Post-diagnosis soy food intake and breast cancer survival: a meta-analysis of cohort studies

Perspective: Isoflavones-Intriguing Molecules but Much Remains to Be Learned about These Soybean Constituents

Isoflavones are naturally occurring compounds found in a wide range of plants, but among commonly consumed foods are especially abundant in soybeans and foods derived from this legume. Much of the substantial amount of research conducted on soy protein and soy foods over the past 30 y is because of their isoflavone content. Research interest in isoflavones increased dramatically beginning in the early 1990s as evidence highlighted their possible role in the prevention of a wide range of cancers, including breast, prostate, and colon cancer. Recognition that isoflavones preferentially bind to estrogen receptor (ER)β in comparison with ERα provided a conceptual basis for classifying these diphenolic molecules as selective ER modulators (SERMs). Isoflavone research soon greatly expanded beyond cancer to include areas such as coronary artery disease, bone health, cognitive function, and vasomotor symptoms of menopause. Nevertheless, safety concerns about isoflavones, based primarily on the results of rodent studies and presumed estrogenic effects, also arose. However, recent work challenges the traditional view of the estrogenicity of isoflavones. Furthermore, safety concerns have largely been refuted by intervention and population studies. On the other hand, investigation of the proposed benefits of isoflavones has produced inconsistent data. The small sample size and short duration common to many intervention trials, combined with marked interindividual differences in isoflavone metabolism, likely contribute to the conflicting findings. Also, many different intervention products have been employed, which vary not only in the total amount, but also in the relative proportion of the 3 soybean isoflavones, and the form in which they are delivered (glycoside compared with aglycone). For those interested in exploring the proposed benefits of isoflavones, studies justify an intake recommendation of ∼50 mg/d, an amount provided by ∼2 servings of traditional Asian soy foods.

Exploring the Complex Mechanisms of Isoflavones: From Cell Bioavailability, to Cell Dynamics and Breast Cancer

In Western countries, the increase in the consumption of soy-derived products raises the population's exposure to isoflavones. These molecules, present in many foods, have numerous effects on the body's cells, including regulation of the transcription and epigenetics, cell signaling, cell cycle, cell growth, apoptosis, and oxidative stress. However, despite the multitude of studies conducted, on these compounds, it remains difficult to draw definitive conclusions regarding their safety or dangerousness in the diet. Indeed, some epidemiological studies highlight health benefits in consuming isoflavone-rich foods, notably by reducing the risk of certain cancers. However, several studies conducted on cell models show that these molecules can have negative effects on cell fate, particularly with regard to proliferation and survival of mammary tumor cells. Isoflavones are mainly genistein, daidzein, formononetin, and biochanin A. These molecules belong to the family of phytoestrogens, which are capable of interacting with both nuclear estrogen receptor, ERα and ERβ, to trigger agonistic and antagonistic effects. Due to their estrogenic properties, isoflavones are suspected to promote hormone-dependent cancers such as breast cancer. This suspicion is based primarily on their ability to bind to ERα in breast cells, thereby altering the signaling pathways that control cell growth. However, study results are sometimes contradictory. Some studies suggest that isoflavones may protect against breast cancer by acting as selective estrogen receptor modulators, while others highlight their potential role in stimulating tumor growth. This review explores the literature on the effects of isoflavones, focusing on their influence on ERα-dependent signaling in breast tumor cells.

Harnessing tumor metabolism during cancer treatment: A narrative review of emerging dietary approaches

Cancer is currently one of the biggest public health challenges worldwide, ranking as the second leading cause of death globally. To date, strong epidemiological associations have been demonstrated between unhealthy lifestyles and eating habits, i.e. obesity, and an increased risk of developing cancer. However, there is limited evidence regarding the impact of specific dietary regimes on cancer outcomes during conventional cancer treatments. This paper systematically reviews and evaluates preclinical and clinical evidence regarding the effects of fasting, fast-mimicking diet, ketogenic diet, vegan diet, alkaline diet, paleolithic diet, the Gerson regimen, and macrobiotic diet in the context of cancer treatments. Clinical trials on dietary regimes as complementary cancer therapy are limited by significant differences in trial design, patient characteristics, and cancer type, making it difficult to draw conclusions. In the future, more uniformly controlled clinical trials should help to better define the role of diets in cancer management.

Role of a Whole Plant Foods Diet in Breast Cancer Prevention and Survival

Breast cancer (BC) is one of the leading causes of death and morbidity among women worldwide. Epidemiologic evidence shows that the risk of BC and other chronic diseases decreases as the proportion of whole plant foods increases, while the proportion of animal foods (fish, meat, poultry, eggs, seafood, and dairy products) and non-whole plant foods (e.g., refined grains, added sugars, French fries) in the diet decreases. Whole plant foods include fruits, vegetables, roots, tubers, whole grains, legumes, nuts, and seeds from which no edible part has been removed and to which no non-whole food been added. A whole plant foods diet lowers insulin resistance, inflammation, excess body fat, cholesterol, and insulin-like growth factor 1 and sex hormone bioavailability; it also increases estrogen excretion, induces favorable changes in the gut microbiota, and may also favorably affect mammary microbiota composition and decrease the risk of early menarche, all contributing to reduced BC incidence, recurrence, and mortality. This review explores the connection between a whole plant foods diet and BC risk and mortality as well as the potential mechanisms involved. Additionally, this diet is compared with other dietary approaches recommended for BC. A whole plant foods diet seems the optimal dietary pattern for BC and overall disease prevention as it exclusively consists of whole plant foods which, based on existing evidence, lead to the best health outcomes.

