Instruct: Given a question, retrieve passages that answer the question.
Query: Breast Cancer Survival and Lignan Intake
Flavonoids have been hypothesized to reduce cancer risk. Previous epidemiological studies conducted to evaluate this hypothesis have not assessed all flavonoids, including classes that could contribute to intake among Americans, which would result in an underestimation of intake. This misclassification could mask variability among individuals, resulting in attenuated effect estimates for the association between flavonoids and cancer. To augment flavonoid and lignan intake estimates, we developed a database that can be used in conjunction with a food-frequency questionnaire (FFQ). Coupling information derived from the available literature with the U.S. Department of Agriculture databases, we estimated content of 6 flavonoid classes and lignans for 50 food group items. We combined these estimates with responses from a modified Block FFQ that was self-completed in 1996-1997 by a population-based sample of women without breast cancer on Long Island, New York (n = 1,500). Total flavonoid and lignan content of food items ranged from 0 to 129 mg/100 g, and the richest sources were tea, cherries, and grapefruit. Individual intake estimates, from highest to lowest, were flavan-3-ols, flavanones, flavonols, lignans, isoflavones, anthocyanidins, and flavones. Each class of flavonoids and lignans exhibited a wide range of intake levels. This database is useful to quantify flavonoid and lignan intake for other observational studies conducted in the United States that utilize the Block FFQ.
Background. Flax is a food and dietary supplement commonly used for menopausal symptoms. Flax is known for its lignan, α-linolenic acid, and fiber content, components that may possess phytogestrogenic, anti-inflammatory, and hormone modulating effects, respectively. We conducted a systematic review of flax for efficacy in improving menopausal symptoms in women living with breast cancer and for potential impact on risk of breast cancer incidence or recurrence. Methods. We searched MEDLINE, Embase, the Cochrane Library, and AMED from inception to January 2013 for human interventional or observational data pertaining to flax and breast cancer. Results. Of 1892 records, we included a total of 10 studies: 2 randomized controlled trials, 2 uncontrolled trials, 1 biomarker study, and 5 observational studies. Nonsignificant (NS) decreases in hot flash symptomatology were seen with flax ingestion (7.5 g/d). Flax (25 g/d) increased tumor apoptotic index (P < .05) and decreased HER2 expression (P < .05) and cell proliferation (Ki-67 index; NS) among newly diagnosed breast cancer patients when compared with placebo. Uncontrolled and biomarker studies suggest beneficial effects on hot flashes, cell proliferation, atypical cytomorphology, and mammographic density, as well as possible anti-angiogenic activity at doses of 25 g ground flax or 50 mg secoisolariciresinol diglycoside daily. Observational data suggests associations between flax and decreased risk of primary breast cancer (adjusted odds ratio [AOR] = 0.82; 95% confidence interval [CI] = 0.69-0.97), better mental health (AOR = 1.76; 95% CI = 1.05-2.94), and lower mortality (multivariate hazard ratio = 0.69; 95% CI = 0.50-0.95) among breast cancer patients. Conclusions. Current evidence suggests that flax may be associated with decreased risk of breast cancer. Flax demonstrates antiproliferative effects in breast tissue of women at risk of breast cancer and may protect against primary breast cancer. Mortality risk may also be reduced among those living with breast cancer. © The Author(s) 2013.
Phytoestrogens have been linked to a risk of breast cancer. The main phytoestrogens in the Finnish diet are lignans, and enterolactone is quantitatively the most important circulating lignan. The purpose of this study was to examine the association between serum enterolactone and risk of breast cancer in Finnish women. The subjects were participants of the Kuopio Breast Cancer Study: This analysis concerns 194 breast cancer cases (68 premenopausal and 126 postmenopausal) who entered the study before diagnosis and 208 community-based controls. They completed a validated food frequency questionnaire referring to the previous 12 months and gave serum samples before the examinations. The measurement of serum enterolactone was performed by time-resolved fluoroimmunoassay. The statistical analyses were done by the logistic regression method. The mean serum enterolactone concentration was 20 nmol/l for the cases and 26 nmol/l for the controls (P 0.003). The mean serum enterolactone concentration in the lowest quintile was 3.0 nmol/l and 54.0 nmol/l in the highest. The odds ratio in the highest quintile of enterolactone values adjusted for all of the known risk factors for breast cancer was 0.38 (95% confidence interval,0.18-0.77; P for trend, 0.03). The inverse association between serum enterolactone and risk of breast cancer was seen both among premenopausal and postmenopausal women. High enterolactone level was associated with higher consumption of rye products and tea and higher intake of dietary fiber and vitamin E compared with those with low serum enterolactone values. Serum enterolactone level was significantly inversely associated with risk of breast cancer.
