Dietary and stored iron as predictors of breast cancer risk: A nested case-control study in Shanghai

Dietary Trace Element Intake and Risk of Breast Cancer: A Mini Review

Trace elements are essentially required for various physiological and metabolic functions, and any disturbance in the trace elements homeostasis may result in the development of chronic diseases including breast cancer. Breast cancer is the most prevalent cancer type reported in women equally affecting both the high-income and low-income countries. This review therefore aimed to evaluate the impact of dietary trace element intake in relation to the incidence of breast cancer. We focused on five trace elements, thus emphasizing dietary selenium, zinc, iron, copper, and cadmium intake and risk of breast cancer. A systematic approach was applied to perform this review through entering a search term in PubMed and Scopus databases. A total of 24 articles were included after meeting the inclusion and exclusion criteria. Most of the studies regarding dietary iron intake showed a detrimental effect of increased dietary heme iron on breast cancer incidence risk. In addition, there is a limited evidence of high dietary intake of selenium and zinc to reduce the risk of breast cancer. Also, a few studies showed a relationship between high cadmium consumption and risk of breast cancer. More studies related to cadmium and copper exposure are needed to confirm this relationship. As a result, the findings of this review suggested that high dietary heme iron is a potential risk factor for breast cancer.

Pre-Clinical Insights into the Iron and Breast Cancer Hypothesis

Population studies, systematic reviews, and meta-analyses have revealed no relationship between iron status and breast cancer, a weak positive association, or a small protective effect of low iron status. However, in those studies, the authors concluded that further investigation was merited. The set of experiments reported here used preclinical models to assess the likely value of further investigation. The effects of iron status on the initiation and promotion stage of mammary carcinogenesis are reported. Using the classical model of cancer initiation in the mammary gland, 7,12 dimethyl-benz[α]anthracene-induced carcinogenesis was unaffected by iron status. Similarly, excess iron intake showed no effect on the promotion stage of 1-methyl-1-nitrosurea-induced mammary carcinogenesis, though iron deficiency exerted a specific inhibitory effect on the carcinogenic process. Though iron-mediated cellular oxidation is frequently cited as a potential mechanism for effects on breast cancer, no evidence of increased oxidative damage to DNA attributable to excess iron intake was found. The reported preclinical data fail to provide convincing evidence that the further evaluation of the iron–breast cancer risk hypotheses is warranted and underscore the value of redefining the referent group in population-based studies of iron–cancer hypotheses in other tissues.

Iron intake with the risk of breast cancer among Chinese women: a case-control study

OBJECTIVE

The current study evaluated the associations between different forms and sources of Fe and breast cancer risk in Southern Chinese women.

DESIGN

Case-control study. We collected data on the consumption of Fe from different forms and food sources by using a validated FFQ. Multivariable logistic regression and restricted cubic spline (RCS) analysis was used to reveal potential associations between Fe intake and breast cancer risk.

SETTING

A case-control study of women at three major hospitals in Guangzhou, China.

PARTICIPANTS

From June 2007 to March 2019, 1591 breast cancer cases and 1622 age-matched controls were recruited.

RESULTS

In quartile analyses, Fe from plants and Fe from white meat intake were inversely associated with breast cancer risk, with OR of 0·65 (95 % CI 0·47, 0·89, Ptrend = 0·006) and 0·76 (95 % CI 0·61, 0·96, Ptrend = 0·014), respectively, comparing the highest with the lowest quartile. No associations were observed between total dietary Fe, heme or non-heme Fe, Fe from meat or red meat and breast cancer risk. RCS analysis demonstrated J-shaped associations between total dietary Fe, non-heme Fe and breast cancer, and reverse L-shaped associations between heme Fe, Fe from meat and Fe from red meat and breast cancer.

CONCLUSION

Fe from plants and white meat were inversely associated with breast cancer risk. Significant non-linear J-shaped associations were found between total dietary Fe, non-heme Fe and breast cancer risk, and reverse L-shaped associations were found between heme Fe, Fe from meat or red meat and breast cancer risk.