Genistein and daidzein induce ferroptosis in MDA-MB-231 cells

OBJECTIVES

In recent years, there has been a growing interest in targeting ferroptosis for the treatment and prevention of multiple cancers. This study aimed to assess the contribution of ferroptosis to the antiproliferative effects of genistein (GN) and daidzein (DZ) in breast cancer cell lines.

METHODS

MDA-MB-231 and MCF-7 cells were employed as an in vitro model. The antiproliferative effects of GN and DZ were determined by WST-1 assay in the presence of specific inhibitors of different cell death pathways. The mRNA expressions of Gpx4 and Fsp-1, the levels of lipid peroxidation, glutathione (GSH)/glutathione disulfide (GSSG) ratio, and intracellular iron ion content were assessed in GN- or DZ-treated cells.

RESULTS

GN and DZ were found to cause ferroptotic cell death in MDA-MB-231, as confirmed by the reversal of viability when cells were pretreated with ferrostatin-1. Furthermore, both phytochemicals induced biochemical markers of ferroptosis, including lipid peroxidation and iron ions levels, and decreased GSH/GSSG levels. The mRNA expression levels of the main anti-ferroptotic genes, Gpx4 and Fsp-1, were diminished by the treatment of both phytochemicals. Surprisingly, ferroptosis did not play a role in GN- or DZ-induced cell death in MCF-7 cells.

CONCLUSION

Our findings highlight the potential of GN and DZ as ferroptosis inducers in triple-negative breast cancer cells.

Breast cancer risk and prevention in 2024: An overview from the Breast Cancer UK - Breast Cancer Prevention Conference

The Breast Cancer UK-Breast Cancer Prevention Conference addressed risk from environmental pollutants and health behaviour-related breast-cancer risk. Epidemiological studies examining individual chemicals and breast cancer risk have produced inconclusive results including endocrine disrupting chemicals (EDCs) Bisphenol A, per- and polyfluorinated alkyl substances as well as aluminium. However, laboratory studies have shown that multiple EDCs, can work together to exhibit effects, even when combined at levels that alone are ineffective. The TEXB-α/β assay measures total estrogenic load, and studies have provided evidence of a link between multiple-chemical exposures and breast cancer. However, prospective studies using TEXB-α/β are needed to establish a causative link. There is also a need to assess real-life exposure to environmental-chemical mixtures during pregnancy, and their potential involvement in programming adverse foetal health outcomes in later life. Higher rates of breast cancer have occurred alongside increases in potentially-modifiable risk factors such as obesity. Increasing body-mass index is associated with increased risk of developing postmenopausal breast cancer, but with decreased risk of premenopausal breast cancer. In contrast, lower rates of breast cancer in Asian compared to Western populations have been linked to soya/isoflavone consumption. Risk is decreased by breastfeeding, which is in addition to the decrease in risk observed for each birth and a young first-birth. Risk is lower in those with higher levels of self-reported physical activity. Current evidence suggests breast-cancer survivors should also avoid weight gain, be physically active, and eat a healthy diet for overall health. A broad scientific perspective on breast cancer risk requires focus on both environmental exposure to chemicals and health behaviour-related risk. Research into chemical exposure needs to focus on chemical mixtures and prospective epidemiological studies in order to test the effects on breast cancer risk. Behaviour-related research needs to focus on implementation as well as deeper understanding of the mechanisms of cancer prevention.

The Effect of Diet on Breast Cancer Recurrence: The DIANA-5 Randomized Trial

PURPOSE

The DIANA-5 randomized controlled trial assessed the effectiveness of a diet based on Mediterranean and macrobiotic traditions (macro-Mediterranean diet) in reducing breast cancer recurrence.

PATIENTS AND METHODS

The DIANA-5 study involved 1,542 patients with breast cancer at high risk of recurrence because of estrogen receptor-negative cancer, or metabolic syndrome, or high plasma levels of insulin or testosterone. Women were randomly assigned to an active dietary intervention (IG) or a control group (CG). Both groups received the 2007 American Institute for Cancer Research/World Cancer Research Fund recommendations for cancer prevention. The intervention consisted of meetings with kitchen classes, community meals, and dietary recommendations. Recommended foods included whole grain cereals, legumes, soy products, vegetables, fruit, nuts, olive oil, and fish. Foods to be avoided were refined products, potatoes, sugar and desserts, red and processed meat, dairy products, and alcoholic drinks. A compliance Dietary Index was defined by the difference between recommended and discouraged foods.

RESULTS

Over the 5 years of follow-up, 95 patients of the IG and 98 of the CG developed breast cancer recurrence [HR = 0.99; 95% confidence interval (CI): 0.69-1.40]. The analysis by compliance to the dietary recommendations (IG and CG together) showed that the women in the upper tertile of Dietary Index change had an HR of recurrence of 0.59 (95% CI: 0.36-0.92) compared with women in the lower tertile.

CONCLUSIONS

The DIANA-5 dietary intervention trial failed to show a reduction in breast cancer recurrence, although self-reported diet at year 1 in IG and CG combined showed a protective association with the higher Dietary Index change. See related commentary by McTiernan, p. 931.