PURPOSE: To investigate the association between intake of flaxseed-the richest source of dietary lignans (a class of phytoestrogens)-and breast cancer risk. METHODS: A food frequency questionnaire was used to measure the consumption of flaxseed and flax bread by 2,999 women with breast cancer and 3,370 healthy control women who participated in the Ontario Women's Diet and Health Study (2002-2003). Logistic regression was used to investigate associations between consumption of flaxseed and flax bread and breast cancer risk. Confounding by established and suspected breast cancer risk factors, as well as dietary factors, was assessed. RESULTS: Flaxseed or flax bread was consumed at least weekly by 21 % of control women. None of the 19 variables assessed were identified as confounders of the associations between flaxseed or flax bread and breast cancer risk. Consumption of flaxseed was associated with a significant reduction in breast cancer risk (odds ratio (OR) = 0.82, 95 % confidence interval (CI) 0.69-0.97), as was consumption of flax bread (OR = 0.77, 95 % CI 0.67-0.89). CONCLUSIONS: This Canadian study is, to our knowledge, the first to report on the association between flaxseed alone and breast cancer risk and has found that flaxseed intake is associated with a reduction in breast cancer risk. As dietary intake of flaxseed is modifiable, this finding may be of public health importance with respect to breast cancer prevention.
PURPOSE: Phytoestrogens are plant-derived, non-steroidal phytochemicals with anticarcinogenic potential. The major structural classes are the isoflavones and lignans. The aim of this study was to compare the effect of the plant-derived lignans secoisolariciresinol and matairesinol with the human lignans enterodiol and enterolactone as well as with 17β estradiol and tamoxifen on cell proliferation of breast carcinoma cell lines. METHODS: The influence of the lignans, 17β estradiol and tamoxifen on cell proliferation was determined using the BrdU test in MCF 7 and BT 20 cell lines. RESULTS: Enterodiol and enterolactone induced a stronger inhibition of cell growth in MCF 7 and BT 20 cells than secoisolariciresinol and matairesinol. The inhibition effects were less expressed in the BT 20 than in the MCF 7 cells. CONCLUSIONS: The human lignans enterodiol and enterolactone are more biologically active than their precursors secoisolariciresinol and matairesinol, and may be defined as the real drugs in cancer prevention.
BACKGROUND: Laboratory research and a growing number of epidemiologic studies have provided evidence for a reduced risk of breast cancer associated with dietary intake of certain classes of flavonoids. However, the effects of flavonoids on survival are not known. In a population-based cohort of breast cancer patients, we investigated whether dietary flavonoid intake before diagnosis is associated with subsequent survival. METHODS: Women ages 25 to 98 years who were newly diagnosed with a first primary invasive breast cancer between August 1, 1996, and July 31, 1997, and participated in a population-based, case-control study (n=1,210) were followed for vital status through December 31, 2002. At the case-control interview conducted shortly after diagnosis, respondents completed a FFQ that assessed dietary intake in the previous 12 months. All-cause mortality (n=173 deaths) and breast cancer-specific mortality (n=113 deaths) were determined through the National Death Index. RESULTS: Reduced hazard ratios [age- and energy-adjusted hazard ratio (95% confidence interval)] for all-cause mortality were observed among premenopausal and postmenopausal women for the highest quintile of intake, compared with the lowest, for flavones [0.63 (0.41-0.96)], isoflavones [0.52 (0.33-0.82)], and anthocyanidins [0.64 (0.42-0.98)]. No significant trends in risk were observed. Results were similar for breast cancer-specific mortality only. CONCLUSION: Mortality may be reduced in association with high levels of dietary flavones and isoflavones among postmenopausal U.S. breast cancer patients. Larger studies are needed to confirm our findings.
