A higher Dietary Inflammatory Index score is associated with a higher risk of breast cancer among Chinese women: a case-control study

Differences of nutritional intake habits and Dietary Inflammatory Index score between occupational classifications in the Korean working population

Background

Human nutrient intake is closely related to the conditions of their workplace.

Methods

This study used data from the Korean National Health and Nutritional Examination Survey (KNHANES) conducted between 2016 and 2020. The study population comprised individuals aged 19 to 65 years who were engaged in paid work, excluding soldiers (total = 12,201, male = 5,872, female = 6,329). The primary outcome of interest was the Dietary Inflammatory Index (DII) score, which was calculated using dietary intake data. Generalized linear models were used for statistical analyses.

Results

Pink-collar workers had higher DII scores, indicating a potentially higher inflammatory diet than white-collar workers (mean: 2.18 vs. 1.89, p < 0.001). Green and blue-collar workers displayed lower levels of dietary inflammation (green: 1.64 vs. 1.89, p = 0.019, blue: 1.79 vs. 1.89, p = 0.022). After adjusting for sex, age, income, education, and energy intake, the sole trend that persisted was the comparison between white-collar and pink-collar workers.

Conclusions

DII scores and dietary patterns differed among occupational groups and genders.

How Does Dietary Intake Relate to Dispositional Optimism and Health-Related Quality of Life in Germline BRCA1/2 Mutation Carriers?

Background: The Mediterranean diet (MD) is an anti-inflammatory diet linked to improved health-related quality of life (HRQoL). Germline (g)BRCA1/2 mutation carriers have an increased risk of developing breast cancer and are often exposed to severe cancer treatments, thus the improvement of HRQoL is important. Little is known about the associations between dietary intake and HRQoL in this population. Methods: We included 312 gBRCA1/2 mutation carriers from an ongoing prospective randomized controlled lifestyle intervention trial. Baseline data from the EPIC food frequency questionnaire was used to calculate the dietary inflammatory index (DII), and adherence to MD was captured by the 14-item PREDIMED questionnaire. HRQoL was measured by the EORTC QLQ-C30 and LOT-R questionnaires. The presence of metabolic syndrome (MetS) was determined using anthropometric measurements, blood samples and vital parameters. Linear and logistic regression models were performed to assess the possible impact of diet and metabolic syndrome on HRQoL. Results: Women with a prior history of cancer (59.6%) reported lower DIIs than women without it (p = 0.011). A greater adherence to MD was associated with lower DII scores (p < 0.001) and reduced odds for metabolic syndrome (MetS) (p = 0.024). Women with a more optimistic outlook on life reported greater adherence to MD (p < 0.001), whereas a more pessimistic outlook on life increased the odds for MetS (OR = 1.15; p = 0.023). Conclusions: This is the first study in gBRCA1/2 mutation carriers that has linked MD, DII, and MetS to HRQoL. The long-term clinical implications of these findings are yet to be determined.

Dietary Inflammatory Index and risk of breast cancer: evidence from a prospective cohort of 67,879 women followed for 20 years in France

BACKGROUND

Inflammation is implicated in breast cancer development, and diet is one of the modifiable risk factors involved in the regulation of chronic inflammation. Previous studies on the association between breast cancer risk and Dietary Inflammatory Indexes (DII) derived from food frequency questionnaires and data on inflammatory potential of dietary components have reported inconsistent results.

OBJECTIVE

To investigate the association between the DII and the risk of breast cancer using data from a large population-based cohort study.

DESIGN

A total of 67,879 women from the E3N cohort were followed from 1993 to 2014. A total of 5686 breast cancer cases were diagnosed during the follow-up. The food frequency questionnaire administered at baseline in 1993 was used to calculate an adapted DII. Cox proportional hazard models using age as the time scale were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Spline regression was used to determine any dose-response relationship. We also evaluated effect modification by menopausal status, body mass index, smoking status and alcohol consumption.

RESULTS

The median DII score of the study population was slightly pro-inflammatory (DII = + 0.39); ranged from - 4.68 in the lowest quintile to + 4.29 in the highest quintile. The HR increased linearly with the DII (HR per 1SD = 1.04 [95% CI: 1.01, 1.07]), and reached 1.13 [95% CI: 1.04, 1.23] in the 5th quintile group as compared to the first. A positive linear dose-response relationship was also observed when modeling DII with spline functions. Slightly higher HRs were observed in non-smokers (HR _{for 1-SD increase} 1.06 [95% CI: 1.02, 1.10]; p trend = 0.001) and in low-alcohol consumers (≤ 1 glass/day) (HR _{for 1-SD increase} 1.05 [95% CI: 1.01, 1.08]; p trend = 0.002).

CONCLUSION

Our results suggest a positive association between DII and breast cancer risk. Consequently, the promotion of anti-inflammatory diet may contribute to breast cancer prevention.

Dietary inflammatory index and breast cancer risk: an updated meta-analysis of observational studies

This updated meta-analysis sought to determine whether the pro-inflammatory potential of diet is a risk factor for breast cancer (BrCa) development, for the first time focusing on the effects of design heterogeneity. The search was performed using Scopus, PubMed, and Embase databases. Data were extracted from twenty-one eligible studies, including eleven cohorts (336,085 participants/20,033 incidence cases), and ten case-control studies (9,833 cases/12,752controls). The random-effect was used to calculate the relative risk (RR) using STATA 16 software. The highest dietary inflammatory index (DII) vs. the lowest category showed 16% increased risk of BrCa (95% CI: 1.06-1.26; I² = 62.8%, P (I²) < 0.001). This was notable in post-menopausal status (RR = 1.13, 95% CI: 1.04-1.22), women with body mass index (BMI) ≥ 30 kg/m² (RR = 1.35, 95% CI: 1.07-1.63), and study populations from developing countries (RR = 1.79, 95% CI: 1.12-2.47). Methodological covariates were subject to subgroup meta-analyses and showed stronger results among case-control studies (RR = 1.50, 95% CI: 1.20-1.80), studies considered age-matched controls (RR = 1.56, 95% CI: 1.19-1.93) and hospital-based controls (RR = 2.11, 95% CI: 1.58-2.64), and cohort studies identified by prolong follow-up durations (RR = 1.13, 95% CI: 1.03-1.22). This updated meta-analysis highlighted the pro-inflammatory diet as a risk factor for BrCa, especially among women in post-menopausal status, obese groups, and developing countries. Meta-analysis in methodological subgroups could improve results, less affected by heterogeneity, and suggested subclassification with important implications for future epidemiological designs and even clinical management.