Phytonutrients and outcomes following breast cancer: a systematic review and meta-analysis of observational studies

BACKGROUND

Phytonutrient intakes may improve outcomes following breast cancer, but the impact of postdiagnosis introduction vs established prediagnostic exposure as well as optimum doses has not been established. Evidence from observational studies for key exposures was evaluated, including dosage and intake time frames.

METHODS

MEDLINE, EMBASE, CINAHL, Cochrane Library, ClinicalTrials.gov, and the ISRCTN registry were searched for prospective and retrospective observational studies investigating the impact of soybean, lignans, cruciferous (cabbage-family) vegetables, green tea, or their phytonutrients on breast cancer survival outcomes. A random-effects model was used to calculate summary hazard ratios (HRs) and 95% confidence intervals (CIs). Nonlinear dose-response analyses were conducted using restricted cubic splines.

RESULTS

Thirty-two articles were included. Soy isoflavones were associated with a 26% reduced risk of recurrence (HR = 0.74, 95% CI = 0.60 to 0.92), particularly among postmenopausal (HR = 0.72, 95% CI = 0.55 to 0.94) and estrogen receptor-positive survivors (HR = 0.82, 95% CI = 0.70 to 0.97), with the greatest risk reduction at 60 mg/day. In mortality outcomes, the reduction was mostly at 20 to 40 mg/day. Soy protein and products were inversely associated with cancer-specific mortality for estrogen receptor-positive disease (HR = 0.75, 95% CI = 0.60 to 0.92). An inverse association was observed for serum or plasma enterolactone, measured prediagnosis and early postdiagnosis, with cancer-specific mortality (HR = 0.72, 95% CI = 0.58 to 0.90) and all-cause mortality (HR = 0.69, 95% CI = 0.57 to 0.83). No effects were observed for cruciferous vegetables. There was a 44% reduced risk of recurrence with prediagnostic green tea for stage I and II breast cancer (HR = 0.56, 95% CI = 0.38 to 0.83).

CONCLUSIONS

Soy, enterolactone, and green tea demonstrated significant risk reductions in outcomes following breast cancer. Evidence is needed regarding the impact of postdiagnostic introduction or substantial increase of these exposures.

Benefits of Soybean in the Era of Precision Medicine: A Review of Clinical Evidence

Soybean (Glycine max) is an important ingredient of cuisines worldwide. While there is a wealth of evidence that soybean could be a good source of macronutrients and phytochemicals with health-promoting effects, concerns regarding adverse effects have been raised. In this work, we reviewed the current clinical evidence focusing on the benefits and risks of soybean ingredients. In breast, prostate, colorectal, ovarian, and lung cancer, epidemiological studies showed an inverse association between soybean food intake and cancer risks. Soybean intake was inversely correlated with risks of type 2 diabetes mellitus (T2DM), and soy isoflavones ameliorated osteoporosis and hot flashes. Notably, soybean was one of the dietary protein sources that may reduce the risk of breast cancer and T2DM. However, soybean had adverse effects on certain types of drug treatment and caused allergies. In sum, this work provides useful considerations for planning clinical soybean research and selecting dietary protein sources for human health.

Top Ten Tips Palliative Care Clinicians Should Know About Integrative Palliative Care

Integrative medicine (IM) use is widespread among individuals living with serious illness. There is a natural alignment between the fields of IM and palliative care (PC) rooted in their shared core values. Integrative palliative care (IPC) is an emerging focus within the field of PC that aims to broaden the healing toolkit available to patients with serious illness by combining standard-of-care biomedical treatments with evidence-informed integrative and complementary medicine practices with the goal of enhancing quality of life at every stage of a person's health journey. This article is an evidence-based guide to incorporating IPC practices into the care of seriously ill individuals.

Role of the intestinal microbiota and diet in the onset and progression of colorectal and breast cancers and the interconnection between both types of tumours

Colorectal cancer (CRC) is among the leading causes of mortality in adults of both sexes worldwide, while breast cancer (BC) is among the leading causes of death in women. In addition to age, gender, and genetic predisposition, environmental and lifestyle factors exert a strong influence. Global diet, including alcohol consumption, is one of the most important modifiable factors affecting the risk of CRC and BC. Western dietary patterns promoting high intakes of xenobiotics from food processing and ethanol have been associated with increased cancer risk, whereas the Mediterranean diet, generally leading to a higher intake of polyphenols and fibre, has been associated with a protective effect. Gut dysbiosis is a common feature in CRC, where the usual microbiota is progressively replaced by opportunistic pathogens and the gut metabolome is altered. The relationship between microbiota and BC has been less studied. The estrobolome is the collection of genes from intestinal bacteria that can metabolize oestrogens. In a dysbiosis condition, microbial deconjugating enzymes can reactivate conjugated-deactivated oestrogens, increasing the risk of BC. In contrast, intestinal microorganisms can increase the biological activity and bioavailability of dietary phytochemicals through diverse microbial metabolic transformations, potentiating their anticancer activity. Members of the intestinal microbiota can increase the toxicity of xenobiotics through metabolic transformations. However, most of the microorganisms involved in diet-microbiota interactions remain poorly characterized. Here, we provide an overview of the associations between microbiota and diet in BC and CRC, considering the diverse types and heterogeneity of these cancers and their relationship between them and with gut microbiota.