The content of low density lipoprotein (LDL) receptors in tissue from primary breast cancers was determined and its prognostic information compared with that of variables of established prognostic importance. Frozen tumour specimens were selected, and tissue from 72 patients (32 of whom had died) were studied. The LDL receptor content showed an inverse correlation with the survival time. Analysis by a multivariate statistical method showed that the presence of axillary metastasis, content of receptors for oestrogen and LDL, diameter of the tumour, and DNA pattern were all of prognostic value with regard to patient survival. Improved methods of predicting survival time in patients with breast cancer may be of value in the choice of treatment for individual patients.
AIM: Soy foods are the major source of isoflavones, which are believed to play important roles in genesis of breast cancer and its progression. We here conducted a prospective study to evaluate the association of soy isoflavone food consumption with breast cancer prognosis. METHODS: A prospective study was performed from January 2004 and January 2006 in China. Trained interviewers conducted face-to-face interviews using a structured questionnaire to collect information on dietary habits and potential confounding factors. The relative risk [hazard ratio (HR)] and 95% CI were calculated from the Cox regression model for all significant predictors from cancer diagnosis to the endpoint of the study (event). RESULTS: After a median follow up of 52.1 months (range, 9-60 months), a total of 79 breast cancer related deaths were recorded in our study, risk being inversely associated with a high intake of soy isoflavone. With an average intake of soy isoflavone above 17.3 mg/day, the mortality of breast cancer can be reduced by about 38-36%. We also found the decreased breast cancer death with high soy protein intake, with a HR (95% CI) of 0.71 (0.52-0.98). Stratified analysis with reference to the ER status, further demonstrated a better prognosis of ER positive breast cancer with a high intake of soy isoflavone (HR 0.59, 0.40-0.93). CONCLUSION: Our study shows the soy food intake is associated with longer survival and low recurrence among breast cancer patients. A cohort study with a larger sample size and long term follow-up is now needed.
AIM: Isoflavones in soy foods are part of a larger class of flayonoid compounds that have have been demonstrated to be potent dietary anti-cancer agents, and the effect of soy intake on the survival of ovarian cancer is conflicting. Therefore, we aimed to explore the whether soy intake is related to the risk of death of breast cancer. METHODS: A prospective study was conducted. A total of 256 patients included in this study had breast cancer and were recruited between January 2004 and January 2006. All of them were followed up from since January 2011. A univariate Cox's regression analysis was used to assess the association between soy intake and survival. RESULTS: The education level, menopausal status, ER/PR status and TNM stage were significant difference in the survival of breast cancer. The highest soy isoflavone was associated with a decreased death risk of breast cancer (OR=0.25, 95% CI=0.09-0.54). Moreover, the higher consumption of soy protein also presented a trend decreased breast cancer risk, and the highest consumption significantly reduced the cancer risk compared with the lowest consumption (OR=0.38, 95% CI=0.17-0.86). CONCLUSION: The present study suggests soy intake is associated with a significant reduced death risk of breast cancer in Chinese population. Further large sample studies are warranted to confirm the inverse association of soy consumption and breast cancer survival by menopausal status.
Lignans are a class of secondary plant metabolites produced by oxidative dimerization of two phenylpropanoid units. Although their molecular backbone consists only of two phenylpropane (C6-C3) units, lignans show an enormous structural diversity. There is a growing interest in lignans and their synthetic derivatives due to applications in cancer chemotherapy and various other pharmacological effects. This review deals with lignans possessing anticancer, antioxidant, antimicrobial, anti-inflammatory and immunosuppressive activities, and comprises the data reported in more than 100 peer-reviewed articles, so as to highlight the recently reported bioactive lignans that could be a first step towards the development of potential new therapeutic agents.