Targeting ferroptosis in breast cancer

Ferroptosis is a recently discovered distinct type of regulated cell death caused by the accumulation of lipid-based ROS. Metabolism and expression of specific genes affect the occurrence of ferroptosis, making it a promising therapeutic target to manage cancer. Here, we describe the current status of ferroptosis studies in breast cancer and trace the key regulators of ferroptosis back to previous studies. We also compare ferroptosis to common regulated cell death patterns and discuss the sensitivity to ferroptosis in different subtypes of breast cancer. We propose that viewing ferroptosis-related studies from a historical angle will accelerate the development of ferroptosis-based biomarkers and therapeutic strategies in breast cancer.

A meta-analysis of zinc levels in breast cancer

BACKGROUND

Breast cancer is the most commonly occurring neoplasm in females, comprising 16% of all female cancers worldwide. Various studies indicate some discrepancies regarding zinc (Zn) levels in various samples of breast cancer patients.

OBJECTIVE

The present study evaluated by meta-analysed the published data for Zn levels analyzed in breast tissue, plasma, serum, and hair samples and its relationship with breast cancer.

METHODS

The present meta-analysis included 36 studies, all of which were published in the years between 1984 to 2017 and selected by searching the databases MEDLINE, EMBASE, Cochrane Library, PubMed, Scopus, and the ISI Web of Knowledge. The articles were analyzed, and I² statistics were used to examine heterogeneity. The objective analysis was performed on data from the 36 studies, with total 1699 study subjects and 2009 controls.

RESULTS

Significant statistical differences overall were observed, based on a random effects model (SMD (95 % CI), -0.78[-1.40, -0.16], P = 0.014). Data from 19 of these studies indicated significant statistical differences between cancerous patients and controls with regard to serum and plasma Zn concentration (SMD [(95 %CI): -1.61(-2.43, -0.79)]. There was a significant statistical difference between the breast tissue and hair as regards Zn status (SMD (95%CI): 2.32(1.42, 3.21)) and (SMD (95v%CI): -1.80(-3.41, -0.20), respectively. Zn concentration levels typically decreased in blood and hair samples of patients with breast cancer, whereas it was elevated in tumor tissues.

CONCLUSIONS

There is a significant relationship between lowered serum Zn concentrations and risk of breast cancer onset or recurrences in women, but because of high heterogeneity, we recommend other primary studies.

Dietary Micronutrients Intake Status among Chinese Elderly People Living at Home: Data from CNNHS 2010-2012

The aim of this study was to examine the status of usual dietary micronutrient intakes among Chinese elderly living at home. The data was based on China National Nutrition and Health Survey (CNNHS) 2010-2012. We analyzed data from the participants aged 60-year-old and more (n = 16,612) living at home, who provided dietary data on three days 24 h dietary survey combining with the household weighing method. The means and distribution percentiles for usual intakes of dietary micronutrients were estimated using the Multiple Source Method (MSM). The prevalence of inadequacy for the selected micronutrients was expressed using the proportion of individuals with usual intakes below the Estimated Average Requirement (EAR). For vitamin E, sodium and potassium, the means and the distribution of intakes were compared to the Adequate Intake (AI) level. Usual dietary intakes of most micronutrients were inadequate in the participants, especially folate, calcium, vitamin B6 and vitamin B2, with the prevalence of inadequacy more than 90%. However, dietary sodium intake was extremely high with an average usual intake of 4702 mg/day. The usual dietary intakes of all selected micronutrients in old males were higher than females, and the prevalence of inadequacy of most micronutrients was higher in old women (p < 0.01). The subjects aged 60-74 years tended to have higher usual dietary micronutrient intakes and lower prevalence of inadequate micronutrients than those aged 75 years and over (p < 0.01). Higher usual dietary intakes and lower prevalence of inadequacy of most micronutrients were found in the elderly living in the southern region (p < 0.01). The average usual intakes of most micronutrients declined with socioeconomic status. The prevalence of inadequate vitamin A, B2, C, calcium and selenium below EAR increased with socioeconomic status (p < 0.01, p for trend < 0.01). Thus, essential micronutrients insufficient intake is a public health concern among Chinese community-dwelling old population, especially the females, older people, the elderly in undeveloped areas or living in northern regions. Nutrition education and appropriate approach should be undertaken to address these problems.

Iron intake, body iron status, and risk of breast cancer: a systematic review and meta-analysis

BACKGROUND

Iron has been shown to promote breast carcinogenesis in animal models through generation of oxidative stress and interaction with estrogen. Heme iron, which is found exclusively in animal-sourced foods, is suggested to have a more detrimental effect. Epidemiological evidence of the association between iron and breast cancer risk remains inconclusive and has not been comprehensively summarized. This systematic review and meta-analysis evaluated associations between both iron intake and body iron status and breast cancer risk.