Soy Protein Containing Isoflavones Improves Facial Signs of Photoaging and Skin Hydration in Postmenopausal Women: Results of a Prospective Randomized Double-Blind Controlled Trial

Preliminary findings from multiple studies indicate that dietary intake of soy-derived isoflavones exert beneficial effects on the skin including defense against oxidant damage, stimulation of collagen synthesis, and increased hydration. This study aims to investigate how oral supplementation of a soy protein isolate with added isoflavones (SPII) affects components of photoaging such as facial wrinkles and dyspigmentation, and skin biophysical measures such as skin hydration and sebum excretion in postmenopausal women. This 6-month prospective, randomized double-blind controlled study was conducted on 44 postmenopausal women with Fitzpatrick skin types I, II, and III who were randomized to receive either casein protein or SPII. A high-resolution facial photography system was used to measure wrinkle severity and pigmentation at 0, 8, 16, and 24 weeks. Skin biophysical measurements included skin hydration and sebum production. The average wrinkle severity was decreased in the SPII intervention group at week 16 and week 24 by 5.9% and 7.1%, respectively, compared to the baseline. Compared to the casein group, average wrinkle severity was significantly decreased at week 16 (p < 0.05) and week 24 (p < 0.0001). Facial pigment intensity was decreased by -2.5% (p < 0.05) at week 24, whereas there was no significant change in the casein group. Compared to baseline, skin hydration in the SPII group was significantly increased by 39% and 68% on the left and right cheeks (p < 0.05), respectively, at 24 weeks. There were no significant differences in sebum production. Dietary soy protein supplementation with isoflavones may improve skin photoaging, including wrinkles and dyspigmentation, and increase skin hydration in postmenopausal women with Fitzpatrick skin types I, II, and III.

Phytochemicals in Cancer Treatment and Cancer Prevention-Review on Epidemiological Data and Clinical Trials

Phytochemicals are a non-nutritive substances that are present in plants and contribute significantly to their flavor and color. These biologically active compounds are classified into five major groups, namely phenolics, carotenoids, organosulfur compounds, nitrogen-containing compounds, and alkaloids, and are known for their potential health benefits in the prevention of various diseases, including cancer. The purpose of this review article is to explore the potential therapeutic benefits of the dietary phytochemicals, such as flavonoids, phenolic acids, phytosterols, carotenoids, and stilbenes, in cancer treatment and prevention based on the epidemiological studies and clinical trials. Although the majority of epidemiological studies report a significant advantage of the heightened phytochemical consumption and increased serum levels of these compounds, linking increased exposure with a lower cancer risk across most cancer types, these effects could not be replicated in the most available clinical trials. In fact, many of these trials were withdrawn early due to a lack of evidence and/or risk of harm. Despite the strong anticancer effect of phytochemicals, as well as their proven efficacy in multiple epidemiological studies, there is still a great need for human studies and clinical trials, with great caution regarding the safety measures. This review article provides an overview of the epidemiological and clinical evidence supporting the potential chemopreventive and anticancer properties of phytochemicals, with a focus on the need for further research in this area.

Association of Fermented Products with Risk of Cancer Recurrence and Mortality among Breast Cancer Survivors: A Prospective Cohort Study

We hypothesized that the intake of fermented soy and dairy products, but not fermented vegetable products, was associated with reduced cancer recurrence and mortality in breast cancer survivors. Women (n = 606) who underwent dietary survey using a 24-h recall within 3 years of breast cancer surgery were recruited, and were followed up for a mean of 89 mo,. Cox proportional hazards regression analysis showed that the risk of cancer recurrence was inversely associated with the intake of fermented soy products (Hazard ratios (HRs):0.976, 95% confidence intervals (CI):0.95-0.99) and fermented dairy products (HRs:0.992, 95% CI:0.98-0.99). Furthermore, the risk of cancer recurrence was inversely associated with the intake of fermented soy products in hormone receptor-positive (HRs:0.296, 95% CI:0.11-0.79), estrogen receptor-positive (HRs:0.971, 95% CI:0.94-0.99), and progesterone receptor-positive (HRs:0.972, 95% CI:0.94-0.99) patients. Mortality was inversely associated with the intake of fermented soy products (HRs:0.967, 95% CI:0.93-0.99). Disease-free survival (P = 0.001) and overall survival (P = 0.004) were positively associated with intake of fermented soy products. Intake of fermented vegetable products had no significant effect on cancer recurrence or mortality. This study suggests that the intake of fermented soy and dairy could be beneficial in preventing cancer recurrence.

The health effects of soy: A reference guide for health professionals

Soy is a hotly debated and widely discussed topic in the field of nutrition. However, health practitioners may be ill-equipped to counsel clients and patients about the use of soyfoods because of the enormous, and often contradictory, amount of research that has been published over the past 30 years. As interest in plant-based diets increases, there will be increased pressure for practitioners to gain a working knowledge of this area. The purpose of this review is to provide concise literature summaries (400-500 words) along with a short perspective on the current state of knowledge of a wide range of topics related to soy, from the cholesterol-lowering effects of soy protein to the impact of isoflavones on breast cancer risk. In addition to the literature summaries, general background information on soyfoods, soy protein, and isoflavones is provided. This analysis can serve as a tool for health professionals to be used when discussing soyfoods with their clients and patients.