The dietary inflammatory index is directly associated with polycystic ovary syndrome: A case-control study

INTRODUCTION

The association between diet and polycystic ovary syndrome (PCOS) might be mediated by the inflammatory properties of the diet. The study aimed to investigate the relationships between the dietary inflammatory index (DII) with odds of PCOS among the adult population.

METHODS

In the hospital-based case-control study, 203 patients with PCOS and 291 non-PCOS controls were enroled. DII was calculated via a validated 147-item quantitative food frequency questionnaire (FFQ). Thirty-six macro- and micronutrients were extracted from FFQ and used to calculate DII. Employing a case-control design, odds ratios (ORs) and 95% confidence intervals (CIs) were obtained, with a dose-response effect confirmed by the test for trend (p for trend).

RESULTS

The mean ± SD age and body mass index (BMI) of the study participants were 29.67 ± 5.92 years and 24.51 ± 4.71 kg/m² , respectively. Compared with controls subjects, PCOS patients had significantly higher weight, BMI, and waist circumferences, but had lower physical activity. PCOS subjects had higher intakes of carbohydrate, cholesterol, and refined grains, but lower intakes of polyunsaturated fatty acids, fibre, vitamin B₁₂ , vitamin D, and dairy as compared to controls. Compared with participants in the lowest quartile of DII, those in the highest quartile had a significantly higher OR for PCOS after further adjustment for potential confounders (OR = 1.75, 95% CI: 0.95-3.22).

CONCLUSION

Our data suggest that high DII was associated with an increased odds of PCOS diagnosis. Prospective dietary intervention studies and observational prospective cohorts are required to confirm these findings.

Association between Dietary Inflammatory Index Scores and Diabetes Sensorimotor Polyneuropathy in Patients with Type 2 Diabetes Mellitus: A Case-Control Study

Background

Diabetes sensorimotor polyneuropathy (DSPN) is a common complication of diabetes. Diet has been previously related to DSPN. However, no studies have investigated the relationship between the inflammatory potential of the whole diet and DSPN. So, we aimed to examine the association between dietary inflammatory index (DII) and DSPN in Iranian adults.

Methods

A total of 185 subjects with DSPN and 185 sex- and age-matched controls were selected in this case-control study. A 168-item validated food frequency questionnaire (FFQ) was used to assay dietary intakes. DII was calculated based on the developed formula. The Toronto clinical neuropathy score was applied to define DSPN. Binary logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (95% CIs) of DII in relation to DSPN.

Results

Mean values of age and BMI for all the participants were reported as 50.79 and 28.60, respectively. Also, the median (IQR) of DII for all the participants was estimated as −0.091 (−0.93, 1.07). Our findings suggest that participants in the highest quartile of the DII had higher odds of DSPN (OR = 1.76; 95% CI: 1.03, 3.36) (p-trend = 0.01) compared to subjects in the lowest quartile of DII scores after adjustment for age and sex. Additionally, a strong association was observed after adjusting for energy intake, physical activity, education, smoking status, economic status, marital status, job, BMI, and WC in model 2 (OR = 2.23, 95% CI = 1.13–4.39) (p-trend = 0.0048).

Conclusion

Higher DII score was associated with an increased risk of DSPN. Therefore, it is possible that a diet rich in anti-inflammatory nutrients and foods could improve and prevent DSPN.

The association between the inflammatory potential of diet and the risk of histopathological and molecular subtypes of breast cancer in northwestern Iran: Results from the Breast Cancer Risk and Lifestyle study

BACKGROUND

This study explored the association between diet-associated inflammation and the risk of different molecular subtypes of breast cancer (BrCA) in a large, population-based case-control study conducted in northwestern Iran.

METHODS

The study consisted of 1007 women with histopathologically confirmed BrCA and 1004 controls admitted to hospitals in Tabriz, northwestern Iran, for nonneoplastic conditions. Dietary Inflammatory Index scores and energy-adjusted Dietary Inflammatory Index (E-DII) scores, with and without supplements, were computed on the basis of dietary intake collected using a validated 136-item food frequency questionnaire.

RESULTS

Women with the highest E-DII scores (quartile 4) versus those with the lowest E-DII scores (quartile 1) showed a significantly increased BrCA risk (odds ratio for quartile 4 vs quartile 1 [OR_Q4vsQ1 ], 1.87; 95% confidence interval [CI], 1.42-2.47), particularly for lobular carcinoma (OR_Q4vsQ1 , 3.07; 95% CI, 1.34-7.02). Findings were similar for premenopausal women diagnosed with luminal A BrCA (OR_Q4vsQ1 , 2.71; 95% CI, 1.74-4.22) or luminal B BrCA (OR_Q4vsQ1 , 2.86; 95% CI, 1.39-5.89). Women consuming the most proinflammatory diets were 3 times more likely to have triple-negative BrCA (OR_Q4vsQ1 , 3.00; 95% CI, 1.002-8.96) while compared to luminal A BrCA. The BrCA risk for women consuming diets in the highest half of E-DII scores (E-DII > 0) was 59% greater than the risk for those in the lowest half (95% CI, 1.29-1.97). Also, higher E-DII scores that took into account supplements were associated with larger tumor sizes (T3 > 5 cm; P < .05).

CONCLUSIONS

A proinflammatory diet, as indicated by higher E-DII scores, appears to increase the risk of BrCA in Iranian women. Large increases in risk were seen in invasive molecular subtypes of BrCA. Anti-inflammatory diets are suggested to prevent the risk of overall BrCA and more aggressive forms of BrCA in particular.

