glycemic indices, and low high-density lipoprotein cholesterol (HDL-C) were not significant (p<0.05). Conclusion: Evidence showed adverse associations between dietary PI and some cardio-metabolic risk factors such as obesity, hypertriglyceridemia, hypertension and metabolic syndrome.

Association between Total Dietary Phytochemical Intake and Cardiometabolic Health Outcomes-Results from a 10-Year Follow-Up on a Middle-Aged Cohort Population

Dietary phytochemical intake associations with cardiovascular health and mortality remain unknown. We studied the relations between total dietary phytochemical intake and cardiovascular health outcomes in a middle-aged Swiss population. We analyzed data spanning 2009 to 2021 from a prospective cohort study in Lausanne, Switzerland, including 3721 participants (54.8% women, 57.2 ± 10.3 years) without cardiovascular disease (CVD) history. Dietary intake was assessed using a validated self-reported food frequency questionnaire. The Dietary Phytochemical Index (DPI) and the healthy Dietary Phytochemical Index (hDPI) were calculated as the total energy intake percentage obtained from phytochemical-rich food consumption. The Healthy Plant-Based Diet Index (hPBD) was estimated by scoring healthy plant foods positively and less-healthy plant foods negatively. Indices tertiles and cardiometabolic outcome associations were determined using Cox proportional hazard models. Over 30,217 person-years of follow-up, 262 CVD events, and 178 deaths occurred. Unadjusted analyses found 36%, 33%, and 32% lower CVD risk for the highest hDPI, DPI, and hPBD tertiles, respectively. After adjustment, only the second hDPI tertile showed a 30% lower CVD risk (HR 0.70, 95% CI 0.51-0.95; P for trend 0.362). No other associations emerged. In this middle-aged Swiss cohort, no associations between dietary indices reflecting a phytochemical-rich dietary pattern and incident CVD, all-cause, or CVD mortality were observed.

Dietary phytochemical index and psychological disorders in a large sample of Iranian adults: a population-based study

BACKGROUND

Intake of plant foods and phytochemicals can decrease the odds of mental health.

AIM

The aim of study is to investigate the association between Dietary Phytochemical Index (DPI) with symptoms of depression, anxiety and stress in a large sample of Iranian adults.

METHODS

In this cross-sectional study, a total of 7385 adults aged 20-50 years old were provided from the recruitment phase of Yazd Health Study, a population-based cohort research on Iranian adults. Food intakes were assessed via a validated and reliable food frequency questionnaire. Symptoms of depression, anxiety and stress were assessed using a validated Depression, Anxiety and Stress Scales questionnaire with 21-items. DPI was calculated by the percent of daily energy intake taken from phytochemical-rich foods.

RESULTS

After adjustment for potential confounders, normal weight subjects in the highest tertile of DPI had lower odds of depression (OR 0.65; 95% CI 0.44-0.97) and anxiety symptoms (OR 0.65; 95% CI 0.45-0.93) compared with those in the lowest tertile. However, the apparent association was not found between depression, anxiety and stress in overweight and obese subjects.

CONCLUSION

We found a significant association between DPI and mental health in normal weight adults. Prospective studies are required to approve these conclusions.

Association between dietary phytochemical index, cardiometabolic risk factors and metabolic syndrome in Switzerland. The CoLaus study

BACKGROUND AND AIMS

Plant-based diets are associated with reduced cardiometabolic risk factors (CRFs) and lower risk of metabolic syndrome (MetS), probably via phytochemicals acting synergistically. However, dietary phytochemical content estimation is challenging; therefore, the dietary phytochemical index (DPI) was proposed as a practical way to assess total dietary phytochemical content from phytochemical-rich foods (PRFs). We evaluated the association between DPI with CRFs and MetS and its components.

METHODS AND RESULTS

Cross-sectional analysis of 2009-2012 data of Colaus cohort study (Lausanne, Switzerland), including 3879 participants (mean age 57.6 ± 10.4 years, 53.5% women). Dietary intake was assessed via a validated food frequency questionnaire. DPI was calculated as the total energy intake percentage obtained from PRFs consumption and assessed as quartiles. Associations were determined using multivariable linear and logistic regression for CRFs and MetS, respectively. Median DPI value was 25.5 (interquartile range: 17.7-34.6). After multivariable-adjusted analyses, significant inverse associations were observed between the last two highest DPI quartiles and waist circumference (WC), body mass index (BMI), insulin, leptin, and hs-CRP. No significant associations were observed for MetS or its components except for central obesity, as subjects in the highest DPI quartile had lower odds (OR: 0.78; 95% CI: 0.62, 0.97) than those in lowest quartile.

CONCLUSION

A diet high in PRFs assessed via DPI is associated with lower WC, BMI, insulin, leptin, hs-CRP values, and lower odds of central obesity, indicating a potential protective effect of phytochemical intake on these CRFs and highlighting the importance of high PRFs intake in promoting cardiometabolic health.

Dietary intake of phytochemicals in association with irritable bowel syndrome in adults

BACKGROUND & AIM

There is limited data regarding the association between phytochemical-rich diets and irritable bowel syndrome (IBS). The current study aimed to cross-sectionally evaluate the association of dietary phytochemical index (DPI) with the odds and severity of IBS.

METHODS

In this study, which included 3362 Iranian healthcare staffs, a dish-based semi-quantitative food frequency questionnaire (DS-FFQ) was utilized to collect dietary information. The DPI was defined as the daily percentage of calories consumed from phytochemical-rich foods. The IBS assessment was performed using a revised Iranian version of the Rome III questionnaire. We applied the restricted cubic spline (RCS) to detect the possible non-linear dependency of the relationship between DPI and the odds of IBS.

RESULTS

The mean age, Body Mass Index (BMI), and DPI scores of the participants were 36.29 ± 7.8 years, 24.90 ± 3.8 kg/m2, and 16.07 ± 9.01, respectively. After adjusting for possible confounders, no significant association was observed between DPI and odds of IBS in the whole study population or in gender- and BMI-stratified analyses. We found a significant inverse association between DPI and IBS severity in the study population (OR: 0.70; 95% CI: 0.51-0.98). Concerning gender, such an association was only found in women (OR: 0.65; 95% CI: 0.44-0.96). However, there was no significant relationship between DPI and IBS severity in BMI subgroups. In addition, we found no meaningful relationship between DPI and IBS subtypes. The RCS model showed that there is no non-linear relationship between DPI classification and IBS (non-linear test, χ2 = 1.14, Pnon-linearity = 0.513).

CONCLUSIONS

Higher phytochemical intake was associated with reduced IBS severity, particularly in women. Further prospective studies are required to confirm these findings.