METHODS

Four electronic databases (MEDLINE, EMBASE, CINAHL, and Scopus) were searched up to December 2018 for studies assessing iron intake and/or biomarkers of iron status in relation to breast cancer risk. Using random-effects meta-analyses, pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated comparing the highest vs. lowest category of each iron measure. Dose-response meta-analyses were also performed to investigate linear and nonlinear associations.

RESULTS

A total of 27 studies were included in the review, of which 23 were eligible for meta-analysis of one or more iron intake/status measures. Comparing the highest vs. lowest category, heme iron intake was significantly associated with increased breast cancer risk, with a pooled RR of 1.12 (95% CI: 1.04-1.22), whereas no associations were found for dietary (1.01, 95% CI: 0.89-1.15), supplemental (1.02, 95% CI: 0.91-1.13), or total (0.97, 95% CI: 0.82-1.14) iron intake. Associations of iron status indicators with breast cancer risk were generally in the positive direction; however, a significant pooled RR was found only for serum/plasma levels (highest vs. lowest) of iron (1.22, 95% CI: 1.01-1.47), but not for ferritin (1.13, 95% CI: 0.78-1.62), transferrin saturation (1.16, 95% CI: 0.91-1.47), or total iron-binding capacity (1.10, 95% CI: 0.97-1.25). In addition, a nonlinear dose-response was observed for heme iron intake and serum iron (both P_nonlinearity < 0.05).

CONCLUSIONS

Heme iron intake and serum iron levels may be positively associated with breast cancer risk. Although associations were modest, these findings may have public health implications given the widespread consumption of (heme) iron-rich foods. In light of methodological and research gaps identified, further research is warranted to better elucidate the relationship between iron and breast cancer risk.

High-Dose Deferoxamine Treatment Disrupts Intracellular Iron Homeostasis, Reduces Growth, and Induces Apoptosis in Metastatic and Nonmetastatic Breast Cancer Cell Lines

Mounting evidence suggest that iron overload enhances cancer growth and metastasis; hence, iron chelation is being increasingly used as part of the treatment regimen in patients with cancer. Now whether iron chelation depletes intracellular iron and/or disrupts intracellular iron homeostasis is yet to be fully addressed. MCF-7 and MDA-MB-231 breast cancer cells treated with increasing concentrations of the iron chelator deferoxamine were assessed for intracellular iron status, the expression of key proteins involved in iron metabolism, cell viability, growth potential, and apoptosis at different time points following treatment. Treatment with deferoxamine at 1, 5, or 10 μM for 24 or 48 hours, while not leading to significant changes in intracellular labile iron content, upregulated the expression of hepcidin, ferroportin, and transferrin receptors 1 and 2. In contrast, deferoxamine at 30, 100, or 300 μM for 24 hours induced a significant decrease in intracellular labile iron, which was associated with increased expression of hepcidin, ferritin, and transferrin receptors 1 and 2. At 48 hours, there was an increase in intracellular labile iron, which was associated with a significant reduction in hepcidin and ferritin expression and a significant increase in ferroportin expression. Although low-dose deferoxamine treatment resulted in a low to moderate decrease in MCF-7 cell growth, high-dose treatment resulted in a significant and precipitous decrease in cell viability and growth, which was associated with increased expression of phosphorylated Histone 2A family member X and near absence of survivin. High-dose deferoxamine treatment also resulted in a very pronounced reduction in wound healing and growth in MDA-MB-231 cells. These findings suggest that high-dose deferoxamine treatment disrupts intracellular iron homeostasis, reduces cell viability and growth, and enhances apoptosis in breast cancer cells. This is further evidence to the potential utility of iron chelation as an adjunctive therapy in iron-overloaded cancers.