Nutritional Factors during and after Cancer: Impacts on Survival and Quality of Life

The French National Cancer Institute conducted a collective expertise study with researchers and clinical experts from the French Network for Nutrition And Cancer Research (NACRe Network). The objective was to update the state of knowledge on the impacts of nutritional factors on clinical endpoints during or after cancer. Data from 150 meta-analyses, pooled analyses or intervention trials and 93 cohort studies were examined; they concerned 8 nutritional factors, 6 clinical events and 20 cancer locations. This report shows that some nutritional factors have impacts on mortality and on the risks of recurrence or second primary cancer in cancer patients. Therefore, high-risk nutritional conditions can be encountered for certain cancer sites: from the diagnosis and throughout the health care pathways, weight loss (lung and esophageal cancers), malnutrition (lung, esophageal, colorectal, pancreatic, gastric and liver cancers), weight gain (colorectal, breast and kidney cancers) and alcohol consumption (upper aerodigestive cancers) should be monitored; and after cancer treatments, excess weight should be detected (colorectal, breast and kidney cancers). These situations require nutritional assessments, and even support or management by health care professionals, in the context of tertiary prevention. This report also highlights some limitations regarding the existing literature and some needs for future research.

Targeting Breast Cancer Stem Cells Using Naturally Occurring Phytoestrogens

Breast cancer therapies have made significant strides in improving survival for patients over the past decades. However, recurrence and drug resistance continue to challenge long-term recurrence-free and overall survival rates. Mounting evidence supports the cancer stem cell model in which the existence of a small population of breast cancer stem cells (BCSCs) within the tumor enables these cells to evade conventional therapies and repopulate the tumor, giving rise to more aggressive, recurrent tumors. Thus, successful breast cancer therapy would need to target these BCSCs, as well the tumor bulk cells. Since the Women’s Health Initiative study reported an increased risk of breast cancer with the use of conventional hormone replacement therapy in postmenopausal women, many have turned their attention to phytoestrogens as a natural alternative. Phytoestrogens are plant compounds that share structural similarities with human estrogens and can bind to the estrogen receptors to alter the endocrine responses. Recent studies have found that phytoestrogens can also target BCSCs and have the potential to complement conventional therapy eradicating BCSCs. This review summarized the latest findings of different phytoestrogens and their effect on BCSCs, along with their mechanisms of action, including selective estrogen receptor binding and inhibition of molecular pathways used by BCSCs. The latest results of phytoestrogens in clinical trials are also discussed to further evaluate the use of phytoestrogen in the treatment and prevention of breast cancer.

Association of Healthy Diet and Physical Activity With Breast Cancer: Lifestyle Interventions and Oncology Education

Global cancer statistics suggest that breast cancer (BC) is the most diagnosed cancer in women, with an estimated 2. 3 million new cases reported in 2020. Observational evidence shows a clear link between prevention and development of invasive BC and lifestyle-based interventions such as a healthy diet and physical activity. The recent findings reveal that even minimal amounts of daily exercise and a healthy diet reduced the risk of BC, mitigated the side effects of cancer treatment, and stopped the recurrence of cancer in the survivors. Despite the myriad benefits, the implementation of these lifestyle interventions in at-risk and survivor populations has been limited to date. Given the need to disseminate information about the role of physical activity and nutrition in BC reduction, the review aimed to present the recent scientific outreach and update on associations between the lifestyle interventions and BC outcomes to narrow the gap and strengthen the understanding more clearly. This review covers more direct, detailed, and updated scientific literature to respond to frequently asked questions related to the daily lifestyle-based interventions and their impact on BC risk and survivors. This review also highlights the importance of the oncology provider's job and how oncology education can reduce the BC burden.

Trending Nutrition Controversies #3: Top Controversies in 2021

Each year, patients are bombarded with diverging and even contradictory reports concerning the impact of certain additives, foods, and nutrients on cardiovascular health and its risk factors. Accordingly, this third review of nutrition controversies examines the impact of artificial sweeteners, cacao, soy, plant-based meats, nitrates, and meats from grass compared to grain-fed animals on cardiovascular and other health outcomes with the goal of optimizing clinician-led diet counseling.

Dietary Factors and Breast Cancer Prognosis among Breast Cancer Survivors: A Systematic Review and Meta-Analysis of Cohort Studies

Simple Summary

While most systematic reviews have focused on the association between dietary factors and breast cancer incidence, this current study focuses on the association between comprehensive dietary factors and breast cancer prognosis among breast cancer survivors by systematic review and meta-analysis. We reviewed a total of 63 cohort studies to assess the association between dietary factors and breast cancer prognosis by subgroup analysis with prediagnostic or postdiagnostic dietary intake, menopausal status, and dietary or supplementary micronutrient intake. We found that unhealthy dietary patterns, including the intake of beer and saturated fat, exacerbated the risk of breast cancer prognosis; however, the supplementation of most vitamins was desirable for breast cancer prognosis. Therefore, this study’s systematic review and meta-analysis provide useful dietary information for the development of dietary guidelines/recommendations to improve prognosis among breast cancer survivors.

Abstract

Few studies have summarized the association between dietary factors and breast cancer (BC) prognosis among breast cancer survivors (BCS). Therefore, we carried out a systematic review and meta-analysis to determine the associations between dietary factors and BC prognosis among BCS. We performed a literature search in PubMed and Embase to investigate the association between dietary factors and BC prognosis. We applied a random-effects model to compute the hazard ratio/relative risk and their 95% confidence intervals and heterogeneity (Higgins I²) and to generate forest plots using STATA. Among the 2279 papers identified, 63 cohort studies were included in the systematic review and meta-analysis. Our main finding was that higher consumption of beer and saturated fat negatively affected BC prognosis. However, the intake of lignans, fiber, multivitamins, and antioxidants was negatively associated with the risk of mortality. Furthermore, we performed subgroup analyses by menopausal status and dietary or supplementary micronutrient intake. Most trends were similar to the main findings; in particular, the vitamin C, vitamin D, and vitamin E supplements decreased the risk of mortality. This study’s current systematic review and meta-analysis provide comprehensive dietary information for the development of dietary guidelines/recommendations to improve prognosis among BCS.