The relation between dietary phytochemical index and metabolic health status in overweight and obese adolescents

Previous studies have rarely investigated dietary phytochemicals consumption in relation to metabolic health of adolescents. The current study was performed to investigate dietary phytochemical index (DPI) in relation to metabolic health status in overweight and obese adolescents. This cross-sectional study was conducted among 203 adolescents with overweight or obesity. Dietary intakes of participants were obtained through a validated 147-item food frequency questionnaire. DPI was calculated [(dietary energy derived from phytochemical-rich foods (kcal)/total daily energy intake (kcal)) ⨯100]. Glycemic and lipid profiles, blood pressure, and anthropometric indices were also measured. A metabolically unhealthy overweight/obesity (MUO) profile was determined based on the International Diabetes Federation (IDF) and IDF/Homeostasis Model Assessment Insulin Resistance (HOMA-IR) definitions. Study subjects had a mean age of 13.98 years and 50.2% of them were girls. According to IDF and IDF/HOMA-IR criteria, 38.9% (37 boys, and 42 girls) and 33% (35 boys, and 32 girls) of the study participants were respectively MUO. According to IDF and IDF/HOMA-IR definitions, adolescents in the third DPI tertile had respectively 61% (maximally-adjusted OR = 0.39, 95%CI 0.16-0.91) and 67% (maximally-adjusted OR = 0.33, 95%CI 0.13-0.83) lower odds of being MUO, compared to the first tertile. Stratified analysis by sex indicated that DPI was inversely related to MUO phenotype based on IDF criteria in girls (maximally-adjusted OR = 0.25, 95%CI 0.06-0.98), but not in boys. The current study found that adolescents with a higher dietary intake of phytochemicals have lower odds of being MUO, particularly among girls. However, further large-scale prospective cohort studies are required to confirm this finding.

The association of dietary phytochemical index and nonalcoholic fatty liver disease

Consumption of phytochemical-rich foods relates to the prevention of chronic diseases. In this study we assessed the dietary phytochemical index (PI) in metabolic parameters, liver enzymes, and severity of fibrosis among nonalcoholic fatty liver disease patients. This cross-sectional study was conducted on 210 patients with NAFLD. Fibrosis-4 index (FLB4), nonalcoholic fatty liver disease fibrosis score (NFS), FBS, lipids profile, AST, ALT, ALP, and GGT were measured. PI was calculated through the information obtained from a validated semi-quantitative food frequency. Multiple regression models were used to estimate mean difference changes in the evaluated variables associated with various dietary PI. Participants' mean ± SD of age and BMI were 39.23 ± 10.52 and 24.40 ± 2.64, respectively. We found that DPI is inversely associated with serum TG, TC, and LDL-C and directly associated with serum HDL-C and a higher score in DPI is associated with lower scores in NFS and FIB-4. Multivariate linear regression showed that there is an inverse association between DPI and AST, ALT, ALP, GGT, NFS, and FIB-4. Higher dietary PI could impact on reduction of NAFLD progression and improvement of metabolic parameters.

Oxidative balance score and dietary phytochemical index can reduce the risk of colorectal cancer in Iranian population

BACKGROUND

No previous study has assessed the association between oxidative balance score (OBS) and dietary phytochemical index (DPI) with colorectal cancer (CRC) simultaneously. Therefore, this study investigated the association between OBS and DPI with the odds of CRC among the Iranian population.

METHODS

This hospital-based age and sex-matched case-control study was conducted between September 2008 and January 2010 (142 controls and 71 cases were entered for analysis). New diagnosed CRC cases were selected from the Cancer Institute, Imam Khomeini Hospital of Tehran. Dietary intakes were determined by a semi-quantitative food frequency questionnaire (FFQ). Then, dietary indices were calculated by food items and nutrient intake. Logistic regression was utilized for assessing the tertiles of OBS and DPI.

RESULTS

In multivariate analysis, OBS was associated with a 77% reduction in CRC odds in the last tertile than the first tertile (odds ratio (OR) = 0.23, confidence interval (CI): 0.07-0.72, P_trend = 0.017). Also, we found a 64% reduction in CRC odds in the last tertile of DPI compared to the first tertile (OR = 0.36, CI: 0.15-0.86, P_trend = 0.015).

CONCLUSIONS

A diet rich in phytochemicals and anti-oxidants, including fruits and vegetables (citrus fruits, colored berries, and dark-green leafy vegetables) and whole grains, may reduce the CRC odds.

Association between the Dietary Phytochemical Index and Lower Prevalence of Obesity in Korean Preschoolers

Little is known regarding Korean preschooler dietary phytochemical index (DPIs). We used the 24 h recall data of 1196 participants aged 3-5 years from the Korea National Health and Nutrition Examination Survey to study the association between dietary food intake and obesity prevalence. The amount of dietary intake by food group was compared according to sex and DPI quartile. Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression models. The average total DPI and energy from phytochemical food groups were not significantly different according to sex, although boys had a higher total daily food intake. Different inclinations between DPI quartiles and amount of intake were observed in the food groups; specifically, beans showed a higher intake difference between Q1 and Q4 for boys than in the other food groups. The highest DPI quartile had a significantly lower obesity prevalence than the lowest DPI quartile in all models for boys only when obesity prevalence by weight percentile was analyzed (Model 3, OR: 0.287, 95% CI: 0.095-0.868, p for trend < 0.05). Our results suggest a high DPI could help prevent obesity in preschoolers.

Dietary phytochemical index is favorably associated with oxidative stress status and cardiovascular risk factors in adults with obesity

Phytochemicals are bioactive compounds found in plant-based foods. Consumption of phytochemical-rich foods has been associated with cardiovascular and metabolic diseases prevention in various populations. To quantify the phytochemical content of the diet, dietary phytochemical index (DPI) was established which is defined as the proportion of daily energy intake derived from foods rich in phytochemicals. The purpose of this study was to evaluate the association between the DPI and oxidative stress markers and cardiovascular risk factors in obese adults. In this cross-sectional study, a total of 140 adults aged 20-60 years and body mass index (BMI) of ≥ 30 kg/m² were included. A validated food frequency questionnaire (FFQ) was used to collect information on dietary intakes. The DPI was calculated based on the following formula: DPI = [daily energy obtained from foods rich in phytochemicals (kcal)/total daily energy intake (kcal) × 100]. There was an inverse association between DPI and serum concentrations of Malondialdehyde (MDA) (P = 0.004), triglyceride (TG) (P-trend = 0.003), high-sensitive C-reactive protein (hs-CRP) (P = 0.017), and erythrocyte superoxide dismutase (SOD) activity (P = 0.024). Total antioxidant capacity (TAC) was positively associated with DPI score (P = 0.045). No significant relationship was found between the DPI score and fasting blood sugar (FBS), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total oxidant status (TOS), glutathione peroxidase (GPx), catalase (CAT), and anthropometric parameters as well as systolic and diastolic blood pressure. The current study found that there was a significant inverse association between DPI and oxidative stress, inflammation, and hypertriglyceridemia as cardiovascular disease (CVD) risk factors in obese population. However, further research is needed to confirm these findings.

Interactions of BDNF Val66met and dietary indices in relation to metabolic markers among patient with type 2 diabetes mellitus: a cross-sectional study

BACKGROUND

Gene-diet interaction is related to the progression of diabetes and cardiovascular diseases biomarkers. We aimed to evaluate the interaction between diet quality indices and BDNF Val66Mat (rs6265) on cardiometabolic markers among diabetic patients.