The protective effect of vegetables on the risk of breast cancer recurrence is uncertain. We sought to evaluate the association between breast cancer recurrence and vegetable intake including analyses stratified on tamoxifen use. Experimental evidence of anti-carcinogenic activity of phytochemicals in cruciferous vegetables in combination with tamoxifen led to specific evaluation of this class of vegetables as well. To assess the association between vegetable intake and breast cancer recurrence, vegetable intake from repeat 24-h dietary recalls were examined as a secondary analysis of 3,080 breast cancer survivors enrolled in the Women's Healthy Eating and Living (WHEL) Study. At the time of enrollment women were, on average, 23.5 months post-diagnosis. The hazard of recurrence, controlling for relevant and significant clinical and demographic variables, with vegetable intake was assessed overall and separately for women taking tamoxifen. WHEL participants reported mean baseline intakes (⁻x, SE) of 3.1 ± 0.05 and 0.5 ± 0.02 servings/day of total and cruciferous vegetables, respectively. Baseline vegetable intake in the highest as compared to lowest tertiles was associated with an overall lower adjusted hazard ratios (HR) for recurrence of 0.69, 95% CI 0.55-0.87. Among women taking tamoxifen, the HRs were 0.56, 95% CI 0.41-0.77 for total vegetables and 0.65, 95% CI 0.47-0.89 for cruciferous vegetable intake. The hazard in women using tamoxifen who reported cruciferous vegetable intake above the median and who were within the highest tertile of total vegetable intake was HR 0.48; 95% CI 0.32-0.70. This secondary analysis in over 3,000 breast cancer survivors suggests that baseline vegetable intake may be associated with a reduction in the risk of breast cancer recurrent or new events particularly for those using tamoxifen. Such associations should be explored further as the possibility that vegetable intake is simply a surrogate for other health-promoting behaviors cannot be ruled out.
To investigate effects of dietary mushrooms and joint effects of mushrooms and green tea on breast cancer, a case-control study was conducted in southeast China in 2004-2005. The incident cases were 1,009 female patients aged 20-87 years with histologically confirmed breast cancer. The 1,009 age-matched controls were healthy women randomly recruited from outpatient breast clinics. Information on frequency and quantity of dietary intake of mushrooms and tea consumption, usual diet, and lifestyle were collected by face-to-face interview using a validated and reliable questionnaire. Compared with nonconsumers, the Odds ratios (Ors) were 0.36 (95% CI = 0.25-0.51) and 0.53 (0.38-0.73) for daily intake of >or=10 g fresh mushrooms and >or=4 g dried mushrooms, based on multivariate logistic regression analysis adjusting for established and potential confounders. There were dose-response relationships with significant tests for trend (p < 0.001). The inverse association was found in both pre- and postmenopausal women. Compared with those who consumed neither mushrooms nor green tea, the ORs were 0.11 (0.06-0.20) and 0.18 (0.11-0.29) for daily high intake of fresh and dried mushrooms combined with consuming beverages made from >or=1.05 g dried green tea leaves per day. The corresponding linear trends were statistically significant for joint effect (p < 0.001). We conclude that higher dietary intake of mushrooms decreased breast cancer risk in pre- and postmenopausal Chinese women and an additional decreased risk of breast cancer from joint effect of mushrooms and green tea was observed. More research is warranted to examine the effects of dietary mushrooms and mechanism of joint effects of phytochemicals on breast cancer.
BACKGROUND: Mammalian lignans, enterolactone (EL) and enterodiol (ED), have been shown to inhibit breast and colon carcinoma. To date, there have been no reports of the effect of lignans on prostatic carcinoma. We investigated the effects of ED and EL on three human prostate cancer cell lines (PC-3, DU-145 and LNCaP). MATERIALS AND METHODS: Cells were treated with either 0.1% (v/v) DMSO (vehicle) or 10-100 microM of EL, ED or genistein (positive control) for 72 hours. Cell viability was measured by the propidium iodide nuclei staining fluorometric assay with each assay performed in triplicate. RESULTS: At 10-100 microM, EL significantly inhibited the growth of all cell lines, whereas ED only inhibited PC-3 and LNCaP cells. While EL was a more potent growth inhibitor than ED, both were less potent than genistein. The dose for 50% growth inhibition of LNCaP cells (IC50) by EL was 57 microM, whereas IC50 was 100 microM for ED, (the observed IC50 for genistein was 25 microM). CONCLUSION: ED and EL suppress the growth of prostate cancer cells, and may do so via hormonally-dependent and independent mechanisms.