A case-control study in France showing that a pro-inflammatory diet is associated with a higher risk of breast cancer

Dietary regimens promoting inflammatory conditions have been implicated in breast cancer development, but studies on the association between pro-inflammatory diet and breast cancer risk have reported inconsistent results. We investigated the association between the inflammatory potential of diet and breast cancer risk in a case-control study in France including 872 breast cancer cases and 966 population controls. All women completed a food frequency questionnaire that was used to compute a Dietary Inflammatory Index (DII) based on the inflammatory weight of 33 dietary components. The DII ranged from a median of - 3.22 in the lowest quartile (anti-inflammatory) to + 2.96 in the highest quartile (pro-inflammatory). The odds ratio contrasting quartile 4 to quartile 1 was 1.31 (95% CI 1.00, 1.73; p-trend = 0.02). Slightly higher odds ratios were observed in post-menopausal women, particularly those with body mass index > 25 kg/m2 (odds ratio 1.62; 95% CI 0.92, 2.83; p-trend = 0.02), and among ever smokers (odds ratio 1.71; 95% CI 1.11, 2.65; p-trend 0.01). The analyses by breast cancer subtype showed that the DII was associated with breast tumors that expressed either the estrogen (ER) or progesterone (PR) hormone receptors or the Human Epidermal Growth Factor Receptor-2 (HER2), but no association was seen for the triple negative breast tumor subtype. Our results add further evidence that a pro-inflammatory diet is associated with breast cancer risk with possible effect variation according to tumor subtype.

Dietary Inflammatory Index and Breast Cancer: report from a Large-Scale Case-Control Study

OBJECTIVE

The relationship between diet, including its inflammatory potential, and breast cancer has led to inconsistent results. We investigated the association between a dietary inflammatory index (DII) and the odds of breast cancer in a large case-control study among women.

METHODS

This case-control study was carried out on 412 women with pathologically confirmed breast cancer and 456 apparently healthy controls. DII scores were calculated from dietary intake data. Multi-variable adjusted logistic regression was used to obtain odds ratios for breast cancer across quartiles of DII.

RESULTS

A total participants aged 45 ± 10.8 years were included in the present study. After adjustment for potential confounders, individuals in the highest quartile of DII scores had 1.5 times higher odds of breast cancer than those with the lowest (OR= 1.56; 95%CI: 1.04-2.35, Ptrend=0.02). Premenopausal women with the greatest DII had higher odds for breast cancer, compared with those with the lowest DII (OR= 1.92; 95% CI: 1.14-3.25, Ptrend=0.01). No significant association was seen between DII and odds of breast cancer in postmenopausal women.

CONCLUSION

Dietary inflammatory index might be directly associated with odds of breast cancer particularly in premenopausal women. Prospective cohort studies are needed to confirm these findings.

Dietary inflammatory potential, oxidative balance score, and risk of breast cancer: Findings from the Sister Study

Diet, inflammation, and oxidative stress may be important in breast carcinogenesis, but evidence on the role of the inflammatory and prooxidative potential of dietary patterns is limited. Energy adjusted-Dietary Inflammatory Index (E-DII™) and dietary oxidative balance score (D-OBS) were calculated for 43 563 Sister Study cohort participants who completed a Block 1998 food frequency questionnaire at enrollment in 2003-2009 and satisfied eligibility criteria. D-OBS was validated using measured F2 -isoprostanes and metabolites. High E-DII score and low D-OBS represent a more proinflammatory and prooxidant diet, respectively, and associations of quartiles of each index with breast cancer (BC) risk were estimated using multivariable Cox proportional hazards regression. There were 2619 BCs diagnosed at least 1 year after enrollment (mean follow-up 8.4 years). There was no overall association between E-DII and BC risk, whereas there was a suggestive inverse association for the highest vs lowest quartile of D-OBS (HR 0.92 [95% CI, 0.81-1.03]). The highest quartile of E-DII was associated with risk of triple-negative BC (HR 1.53 [95% CI, 0.99-2.35]). When the two indices were combined, a proinflammatory/prooxidant diet (highest tertile of E-DII and lowest tertile of D-OBS) was associated with increased risk for all BC (HR 1.13 [95% CI, 1.00-1.27]) and for triple-negative BC (1.72 [95% CI, 1.10-2.70]), compared to an antiinflammatory/antioxidant diet (lowest tertile of E-DII and highest tertile of D-OBS). Diets with increased inflammatory potential and reduced oxidative balance were positively associated with overall and triple-negative BC.

Strong association between the dietary inflammatory index(DII) and breast cancer: a systematic review and meta-analysis

The association between the Dietary Inflammatory Index (DII) and breast cancer risk has been widely reported in recent years, but there is still controversy about whether a pro-inflammatory diet is a risk factor for breast cancer. We conducted a meta-analysis to investigate the relationship between the DII and breast cancer risk in pre-menopausal and post-menopausal women. We comprehensively searched PubMed, Embase and the Cochrane Library in January 2021 to identify articles reporting an association between the DII and breast cancer risk. A pooled analysis was conducted with 14 studies covering 312,885 participants. Overall, women in the most pro-inflammatory diet category were at greater risk for breast cancer than those in the most anti-inflammatory category (relative risk [RR]=1.37, 95% confidence interval [CI] 1.17-1.60, P<0.001). This association was strong in both pre-menopausal women (RR=1.87, 95% CI 1.17-2.99, P=0.001) and post-menopausal women (RR=1.23, 95% CI 1.08-1.40, P<0.001). Thus, a strong and independent association was observed between a pro-inflammatory diet (assessed using the DII score) and breast cancer risk, irrespective of menopausal status. Further studies will be required to determine the relationship between a pro-inflammatory diet and different subtypes of breast cancer.