METHODS

This cross-sectional study was conducted on 634 patients with type 2 diabetes mellitus, which were randomly recruited from diabetic centers in Tehran. Dietary intakes were estimated by a previously validated semi-quantitative food frequency questionnaire comprising 147 items. All participants were categorized into three categories, based on healthy eating index (HEI), diet quality index (DQI), and phytochemical index (PI) scores. Polymerase chain reaction was used for genotyping the BDNF Val66Met. Interactions were tested using analysis of covariance in adjusted and crude models.

RESULTS

Our result showed that higher DQI, HEI, and PI scores significantly decrease body mass index and waist circumference among individuals with Met/Met, Val/Met, and Val/Val genotypes (P interactions < 0.05). Moreover, the highest quartile of the DQI and PI, compared to the lowest, showed lower TG level among Met allele carriers compared to Val/Val homozygotes (P interaction = 0.004 and 0.01, respectively) and a faster reduction in IL-18 and TC level was seen among Met/Met, Val/Met who had higher HEI intake than those with Val/Val genotype.

CONCLUSIONS

BDNF Val66Met polymorphism may interact with HEI, DQI, and PI. We have revealed that Met allele acts as a protective allele for diabetic patients and may have a beneficial influence on cardio-metabolic factors through regulating dietary intake.

Association between Phytochemical Index and Osteoporosis in Women: A Prospective Cohort Study in Korea

Osteoporosis is a prevalent issue among postmenopausal women, who have a higher incidence of the condition than men. This study aimed to examine the relationship between phytochemical-rich food intake and osteoporosis incidence in premenopausal and postmenopausal women. The data analyzed included 4600 women aged 40–69 who were free of osteoporosis at baseline, with dietary intake evaluated through a semi-quantitative food frequency questionnaire and osteoporosis prevalence determined using interviewer-administered questionnaires and bone mineral density tests. The phytochemical index (PI) was calculated to reflect the intake levels of phytochemical-rich foods. Postmenopausal women in the highest PI quartile had a 16% lower risk of osteoporosis (95% confidence interval (CI): 0.71 to 0.99, p for trend = 0.02) than those in the lowest quartile, while no significant association was observed among premenopausal women (hazard ratio: 0.98, 95% CI: 0.78 to 1.24, p for trend = 0.8). These findings suggest that consuming phytochemical-rich foods may have a protective effect against osteoporosis in postmenopausal women, offering valuable scientific insights. However, additional research is needed to validate these findings using biochemical data. Overall, this study highlights the potential of dietary interventions to reduce the risk of osteoporosis in postmenopausal women.

Dietary Phytochemical Index and the Risk of Breast Cancer: A Case-Control Study

High intakes of phytochemical-rich foods might have beneficial effects on reducing breast cancer risk. In this study, we assessed the association between the dietary phytochemical index (PI) and breast cancer risk in a sample of premenopausal Turkish women. This case-control study was conducted on 70 newly diagnosed breast cancer cases and matched 70 healthy controls. Dietary intake was assessed using a validated food frequency questionnaire and dietary phytochemical indexes were calculated with two different methods. The mean PI score of participants was 19.9 ± 9.52 and 23.0 ± 8.95 in cases and controls, respectively (p = 0.046). After adjusting for energy intake, the risk of breast cancer significantly increased by 29.5% in the third quartile as compared to the fourth quartile of dietary PI (OR = 0.295, 95%CI = 0.106-0.822). Higher dietary PI was negatively associated with breast cancer risk; therefore, dietary PI may be suggested as an important contributor to dietary intake for breast cancer.

Association between urinary levels of 8-hydroxy-2-deoxyguanosine and F2a-isoprostane in male football players and healthy non-athlete controls with dietary inflammatory and antioxidant indices

Purpose

The relationship between the inflammatory and antioxidant potential of an athlete's diet and their oxidative biomarkers is an important area of investigation. Therefore, this study aimed to assess the excretion of 8-hydroxy-2-deoxyguanosine (8-OHdG) and F_2alpha-isoprostane (F_2a-IP) in the urine of male football players and healthy non-athlete controls. This study also aimed to examine the associations among the dietary inflammatory index (DII), the dietary total antioxidant capacity (DTAC), and the dietary phytochemical index (PI) with 8-OHdG and F_2a-IP.

Methods

In this descriptive-analytical study, 45 male football players and 45 healthy non-athletes, who were individually matched based on age and body mass index (BMI), were recruited from Shiraz City, Iran. Fasted urine samples were analyzed for 8-OHdG and F_2a-IP levels. Anthropometric measurements were performed, and body composition was assessed using a body composition analyzer. A valid food frequency questionnaire (FFQ) was used to calculate DII, DTAC, and PI scores. Data analysis was conducted using a generalized estimating equation (GEE) model.

Results

We found that 8-OHdG (β = -6.96), F_2a-IP (β = -82.58), and DII (β = -2.06) were significantly lower, while DTAC (β = 2.37) and PI (β = 0.084) were significantly higher in the football player group compared with the non-athlete group (P < 0.001 for all variables). In all participants, dietary indices were significantly associated with oxidative biomarkers. DII was positively associated with 8-OHdG (β = 2.25; P < 0.001) and F_2a-IP (β = 38.34; P < 0.001). Furthermore, negative associations between DTAC (β = -1.42; P < 0.001) and PI (β = -35.37; P < 0.001) with 8-OHdG were found. Moreover, DTAC (β = -17.34; P < 0.001) and PI (β = -428.11; P = 0.003) were negatively associated with F_2a-IP.

Conclusion

The results of this study highlighted the importance of a healthy diet in reducing oxidative stress among football athletes. The levels of urinary biomarkers for DNA and lipid oxidation were found to be lower in football players compared to non-athletes. This suggests that following an anti-inflammatory and antioxidant-rich diet may help reduce oxidative stress in these individuals.

High intake of dietary phytochemical index may be related to reducing risk of diabetic nephropathy: a case-control study

OBJECTIVE

Diabetic nephropathy (DN) is involved in 40% of patients with type 2 diabetes, Phytochemical index (PI) foods are known as antioxidant and anti-inflammatory agents. Higher intake of phytochemicals can improve glucose tolerance, hypertension and complications of DN. This study sought to discern the relationship between dietary PI and DN.

METHODS

This was a case-control study which was conducted between 210 diabetic women. General characteristics, blood pressure, biochemical serum levels, and anthropometric measurements were evaluated. Physical activity and dietary intakes were assessed via short form of physical activity questionnaire and 147 items-validated food frequency questionnaires, respectively. Then, PI was calculated through method of McCarty and divided to 2 groups of lower and higher of median. Independent samples T tests were used to identify differences in quantitative variables. To investigate the relationship between dietary PI and risk of DN, logistic regression was used. The odds ratio (OR) of DN, and its 95% confidence interval (CI), in each groups of PI were shown.

