Dietary factors modifying breast cancer risk and relation to time of intake

Low Diet Quality and Nutritional Knowledge in Women with Endometriosis: A Pilot Study

Endometriosis is a chronic gynecological disease characterized by ectopic endometrial tissue outside the uterus that can cause chronic pain, dysmenorrhea, fatigue, and infertility. The aim of this study was to assess diet quality and nutritional knowledge of women with endometriosis. A questionnaire was used to collect data on lifestyle, dietary habits and nutritional knowledge from 90 women. More than 80% of women with endometriosis (82.2%) confirmed that diet and lifestyle are related to the progression of endometriosis. After being diagnosed with endometriosis, 77.3% of respondents reported a change in their dietary habits and made various changes to their diet by increasing or eliminating the consumption of certain foods. The majority declared reducing pro-inflammatory products, increasing anti-inflammatory foods, including the consumption of vegetables and fruits, avoiding white/or red/or processed meat, and avoiding sweets. Nevertheless, diet quality as assessed by the pro-healthy diet index (pHDI-10) and the Mediterranean Diet Score (MDS) showed a low intensity of consumption of pro-healthy food (average pHDI-10 value 31.4%; MDS 7.55/14 points, p = 0.0001). Women with endometriosis reported lower than recommended consumption of fruits, vegetables, dairy products and whole grains. A higher percentage of healthy controls had a "good" level of nutritional knowledge than women with endometriosis. The results of our study highlight the need to improve diet quality and nutritional knowledge among women with endometriosis as well as developing targeted dietary recommendations to help improve well-being and reduce the pain symptoms of endometriosis.

The Role of Dietary Fats in the Development and Treatment of Endometriosis

Endometriosis is an estrogen-dependent disease in women of childbearing age that affects approximately 5–15% of the female population. The etiology of endometriosis is complex, multifaceted, and not fully understood. In endometriosis, which is an estrogen-related chronic inflammatory condition, estrogen plays a major role in endometrial cellular growth. High estrogen levels could be another risk factor for developing endometriosis. The aim of this review is to update knowledge on the impact of dietary fats on the development of endometriosis and chronic inflammation in women with endometriosis and diet therapy. Dietary fat may be linked with the progression and development of endometriosis, but studies have been contradictory due to various issues including sample size, different study designs, and different methodological aspects. Results have shown that the risk of endometriosis may increase with a higher consumption of products rich in saturated fats, especially palmitic acid and trans-unsaturated fatty acids. Monounsaturated fats and omega-3 polyunsaturated fatty acids may likely be connected with a lower risk of developing endometriosis and with reductions in the severity of disease. Monounsaturated fats, omega-3 polyunsaturated fatty acids, and a suitable eicosapentaenoic acid to arachidonic acid ratio can be used in diet therapy to improve quality of life by reducing pain and inflammation. Further research is needed in order to fully understand the influence of dietary fats on the risk of development of this disease.

Bovine holo-lactoferrin inhibits migration and invasion in MDA-MB-231 breast cancer cells

PURPOSE

Breast cancer is the most common malignancy in developed countries and the main cause of deaths in women worldwide. Lactoferrin (Lf) is an iron-binding protein constituted for a single polypeptide chain that is folded into two symmetrical lobes that bind Fe²⁺ or Fe³⁺. Lf has the ability to reversibly bind Fe³⁺ and is found free of Fe³⁺ (Apo-Lf) or associated with Fe³⁺ (Holo-Lf) with a different three-dimensional conformation. However, the role of bovine Apo-Lf (Apo-BLf) and bovine Holo-Lf (Holo-BLf) in the migration and invasion induced by linoleic acid (LA) and fetal bovine serum (FBS), as well as in the expression of mesenchymal and epithelial proteins in breast cancer cells has not been studied.

METHODS AND RESULTS

Scratch wound assays demonstrated that Holo-BLf and Apo-BLf do not induce migration, however they differentially inhibit the migration induced by FBS and LA in breast cancer cells MDA-MB-231. Western blot, invasion, zymography and immunofluorescence confocal microscopy assays demonstrated that Holo-BLf partly inhibit the invasion, FAK phosphorylation at tyrosine (Tyr)-397 and MMP-9 secretion, whereas it increased the number and size of focal adhesions induced by FBS in MDA-MB-231 cells. Moreover, Holo-BLf induced a slight increase of E-cadherin expression in MCF-7 cells, and inhibited vimentin expression in MCF-7 and MDA-MB-231 breast cancer cells.