Background: Soy isoflavones have antiestrogenic and anticancer properties but also possess estrogen-like properties, which has raised concern about soy food consumption among breast cancer survivors. Objective: We prospectively evaluated the association between postdiagnosis soy food consumption and breast cancer outcomes among US and Chinese women by using data from the After Breast Cancer Pooling Project. Design: The analysis included 9514 breast cancer survivors with a diagnosis of invasive breast cancer between 1991 and 2006 from 2 US cohorts and 1 Chinese cohort. Soy isoflavone intake (mg/d) was measured with validated food-frequency questionnaires. HRs and 95% CIs were estimated by using delayed-entry Cox regression models, adjusted for sociodemographic, clinical, and lifestyle factors. Results: After a mean follow-up of 7.4 y, we identified 1171 total deaths (881 from breast cancer) and 1348 recurrences. Despite large differences in soy isoflavone intake by country, isoflavone consumption was inversely associated with recurrence among both US and Chinese women, regardless of whether data were analyzed separately by country or combined. No heterogeneity was observed. In the pooled analysis, consumption of ≥10 mg isoflavones/d was associated with a nonsignificant reduced risk of all-cause (HR: 0.87; 95% CI: 0.70, 1.10) and breast cancer–specific (HR: 0.83; 95% CI: 0.64, 1.07) mortality and a statistically significant reduced risk of recurrence (HR: 0.75; 95% CI: 0.61, 0.92). Conclusion: In this large study of combined data on US and Chinese women, postdiagnosis soy food consumption of ≥10 mg isoflavones/d was associated with a nonsignificant reduced risk of breast cancer–specific mortality and a statistically significant reduced risk of recurrence. One of the studies included in the After Breast Cancer Pooling Project, the Women's Healthy Eating & Living Study, was registered at clinicaltrials.gov as NCT00003787.
CONTEXT: Restricting caloric intake is one of the most effective ways to extend lifespan and to reduce spontaneous tumor occurrence in experimental animals, but whether similar associations hold in humans has not been appropriately studied. OBJECTIVE: To determine whether caloric restriction in early life reduces the risk of invasive breast cancer. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study using data from the Swedish Inpatient Registry, the Swedish Cancer Registry, the Swedish Death Registry, and the Swedish Fertility Registry. Participants were 7303 Swedish women hospitalized for anorexia nervosa prior to age 40 years between 1965 and 1998. Women were excluded (n = 31) if they were diagnosed with cancer prior to their first discharge from hospitalization for anorexia nervosa. MAIN OUTCOME MEASURE: Incidence of invasive breast cancer. RESULTS: Compared with the Swedish general population, women hospitalized for anorexia nervosa prior to age 40 years had a 53% (95% confidence interval [CI], 3%-81%) lower incidence of breast cancer; nulliparous women with anorexia nervosa had a 23% (95% CI, 79% higher to 75% lower) lower incidence, and parous women with anorexia nervosa had a 76% (95% CI, 13%-97%) lower incidence. CONCLUSIONS: Severe caloric restriction in humans may confer protection from invasive breast cancer. Low caloric intake prior to first birth followed by a subsequent pregnancy appears to be associated with an even more pronounced reduction in risk.