Dietary Inflammatory Index and Epithelial Ovarian Cancer in Southern Chinese Women: A Case-Control Study

The association between inflammatory properties of diet and ovarian cancer risk has been investigated in some Western populations. However, little evidence is available from Asian women whose ovarian cancer incidence rates are low and dietary and lifestyle patterns are very different from their Western counterparts. We aimed to examine whether more pro-inflammatory diets, as indicated by higher dietary inflammatory index (DII®) scores, are associated with increased odds of epithelial ovarian cancer in southern China. A case-control study was conducted during 2006-2008 in Guangzhou, Guangdong Province. Energy-adjusted DII (E-DII) scores were calculated based on dietary intake assessed by a validated food frequency questionnaire administered to 500 incident epithelial ovarian cancer patients and 500 hospital-based controls. Logistic regression models were used to assess the relationship between E-DII scores and odds of ovarian cancer. Positive associations were observed between higher E-DII scores and ovarian cancer odds, using both continuous DII scores (odds ratio (OR) 1.87; 95% confidence interval (CI) 1.65, 2.13) and by DII tertiles (OR_tertile3vs1 7.04, 95% CI: 4.70, 10.54, p for trend < 0.001). Likewise, a more pro-inflammatory diet was associated with a higher chance of serous and mucinous ovarian tumors. Our results suggest that a pro-inflammatory diet was associated with increased odds of developing epithelial ovarian cancer in southern Chinese women. The findings add to epidemiological evidence for the role of dietary inflammatory potential in ovarian cancer development.

Hybrid Dietary-Blood Inflammatory Profiles and Postmenopausal Breast Cancer: A Case-Control Study

The carcinogenesis process is associated with inflammation, which can be modified by diet. There is limited evidence regarding the inflammatory status and diet in association with breast cancer (BC). The aim of this study was to investigate the association of hybrid dietary-blood inflammatory profiles (HD-BIPs) with postmenopausal breast cancer occurrence. The case-control study was conducted among 420 women (230 controls, 190 primary BC cases) aged 40–79 years from north-eastern Poland. Blood levels of C-reactive protein (CRP), interleukin-6 (IL-6) and leukocyte count were marked in 129 postmenopausal women (82 controls, 47 cases). The 62-item food frequency questionnaire (FFQ-6) was used to the dietary data collection. Two HD-BIPs were found using the Principal Component Analysis (PCA). The “Pro-healthy/Neutral-inflammatory” profile was characterized by the frequent consumption of wholemeal cereals/coarse groats, legumes, vegetables, fruits, nuts/seeds and fish. The “Unhealthy/Pro-inflammatory” profile was characterized by the frequent consumption of red/processed meats, animal fats, sugar/honey/sweets, refined cereals/fine groats, and an increased concentration of CRP, IL-6 and granulocyte-to-lymphocyte ratio. The lower odds ratio (OR) of breast cancer was associated with the higher adherence to the “Pro-healthy/Neutral-inflammatory” profile (OR = 0.38; 95% Cl: 0.18–0.80; p < 0.01 for the higher level vs. lower level, crude model; OR for one-point score increment: 0.61; 95% Cl: 0.42–0.87; p < 0.01, adjusted model). The higher OR of breast cancer was associated with the higher adherence to the “Unhealthy/Pro-inflammatory” profile (OR = 3.07; 95%Cl: 1.27–7.44; p < 0.05 for the higher level v.s. lower level, adjusted model; OR for one-point score increment: 1.18; 95%Cl: 1.02–1.36; p < 0.05, adjusted model). This study revealed that the consumption of highly processed, high in sugar and animal fat foods should be avoided because this unhealthy diet was positively associated with postmenopausal breast cancer occurrence through its pro-inflammatory potential. Instead, the frequent consumption of low-processed plant foods and fish should be recommended since this pro-healthy diet was inversely associated with the cancer occurrence even though its anti-inflammatory potential has not been confirmed in this study sample.

The Inflammatory Potential of Diet is Associated with Breast Cancer Risk in Urban Argentina: A Multilevel Analysis

Dietary patterns have been associated with breast cancer (BC) in Argentina. However, little evidence exists relating the inflammatory potential of diet and BC in Latin American countries and how this may relate to rurality.The aim of the present study was to evaluate the association between the Dietary Inflammatory Index (DII^®) and BC considering urbanization contexts in Córdoba, Argentina.A frequency-matched case-control study (317 BC cases, 526 controls) was conducted from 2008 through 2016. DII scores were computed based on dietary intake assessed by a validated food frequency questionnaire. Multi-level logistic regression models were fit to evaluate the association between DII and BC, following adjustment for age, body mass index, age at menarche, number of children, smoking habits, socio-economic status and family history of BC as first-level covariates and urbanization level as the contextual variable.Increasing DII score showed significant positive associations with BC risk (OR_{tertile3vs.tertile1} 1.34; 95%CI 1.05, 1.70). The association was stronger in overweight and obese women (OR_{tertile3vs.tertile1} 1.98; 95%CI 1.86, 2.10). The DII effect on BC was higher with increased urbanization.A pro-inflammatory diet, reflected by higher DII scores, was positively associated with BC, especially in overweight women and with increased urbanization.

Dietary Habits and Breast Cancer Risk: A Hospital-Based Case-Control Study in Chinese Women

PURPOSE

To investigate the relationship between dietary habits and breast cancer (BC) risk in Chinese women.

PATIENTS AND METHODS

We performed a hospital-based matched case-control study that included 654 BC cases and 654 healthy controls matched by age and residence. A qualified structured questionnaire was used to collect detailed sociodemographic factors and information about dietary habits. The odds ratios (ORs) and 95% confidence intervals were calculated with unconditional logistic regression analysis; the patients were grouped according to their estrogen receptor (ER) status and analyzed separately. The propensity score analysis was performed according to different postmenopause status.

RESULTS

ER-negative BC participants with intake of cured foods had increased BC risk (adjusted OR, 2.72, P = .017). Participants diagnosed as having ER-positive BC with intake of grilled foods had increased BC risk compared to those who did not consume such foods (adjusted OR, 2.14, P = .026). After propensity score analysis, fried (OR, 3.19, P = .001) and grilled (OR, 1.77, P = .031) food were considered to be risk factors for BC in premenopausal women; and fried (OR, 1.61, P = .006), grilled (OR, 4.62, P = .001), and smoked foods (OR, 2.28, P = .001) are considered risk factors for BC in postmenopausal women.