CONCLUSION

Holo-BLf inhibits cellular processes that mediate the invasion process in breast cancer cells.

Fruit and vegetable intake and breast cancer prognosis: a meta-analysis of prospective cohort studies

The effect of fruit and vegetable intake on breast cancer prognosis is controversial. Thus, a meta-analysis was carried out to explore their associations. A comprehensive search was conducted in PubMed, Web of Science, OVID, ProQuest and Chinese databases from inception to April 2016. The summary hazard ratios (HR) and 95 % CI were estimated using a random effects model if substantial heterogeneity existed and using a fixed effects model if not. Subgroup analyses and sensitivity analyses were also performed. In total, twelve studies comprising 41 185 participants were included in the meta-analysis. Comparing the highest with the lowest, the summary HR for all-cause mortality were 1·01 (95 % CI 0·72, 1·42) for fruits and vegetables combined, 0·96 (95 % CI 0·83, 1·12) for total vegetable intake, 0·99 (95 % CI 0·89, 1·11) for cruciferous vegetable intake and 0·88 (95 % CI 0·74, 1·05) for fruit intake; those for breast cancer-specific mortality were 1·05 (95 % CI 0·77, 1·43) for total vegetable intake and 0·94 (95 % CI 0·69, 1·26) for fruit intake; and those for breast cancer recurrence were 0·89 (95 % CI 0·53, 1·50) for total vegetable intake and 0·98 (95 % CI 0·76, 1·26) for cruciferous vegetable intake. This meta-analysis found no significant associations between fruit and vegetable intake and breast cancer prognosis.

Dietary effects of mead acid on N-methyl-N-nitrosourea-induced mammary cancers in female Sprague-Dawley rats

The effect of mead acid (MA; 5,8,11-eicosatrienoic acid) on the suppression of the development and growth of N-methyl-N-nitrosourea (MNU)-induced mammary cancer in female Sprague-Dawley rats was examined. The MA diet (2.4% MA) or control (CTR) diet (0% MA) was started at 6 weeks of age, MNU was injected intraperitoneally at 7 weeks of age, and the rats were maintained on the respective diets for the whole experimental period (until 19 weeks of age). All induced mammary tumors were luminal A subtype carcinomas (estrogen and progesterone receptor positive and HER2/neu negative). The MA diet significantly suppressed the initiation and promotion phases of mammary carcinogenesis; MA suppressed the development (incidence, 61.5 vs. 100%; multiplicity, 2.1 vs. 4.5) and the growth (final tumor weight, 427.1 vs. 1,796.3 mg) of mammary cancers by suppressing cell proliferation, but not by accelerating cell death. There were evident changes in the major fatty acid composition of n-3, n-6, and n-9 fatty acids in the serum of the MA diet group; there was a significant increase in MA and significant decreases in oleic acid (OA), linoleic acid, arachidonic acid and docosahexaenoic acid. In non-tumorous mammary tissue, there was a significant increase in MA and a significant decrease in OA in the MA diet group. The n-6/n-3 ratios in serum and mammary tissue of the MA diet group were significantly decreased. The MA diet suppressed MNU-induced luminal A mammary cancer by lowering cancer cell proliferation. Therefore, MA may be a chemopreventive and chemotherapeutic agent. In addition to hormone therapy, MA supplementation may be a beneficial chemotherapeutic agent for the luminal A subtype of breast cancer.

Normolipidic dietary fat modifies circulating Renin-Angiotensin system-regulating aminopeptidase activities in rat with breast cancer

HYPOTHESIS

Renin-angiotensin system (RAS) has been considered not only as a regulator of systemic volume and electrolyte balance but also has been recently involved in various pathological processes such as cancer. In the etiology of breast cancer, dietary factors have been analyzed and especially the influence of dietary fat has been studied, but the underlying mechanisms remain unclear. In this study, we analyzed RAS-regulating enzymes in serum of rats with N-methyl nitrosourea (NMU)-induced breast cancer fed with different diets.