Purpose Soy isoflavones, structurally similar to endogenous estrogens, may affect breast cancer through both hormonally-mediated and non-hormonally related mechanisms. Although the effects of soy are not well understood, some breast cancer survivors increase their soy intake post-diagnosis in attempt to improve their prognosis. Therefore, we examined the role of soy isoflavone intake and the risk of breast cancer recurrence by hormone receptor status, menopausal status, and tamoxifen therapy. Materials and methods A cohort of 1954 female breast cancer survivors, diagnosed during 1997–2000, was prospective followed for 6.31 years and 282 breast cancer recurrences were ascertained. Isoflavone intake was assessed by mailing modified Block and supplemental soy food frequency questionnaires to participants, on average 23 months post-diagnosis. Risk of breast cancer recurrence, measured by hazard ratios (HR) and 95% confidence intervals (CI), was estimated using multivariable delayed-entry Cox proportional hazards models. Results Suggestive trends for a reduced risk of cancer recurrence were observed with increasing quintiles of daidzein and glycetin intake compared to no intake among postmenopausal women (P for trend: P = .08 for daidzein, P = .06 for glycetin) and among tamoxifen users (P = .10 for daidzein, P = .05 for glycetin). Among postmenopausal women treated with tamoxifen, there was an approximately 60% reduction in breast cancer recurrence comparing the highest to the lowest daidzein intakes (>1453 micrograms (µg)/day versus < 7.7 µg/day) (HR, 0.48; 95% CI, 0.21–0.79, P = .008). Conclusion Soy isoflavones consumed at levels comparable to those in Asian populations may reduce the risk of cancer recurrence in women receiving tamoxifen therapy and moreover, appears not to interfere with tamoxifen efficacy. Further confirmation is required in other large prospective studies before recommendations regarding soy intake can be issued to breast cancer survivors.
Rye bran contains a high content not only of dietary fibre, but also of plant lignans and other bioactive compounds in the so-called dietary fibre complex. Blood concentrations of lignans such as enterolactone have been used as biomarkers of intake of lignan-rich plant food. At present,evidence from studies in human subjects does not warrant the conclusion that rye, whole grains orphyto-oestrogens protect against cancer. Some studies, however, have pointed in that direction,especially in relation to cancers of the upper digestive tract. A number of prospective epidemiological studies have clearly shown a protective effect of wholegrain cereals against myocardial infarctions. A corresponding protective effect against diabetes and ischaemic stroke(brain infarct) has also been demonstrated. It seems reasonable to assume that these protective effects are associated with one or more factors in the dietary fibre complex.
Breast cancer is the leading cause of cancer-related deaths in women in the United States and many other countries. There is an immediate need for more effective and less toxic therapeutic and preventive strategies for many cancers, especially for breast cancer. Natural products are being tested with a hope of identifying novel potent molecules as anticancer agents. Phytochemicals and dietary compounds have been used for the treatment of various illnesses throughout history due to their safety, low toxicity, and general availability. Currently, many active phytochemicals are in clinical trials. Preclinical and clinical studies have indicated that daily consumption of dietary phytochemicals reduces the risk of several cancers. Phytochemicals can inhibit, delay, or reverse carcinogenesis by inducing detoxifying and antioxidant enzymes, by regulating inflammatory/proliferative signaling pathways, and by inducing apoptosis. This review article describes some of the potential natural cancer preventive compounds, along with a mechanistic discussion of their interactions with key cellular signal transduction pathways as well as their contribution to the suppression of breast cancer cell growth.
The present study investigated the effects of a diet and exercise intervention on known breast cancer (BCa) risk factors, including estrogen, obesity, insulin, and insulin-like growth factor-I (IGF-I), in overweight/obese, postmenopausal women. In addition, using the subjects' pre- and postintervention serum in vitro, serum-stimulated growth and apoptosis of three estrogen receptor-positive BCa cell lines were studied. The women where placed on a low-fat (10-15% kcal), high-fiber (30-40 g per 1,000 kcal/day) diet and attended daily exercise classes for 2 wk. Serum estradiol was reduced in the women on hormone treatment (HT; n = 28) as well as those not on HT (n = 10). Serum insulin and IGF-I were significantly reduced in all women, whereas IGF binding protein-1 was increased significantly. In vitro growth of the BCa cell lines was reduced by 6.6% for the MCF-7 cells, 9.9% for the ZR-75-1 cells, and 18.5% for the T-47D cells. Apoptosis was increased by 20% in the ZR-75-1 cells, 23% in the MCF-7 cells, and 30% in the T-47D cells (n = 12). These results show that a very-low-fat, high-fiber diet combined with daily exercise results in major reductions in risk factors for BCa while subjects remained overweight/obese. These in vivo serum changes slowed the growth and induced apoptosis in serum-stimulated BCa cell lines in vitro.