CONCLUSION

Chinese women who ate cured, grilled, and fried foods had higher BC risk. Consumption of smoked food might contribute to increased BC risk in Chinese women.

Higher Dietary Inflammatory Index Scores are Associated with Increased Odds of Benign Breast Diseases in a Case-Control Study

Purpose

Dietary inflammatory index (DII) is a new tool for assessing the inflammatory potential of diet. Since there is no study that has investigated the association of DII and benign breast diseases (BBD), the aim of our study was to compare DII scores in patients with and without BBD.

Methods

One hundred and eleven (111) subjects with BBD and 104 healthy women attending the Iranian Center for Breast Cancer affiliated with the Academic Center for Education, Culture and Research were enrolled in a case–control study. Dietary data collected using a 168‑item validated food frequency questionnaire (FFQ). Energy-adjusted DII was calculated based on FFQ. Socio demographic data were collected by interview. In addition, physical activity was measured by the International Physical Activity Questionnaire (IPAQ). Weight, height and waist circumference were also measured.

Results

After adjustment for multiple confounding variables, participants at the highest tertile of DII had increased OR for BBD (OR=1.7, 95% CI=0.75–3.95) (P-trend =0.04).

Conclusion

The increased chance of BBD was suggested with a higher consumption of diets with inflammatory potential. However, this result should be interpreted with caution as OR was not statistically significant. Interventional studies are warranted to elucidate the role of inflammatory diets in the development of BBD.

The Association between Dietary Inflammatory Index (DII) and Cancer Risk in Korea: A Prospective Cohort Study within the KoGES-HEXA Study

Several epidemiological studies have shown that there are consistent positive associations between dietary inflammatory index (DII®) and cancer incidence in Western populations. However, few DII-cancer studies have been conducted in East Asian populations. In a large cohort representative of the general Korean population, we investigated whether the DII is associated with overall cancer risk. A total of 163,660 participants (56,781 males and 106,879 females) had evaluable data for analyses. This follow-up study was carried out over the course of 7.9 years. DII was calculated based on Semi-Quantitative Food-Frequency Questionnaire (SQ-FFQ) data for 106 food items. Cancers were self-reported based on notification by the participants' medical doctors. Multivariable Cox proportional hazard regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). After the follow-up, 1,643 cases of cancer (520 males and 1123 females) had developed. In a fully adjusted model, women in the highest DII quintile showed a 44% increased risk of getting cancer (HRQ5vsQ1 = 1.44; 95% CI = 1.14-1.82; p-trend = 0.0006), while men showed no apparent association (HRQ5vsQ1 = 0.80; 95% CI = 0.58-1.10). These results indicate that in Korean women, a more pro-inflammatory diet is associated with a higher risk of cancer incidence.

Association between dietary inflammatory index and the risk of oral cancer in the southeast of China

BACKGROUND/OBJECTIVES

To evaluate the role of the potential inflammatory effects of diet using the Energy adjusted Dietary Inflammatory Index (E-DII) for oral cancer.

SUBJECTS/METHODS

A case-control study including 295 oral cancer cases and 425 controls from September 2010 to June 2018 was performed in Fujian Province, China. The E-DII was calculated based on the food frequency questionnaire (FFQ) and adjusted by total energy intake. The association between E-DII and the risk of oral cancer was estimated with unconditional logistic regression model.

RESULTS

Compared with E-DII score in the lowest quartile, those with E-DII score in the fourth quartile were at the higher risk of oral cancer (OR = 2.57; 95% CI: 1.54, 4.29, P_trend = 0.013). When analyses were carried out using E-DII as a continuous variable, one-unit increase in E-DII increased the odds of having oral cancer by 3% (95% CI: 1.00, 1.06). Moreover, there was a significant interaction between the E-DII and oral hygiene for oral cancer (P_interaction < 0.001, in those without and with poor hygiene, the OR (95% CI) were 1.96 (0.96, 4.00) and 4.23 (1.83, 9.81), respectively).

CONCLUSIONS

The present study suggests that the higher E-DII score, indicated a pro-inflammatory diet, may be a risk factor for oral cancer in southeast of China. More large samples and prospective studies need to validate our results and explore the prevention strategies of oral cancer via changing dietary habits.

Dietary Phytochemical Index and Benign Breast Diseases: A Case-Control Study

Background: Dietary phytochemical index (DPI) is an inexpensive method for estimating the amounts of phytochemicals in foods. No study has investigated the association of DPI and benign breast diseases (BBD). Our study aimed to compare DPI in patients with BBD and the control group.Subjects: This is a case-control study of 115 subjects with BBD and 116 healthy women attending the Iranian Center for Breast Cancer affiliated with Academic Center for Education, Culture and Research. Energy-adjusted DPI was calculated based on data collected from 168-item validated food frequency questionnaire. Sociodemographic data, physical activity, and anthropometric measures such as body weight, height, and waist circumference were determined.Results: After adjustment for age, estrogen therapy, family history of breast disease, intake of dietary supplement, menopause status, waist circumference and physical activity, the odds ratio (OR) of BBD across the energy-adjusted DPI quartiles decreased significantly (OR = 0.3, 95%CI = 0.12-0.93) (P‑trend = 0.02).Conclusion: We found that higher DPI score is related to lower BBD OR. This simple method may be used for the improvement of dietary intake to prevent BBD.