Genistein: A Potent Anti-Breast Cancer Agent

Genistein is an isoflavonoid present in high quantities in soybeans. Possessing a wide range of bioactives, it is being studied extensively for its tumoricidal effects. Investigations into mechanisms of the anti-cancer activity have revealed many pathways including induction of cell proliferation, suppression of tyrosine kinases, regulation of Hedgehog-Gli1 signaling, modulation of epigenetic activities, seizing of cell cycle and Akt and MEK signaling pathways, among others via which the cancer cell proliferation can be controlled. Notwithstanding, the observed activities have been time- and dose-dependent. In addition, genistein has also shown varying results in women depending on the physiological parameters, such as the early or post-menopausal states.

Therapeutic Potential of Isoflavones with an Emphasis on Daidzein

Daidzein is a phytoestrogen isoflavone found in soybeans and other legumes. The chemical composition of daidzein is analogous to mammalian estrogens, and it could be useful with a dual-directional purpose by substituting/hindering with estrogen and estrogen receptor (ER) complex. Hence, daidzein puts forth shielding effects against a great number of diseases, especially those associated with the control of estrogen, such as breast cancer, diabetes, osteoporosis, and cardiovascular disease. However, daidzein also has other ER-independent biological activities, such as oxidative damage reduction acting as an antioxidant, immune regulator as an anti-inflammatory agent, and apoptosis regulation, directly linked to its potential anticancer effects. In this sense, the present review is aimed at providing a deepen analysis of daidzein pharmacodynamics and its implications in human health, from its best-known effects alleviating postmenopausal symptoms to its potential anticancer and antiaging properties.

Association between Dietary Intake of Flavonoids and Cancer Recurrence among Breast Cancer Survivors

Intake of flavonoids is associated with the incidence of breast cancer, but the association between the intake of flavonoids and cancer recurrence is unclear. This study aimed to investigate the hypothesis that intake of flavonoids and flavonoid-rich foods is negatively associated with cancer recurrence. Among 572 women who underwent breast cancer surgery, 66 patients had a cancer recurrence. Dietary data were collected using a structured 24-h dietary recall, and intake of flavonoids was calculated based on the Korea Rural Development Administration flavonoid database. Among overweight and obese patients, disease-free survival was associated with intake of flavonoids (p = 0.004) and flavonoid-rich foods (p = 0.003). Intake of flavonoids (hazard ratio (HR) = 0.249, 95% confidence interval (CI): 0.09–0.64) and flavonoid-rich foods (HR = 0.244, 95% CI: 0.09–0.66) was negatively associated with cancer recurrence after adjusting for confounding factors in overweight and obese patients. Consumption of flavonoids and flavonoid-rich foods was lower in overweight and obese patients with cancer recurrence than those without recurrence and in normal-weight patients. This study suggests that intake of flavonoids and flavonoid-rich foods could have beneficial effects on cancer recurrence in overweight and obese breast cancer survivors.

A practical nutritional guide for the management of sleep disturbances in menopause

Sleep disturbances (SD) represent one of the main symptoms of menopause and they are caused by several factors. Hormonal changes such as the reduction of oestrogen levels and the consequent vasomotor symptoms (VMS) along with psychiatric disorders such as depression and anxiety could contribute to the onset of SD. Furthermore, obesity per sè or through the obstructive sleep apnoea (OSA) could blunt sleep. Moreover, in menopause is usual a reduction in melatonin, that could contribute to SD. Nutritional strategies are paramount because they could contribute to manage menopause-related SD, in particular tackling obesity and overweight. Furthermore, some foods, such as soy, fish, whole grains, vegetables and fruit could decrease symptoms like depression and VMS, correlated with SD in postmenopausal women. Therefore, the aim of this review is to provide an overview of the current evidence on SD in menopause and to provide nutritional strategies for managing SD in this context.

Pleiotropic Effects of Isoflavones in Inflammation and Chronic Degenerative Diseases

Isoflavones are phytoestrogens of plant origin, mostly found in the members of the Fabaceae family, that exert beneficial effects in various degenerative disorders. Having high similarity to 17-β-estradiol, isoflavones can bind estrogen receptors, scavenge reactive oxygen species, activate various cellular signal transduction pathways and modulate growth and transcription factors, activities of enzymes, cytokines, and genes regulating cell proliferation and apoptosis. Due to their pleiotropic activities isoflavones might be considered as a natural alternative for the treatment of estrogen decrease-related conditions during menopause. This review will focus on the effects of isoflavones on inflammation and chronic degenerative diseases including cancer, metabolic, cardiovascular, neurodegenerative diseases, rheumatoid arthritis and adverse postmenopausal symptoms.