STUDY DESIGN

Four groups of rats were injected intraperitoneally with 3 doses of 50 mg/kg body weight of NMU at different days after birth and were fed with an AIN-93 commercial diet or AIN-93 diets with 4% fat constituted respectively by extra virgin olive oil, refined sunflower oil, and refined sunflower oil enriched to 50% with oleic acid.

METHOD

After sacrifice, blood and tumor samples were collected by spectrophotometric determinations of RAS-regulating enzymes in plasma and histopathology studies.

RESULTS

We show that the type of dietary fat does not influence latency period, incidence of animals with tumors, incidence of mortality, or tumor yield per rat. However, changes were observed in tumor volume and the histopathology. The type of dietary fat also differently modified the enzymes involved in RAS regulation.

CONCLUSIONS

It might suggest that one of the mechanisms by which dietary fat affects breast cancer is the modification of the RAS system, which may be consider as a new target for integrative therapies.

Endometriosis, dysmenorrhoea and diet

OBJECTIVE

To review the literature on the effects of diet on endometriosis and dysmenorrhoea.

STUDY DESIGN

A systematic search for trials investigating a relationship between diet and endometriosis/dysmenorrhoea was undertaken, and 23 studies were included in this review.

RESULTS

Data on the relationship between diet and endometriosis were limited to 12 trials, three of which were animal studies, resulting in a total of 74,708 women. One large study (n=70,709) found a relatively strong association between endometriosis and trans-fatty acid consumption, and a lower risk of endometriosis with increased consumption of long-chain omega-3 fatty acids. The latter finding was also supported by smaller studies. No further dietary recommendations for reducing the risk of endometriosis were possible, and results for intake of vegetable, fibre and fruit were equivocal. The relationship between diet and dysmenorrhoea was investigated in 11 trials with different designs, including a total of 1433 women. Intake of fish oil seemed to reduce dysmenorrhoea.

CONCLUSION

The literature on endometriosis and dysmenorrhoea in relation to diet is sparse, yielding equivocal results on specific elements. Overall, however, the literature suggests that specific types of dietary fats are associated with endometriosis and/or dysmenorrhoea, thereby indicating that there may be modifiable risk factors. Further research is recommended on both subjects.

Autophagy inhibition enhances apigenin-induced apoptosis in human breast cancer cells

Apigenin (4',5,7-trihydroxyflavone) is a member of the flavone subclass of flavonoids present in fruits and vegetables. The involvement of autophagy in the apigenin-induced apoptotic death of human breast cancer cells was investigated. Cell proliferation and viability were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and clonogenic assays. Flow cytometry, fluorescent staining and Western blot analysis were employed to detect apoptosis and autophagy, and the role of autophagy was assessed using autophagy inhibitors. Apigenin dose- and time-dependently repressed the proliferation and clonogenic survival of the human breast cancer T47D and MDA-MB-231 cell lines. The death of T47D and MDA-MB-231 cells was due to apoptosis associated with increased levels of Caspase3, PARP cleavage and Bax/Bcl-2 ratios. The results from flow cytometry and fluorescent staining also verified the occurrence of apoptosis. In addition, the apigenin-treated cells exhibited autophagy, as characterized by the appearance of autophagosomes under fluorescence microscopy and the accumulation of acidic vesicular organelles (AVOs) by flow cytometry. Furthermore, the results of the Western blot analysis revealed that the level of LC3-II, the processed form of LC3-I, was increased. Treatment with the autophagy inhibitor, 3-methyladenine (3-MA), significantly enhanced the apoptosis induced by apigenin, which was accompanied by an increase in the level of PARP cleavage. Similar results were also confirmed by flow cytometry and fluorescence microscopy. These results indicate that apigenin has apoptosis- and autophagy-inducing effects in breast cancer cells. Autophagy plays a cyto-protective role in apigenin-induced apoptosis, and the combination of apigenin and an autophagy inhibitor may be a promising strategy for breast cancer control.