RESULTS

The percentage of daily intake of energy from fruits and vegetables were higher than the other sources of phytochemical rich foods. Higher consumption of vitamin A was seen in higher group of PI among the control group, after adjusting for energy intake. In the higher adherence of median of dietary PI group, intake of fruits, vegetables, legumes, grains, and olives of controls were higher than cases. In addition, soy consumption was statistically different between lower and higher adherence of median of dietary PI among cases. There was an inverse relationship between dietary PI and risk of DN (OR = 0.44; 95% CI: 0.25-0.77; P = 0.04). After adjusting for potential confounders, the association remained significant, albeit with lower odds of having DN (OR = 0.15; 95% CI: 0.06-0.36; P < 0.001).

CONCLUSION

Finally, the present study found evidence indicating an inverse relationship between consumption of foods rich in phytochemicals and risk of DN in this sample.

Dietary Antioxidant Capacity Indices are Negatively Correlated to LDL-Oxidation in Adults

INTRODUCTION

Former research studies have demonstrated controversial associations between dietary indices and oxidative stress biomarkers including oxidized low-density lipoprotein (ox-LDL) and malondialdehyde (MDA). So, in this cross-sectional study, we aimed to assess the association of dietary total antioxidant capacity (DTAC), oxidative balance score, and phytochemical index (PI) with ox-LDL/MDA in a healthy adult population of Shiraz, Iran.

METHODS

236 individuals participated in this cross-sectional study. DTAC, OBS, and PI were calculated using a 168-item food frequency questionnaire (FFQ), which was previously validated in Iran. We measured ox-LDL and MDA in blood samples of the participants using commercially existing kits. Crude and adjusted models of linear regression were used to evaluate the relation of dietary indices with ox-LDL and MDA.

RESULTS

There was a significant association between ox-LDL and DTAC in both crude (β = -1.55; 95% CI: -2.53, -0.58; P-trend = 0.002) and adjusted (β = -1.65 95% CI: -2.66, -0.64; P-trend = 0.001) models. Also, a negative association was observed between ox-LDL and PI in the crude (β = -1.26 95% CI: -2.33, -0.29; P-trend = 0.01) and adjusted (β = -1.36 95% CI: -2.38, -0.34; P-trend = 0.01) models.

CONCLUSION

Results of this study showed that DTAC and PI were inversely associated with ox-LDL as markers of lipid peroxidation. But no correlations were seen between MDA and dietary antioxidant indices.

Examining dietary behaviours, diet quality, motives and supplementation use in physically active individuals following vegetarian-based eating patterns

The adoption of vegetarian-based dietary patterns among athletes has been gaining popularity. However, limited research examines the dietary behaviours within this group. Therefore, the aim of this study was to examine self-reported dietary behaviours in a cohort of physically active individuals following vegetarian-based dietary patterns, recruited via social media. A 52-item online survey was created with questions related to demographics, physical activity, eating patterns and supplementation use. An external link to the Australian Automated Self-Administered 24-h (ASA24-AU) recall was included to examine nutrient intakes. Dietary quality was assessed using the Alternate Healthy Eating Index-2010 (AHEI-2010) and the Dietary Phytochemical Index (DPI) tools. A total of 781 (84.8%) respondents completed the survey in 2018. Principal motives for adhering to a vegetarian-based dietary pattern included animal rights (86.5%), environmental concerns (75.4%), health reasons (69.6%) and improving physical performance (24.1%). Vitamin B12 was the most commonly reported supplement (58.1%) followed by protein powder (36.3%) and vitamin D (35.9%). A total of 133 respondents completed the ASA24-AU dietary recall with generally adequate nutrient intakes and a high-quality diet as assessed by the AHEI-2010 and DPI. A significant minority of physically active individuals following vegetarian-based diets do so with the aspiration of improving their exercise performance. Dietary quality was considered high in this group for recreational physical activity, although intakes of vitamin B12 and LC n-3 PUFA were low.

Dietary phytochemical index and the risk of non-alcoholic fatty liver disease: A case-control study among Iranian adults

BACKGROUNDS

Dietary phytochemical index (DPI) is an inexpensive method for estimating the amounts of phytochemicals in foods. No study has investigated the association between DPI and non-alcoholic fatty liver disease (NAFLD). Our study aimed to compare DPI in patients with NAFLD and the control group.

METHODS

This is a case-control study of 250 subjects with NAFLD and 450 healthy subjects attending the Metabolic Liver Disease Research Center as a referral center affiliated to Isfahan University of Medical Sciences. DPI was calculated based on data collected from a 168-item validated food frequency questionnaire. Sociodemographic data, physical activity, and anthropometric measures such as body weight, height, and waist circumference were determined.

RESULTS

In the final adjusted model, the odds ratio (OR) of NAFLD across the DPI tertiles decreased significantly (OR = 0.55, 95 %CI = 0.31-0.95) (P-trend = 0.03). The highest vs. lowest tertiles of vegetable and olives PI were significantly associated with a lower risk of NAFLD (OR and 95 % CI = 0.26 (0.14-0.47); OR and 95 % CI = 0.51 (0.29-0.90), p for trend < 0.001, respectively), however, there was no significant relation between other PI components and NAFLD.

CONCLUSION

This case-control study suggested that a higher PI score is associated with a reduced chance of NAFLD after adjusting for confounding variables. In addition, the highest tertile of vegetable and olives PI was significantly associated with a lower risk of NAFLD.

The relationship between dietary phytochemical index and resting metabolic rate mediated by inflammatory factors in overweight and obese women: a cross-sectional study

Background

Unhealthy dietary patterns are the most important modifiable risk factors for obesity and overweight. This study aimed to examine the relationship between Dietary Phytochemical Index (DPI) and resting metabolic rate (RMR), mediated by inflammatory factors, in overweight and obese women.

Methods

A total of 404 women, aged 18–48 years, were included in the cross-sectional study. DPI was calculated using the 147-item food frequency questionnaire (FFQ). Anthropometric measurements, RMR, and blood biomarkers were assessed using standard protocols.

Results

There was marginally significant association between adherence to DPI and RMR status in the crude model (OR = 1.41, 95% CI 0.94–2.11, P = 0.09). After adjusting for potential confounders, a significant association was seen between the DPI and increase RMR.per.kg (OR = 2.77, 95% CI 0.98–7.82, P = 0.05). Our results indicated that plasminogen activator inhibitor-1 (PAI-1), transforming growth factor (TGF-β), and monocyte chemoattractant protein-1 (MCP-1) had a mediatory effect on the association between RMR and DPI (P > 0.05). Indeed, it was shown that, PAI-1, TGF-β, and MCP-1 destroyed the significance of this association and could be considered as mediating markers. However, no mediating effect was observed for high-sensitivity C reactive protein (hs-CRP).

Conclusions

Adherence to DPI can improve the RMR by reducing levels of inflammatory markers, and may be considered as a treatment for obesity. However, more long-term studies are recommended.

Migraine severity, disability, and duration: Is a good diet quality, high intake of phytochemicals and polyphenols important?

OBJECTIVES

Dietary pattern may be the determinant of migraine prognosis through various mechanisms such as systemic inflammation, vasodilation, cerebral glucose metabolism, and mitochondrial dysfunction.This study was conducted to examine the relationship of the symptoms and signs of migraine with dietary polyphenols and the phytochemical intake and the quality of the diet.