Recent studies of shift-working women have reported that excessive exposure to light at night (LAN) may be a risk factor for breast cancer. However, no studies have yet attempted to examine the co-distribution of LAN and breast cancer incidence on a population level with the goal to assess the coherence of these earlier findings with population trends. Coherence is one of Hill's "criteria" (actually, viewpoints) for an inference of causality. Nighttime satellite images were used to estimate LAN levels in 147 communities in Israel. Multiple regression analysis was performed to investigate the association between LAN and breast cancer incidence rates and, as a test of the specificity of our method, lung cancer incidence rates in women across localities under the prediction of a link with breast cancer but not lung cancer. After adjusting for several variables available on a population level, such as ethnic makeup, birth rate, population density, and local income level, a strong positive association between LAN intensity and breast cancer rate was revealed (p<0.05), and this association strengthened (p<0.01) when only statistically significant factors were filtered out by stepwise regression analysis. Concurrently, no association was found between LAN intensity and lung cancer rate. These results provide coherence of the previously reported case-control and cohort studies with the co-distribution of LAN and breast cancer on a population basis. The analysis yielded an estimated 73% higher breast cancer incidence in the highest LAN exposed communities compared to the lowest LAN exposed communities.
The mammalian lignans enterolactone and enterodiol, which are produced by the microflora in the colon of humans and animals from precursors in foods, have been suggested to have potential anticancer effects. This study determined the production of mammalian lignans from precursors in food bars containing 25 g unground whole flaxseed (FB), sesame seed (SB), or their combination (FSB; 12.5 g each). In a randomized crossover study, healthy postmenopausal women supplemented their diets with the bars for 4 wk each separated by 4-wk washout periods, and urinary mammalian lignan excretion was measured at baseline and after 4 wk as a marker of mammalian lignan production. Results showed an increase with all treatments (65.1-81.0 mumol/day; P < 0.0001), which did not differ among treatments. Lignan excretion with the whole flaxseed was similar to results of other studies using ground flaxseed. An unidentified lignan metabolite was detected after consumption of SB and FSB but not of FB. Thus, we demonstrated for the first time that 1) precursors from unground whole flaxseed and sesame seed are converted by the bacterial flora in the colon to mammalian lignans and 2) sesame seed, alone and in combination with flaxseed, produces mammalian lignans equivalent to those obtained from flaxseed alone.
Gim (Porphyra sp.) and miyeok (Undaria pinnatifida) are the seaweeds most consumed by Koreans. We investigated the association between the intake of gim and miyeok and the risk of breast cancer in a case-control study. Cases were 362 women aged 30-65 years old, who were histologically confirmed to have breast cancer. Controls visiting the same hospital were matched to cases according to their age (sd 2 years) and menopausal status. Food intake was estimated by the quantitative FFQ with 121 items, including gim and miyeok. Conditional logistic regression analysis was used to obtain the OR and corresponding 95 % CI. The average intake and consumption frequency of gim in cases were lower than in controls. The daily intake of gim was inversely associated with the risk of breast cancer (5th v. 1st quintile, OR, 0.48; 95 % CI, 0.27, 0.86; P for trend, 0.026) after adjustment for potential confounders. After stratification analysis was performed according to menopausal status, premenopausal women (5th v. 1st quintile, OR, 0.44; 95 % CI, 0.24, 0.80; P for trend, 0.007) and postmenopausal women (5th v. 1st quintile, OR, 0.32; 95 % CI, 0.13, 0.80; P for trend, 0.06) showed similar inverse associations between gim intake and the risk of breast cancer after an adjustment for potential confounders except dietary factors. Miyeok consumption did not have any significant associations with breast cancer. These results suggest that high intake of gim may decrease the risk of breast cancer.