ASSESSMENT OF ANIMAL MODELS AS SURROGATES FOR HUMAN TUMORS FROM THREE DIFFERENT ORGANS

The compositional balance and distribution of trace metals/elements in various body tissues are essential key players in tissue and cellular homeostasis. Low Zn levels as well as overexpression of metalothioneins were implicated in the development and progression of various cancers including the prostate. Nonetheless, wider elemental profiles that relate cancer and normal phenotypes with regards to metal homeostasis were not well elucidated in the literature. Moreover, laboratory animals are currently used as accepted models for studying cancer but the level of their representation of actual cancer tissues was not clear. This study is attempting to assess the relevance of animal models currently in use, as surrogates for cancer and establish their relationship to actual normal and cancer tissues from humans. The major focus of this study was to investigate the differential relationship of metal concentrations and profiles in cancer and normal tissues from cadavers of humans and their comparison to established animal models representing organ cancers. The working hypothesis was that elemental/metal concentrations and profiles seen in post mortem will show significant differences between normal and cancer-derived tissues as well as between various tissue types in humans, rats, and dogs. This study also establishes critical elemental/metal profiles that may be relevant in providing correlations with the development of three major cancers. Normal human and tumor tissues of cadaverous lung, breast, and liver used in this study were obtained from US Biomax Company and relevant animal models (Sprague-dawley and Brown Norwegian rats as well as dogs; were obtained from Jackson Laboratories and the Mississippi State Veterinary Laboratory in Pearl, MS), to analyze for elements and test the hypothesis. Tissue samples were prepared using standardized digestion procedures necessary for use with the Inductively Coupled Plasma-Atomic Emission mass Spectrometry (ICP-MS) to determine the concentrations and profiles of 21 elements including Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni, Pb, Sb, Se, Sr, Tl, V, and Zn. Our data supports the notion that metal/elemental homeostasis is essential for normal tissue function and that elemental variations in content, distributions, and ranking are tissue specific as well as carcinoma and species-specific. Analysis of data showed significant variations in elemental content and distribution profiles/ranking between animal models and actual human tissues consistent with the hypothesis. It is concluded that elemental homeostasis is essential for normal tissue function and that shifts in their distribution and content are essential in determining the use of animal models as surrogates for studying cancer. These results are promising and warrant further studies to confirm the relevance of animal models in relation to their use as pre-clinical tools for examining targeted cancer therapeutics.

Comparison of hematological parameters, iron levels, and oxidative stress in women with and without breast cancer: A case- control study

Background: Iron is one of the nutrients that has recently received considerable attention because of its dual role in the incidence of breast cancer. The present study aimed at comparing hematological parameters, iron levels, and oxidative stress in women with and without breast cancer. Methods: The participants in this case-control study were 55 women, of whom 26 were new cases of breast cancer (confirmed by biopsy) as the case, and 29 without cancer (confirmed by mammography) as the control group. All participants underwent blood testing for complete blood count (CBC (free iron, ferritin, total iron binding capacity) TIBC (2, 2-diphenyl-1-picrylhydrazyl (DPPH), and Malondialdehyde (MDA). Results: The mean±SD age of the participants was 44.25±9.82 years, and there was no significant difference between groups. Also, no statistically significant difference was found between the 2 groups in variables, except the mean corpuscular volume of red cells (MCV), mean corpuscular hemoglobin concentration (MCHC), and mean cell hemoglobin (MCH). The use of iron supplements was significantly higher in the control than in the case group (p= 0. 01), with an odds ratio of 0.19% (95% CI: 0.45-0.7). The mean serum DPPH was significantly higher in the control than in the case group (p= 0. 006), but comparison of serum MDA showed no significant difference between the 2 groups. Conclusion: Iron deficiency anemia was greater in patients with breast cancer than in those without it. Moreover, iron supplementation appears to have a protective effect against breast cancer incidence. In addition, serum DPPH, as a total antioxidant index, was significantly higher in the control group.

Deferoxamine-induced increase in the intracellular iron levels in highly aggressive breast cancer cells leads to increased cell migration by enhancing TNF-α-dependent NF-κB signaling and TGF-β signaling

Recent studies have suggested that excess iron accumulation may be a risk factor for breast cancer. However the role of iron in breast cancer metastasis has remained unclear. The major goal of our study is to investigate the roles of iron in breast cancer metastasis. We modulated the intracellular iron levels of human breast cancer cells, including the aggressive MDA-MB-231 cells and non-aggressive MCF-7 cells, by using Deferoxamine (DFO) - a most widely used iron chelator. We found that DFO treatment could deplete intracellular iron in MCF-7 cells. In contrast, DFO treatment led to a significant increase in the intracellular iron level in MDA-MB-231 cells. The MDA-MB-231 cells with the increased intracellular iron level exhibited increases in both mesenchymal markers and cell migration. Furthermore, the DFO-treated MDA-MB-231 cells showed increases in both tumor necrosis factor α (TNF-α)-induced nuclear factor kappa B (NF-κB) signaling and transforming growth factor-β (TGF-β) signaling, which could contribute to the enhanced cell migration. Collectively, our study has provided the first evidence suggesting that increased intracellular iron levels could lead to enhanced migration of aggressive breast cancer cells by increasing TNF-α-dependent NF-κB signaling and TGF-β signaling. Our study has also suggested that caution should be taken when DFO is applied for treating breast cancer cells, since DFO could produce differential effects on the intracellular iron levels for aggressive breast cancer cells and non-aggressive breast cancer cells.