MATERIALS AND METHODS

Individuals (n = 90), who were admitted to the headache outpatient clinic due to the diagnosis of episodic migraine, underwent physical examination by a neurologist. Migraine characteristics were assessed using the Migraine Disability Assessment Questionnaire and the Visual Analogue Scale. The Healthy Eating Index-2015 (HEI-2015) was used to evaluate the diet quality of individuals, and the Phytochemical Index developed by McCarty was used to determine the dietary intake of phytochemicals. Phenol-Explorer version 3.6 and the USDA Database for the Flavonoid Content of Selected Foods-Release 3.3 were used to calculate the dietary polyphenol intake.

RESULTS

Migraine severity was negatively correlated with the intake of phytochemicals and good diet quality (r = -0.37, p = 0.0003; r = -0.37, p = 0.0003, respectively), and with the intake of phenolic components flavanones (r = -0.27, p = 0.01) and lignans (r = -0.27, p = 0.01). With respect to the food groups; migraine severity was found to be inversely correlated with the total phenol intake from olive oil, oil, and fruits (r = -0.26, p = 0.01; r = -0.21, p = 0.04; r = -0.24, p = 0.02, respectively), and the flavonoid intake from olive oil, oil, fruits, and vegetables (r = -0.26, p = 0.01; r = -0.26, p = 0.01; r = -0.35, p = 0.0007; r = -0.22, p = 0.04, respectively). Strikingly, fruit flavanone intake was correlated with low migraine severity (r = -0.39, p = 0.0002), and fruit flavanol intake was correlated with low migraine disability (r = -0.21, p = 0.04).

CONCLUSION

A high-quality diet rich in phytochemicals and polyphenols (especially flavanones and lignans) is associated with low migraine severity. Lower intake of phenols and flavonoids from vegetable oil, olive oil, fruits, and vegetables were associated with more severe migraine attacks. Examination of migraine characteristics and dietary pattern together with phytochemical and polyphenol intake may guide the development of dietary strategies to be used in migraine patients.

Association of dietary phytochemical index with metabolically unhealthy overweight/obesity phenotype among Iranian women: A cross-sectional study

Background

Phytochemicals have been recently studied as adjuvants for the treatment of obesity. No study has investigated the association of phytochemical-rich foods with metabolically unhealthy overweight/obesity phenotype (MUOW/O). This study aimed to determine the association of dietary phytochemical index (DPI) with MUOW/O based on Karelis criteria among Iranian female adults.

Methods

In this cross-sectional study, a total of 228 overweight and obese women aged 18–48 years were included. Anthropometric measurements were evaluated for all participants. A validated 147-item Food Frequency Questionnaire (FFQ) was used for dietary assessment. DPI was calculated as [dietary energy derived from phytochemical-rich foods (kcal)/total daily energy intake (kcal)] × 100. Participants’ body composition and biochemical parameters of Karelis criteria [triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), insulin, and high-sensitivity C-reactive protein (hs-CRP)] were determined.

Results

The mean age of the study participants was 36.69 ± 9.20, and the mean DPI score was 26.23 ± 9.48 among participants with MUOW/O phenotype. After controlling for potential confounders, women in the highest tertile of DPI had lower odds for MUOW/O phenotype [odds ratio (OR): 0.23, 95% confidence interval (CI): 0.07–0.68, P = 0.008] compared to the lowest tertile. Among the components of Karelis criteria, homeostatic model assessment for insulin resistance (HOMA-IR) was significantly associated with MUOW/O phenotype in the fully adjusted model (OR: 0.29, 95% CI: 0.10–0.79, P = 0.01).

Conclusion

We found a significant association between DPI and MUOW/O phenotype in Iranian women. Prospective studies are needed to confirm these findings.

Índice de Fitoquímicos da Dieta: Aplicação com Pacientes em Tratamento Oncológico

Introdução: O tratamento do câncer provoca efeitos adversos que podem alterar o consumo alimentar e, consequentemente, a ingestão de vitaminas, minerais, fibras e fitoquímicos. Objetivo: Aplicar o Índice de Fitoquímicos (IF) da dieta nos registros alimentares de pacientes em tratamento oncológico. Método: Estudo transversal com indivíduos em tratamento oncológico. Foram coletadas informações sociodemográficas e clínicas dos participantes para caracterização da população. Os dados alimentares foram obtidos por meio de recordatório alimentar de 24 horas e inseridos no software Nutrabem Pro® para obtenção dos valores de macro e micronutrientes, bem como dos fitoquímicos. Para avaliar o IF, aplicou-se a fórmula proposta por McCarty. Resultados: Participaram do estudo 50 pacientes predominantemente do sexo feminino e com média da idade de 58±12,1 anos. A média geral do IF foi de 20,44±11,55, e a ordem crescente de consumo foi: luteína-zeaxantina, alfacaroteno, licopeno, criptoxantina e betacaroteno. Os alimentos que mais contribuíram para a ingestão dos fitoquímicos foram: beterraba, cenoura e abóbora-japonesa para beta e alfacaroteno; laranja e mamão para betacriptoxantina; molho de tomate, melancia e mamão para licopeno; almeirão e beterraba para luteína/zeaxantina; e maçã, banana e azeite para fitoesterol. O IF não se associou com as variáveis sociodemográficas e clínicas da população. Conclusão: Os pacientes em tratamento oncológico apresentaram baixo consumo de fitoquímicos. Esse resultado condiz com a ingestão insuficiente de frutas e hortaliças, as quais representam as principais fontes de carotenoides nas refeições, além do baixo consumo de oleaginosas e sementes, que configuram uma importante fonte de fitoesteróis.

Phytochemical index and hypertension in Korean adults using data from the Korea National Health and Nutrition Examination Survey in 2008-2019

BACKGROUND/OBJECTIVES

Although previous in vivo and in vitro studies have reported the beneficial effects of phytochemical-rich food on cardiovascular health, limited information is available regarding its' health effect on the community-dwelling population. This is especially true in Korea. Here, we examined the cross-sectional association between phytochemical levels and hypertension in Korean adults.

SUBJECTS/METHODS

We analyzed data from 38,198 Koreans aged ≥30 years who participated in the Korea National Health and Nutrition Examination Survey (2008-2019) and met the study's inclusion criteria. The Korean version of the Phytochemical Index (PI) was computed based on 24 h recall data. Hypertension was defined based on the American College of Cardiology/American Heart Association definition in 2017. Multivariate logistic regression analysis was used to examine the association between PI and hypertension.

RESULTS

In the multivariable adjusted model, participants in the highest PI quintile had a significantly low prevalence of hypertension (Odd ratio, 0.86; 95% confidence interval, 0.79-0.95). A dose-response analysis confirmed the inverse linearity between PI and hypertension (p for nonlinearity = 0.2634).

CONCLUSIONS

Consumption of phytochemical-rich foods may lower the prevalence of hypertension. A large-scale, prospective cohort study is required to validate these findings.