[Impact of nutritional factors during and after cancer]

Nutritional factors (diet, weight, alcohol, physical activity) are identified as factors having an impact on the onset of several cancer sites. Less abundant scientific data also underline their impact on the tumor progression. A review of the scientific literature was carried out by a group of experts established by the French National Cancer Institute (INCa) to better document the influence of nutritional factors during and after cancer on outcomes such as overall mortality, cancer specific mortality, recurrence, second primary cancers and quality of life. This analysis of the literature completes messages of reduction of alcohol consumption, prevention of undernutrition or excess weight and adherence to dietary recommendations, avoiding the use of dietary supplements, fasting or restrictive diets and strengthens messages promoting the practice of physical activity and the fight against sedentary lifestyle.

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

Plant Proteins: Assessing Their Nutritional Quality and Effects on Health and Physical Function

Consumer demand for plant protein-based products is high and expected to grow considerably in the next decade. Factors contributing to the rise in popularity of plant proteins include: (1) potential health benefits associated with increased intake of plant-based diets; (2) consumer concerns regarding adverse health effects of consuming diets high in animal protein (e.g., increased saturated fat); (3) increased consumer recognition of the need to improve the environmental sustainability of food production; (4) ethical issues regarding the treatment of animals; and (5) general consumer view of protein as a "positive" nutrient (more is better). While there are health and physical function benefits of diets higher in plant-based protein, the nutritional quality of plant proteins may be inferior in some respects relative to animal proteins. This review highlights the nutritional quality of plant proteins and strategies for wisely using them to meet amino acid requirements. In addition, a summary of studies evaluating the potential benefits of plant proteins for both health and physical function is provided. Finally, potential safety issues associated with increased intake of plant proteins are addressed.

Estrogen Receptor Beta (ERβ): A Ligand Activated Tumor Suppressor

Estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) belong to a superfamily of nuclear receptors called steroid hormone receptors, which, upon binding ligand, dimerize and translocate to the nucleus where they activate or repress the transcription of a large number of genes, thus modulating critical physiologic processes. ERβ has multiple isoforms that show differing association with prognosis. Expression levels of the full length ERβ1 isoform are often lower in aggressive cancers as compared to normal tissue. High ERβ1 expression is associated with improved overall survival in women with breast cancer. The promise of ERβ activation, as a potential targeted therapy, is based on concurrent activation of multiple tumor suppressor pathways with few side effects compared to chemotherapy. Thus, ERβ is a nuclear receptor with broad-spectrum tumor suppressor activity, which could serve as a potential treatment target in a variety of human cancers including breast cancer. Further development of highly selective agonists that lack ERα agonist activity, will be necessary to fully harness the potential of ERβ.

My health smartphone intervention decreases daily fat sources among Latina breast cancer survivors

Breast cancer is the most common cancer among Latina women, and Latina women are at higher risk for breast cancer mortality than white women. Lifestyle factors, such as consuming a nutritious diet and engaging in regular physical activity, promote health and are protective against heart disease, type 2 diabetes, and breast cancer recurrence. Previous studies have developed and tested interventions for Latina breast cancer survivors to improve diet and increase physical activity, however, no studies to date have developed a smartphone delivered intervention. The purpose of the current study was to compare two Smartphone delivered interventions, My Health, which focused on diet and physical activity, and My Guide, which focused on psychosocial functioning, on dietary and physical activity outcomes, post-intervention, and at a 2-week follow-up assessment. Overall, participants receiving the My Health intervention reported a greater reduction in daily fat sources than the My Guide group over time. However, daily sources of fat did not differ between conditions. Walking, measured by estimated weekly metabolic equivalents, increased across time points in both groups. These preliminary findings suggest that eHealth interventions aimed at improving lifestyle factors may favorably impact nutritional intake and physical activity. Future research should utilize more comprehensive and objective measures of diet and physical activity, and incorporate more behavioral lifestyle components into the intervention in larger samples with a longer follow-up period.

Children and adults should avoid consuming animal products to reduce risk for chronic disease: YES

The consumption of animal products exposes humans to saturated fat, cholesterol, lactose, estrogens, and pathogenic microorganisms, while displacing fiber, complex carbohydrates, antioxidants, and other components needed for health. In the process, consumption of animal products increases the risk for cardiovascular disease, cancer, diabetes, obesity, and other disorders. This dietary pattern also promotes the growth of unhealthful gut bacteria, fostering, among other things, the production of trimethylamine N-oxide, a proinflammatory compound associated with cardiovascular and neurological diseases. When omnivorous individuals change to a plant-based diet, diet quality as measured by the Alternate Healthy Eating Index improves, and the risk of these health problems diminishes. Planning for nutrient adequacy is important with any diet. However, a diet based on vegetables, fruits, whole grains, and legumes, supplemented with vitamin B-12, is nutritionally superior to diets including animal products and is healthful for children and adults.