Dietary Inflammatory Index and Risk of Breast Cancer Based on Hormone Receptor Status: A Case-Control Study in Korea

Breast cancer is the most common cancer in women globally, and the risk of developing breast cancer is associated with inflammation. The present study aimed to examine the association between the Dietary Inflammatory Index (DII^®) and breast cancer in Korean women and investigate whether the tumor’s hormone receptor status affects this association. In this case-control study, we enrolled 364 breast cancer patients and 364 age-matched controls. DII scores were calculated from dietary intake evaluated by a 106-item food frequency questionnaire. The DII score was significantly higher in cases than in controls. After adjusting for potential confounders, the odds ratio (OR) of breast cancer was higher in the highest DII tertile (OR = 3.68, 95% confidence interval (CI): 2.34–5.80, p for trend < 0.0001) than in the lowest tertile. We found that higher DII scores were related to an increased risk of breast cancer for estrogen receptor (ER)+/progesterone receptor (PR)+ tumors regardless of menopausal status (OR = 2.59, 95% CI: 1.37–4.88 in the highest DII category, p for trend = 0.01 for premenopausal women; OR = 11.00, 95% CI: 2.93–41.30 in the highest DII category, p for trend = 0.0004 for postmenopausal women), but not for ER−/PR− status. Our results suggested that the DII scores are positively associated with breast cancer risk in Korean women and that this relationship is more robust in ER+/PR+ tumors.

Dietary Inflammatory Index and Non-Communicable Disease Risk: A Narrative Review

There are over 1,000,000 publications on diet and health and over 480,000 references on inflammation in the National Library of Medicine database. In addition, there have now been over 30,000 peer-reviewed articles published on the relationship between diet, inflammation, and health outcomes. Based on this voluminous literature, it is now recognized that low-grade, chronic systemic inflammation is associated with most non-communicable diseases (NCDs), including diabetes, obesity, cardiovascular disease, cancers, respiratory and musculoskeletal disorders, as well as impaired neurodevelopment and adverse mental health outcomes. Dietary components modulate inflammatory status. In recent years, the Dietary Inflammatory Index (DII®), a literature-derived dietary index, was developed to characterize the inflammatory potential of habitual diet. Subsequently, a large and rapidly growing body of research investigating associations between dietary inflammatory potential, determined by the DII, and risk of a wide range of NCDs has emerged. In this narrative review, we examine the current state of the science regarding relationships between the DII and cancer, cardiometabolic, respiratory and musculoskeletal diseases, neurodevelopment, and adverse mental health outcomes. We synthesize the findings from recent studies, discuss potential underlying mechanisms, and look to the future regarding novel applications of the adult and children's DII (C-DII) scores and new avenues of investigation in this field of nutritional research.

Dietary Inflammatory Index Is Associated with Risk of All-Cause and Cardiovascular Disease Mortality but Not with Cancer Mortality in Middle-Aged and Older Japanese Adults

BACKGROUND

The Dietary Inflammatory Index (DII) is a comprehensive, literature-derived index for assessing the effect of dietary constituents on inflammatory biomarkers. Several studies have shown an association between DII score and mortality, but there are limited prospective studies in Asian populations.

OBJECTIVES

The aim of this study was to investigate the association between DII score and risk of all-cause, total cardiovascular disease (CVD), stroke, coronary heart disease (CHD), total cancer, digestive cancer, and noncancer/non-CVD mortality in the Japanese population.

METHODS

A total of 58,782 Japanese participants aged 40-79 y who were enrolled in the Japan Collaborative Cohort Study during 1988-1990 were included in the analysis. DII scores were calculated based on a food-frequency questionnaire. HRs and 95% CIs for mortality according to DII quintiles were estimated using Cox proportional hazards models.

RESULTS

During the median follow-up period of 19.3 y, a total of 11,693 participants died. The multivariable HR for all-cause mortality for the highest compared with the lowest DII quintiles was 1.13 (95% CI: 1.05, 1.21). For CVD mortality, the highest multivariable HRs were 1.30 (95% CI: 1.13, 1.49), 1.29 (95% CI: 1.05, 1.59), and 1.30 (95% CI: 0.96, 1.76) for total CVD, stroke, and CHD, respectively. No significant associations were observed between DII and risk of total cancer, digestive cancer, and noncancer/non-CVD mortality.

CONCLUSION

Our findings suggest that a higher DII was associated with an increased risk of all-cause and CVD mortality among Japanese adults.

Dietary Inflammatory Index, Dietary Non-Enzymatic Antioxidant Capacity, and Colorectal and Breast Cancer Risk (MCC-Spain Study)

Inflammation and antioxidant capacity have been associated with colorectal and breast cancer. We computed the dietary inflammatory index (DII^®), and the total dietary non-enzymatic antioxidant capacity (NEAC) and associated them with colorectal and breast cancer risk in the population-based multi case-control study in Spain (MCC-Spain). We included 1852 colorectal cancer and 1567 breast cancer cases, and 3447 and 1486 population controls, respectively. DII score and NEAC were derived using data from a semi-quantitative validated food frequency questionnaire. Unconditional logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (95%CI) for energy-adjusted DII (E-DII), and a score combining E-DII and NEAC. E-DII was associated with colorectal cancer risk (OR = 1.93, highest quartile versus lowest, 95%CI:1.60–2.32; p-trend: <0.001); this increase was observed for both colon and rectal cancer. Less pronounced increased risks were observed for breast cancer (OR = 1.22, highest quartile versus lowest, 95%CI:0.99–1.52, p-trend: >0.10). The combined score of high E-DII scores and low antioxidant values were associated with colorectal cancer risk (OR = 1.48, highest quartile versus lowest, 95%CI: 1.26–1.74; p-trend: <0.001), but not breast cancer. This study provides evidence that a pro-inflammatory diet is associated with increased colorectal cancer risk while findings for breast cancer were less consistent.

Dietary inflammatory index and risk of gynecological cancers: a systematic review and meta-analysis of observational studies

OBJECTIVE

There has been growing body of literatures showing that chronic inflammation might play an important role in cancer development. This meta-analysis aimed to assess the association between the dietary inflammation index (DII) score and gynecological cancers.

METHODS

A systematic search of PubMed, EMBASE and Web of Science up until October 20, 2018 was carried out to retrieve all related cohort and case-control studies. The summary risk assessments were pooled using random-effects models. The dose-response relationship was estimated by linear relationship model.