A maternal high n-6 fat diet with fish oil supplementation during pregnancy and lactation in rats decreases breast cancer risk in the female offspring

The timing of dietary fat intake may modify breast cancer risk. In addition, n-3 fatty acids reduce, and n-6 fatty acids increase, the risk of breast cancer and a maternal high n-6 fat diet results in a greater risk of breast cancer in the female offspring. We hypothesized that the timing of n-3 fatty acid-enriched fish oil supplementation would be important for reducing the risk of breast cancer. Female rats were fed to a high n-6 fat diet containing 20% of the sunflower oil by weight during pregnancy and lactation, and the female offspring were exposed to fish oil by oral gavage either during the perinatal period via maternal intake or during puberty or adulthood. Exposure during the perinatal period to a maternal high n-6 fat diet with fish oil supplementation significantly reduced the incidence of carcinogen-induced mammary tumors in the female offspring compared to a maternal high n-6 fat diet with no fish oil supplementation or fish oil supplementation later in life (P=.0228 by Cox proportional hazards model). We found that a maternal high n-6 fat diet during pregnancy is more important in increasing the risk of mammary tumors in the female offspring than a maternal high n-6 fat diet during lactation. This study suggests that fish oil supplementation during the perinatal period decreases the effect of a maternal high n-6 fat diet on subsequent carcinogen-induced mammary tumor risk, whereas fish oil supplementation during puberty or adulthood does not.

Dietary patterns and breast cancer risk in women participating in the Black Women's Health Study

BACKGROUND

No studies have examined dietary patterns and breast cancer risk in a large cohort of African American women.

OBJECTIVE

We investigated the association between dietary patterns and breast cancer risk in the Black Women's Health Study.

DESIGN

This is a prospective cohort study of 50,778 participants followed biennially from 1995 through 2007. During 443,742 person-years of follow-up, 1094 incident cases of breast cancer were identified. Factor analysis was used to derive food patterns based on 69 food variables. We used Cox regression models to obtain incident rate ratios (IRRs) for breast cancer in relation to quintiles of each of the 2 dietary patterns, with adjustment for other breast cancer risk factors.

RESULTS

Through factor analysis, we identified 2 dietary patterns: Western (refined grains, processed meat, and sweets) and prudent (whole grains, vegetables, fruit, and fish). The prudent diet was weakly associated with lower breast cancer risk overall; P for trend = 0.06. In analyses stratified by body mass index (BMI; in kg/m(2)), the prudent dietary pattern was associated with a significantly lower risk of breast cancer in women with a BMI <25 (IRR: 0.64; 95% CI: 0.43, 0.93; P for trend = 0.01). The prudent dietary pattern was also associated with a significantly lower risk of breast cancer in premenopausal women (IRR: 0.70; 95% CI: 0.52, 0.96; P for trend = 0.01), and we found a significant inverse association for the prudent dietary pattern and estrogen receptor-negative breast cancer (IRR: 0.52; 95% CI: 0.28, 0.94; P for trend <0.01).

CONCLUSION

Our findings suggest that the prudent dietary pattern may protect against breast cancer in some black women.

A maternal high-fat diet during pregnancy in rats results in a greater risk of carcinogen-induced mammary tumors in the female offspring than exposure to a high-fat diet in postnatal life

The association between a high-fat diet and breast cancer risk is controversial. We hypothesized that the exposure of rats to a high-fat diet in utero via the maternal diet would result in a greater risk of carcinogen-induced mammary tumors than high-fat diet exposure in postnatal life. Rats were exposed to a high-fat diet with 40% of the energy source as safflower oil in utero (In utero group), at postnatal days 30-50 (Puberty group), postnatal days 150-170 (Adult group), postnatal days 1-230 (Postnatal group) or for their whole life from in utero (Whole group). Chow diet-fed rats were used as the Nonexposure group. Mammary tumor incidence was significantly higher in the In utero (60%), Postnatal (61%) and Whole (91%) groups than in the Nonexposure group (32%), but there was no significant difference between the Puberty (44%), Adult (44%) and Nonexposure groups. Arachidonic acid levels were 10 times higher in mammary tumor tissue than in the normal mammary gland across all groups and were positively correlated with tumor weight. We conclude that the timing, but not the duration, of high-fat diet exposure makes rats more susceptible to carcinogen-induced mammary tumors and that exposure in utero to a maternal high-fat diet during pregnancy is more important in increasing the risk of mammary tumors in the female offspring than exposure of the offspring to the same high-fat diet later in life.