The diagnosis of cancer can motivate survivors to alter their lifestyle habits. Healthcare providers need to be aware of what changes patients are likely to make in order to derive more pertinent recommendations; however, few studies have reported pre- and post-diagnostic lifestyle behaviours. Semi-quantitative food frequency questionnaires (FFQs) completed approximately 1 year after diagnosis were used to evaluate dietary intake and supplement use before and after diagnosis in a cohort of 1,560 breast cancer patients participating in the UK, prospective DietCompLyf study. Intake of fruit and vegetables, wholegrains and lean sources of protein increased significantly post-diagnosis (P < 0.05, each). Conversely, after diagnosis consumption of high-fat, high-sugar products, red meat, coffee, some alcoholic drinks and refined grains significantly decreased (P < 0.05, each). Post-diagnostic changes in diet were accompanied by changes in the intake of macronutrients and a number of vitamins and minerals. Supplement use was highly prevalent (56.1%) pre-diagnosis, increasing to 62.8% after diagnosis (P = 0.001). Fish oils, multivitamin and minerals, and evening primrose oil were most often used and the proportion of users significantly increased (P < 0.05, each) after diagnosis. The percentage of women using oestrogenic botanical supplements (OBSs) was small but more than doubled to 8.4% after diagnosis (P < 0.05). British women participating in the DietCompLyf study reported significant changes in dietary intake and supplement use after their breast cancer diagnosis. These findings contribute to our understanding of female cancer survivors' dietary behaviours which is crucial for developing and implementing recommendations.
Background In 2007 the World Cancer Research Fund (WCRF) and American Institute for Cancer Research (AICR) released eight recommendations related to body fatness, physical activity and diet aimed at preventing the most common cancers worldwide. However, limited information exists on the association between meeting these recommendations and risks of specific cancers, including breast cancer. Methods We operationalized six recommendations (related to body fatness, physical activity, foods that promote weight gain, plant foods, red and processed meats, and alcohol) and examined their association with invasive breast cancer incidence over 6.7 years of follow-up in the VITamins And Lifestyle (VITAL) study cohort. Participants included 30,797 post-menopausal women ages 50–76 years at baseline in 2000–2002 with no history of breast cancer. Breast cancers (n=899) were tracked through the Western Washington Surveillance, Epidemiology and End Results (SEER) database. Results Breast cancer risk was reduced by 60% in women who met at least five recommendations compared to those who met none (HR: 0.40; 95% CI: 0.25–0.65; Ptrend<0.001). Further analyses that sequentially removed individual recommendations least associated with reduced risk suggested that this reduction is due to meeting recommendations related to body fatness, plant foods and alcohol (HR for meeting vs. not meeting these three recommendations: 0.38; 95% CI: 0.25–0.58; Ptrend <0.001). Conclusions Meeting the WCRF/AICR cancer prevention recommendations, specifically those related to alcohol, body fatness and plant foods, is associated with reduced post-menopausal breast cancer incidence. Impact Increased adherence to the WCRF/AICR cancer prevention recommendations could substantially reduce post-menopausal breast cancer risk in US women.
Phytoestrogens are structurally similar to estrogens and may affect breast cancer risk by mimicking estrogenic/antiestrogenic properties. In Western societies, whole grains and possibly soy foods are rich sources of phytoestrogens. A population-based case-control study in German postmenopausal women was used to evaluate the association of phytoestrogen-rich foods and dietary lignans with breast cancer risk. Dietary data were collected from 2,884 cases and 5,509 controls using a validated food-frequency questionnaire, which included additional questions phytoestrogen-rich foods. Associations were assessed using conditional logistic regression. All analyses were adjusted for relevant risk and confounding factors. Polytomous logistic regression analysis was performed to evaluate the associations by estrogen receptor (ER) status. High and low consumption of soybeans as well as of sunflower and pumpkin seeds were associated with significantly reduced breast cancer risk compared to no consumption (OR = 0.83, 95% CI = 0.70-0.97; and OR = 0.66, 95% CI = 0.77-0.97, respectively). The observed associations were not differential by ER status. No statistically significant associations were found for dietary intake of plant lignans, fiber, or the calculated enterolignans. Our results provide evidence for a reduced postmenopausal breast cancer risk associated with increased consumption of sunflower and pumpkin seeds and soybeans.