Higher dietary phytochemical index is associated with lower odds of knee osteoarthritis

Previous studies have shown that adherence to dietary patterns rich in plant-based foods may reduce the odds of osteoarthritis; however, limited data are available on the association of consumption of diets rich in phytochemicals and odds of knee osteoarthritis (KOA). In this case–control study conducted in Iran, we aimed to investigate whether a higher dietary phytochemical index (DPI) is associated with decreased odds of having KOA. A total of 124 cases aged 20–60 years diagnosed with bilateral primary KOA according to the American College of Rheumatology criteria and 124 controls frequency-matched on age, sex, and body mass index (BMI) were included in the study. A validated food frequency questionnaire (FFQ) was used to collect information on dietary intakes. To calculate DPI scores, the dietary energy derived from foods rich in phytochemicals (kcal) was divided by the participant’s total daily energy intake (kcal). Patients with KOA had lower intakes of dietary fiber (P = 0.004), vitamin A (P = 0.007), vitamin C (P = 0.001), and folate (P = 0.021) compared to controls. In the crude model, individuals in the third tertile of DPI had 65% lower odds of having KOA compared to those in the first tertile (OR 0.35, 95% CI 0.19 to 0.67, P-trend = 0.001). After adjustment for potential confounders, including age, sex, physical activity, smoking, and supplement use, this inverse association remained significant (OR 0.37, 95% CI 0.19 to 0.73, P-trend = 0.004). After further adjustment for BMI, this inverse association between DPI and odds of KOA also remained significant (OR 0.35, 95% CI 0.18 to 0.69, P-trend = 0.003). These findings suggest that adherence to a phytochemical-rich diet, as indicated by the increasing DPI score, is associated with lower odds of KOA.

Dietary phytochemical consumption is inversely associated with liver alkaline phosphatase in Middle Eastern adults

BACKGROUND

The hepatoprotective effects of phytochemicals are controversial. A dietary phytochemical index (DPI) has been suggested as an alternative method for quantifying the phytochemical content of foods.

AIM

To assess the DPI in relation to liver function tests among a representative sample of Iranian adults.

METHODS

A total of 5111 participants aged 35-70 years old were included in this cross-sectional study by a multistage cluster random sampling method. Dietary intakes were collected by a validated and reliable food frequency questionnaire with 121 items. DPI was calculated by the percent of daily energy intake taken from phytochemical-rich foods. Fasting serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT) were determined. Linear regression was used to investigate the association between DPI and levels of liver enzymes using crude and adjusted models.

RESULTS

There was an inverse association between DPI score and serum ALP in the crude model (β = -0.05; P < 0.001). This association remained significant after adjustment for body mass index, age, smoking, energy intake, history of diabetes, and education (β = -0.03; P = 0.01). No significant associations were found between DPI score and serum levels of AST, ALT, and GGT. The individuals with the highest DPI scores consumed significantly higher amounts of fruits, vegetables, legumes, nuts, and cereals, yet were shown to have significantly higher serum total cholesterol and low-density lipoprotein cholesterol, as well as several other metabolic abnormalities.

CONCLUSION

Higher adherence to phytochemical-rich foods was associated with lower levels of ALP, but no change in other liver enzymes. Those with higher DPI scores also consumed food items associated with a healthier overall dietary pattern; however, they also presented several unexpected metabolic derangements. Additional randomised trials are needed to better determine the effects of phytochemical-rich foods on liver function.

Association between the Phytochemical Index and Overweight/Obesity: A Meta-Analysis

Some studies suggest that a higher phytochemical index (PI) is associated with a lower risk of overweight/obesity. This meta-analysis is performed to summarize published studies on the relationship of PI and the risk of overweight/obesity. We searched on PubMed, Cochrane Library and Web of Science from the inception dates to February 2022. The random-effect model was used based on heterogeneity. Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Begg’s and Egger’s tests. The dose–response relationship was assessed using a restricted cubic spline model. Nine studies were included in the meta-analysis, with a total of 100,753 participants. The meta-analysis showed that the phytochemical index was associated with a decreased risk of overweight/obesity. The pooled OR (95% CI) was 0.81 (0.74–0.90). The findings from dose–response analysis showed a nonlinear association between the phytochemical index and the risk of overweight/obesity. The results of the meta-regression showed that gender and area were significant covariates influencing the heterogeneity between studies. There was no publication bias in the meta-analysis of this study. In conclusion, although this meta-analysis indicates that a high phytochemical index is associated with a reduced risk of overweight/obesity, all the studies included in this meta-analysis were cross-sectional studies with high heterogeneity. As such, more data from randomized controlled trials are required to confirm the efficacy of PI in evaluating the risk of overweight/obesity.

Dietary phytochemical index and attention-deficit/hyperactivity disorder in Iranian children: a case control study

OBJECTIVE

Attention Deficit/Hyperactivity Disorder (ADHD) is a common behavioral disorder among children. Based on literature, it has been hypothesized that the higher intake of rich sources of phytochemicals may be inversely related to the risk of ADHD. We investigated the association of dietary phytochemical index (DPI) with odds of ADHD.

METHODS

This case-control study was conducted on 360 children and adolescents 7-13 years old in Yazd, Iran. Subjects were categorized into the case (n = 120) and control groups (n = 240) based on matching age and sex. To diagnose ADHD, the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSMIV-TR) was used. Food frequency questionnaire was used to measure food intake. DPI was calculated by percent of daily energy intake from phytochemical-rich foods. The association of DPI with the odds ratio of ADHD was examined by logistic regression.

RESULTS

Subjects in the highest quartile of DPI have higher intake of macronutrient, eicosatetraenoic acid, docosahexaenoic acid, calcium, zinc, iron, vitamins B12, B6, and folic acid compared to lowest quartile. After adjusting for potential confounders, subjects in the highest quartile of DPI compared with subjects in the lowest quartile showed a lower risk of ADHD (OR: 0.44; 95% CI: 0.18-0.90). There was a significant decreasing trend in the odds of ADHD across increasing quartile of DPI (P for trend: 0.02).

CONCLUSION

We found that higher DPI score is associated with lower risk of ADHD in children. Cohort and clinical studies are necessary to approve our results.

Association between Phytochemical Index and Inflammation in Korean Adults

While the relationship between phytochemicals and inflammation has been confirmed by in vivo or in vitro studies, large-scale epidemiological studies comprehensively analyzing phytochemical-rich food groups remain scarce. Therefore, we evaluated the association between the phytochemical index (PI) and the inflammation levels in Korean adults. The data were derived from the 2015–2018 Korea National Health and Nutrition Examination Survey, and a total of 18,699 participants were analyzed. High-sensitivity C-reactive protein (hs-CRP) levels >3.0 mg/L and white blood cell (WBC) counts >10 × 103/μL were defined as “elevated.” The PI was calculated based on eight food groups using a 24-h dietary recall. The odds ratio (OR) and confidence interval (CI) for elevated hs-CRP levels and WBC counts, according to the PI quintile, were calculated using the multivariable logistic regression analysis. Participants in the higher PI group had lower means of hs-CRP levels and WBC counts than those in the lower PI group (all p for trend <0.001). In fully adjusted logistic regression models, elevated hs-CRP levels and WBC counts in the highest PI group were lower by 40% (OR: 0.61, 95% CI: 0.49–0.76) and 34% (OR: 0.66, CI: 0.47–0.93), respectively. Conclusions: A high consumption of phytochemical-rich foods is associated with lower inflammation. This suggests that adopting phytochemical-rich dietary patterns may be an effective approach for reducing inflammation.