The role of dietary measurement error in investigating the hypothesized link between dietary fat intake and breast cancer--a story with twists and turns

The association between dietary fat and breast cancer is one of the most controversial hypotheses in nutritional epidemiology. In this editorial, the authors review the evidence from animal and human studies, including international correlation, case-control, cohort studies, intervention trials, and studies comparing dietary assessment instruments. The authors emphasize the importance of the role played by measurement error arising from assessing dietary habits using self-reported questionnaires, as it can distort estimated associations, not necessarily towards the absence of an association. They describe the twists and turns of the dietary fat and breast cancer debate that have revolved around this issue.

Tumor-protective and tumor-promoting actions of dietary whey proteins in an N-methyl-N-nitrosourea model of rat mammary carcinogenesis

The mammary tumor-protective effects of dietary factors are considered to be mediated by multiple signaling pathways, consistent with the heterogeneous nature of the disease and the distinct genetic profiles of tumors arising from diverse mammary cell populations. In a 7,12-dimethylbenz(a)anthracene-induced model of carcinogenesis, we showed previously that female Sprague-Dawley rats exposed to AIN-93G diet containing whey protein hydrolysate (WPH) beginning at gestation Day 4 had reduced tumor incidence than those exposed to diet containing casein (CAS), due partly to increased mammary differentiation and reduced activity of phase I metabolic enzymes. Here, we evaluated the tumor-protective effects of these same dietary proteins to the direct-acting carcinogen N-methyl-N-nitrosourea (NMU). We found that lifetime exposure to WPH, relative to CAS, decreased mammary tumor incidence and prolonged the appearance of tumors in NMU-treated female rats, with no corresponding effects on tumor multiplicity. At 115 days post-NMU, histologically normal mammary glands from WPH-fed tumor-bearing rats had increased gene expression for the tumor suppressor BRCA1 and the differentiation marker kappa-casein than those of CAS-fed tumor-bearing rats. Tumor-bearing rats from the WPH group had more advanced tumors, with a greater incidence of invasive ductal carcinoma than ductal carcinoma in situ and higher serum C-peptide levels than corresponding rats fed CAS. WPH-fed tumor-bearing rats were also heavier after NMU administration than CAS tumor-bearing rats, although no correlation was noted between body weight and C-peptide levels for either diet group. Results demonstrate the context-dependent tumor-protective and tumor-promoting effects of WPH; provide support for distinct signaling pathways underlying dietary effects on development of mammary carcinoma; and raise provocative questions on the role of diet in altering the prognosis of existing breast tumors.

Endometriosis, dysmenorrhea and diet--what is the evidence?

The objective of this study is to assess the literature concerning the effect of diet on endometriosis and dysmenorrhea and to elucidate evidential support, to give dietary recommendations to women suffering from these conditions. A systematic search in electronic databases on a relationship between diet and endometriosis/dysmenorrhea was performed. Data on diet and endometriosis were limited to four trials of which two were animal studies. The articles concerning human consumption found some relation between disease and low intake of vegetable and fruit and high intake of vegetarian polyunsaturated fat, ham, beef and other red meat. Results concerning fish intake were not consistent. Eight trials of different design, with a total of 1097 women, investigated the relationship between diet and dysmenorrhea. Intake of fish oil seemed to have a positive effect on pain symptoms. This study concludes that literature on diet and endometriosis is sparse, whereas eight studies have looked at diet and dysmenorrhea. No clear recommendations on what diet to eat or refrain from to reduce the symptoms of endometriosis can be given, while a few studies indicate that fish oil can reduce dysmenorrhea. Further research is recommended on both subjects.

Cancer mortality rates among first and second generation migrants in the Netherlands: Convergence toward the rates of the native Dutch population

This study investigates the difference in cancer mortality rates between migrant groups and the native Dutch population, and determines the extent of convergence of cancer mortality rates according to migrants' generation, age at migration and duration of residence. Data were obtained from the national cause of death and population registries in the period 1995-2000. We used Poisson regression to compare the cancer mortality rates of migrants originating from Turkey, Morocco, Surinam, Netherlands Antilles and Aruba to the rates for the native Dutch. All-cancer mortality among all migrant groups combined was significantly lower when compared to that of the native Dutch population (RR = 0.55, CI: 0.52-0.58). For a large number of cancers, migrants had more than 50% lower risk of death, while elevated risks were found for stomach and liver cancers. Mortality rates for all cancers combined were higher among second generation migrants, among those with younger age at migration, and those with longer duration of residence. This effect was particularly pronounced in lung cancer and colorectal cancer. For most cancers, mortality among second generation migrants remained lower compared to the native Dutch population. Surinamese migrants showed the most consistent pattern of convergence of cancer mortality. The generally low cancer mortality rates among migrants showed some degree of convergence but did not yet reach the levels of the native Dutch population. This convergence implies that current levels of cancer mortality among migrants will gradually increase in future years if no specific preventive measurements are taken.