RESULTS

Twelve case-control studies (10,774 cases/15,958 controls) and six prospective cohort studies (330,363 participants/23,133 incident cases) were included in this meta-analysis. The pooled adjusted relative risk (RR) of gynecological cancers for the highest DII category compared to the lowest category was 1.38, (95% confidence intervals [CIs], 1.21-1.56, p<0.001]. A positive dose-response relationship was also noticed. Stratified by study design indicated that, the pooled RRs was significantly higher for case-control studies than cohort studies (p for interaction<0.001), for studies conducted among participants with body mass index (BMI) ≥25 kg/m² than participants with BMI <25 kg/m² (p for interaction=0.026), among participants with ovarian cancer and endometrial cancer than participants with breast cancer (p for interaction = 0.038). Meta-regression analysis further confirmed that study design significantly contributed to inter-study heterogeneity (p<0.001).

CONCLUSION

This meta-analysis suggests that elevated DII is independently associated with a higher risk of gynecological cancers, especially patients with ovarian cancer and endometrial cancer and among obese participants.

Perspective: The Dietary Inflammatory Index (DII)-Lessons Learned, Improvements Made, and Future Directions

The literature on the role of inflammation in health has grown exponentially over the past several decades. Paralleling this growth has been an equally intense focus on the role of diet in modulating inflammation, with a doubling in the size of the literature approximately every 4 y. The Dietary Inflammatory Index (DII) was developed to provide a quantitative means for assessing the role of diet in relation to health outcomes ranging from blood concentrations of inflammatory cytokines to chronic diseases. Based on literature from a variety of different study designs ranging from cell culture to observational and experimental studies in humans, the DII was designed to be universally applicable across all human studies with adequate dietary assessment. Over the past 4 y, the DII has been used in >200 studies and forms the basis for 12 meta-analyses. In the process of conducting this work, lessons were learned with regard to methodologic issues related to total energy and nutrient intake and energy and nutrient densities. Accordingly, refinements to the original algorithm have been made. In this article we discuss these improvements and observations that we made with regard to misuse and misinterpretation of the DII and provide suggestions for future developments.

Association between the Dietary Inflammatory Index and Risk for Cancer Recurrence and Mortality among Patients with Breast Cancer

The dietary inflammatory index (DII) has been associated with breast cancer incidence and survival. However, the association between DII and cancer recurrence and mortality among patients with breast cancer has not been investigated. Therefore, the present study aimed to investigate whether DII was positively associated with risk for cancer recurrence and overall mortality among patients with breast cancer. Among 511 women (51.9 ± 10.7 years; stage 0⁻3) who underwent breast cancer surgery, 88 had cancer recurrence, and 44 died during follow⁻up until 213 months (average disease free survival of 84.3 ± 42.4 months and overall survival of 69.3 ± 38.9 months). The DII assessed after surgery (5.4 ± 5.2 months after diagnosis) was significantly higher in patients with recurrence than those without recurrence, and Cox proportional hazards regression analysis showed that it was positively associated with the risk for cancer recurrence (hazard ratio (HR) 2.347, confidence interval (CI) 1.17⁻4.71) and overall mortality (HR 3.049, CI 1.08⁻8.83) after adjusting for confounding factors. Disease-free survival and overall survival rates were significantly lower in patients with higher DII scores. In addition, the DII was positively associated with the risk for cancer recurrence according to prognostic factors, such as age (<50 years), premenopausal status, body mass index (≥25 kg/m²), HR+, tumor size (>2 cm), and presence of lymph node metastasis. The present study showed that anti-inflammatory diets may decrease the risk of cancer recurrence and overall mortality in patients with breast cancer, particularly those with prognostic factors, such as younger age, premenopausal status, obesity, HR+ breast cancer, tumor size >2 cm, and presence of lymph node metastasis.

Dietary Inflammatory Index and Site-Specific Cancer Risk: A Systematic Review and Dose-Response Meta-Analysis

Existing evidence suggests a link between the inflammatory potential of diet and risk of cancer. This study aimed to test the linear and potential nonlinear dose-response associations of the Dietary Inflammatory Index (DII), as being representative of inflammatory features of the diet, and site-specific cancer risk. A systematic search was conducted with the use of PubMed and Scopus from 2014 to November 2017. Prospective cohort or case-control studies reporting the risk estimates of any cancer type for ≥3 categories of the DII were selected. Studies that reported the association between continuous DII score and cancer risk were also included. Pooled RRs were calculated by using a random-effects model. Eleven prospective cohort studies (total n = 1,187,474) with 28,614 incident cases and 29 case-control studies with 19,718 cases and 33,229 controls were identified. The pooled RRs for a 1-unit increment in the DII were as follows: colorectal cancer, 1.06 (95% CI: 1.04, 1.08; I2 = 72.5%; n = 9); breast cancer, 1.03 (95% CI: 1.00, 1.07; I2 = 84.0%; n = 7); prostate cancer, 1.06 (95% CI: 0.97, 1.15; I2 = 56.2%; n = 6); pancreatic cancer, 1.16 (95% CI: 1.05, 1.28; I2 = 61.6%; n = 2); ovarian cancer, 1.08 (95% CI: 1.03, 1.13; I2 = 0%; n = 2); esophageal squamous cell carcinoma, 1.24 (95% CI: 1.10, 1.38; I2 = 64.3%; n = 2); renal cell carcinoma, 1.08 (95% CI: 1.02, 1.13; I2 = 0%; n = 2); and esophageal adenocarcinoma, 1.26 (95% CI: 1.13, 1.39; I2 = 0%; n = 2). A nonlinear dose-response meta-analysis showed that, after a somewhat unchanged risk within initial scores of the DII, the risk of colorectal cancer increased linearly with increasing DII score. In the analyses of breast and prostate cancers, the risk increased with a very slight trend with increasing DII score. In conclusion, the results showed that dietary habits with high inflammatory features might increase the risk of site-specific cancers.

Associations between dietary inflammatory index and incidence of breast and prostate cancer: a systematic review and meta-analysis

OBJECTIVES

Dietary inflammatory index (DII) scores have been inconsistently linked to cancer risks. Therefore, a systematic review and meta-analysis was performed to examine the associations between the DII and the risks of breast and prostate cancer among men and women.