Methodological problems with population cancer studies: The forgotten confounding factors

Among clinical physicians it is the population study that is considered to be the “gold standard” of medical evidence concerning acceptable treatments. As new information comes to light concerning the many variables and confounding factors that can affect such studies, many older studies lose much of their original impact. While newer population studies take into consideration a far greater number of confounding factors many are still omitted and a number of these omitted factors can have profound effects on interpretation and validity of the study. In this editorial, I will discuss some of the omitted confounding factors and demonstrate how they can alter the interpretation of these papers and their clinical application.

Premenopausal plasma ferritin levels, HFE polymorphisms, and risk of breast cancer in the nurses' health study II

BACKGROUND

Evidence from the Nurses' Health Study II (NHSII) suggests that red meat consumption is associated with increased breast cancer risk in premenopausal women. Iron may be responsible by contributing to oxidative stress or effects on immune function.

METHODS

We conducted a case-control study nested within the NHSII, examining prediagnostic plasma ferritin (n = 795 cases, 795 controls), 15 hemochromatosis gene (HFE) single-nucleotide polymorphisms (SNP; n = 765 cases, 1,368 controls), and breast cancer risk. Cases were diagnosed after providing blood samples between 1996 and 1999. ORs and 95% confidence intervals (CI) were calculated for ferritin levels by conditional logistic regression and for HFE SNPs by unconditional logistic regression.

RESULTS

We did not observe a significant association between ferritin levels and breast cancer (top vs. bottom quartile multivariate OR: 1.05; 95% CI, 0.77-1.45; PTrend = 0.77). Results did not change when restricted to women who were premenopausal at blood draw, and were similar when cases were examined by hormone receptor status, and menopausal status at diagnosis. No HFE SNPs were significantly associated with breast cancer in a log-additive manner. Among controls, ferritin levels were nominally associated with SNPs rs9366637 (PTrend = 0.04), rs6918586 (PTrend = 0.06), and rs13161 (PTrend = 0.07), but results did not remain significant after adjusting for multiple testing.

CONCLUSIONS

Ferritin levels and HFE SNPs were not associated with breast cancer risk in this population.

IMPACT

Components of red meat other than iron are likely responsible for its positive association with breast cancer in premenopausal women.

Epidemiological and nonclinical studies investigating effects of iron in carcinogenesis--a critical review

The efficacy and tolerability of intravenous (i.v.) iron in managing cancer-related anemia and iron deficiency has been clinically evaluated and reviewed recently. However, long-term data in cancer patients are not available; yet, long-term i.v. iron treatment in hemodialysis patients is not associated with increased cancer risk. This review summarizes epidemiological and nonclinical data on the role of iron in carcinogenesis. In humans, epidemiological data suggest correlations between certain cancers and increased iron exposure or iron overload. Nonclinical models that investigated whether iron can enhance carcinogenesis provide only limited evidence relevant for cancer patients since they were typically based on high iron doses as well as injection routes and iron formulations which are not used in the clinical setting. Nevertheless, in the absence of long-term outcome data from prospectively defined trials in i.v. iron-treated cancer patients, iron supplementation should be limited to periods of concomitant anti-tumor treatment.

Serum total oxidant/antioxidant status and trace element levels in breast cancer patients

BACKGROUND

Oxidative stress and trace elements have been implicated in the development of breast cancer. However, how they contribute to the pathogenesis of the disease and the relationship between them remain unclear. In addition, most previous studies detecting one or a few oxidant/antioxidant markers failed to consider the overall oxidant/antioxidant status of the subjects. This study was designed to address this and to investigate the association between oxidative status and trace elements in the pathogenesis of breast cancer.