High-throughput genomic technology in research and clinical management of breast cancer. Evolving landscape of genetic epidemiological studies

Candidate polymorphism-based genetic epidemiological studies have yielded little success in the search for low-penetrance breast cancer susceptibility genes. The lack of progress is partially due to insufficient coverage of genomic regions with genetic markers, as well as economic constraints, limiting both the number of genetic targets and the number of individuals being studied. Recent rapid advances in high-throughput genotyping technology and our understanding of genetic variation patterns across the human genome are now revolutionizing the way in which genetic epidemiological studies are being designed and conducted. Genetic epidemiological studies are quickly progressing from candidate gene studies to comprehensive pathway investigation and, further, to genomic epidemiological studies where the whole human genome is being interrogated to identify susceptibility alleles. This paper reviews the evolving approaches in the search for low-penetrance breast cancer susceptibility gene variants and discusses their potential promises and pitfalls.

Diet, nutrition, and the life-course approach to cancer prevention

Cancer results from the interaction of genetic susceptibility and environmental exposures. The diagnosis of cancer is age related; there is a marked increase in cancer incidence after the reproductive years. Nutrient and toxicant exposures are important contributors to the risk of some cancers. Nutrition, as a determinant of growth and body composition, also influences cancer risk, directly due to carcinogens in foods or indirectly by the hormonal and metabolic response to growth and obesity. There is strong evidence that obesity and rapid growth enhance the risk of cancer. The prevention of cancer should start before conception; mothers should start pregnancy with a healthy weight and avoid excessive or low weight gain during pregnancy. Key micronutrients are important for normal embryonic development and fetal growth. Infant growth should be assessed based on optimal health across all stages of the life course, rather than following the present approach of "bigger is better. " This model may increase cancer risk in later life, because bigger is closely linked to fatter. Recent studies of energy expenditure in children indicate that excess energy intakes may have been recommended over the past decades, contributing to the surge in global obesity. Food preferences and habits regarding physical activity and play become set relatively early in life; parents and teachers provide key guidance leading to the adoption of a healthy or an unhealthy lifestyle. Thus, cancer prevention efforts should begin with childhood and continue through all stages of the life course.

Effects of soy protein and soy phytochemicals on mammary tumor development in female transgenic mice overexpressing human pituitary growth hormone

The objective of this study was to determine the effect of soy-based diets on mammary tumors in female cancer- prone mice. Transgenic virgin female mice expressing human pituitary growth hormone and their respective phenotypically normal littermates were fed a diet containing either casein (C), low-isoflavone soy protein (LIS), or high-isoflavone soy protein (HIS). Indices of tumor development were measured throughout the study. Both days from birth until death and days on diet until death were increased [by 20% (P = .01) and 19% (P = .02), respectively] in the LIS group when compared with the C group. Both intervals were increased also (by 16% and 17%, respectively; P < .05) in the HIS group when compared with the C group. Days from birth to first tumor were increased by 7% (P < .05), as was days on diet to first tumor by 5% (P < .05), in the LIS group when compared with the C group. First-onset number of tumors was decreased (P = .02) by 41% and 34% in the LIS and C groups, respectively, when compared with the HIS group. Final onset of tumors was decreased (P < .05) by 44% and 9% in the LIS and HIS groups, respectively, when compared with the C group. Total area of final tumors was decreased (P < .05) by 30% in the LIS group when compared with the C group. Taken cumulatively, these data suggest that a diet rich in soy protein may provide protective benefits regarding tumor development in female cancer-prone mice. Furthermore, some bioactive compounds in the HIS diet appeared to confound the soy protein-induced beneficial effects.