METHODS

Relevant studies were identified by searching PubMed and EMBASE databases up to March 2018. Data were available from 13 studies; of these, four studies used a prospective cohort design and nine studies were case-control studies. A total of 231 947 individuals from nine countries were included in these studies for the meta-analysis. The results were pooled using a random-effects model.

RESULTS

A pooled, adjusted odds ratio (OR) analysis indicated that there was a direct relationship between the highest versus lowest DII scores and prostate cancer risk in men (OR: 1.31; 95% CI: 1.04-1.57) but not the breast cancer risk (BCR) in women (OR: 1.65; 95% CI: 0.96-2.33). In the subgroup analyses, a more significant association between DII score and increased BCR was noted in premenopausal (OR: 2.03; 95% CI: 1.06-3.00) than in postmenopausal women (OR: 1.52; 95% CI: 0.89-2.16). When the results were stratified by body mass index, a positive association was observed between DII score and increased BCR in women (OR: 1.83; 95% CI: 1.48-2.18). Furthermore, there was no significant association between the highest versus lowest DII score and BCR among women who received hormone therapy (OR: 1.29; 95% CI: 0.93-1.64).

CONCLUSIONS

Men and premenopausal women who exhibit higher DII scores have increased prostate and breast cancer incidence risks, respectively. Moreover, body mass index had positive associations with the relationship between DII score and BCR in women. Further prospective cohort studies with longer follow-up periods are needed to support this possible association between DII score and cancer incidence.

Meta-analysis of the association between the dietary inflammatory index (DII) and breast cancer risk

BACKGROUND

Recent studies have reported mixed results on the association between the pro-inflammatory dietary index and risk of breast cancer. We perform this comprehensive meta-analysis to figure out whether high dietary inflammatory index (DII) score is a risk factor for the occurrence of breast cancer.

METHODS

We comprehensively searched the PubMed, EMBASE and Cochrane databases to identify included studies updated to September 12, 2017. All studies that reported risk estimates by comparing the highest DII score to the lowest were assessed.

RESULTS

A total of seven observational studies were identified: three case controls and four cohorts, involving 319,993 participants. Overall, the meta-analysis reported that individuals with the highest DII score were associated with a 25% increased risk of breast cancer versus those with the lowest DII score (relative risk [RR] = 1.25; 95% confidence interval [CI] 1.09-1.44; I² = 82.7%, p = 0.000). Upon stratified analysis, significant positive associations remained for postmenopausal women (RR = 1.15; 95% CI 1.02-1.30; p = 0.020), case-control studies (RR = 1.68; 95% CI 1.13-2.49; p = 0.010), Asia (RR = 2.30; 95% CI 1.7-3.12; p = 0.0031) and Europe (RR = 1.26; 95% CI 1.01-1.58; p = 0.0477). When analysed on hormonal receptor status, 36% increased risk was explored for hormone-receptor negative.

CONCLUSION

This meta-analysis suggested that more pro-inflammatory diets (higher DII scores) are associated with increased breast cancer incidence. However, the research is not about significant associations but about moderate effect sizes.

Dose-response relation between dietary inflammatory index and human cancer risk: evidence from 44 epidemiologic studies involving 1,082,092 participants

Background

A newly developed dietary inflammatory index (DII) to evaluate the inflammatory potential of diets was published recently. Many studies have investigated the link between diet-related inflammation and human cancer risk, but the results remain controversial.

Objective

We sought to determine the dose-response relation between DII and human cancer risk based on published epidemiologic literature.

Design

To summarize evidence, we performed a dose-response meta-analysis to investigate the association between DII and cancer incidence. We systematically searched PubMed, Embase, Web of Science, and the Cochrane library up to 5 November 2017. After data extraction, pooled RRs were calculated and dose-response analyses were performed using a restricted cubic spline model with 4 knots. Subgroup analyses, sensitivity analyses, and tests for publication bias were also performed.

Results

In all, 44 high-quality studies with 1,082,092 participants were included. The results showed that an elevated DII (continuous-RR: 1.13; 95% CI: 1.09, 1.16; category DIIhighest vs lowest-RR: 1.58; 95% CI: 1.45, 1.72) independently indicated higher cancer risk except for lung cancer and Australian studies. A linear dose-response relation between DII and overall cancer risk was found, with an 8.3% increase in the risk of cancer per DII score. The pooled RR of DII and cancer risk was 1.86 (95% CI: 1.63, 2.13) from 30 case-control studies but was lower in 14 prospective cohorts (RR: 1.29; 95% CI: 1.19, 1.40). The sensitivity analysis and Egger's test supported the main results.

Conclusions

Our analysis indicated that higher DII is significantly correlated with cancer risk. More prospective studies with large sample sizes, involving more ethnic groups and different cancer types, are required in the future. This review was registered with PROSPERO as CRD42017077075.

Dietary Inflammatory Potential Score and Risk of Breast Cancer: Systematic Review and Meta-analysis

Several studies have been conducted on the relationship between dietary inflammatory potential (DIP) and breast cancer. However, the findings are conflicting. This systematic review and meta-analysis summarizes the findings on the association between DIP and the risk of breast cancer. We used relevant keywords and searched online international electronic databases, including PubMed and NLM Gateway (for Medline), Institute for Scientific Information (ISI), and Scopus for articles published through February 2017. All cross-sectional, case-control, and cohort studies were included in this meta-analysis. Meta-analysis was performed using the random effects meta-analysis method to address heterogeneity among studies. Findings were analyzed statistically. Nine studies were included in the present systematic review and meta-analysis. The total sample size of these studies was 296,102, and the number of participants varied from 1453 to 122,788. The random effects meta-analysis showed a positive and significant association between DIP and the risk of breast cancer (pooled odds ratio, 1.14; 95% confidence interval, 1.01-1.27). The pooled effect size was not statistically significant because of the type of studies, including cohort (pooled relative risk, 1.04; 95% confidence interval, 0.98-1.10) and case-control (pooled odds ratio, 1.63; 95% confidence interval, 0.89-2.37) studies. We found a significant and positive association between higher DIP score and risk of breast cancer. Modifying inflammatory characteristics of diet can substantially reduce the risk of breast cancer.