METHODS

Fifty-six patients with breast carcinoma at different clinical stages, 32 patients with benign breast tumor, and 20 healthy subjects (controls) were recruited into this study. Their serum total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and levels of Cu, Zn, Fe, Se, Mg, and Mn were measured.

RESULTS

Levels of TAS, TOS, OSI, and trace elements significantly differed between the study groups. Among subgroups of patients with different clinical stages of breast cancer, the levels of all the trace elements except Zn were similar, whereas TAS, TOS, and OSI levels were all significantly different. There were significant correlations between oxidative stress parameters and levels of trace elements in patients with breast carcinoma but not in patients with benign breast tumor or in the healthy controls.

CONCLUSIONS

Disturbed oxidative stress status and trace element levels may contribute to the pathogenesis of breast tumors. TAS, TOS, and OSI may be useful biomarkers for monitoring the clinical status of breast cancer.

Oh the irony: Iron as a cancer cause or cure?

Iron-oxide nanoparticles facilitate cancer diagnosis through enhanced contrast, selectively enhance tumor cell death with magnetic hyperthermia, and improve drug delivery with magnetic drug targeting. One application that remains largely unexplored is using the iron-oxide nanoparticles themselves to selectively inhibit tumor growth. In this leading opinion paper, we propose that high doses of iron-oxide nanoparticles can be used as a treatment for cancer by generating an oxidative assault against cancer. This proposal may be met with resistance considering the controversy surrounding iron in the field of cancer. Iron generates reactive oxygen species through the Fenton reaction, which may both cause - or cure cancer. Additionally, high demand for iron by cancer cells leads to contradictory therapeutic approaches: iron deprivation or overdose are both potential cancer therapies.

Relationships of lipocalin 2 with breast tumorigenesis and metastasis

Breast cancer is one of the most common cancers in women worldwide and accounts for one-sixth of cancer deaths in the United States. Breast cancer consists of a heterogeneous group of tumours classified into five types, in which the HER2/neu positive and the basal type (most are ER and HER2 negative) have the worst clinical prognosis. In recent years, prognostic/predictive markers such as ER/PR or HER2/neu have been widely used in the selection of the optimal breast cancer treatments for individual patients, which have been proven to be very effective in disease control. These results suggest that further examination of the molecular mechanisms underlying the breast tumorigenesis and identification of the potential biomarkers in different types of breast cancers will greatly benefit clinical diagnosis and facilitate the design of more effective personalized therapies to increase patient survival. This review aims to summarize recent research findings on lipocalin 2 (LCN2), a newly identified biomarker and a potential therapeutic target for breast cancer, and the possible mechanisms underlying its role in tumorigenesis and metastasis.

Serum Ferritin in Healthy Women and Breast Cancer Patients

Serum tumor markers are important tools in managing patients with breast cancer. Currently used CA 15-3 and CEA have found their clinical application particularly in the follow-up of patients with advanced disease. Ferritin belongs to a group of other molecules of potential interest to clinicians whose concentration is also altered in sera of patients with breast tumors. In this study the serum ferritin concentration was estimated in the sera of breast cancer patients before initial surgical treatment or those with advanced disease, and compared to healthy women as control. Ferritin level was measured by an immunoradiometric assay. The aim was to asses whether the serum ferritin concentration was altered in breast cancer and whether it could be related to progression of the disease. In healthy women, a statistically significant difference (p<0.05) in ferritin concentration was observed between premenopausal and postmenopausal women. In both breast cancer groups ferritin levels were higher than in healthy premenopausal women (both p<0.05). In patients with advanced disease, ferritin was further elevated (p<0.05) compared to preoperative levels in the patient group undergoing initial surgical treatment. These results indicate that an elevated ferritin concentration in the serum of younger women could serve as an additional parameter in breast cancer diagnosis and staging.

Nutrient contribution of total and lean beef in diets of US children and adolescents: National Health and Nutrition Examination Survey 1999-2004

This study examined the nutritional contribution of total beef and lean beef (LB) to the diet of US children and adolescents using the US Department of Agriculture definition of LB as defined in MyPyramid. Twenty-four hour dietary recall data from children 4-8 years of age [y] (n=2474), 9-13 y (n=3273), and adolescents 14-18 y (n=4044) participating in the NHANES 1999-2004 were assessed. LB was defined as beef with ≤9.28 grams [g] fat/100 g (excess was discretionary fat). Means and standard errors were determined using appropriate sample weights. Consumption of LB contributed significantly to intake of protein and many key nutrients such as vitamins B6 and B12, zinc, iron, niacin, phosphorus, and potassium by US children and adolescents without providing significantly to intakes of total fat, saturated fatty acids, or sodium.