The association between dietary phytochemical index with depression and quality of life in iranian adolescent girls

Background

There is increasing evidence that the dietary intake of phytochemicals is inversely associated with severity of depression and positively associated with quality of life (QoL). The present study investigated the relationship between dietary phytochemical index (DPI) with depression and QoL scores in Iranian adolescent girls.

Methods

A total of 733 adolescent girls from Mashhad and Sabzevar cities in northeastern Iran were entered into this cross-sectional study. Assessment of depression and QoL was performed utilizing the Beck Depression Inventory (BDI) and SF-12v2 questionnaire, respectively. Assessment of dietary intake was undertaken by a qualified dietitian, using a validated food-frequency questionnaire (FFQ) containing 168 food items. To explore the association between DPI with QoL and depression, logistic regression was used in crude and adjusted models.

Results

The participants in the fourth quartile of DPI compared with the first quartile had a 50% lower odds of depression (OR: 0.50; 95% CI: 0.30-0.84, P = 0.009) This relation remained significant in all adjusted models. The adolescents in highest quartile of DPI compared with the first quartile had 38% lower odds of poor QoL (OR: 0.62; 95% CI: 0.41-0.94, P = 0.02). This association remained significant in adjusted models I and II, but not after adjusting for all confounding variables (OR: 0.67; 95% CI: 0.43-1.02, P = 0.06) (Model III).

Conclusions

DPI was inversely associated with risk of depression. The association between DPI score and QoL remained unclear. Further prospective and interventional studies are required.

Interaction between CETP Taq1B polymorphism and HEI, DQI and DPI on metabolic biomarkers in patients with type 2 diabetes

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a multidimensional consequence of environmental and genetic factors. Cholesteryl ester transfer protein (CETP) Taq1B polymorphism has been reported as a main predictor of dyslipidaemia, comprising an important complication in persons with T2DM. However, diet could affect T2DM patients metabolic health.

METHODS

We investigated the combination of gene-diet effects on some metabolic biomarkers. In our cross-sectional study, blood samples of 220 patients were collected. Dietary indices (healthy eating index, dietary quality index and dietary phytochemical index) were obtained from a validated semi-quantitative food frequency questionnaire. CETP Taq1B polymorphism was genotyped by a polymerase chain reaction-restriction fragment polymorphism method. Data were analysed by analysis of covariance.

RESULTS

The interaction between the CETP Taq1B polymorphism and dietary indices on low density lipoprotein/high density lipoprotein was significant (p < 0.001 both crude and adjusted models). In addition, the interaction between polymorphism and dietary quality index on total antioxidant capacity (p = 0.004 crude model, p = 0.005 after adjusting) and pentraxin 3 (p = 0.01 both crude and adjusted models) was significant. Also, the interaction between polymorphism and healthy eating index on waist circumference (p = 0.005 both crude and adjusted models) and dietary phytochemical index on interleukin-18 (p = 0.03 crude model) was significant.

CONCLUSIONS

Our results indicated the effect of CETP Taq1B polymorphism on some inflammatory and anthropometrics markers (total antioxidant capacity, pentraxin 3, interleukin-18, low density lipoprotein/high density lipoprotein and waist circumference) with high and low adherence to dietary incides.

Dietary quality indices modify the effects of apolipoprotein B polymorphisms on biochemical and anthropometric factors in type 2 diabetes mellitus

We tried to identify the interaction between dietary quality indices and apolipoprotein B Ins/Del and EcoR1 polymorphisms on biochemical and anthropometric factors in patients with type 2 diabetes mellitus (T2DM). This cross-sectional study recruited 700 adults with T2DM in Tehran. The genotypes of Ins/Del and EcoR1 single nucleotide polymorphisms (SNP) were explored via polymerase chain reaction (PCR). Dietary quality index-international (DQI-I), healthy eating index-2015 (HEI-2015) and dietary phytochemical index (DPI) were calculated by semi-quantitative food frequency questionnaire (FFQ). In both crude and adjusted model for confounding factors, we observed significant interactions between DQI-I and Ins/Del SNP on leptin in and 8-iso-prostaglandin F2 α (8-iso-PGF2α), DPI and EcoR1 SNP on total cholesterol (TC) and between Ins/Del SNP and HEI-2015 on interleukin-18 (IL-18). Furthermore, in crude model there were close to meaningful interactions between EcoR1 SNP and DQI-I on total antioxidant capacity (TAC) and between EcoR1 SNP and HEI-2015 on serum leptin and superoxide dismutase (SOD) levels. Our finding indicated that the association between DQI-I, HEI-2015 and DPI with IL-18, TC, leptin and 8-iso-PGF2α in patients with T2DM might be dependent on Ins/Del and EcoR1 variants in ApoB gene.

Relationship between diet, oxidative stress, and inflammation in ankylosing spondylitis

Objectives: This study aims to investigate the relationship between disease activity, dietary phytochemical index (DPI), and serum total oxidant status (TOS) and total antioxidant status (TAS) in patients with ankylosing spondylitis (AS).

Patients and methods: Between August 2020 and January 2021, a total of 37 patients (23 males, 14 females; mean age: 39.3±9.4 years; range, 21 to 61 years) with AS and 36 age-, sex-, and body mass index-matched healthy individuals (24 males, 12 females; mean age: 37.9±8.9 years; range, 20 to 60 years) were included. Serum TAS (μmoLTroloxEq/L) and TOS (μmoL H2O2Eq/L) measurements were performed and the oxidative stress index (OSI) was calculated. Dietary evaluation was made from a one-day dietary record and DPI was calculated.

Results: Serum TAS level in AS patients was significantly lower than the healthy group (p=0.003). Serum TOS level was similar in both groups. The OSI of patients was significantly higher than the controls (p=0.035). The mean DPI, polyunsaturated fatty acid, n-3 fatty acid, and vitamin C intake of patients were significantly lower than controls (p=0.042, p=0.033, and p=0.022, respectively). A moderate positive correlation was found between the TAS level and DPI of the control group (r=0.352, p=0.035). According to medications, no significant difference was seen between the groups in terms of patients’ characteristics, DPI, and laboratory tests and there was no correlation between DPI, TAS, TOS, and OSI.

Conclusion: Lower DPI and lower n-3 fatty acid and vitamin C intake in patient group demonstrated that patients with AS should pay more attention to their diet to increase serum antioxidant status.