Biomarkers of dietary exposure are associated with lower risk of breast fibroadenomas in Chinese women

Fibroadenomas are the most common benign breast condition among women and account for up to 50% of all breast biopsies being performed. Although considered a benign condition, fibroadenomas utilize substantial resources for management and treatment to rule out potential malignancies. Dietary factors may influence benign fibrocystic breast conditions, but little is known of their association with fibroadenomas. We examined possible associations between a broad spectrum of circulating biomarkers of dietary intake and risk of fibroadenomas. Participants were women in a breast self-examination trial in Shanghai, China who were diagnosed with fibroadenomas (n = 258) and 1035 controls. Conditional logistic regression was used to estimate adjusted odds ratios (OR) and 95% CI. Isoflavone concentrations were inversely associated with risk of fibroadenomas. Adjusted OR (95% CI) for the highest versus the lowest quartile of plasma concentration were 0.36 (0.16-0.79; P-trend < 0.001) for daidzein and 0.39 (0.19-0.84; P-trend = 0.010) for genistein. We also observed inverse associations between higher percentages of the RBC (n-3) fatty acids, eicosapentaenoic acid (EPA) ([0.38 (0.19-0.77); P-trend = 0.007] and docosapentaenoic acid (DPA) [0.32 (0.15-0.70); P-trend = 0.024], and fibroadenoma risk. Circulating concentrations of carotenoids, vitamin C, retinol, and ferritin were not associated with fibroadenoma risk. The inverse associations between plasma isoflavone concentrations and RBC EPA and DPA and fibroadenoma risk suggest that higher intakes of soy foods and fatty fish may lower the risk of fibroadenomas.

Significance of differential metal loads in normal versus cancerous cadaver tissues - biomed 2010

The bodys elemental/ metal loads are known to exert essential influence in maintaining normal and abnormal metabolism leading to eventual pathology of some forms of cancer phenotypes. Accumulation of potentially toxic or nonessential trace metals has been observed but not highly noted as an active factor in toxicogenesis and in the development of many diseases including cancers. The compositional balance and distribution of trace metals in various body tissues are essential key players in homeostasis in life. To this end the etiology of diseases including cancer has been linked with the accumulation of potentially toxic or nonessential trace metals. However, scarce literature / experimental evidence exist as a scientific proof that metal concentrations play important role in the etiology and development of cancer phenotypes. The aim of this study was to investigate the differential relationship of metal concentrations and profiles in cancer and normal tissues from cadavers of humans. The originated hypothesis was that elemental / metal concentrations and profiles seen in post mortem will show significant differences between normal and cancer-derived tissues as well as between various tissue types in humans. This study also establishes critical elemental /metal profiles that may be relevant in providing correlations with the development of three major cancers. Normal human and tumor tissues of cadaverous lung, breast and liver tissues used in this study were obtained from US Biomax Company. Tissue samples were prepared using standardized digestion procedures necessary for use with the Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). This equipment was utilized to determine the concentrations and profiles of 21 elements including Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni, Pb, Sb, Se, Sr, Tl, V, and Zn. Twelve major elements of Al, Ba, Ca, Cr, Cu, Fe, Mg, Na, Pb, Se, Sr, and Zn were found to be significantly different in term of their concentrations / profiles in normal and tumor tissues of human lung, breast and liver. These critical elements appeared to be respectively five to ten times more abundant in human lung and breast tumor than in their respective normal tissues. In contrast Ba, Cr, Cu, Fe, Zn, concentrations were shown to be lower in liver tumors than in normal liver tissues, and that Ca and Na appeared to be higher in human liver tumors than in normal liver tissues. Data analysis showed significant variations in elemental concentrations and profiles consistent with the hypothesis. It is concluded that metal / elemental homeostasis is essential for normal tissue function and that elemental variations and distributions are tissue specific as well as carcinoma specific. These results are promising and warrant further studies to confirm / exploit the possibility of manipulating elemental distribution and content as means for diagnosing / utility as therapeutic modalities in chronic human disease as well as cancer management.