The retention and bioavailability of phytochemicals in the manufacturing of baked snacks

There is a growing body of evidence supporting the role that phytochemicals play in reducing the risk of various chronic diseases. Although there has been a rise in health products marketed as being "supergrains," "superfood," or advertising their abundance in antioxidants, these food items are often limited to powdered blends, dried fruit, nuts, or seeds, rarely intercepting the market of baked snacks. This is in part due to the still limited understanding of the impact that different industrial processes have on phytochemicals in a complex food matrix and their corresponding bioavailability. This review brings together the current data on how various industrial dehydration processes influence the retention and bioaccessibility of phytochemicals in baked snacks. It considers the interplay of molecules in an intricate snack matrix, limitations of conventional technologies, and constraints with consumer acceptance preventing wider utilization of novel technologies. Furthermore, the review takes a holistic approach, encompassing each stage of production-discussing the potential for inclusion of by-products to promote a circular economy and the proposal for a shift in agriculture toward biofortification or tailored growing of crops for their nutritional and post-harvest attributes.

The relation between dietary phytochemical index and metabolic syndrome and its components in a large sample of Iranian adults: a population-based study

Background

Despite the protective effects of foods being rich in phytochemicals against chronic diseases, this issue is still poorly understood. The aim of this study was to investigate the association between Dietary Phytochemical Index (DPI) and metabolic syndrome (MetS) and its components.

Methods

This cross-sectional study focused on adults aged between 20 and 70years. The dietary intake was assessed using a validated and reliable food frequency questionnaire. DPI was calculated based on dietary energy, derived from phytochemical-rich food sources (kcal) per total daily energy intake (kcal). The odds ratio of MetS and its components were assessed across DPI quartiles by logistic regression models.

Results

After adjustment for all potential confounders, the risk of MetS (OR: 0.63, 95% CI = 0.41–0.96) and elevated blood pressure (OR: 0.62, 95% CI = 0.40–0.96) in the second category of DPI decreased significantly as compared to that in the first category. Subjects in the second and fourth quartiles of DPI with adjusting for age, sex and total energy intake revealed 30 and 25% lower risk of abdominal obesity, respectively. After full adjustment for confounders, the analysis stratified by sex showed women in the highest quartile of DPI had 59% lower risk of MetS (OR: 0.41, 95% CI = 0.22–0.76) as compared to those in the lowest quartile of DPI.

Conclusions

Greater adherence to phytochemical-rich diet could reduce odds of MetS and some components, especially in women. Further studies with intervention approaches are recommended.

Interaction between the dietary indices and PPAR-γ Pro12Ala gene variants on cardiovascular risk factors in patients with type 2 diabetes mellitus

AIMS

We investigated the interaction between peroxisome proliferator-activated receptor gamma (PPAR-γ) Pro12Ala polymorphism and healthy eating index (HEI), Dietary Quality Index-International (DQI-I), and dietary phytochemical index (DPI) on cardiovascular disease (CVD) risk factors in patients with type 2 diabetes mellitus (T2DM).

METHODS

This cross-sectional study was conducted on 393 diabetic patients. PPAR-γ Pro12Ala was genotyped by the PCR-RFLP method. Biochemical markers including total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), superoxide dismutase (SOD), C-reactive protein (CRP), total antioxidant capacity (TAC), pentraxin-3 (PTX3), isoprostaneF2α (PGF2α). Interleukin 18 (IL18), leptin, and ghrelin were measured by standard protocol. Food-frequency questionnaires (FFQ) were used for dietary indices (DQI-I, DPI, HEI) calculation.

RESULTS

Homozygous carriers of the rs1801282 C allele showed higher leptin compared G allele carriers (P = .015). The rs1801282-DQI-I interactions were significant on waist circumference (WC) (P = .019). Thus, C-allele carriers in the higher tertile of DQI-I had higher WC compared with GG homozygous. Further, an interaction was observed between PPAR rs1801282 polymorphism and DQI-I on serum IL-18 level (P = .032). Besides, a significant rs1801282-DPI interaction was shown on HDL concentration (P = .041), G allele carriers who were in the highest tertile of DPI, had lower HDL. Moreover, there were significant rs1801282-HEI interactions on serum leptin (P = .021). Individuals with (CC, CG) genotypes in the higher tertile of HEI, had lower leptin concentration.

CONCLUSION

Higher dietary indices (DQI-I, DPI, HEI) may affect the relationship between PPAR-γ Pro12Ala polymorphism and WC, ghrelin, leptin, HDL, and IL-18 concentration in patients with T2DM.

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.

Dietary phytochemical index associated with cardiovascular risk factor in patients with type 1 diabetes mellitus

Background

Dietary phytochemical index (DPI) is useful and inexpensive method to identify the role of phytochemicals on cardiovascular disease (CVD) risk factors. This study aimed to assess the relationship between DPI and CVD risk factors in patients with type1 diabetes mellitus.

Methods

A total of 261 participants aged 18–35 years with T1DM were enrolled in this cross-sectional study to assess the relationship between DPI and CVD risk factors. Anthropometric measurements, blood lipids, glucose, and antioxidant level were measured. Food intakes were determined using a food frequency questionnaire to calculate DPI. Logistic regression was used.

Results

The mean age of participants was 25 years. After adjustment for potential confounders, participants in the highest tertile of DPI had 88 % lower chance of hyperglycemia (P for trend = 0.020), 81 % lower chance of low high-density lipoprotein cholesterol (HDL-C) (P for trend = 0.030) and 98 % lower chance of high low-density lipoprotein cholesterol to HDL-C ratio (P for tend = 0.040). There were no relationships between DPI and other CVD risk factors.

Conclusions

Although higher intake of phytochemical-rich foods had a beneficial effect on some risk factors of CVD, more studies more studies are warranted to corroborate the present findings.

The Association of Dietary Phytochemical Index with Metabolic Syndrome in Adults

In this study, we assessed the association between the dietary phytochemical index (DPI) and metabolic syndrome (MetS) among adults in a cross-sectional study. We enrolled 850 adult men and women aged 18–65 years who had been referred to health centers in Tehran, Iran. The DPI was calculated based on 8 components including fruits, vegetables, legumes, whole grains, soy products, nuts, seeds, olive, and olive oil. The odds ratio (OR) and 95% confidence interval (CI) of the MetS across quartiles of the DPI were calculated using the logistic regression analysis, adjusting for age, energy intake, marital status, education status, occupation, smoking status, physical activity, and body mass index. The mean age of participants was 44.7 ± 10.7, of whom 69% were women. The prevalence of MetS was 30.5%. The mean score of DPI in women and men was 36.2 ± 26.8 and 33.7 ± 24.7, respectively. There was no significant association between DPI and odds of MetS in men (OR_{fourth vs. first quartile},1.57; 95% CI, 0.64–3.84) and women (OR_{fourth vs. first quartile}, 0.86; 95% CI, 0.50–1.49) in the fully adjusted model. There was an inverse association between DPI and increased risk of central obesity in women (OR_{fourth vs. first quartile}, 0.54; 95% CI, 0.29–1.00; p trend = 0.03). There was no significant association between DPI and other components of the MetS in men and women. Finally, we observed no significant association between the DPI and the odds of MetS. However, the finding suggests that having a phytochemical-rich diet can be inversely associated with abdominal obesity.