Prognostic associations of circulating phytoestrogens and biomarker changes in long-term survivors of postmenopausal breast cancer

Lignans are associated with improved postmenopausal breast cancer (BC) survival, but whether these associations, particularly with enterolactone (major lignan metabolite), persist over time is unclear. Little is known about other phytoestrogens on prognosis in long-term survivors. The study examines associations of prognosis with 1) circulating postdiagnosis enterolactone, 2) eight circulating phytoestrogen metabolites, and 3) changes in enterolactone and genistein. In a German cohort of 2,105 postmenopausal BC patients with blood samples collected at recruitment 2002-2005 (baseline) and re-interview in 2009 (follow-up), delay-entry Cox proportional hazards regression was used. Landmark analysis showed that circulating enterolactone (log2) associations with 5-year survival changed over time, with strongest hazard ratios of 0.89 (95% CI, 0.80-0.99) at blood draw (BD) and 0.86 (0.77-0.97) at 2 years post-BD for BC mortality, and 0.87 (0.80-0.95) at BD and 0.84 (0.76-0.92) at 3 years post-BD for all-cause mortality, which attenuated thereafter. In long-term survivors, increasing concentrations of genistein (1.17, 1.01-1.36), resveratrol (1.19, 1.02-1.40), and luteolin (1.96, 1.07-3.58) measured in follow-up blood samples were associated with poorer subsequent prognosis. Neither enterolactone at follow-up nor changes in enterolactone/genistein were associated with prognosis. Large long-term longitudinal studies with multiple phytoestrogen measurements are required to understand long-term effects of phytoestrogens after BC.

Nutrition and Breast Cancer: A Literature Review on Prevention, Treatment and Recurrence

Breast cancer (BC) is the second most common cancer worldwide and the most commonly occurring malignancy in women. There is growing evidence that lifestyle factors, including diet, body weight and physical activity, may be associated with higher BC risk. However, the effect of dietary factors on BC recurrence and mortality is not clearly understood. Here, we provide an overview of the current evidence obtained from the PubMed databases in the last decade, assessing dietary patterns, as well as the consumption of specific food-stuffs/food-nutrients, in relation to BC incidence, recurrence and survival. Data from the published literature suggest that a healthy dietary pattern characterized by high intake of unrefined cereals, vegetables, fruit, nuts and olive oil, and a moderate/low consumption of saturated fatty acids and red meat, might improve overall survival after diagnosis of BC. BC patients undergoing chemotherapy and/or radiotherapy experience a variety of symptoms that worsen patient quality of life. Studies investigating nutritional interventions during BC treatment have shown that nutritional counselling and supplementation with some dietary constituents, such as EPA and/or DHA, might be useful in limiting drug-induced side effects, as well as in enhancing therapeutic efficacy. Therefore, nutritional intervention in BC patients may be considered an integral part of the multimodal therapeutic approach. However, further research utilizing dietary interventions in large clinical trials is required to definitively establish effective interventions in these patients, to improve long-term survival and quality of life.

Effects of isoflavones on breast tissue and the thyroid hormone system in humans: a comprehensive safety evaluation

Isoflavones are secondary plant constituents of certain foods and feeds such as soy, linseeds, and red clover. Furthermore, isoflavone-containing preparations are marketed as food supplements and so-called dietary food for special medical purposes to alleviate health complaints of peri- and postmenopausal women. Based on the bioactivity of isoflavones, especially their hormonal properties, there is an ongoing discussion regarding their potential adverse effects on human health. This review evaluates and summarises the evidence from interventional and observational studies addressing potential unintended effects of isoflavones on the female breast in healthy women as well as in breast cancer patients and on the thyroid hormone system. In addition, evidence from animal and in vitro studies considered relevant in this context was taken into account along with their strengths and limitations. Key factors influencing the biological effects of isoflavones, e.g., bioavailability, plasma and tissue concentrations, metabolism, temporality (pre- vs. postmenopausal women), and duration of isoflavone exposure, were also addressed. Final conclusions on the safety of isoflavones are guided by the aim of precautionary consumer protection.

Postdiagnosis Isoflavone and Lignan Intake in Newly Diagnosed Breast Cancer Patients: Cross-Sectional Survey Shows Considerable Intake from Previously Unassessed High-Lignan Foods

BACKGROUND

Isoflavones and lignans (phytoestrogens) are dietary components with potential anticarcinogenic effects. Although the intake of isoflavones and lignans may affect breast cancer treatment and prognosis-and associations may differ by menopausal status-postdiagnosis intake data are limited.

OBJECTIVE

We aimed to describe postdiagnosis isoflavone and lignan intake in newly diagnosed breast cancer patients, examine differences by menopausal status and phytoestrogen type, and inform the assessment of diet and survival in future prognostic studies.

METHODS

Our cross-sectional study included 278 women aged 25-74 y, diagnosed with pathologically confirmed breast cancer in April-May 2010 and identified using the Ontario Cancer Registry. Intake in the previous 2 mo was assessed using questionnaires listing 17 soy and 3 high-lignan foods (flaxseed, flaxseed bread, sesame seeds), completed 71 d after breast cancer diagnosis, on average. Food consumption by menopausal status was examined. Geometric mean and median phytoestrogen intakes were estimated among all patients and in consumers only; differences by menopausal status and phytoestrogen type were assessed.

RESULTS

Among all patients, foods were similarly consumed by menopausal status and isoflavone intakes were low (median: 56 µg/d). Consumers (n = 219) had higher intakes (median isoflavones: 1808 µg/d); 7% of isoflavone and 21% of lignan consumers had intakes ≥10 mg/d. Intakes were higher in premenopausal than in postmenopausal consumers, particularly for lignans, but were not significantly different (median lignans: 4375 compared with 1863 µg/d; P = 0.07). Lignans were significantly higher than isoflavones among most consumers (postmenopausal means: 746 compared with 100 µg/d; P < 0.0001).

CONCLUSIONS

Postdiagnosis lignan intakes from 3 high-content foods may be considerable among newly diagnosed breast cancer patients, yet they have been unassessed in previous prognostic studies. The inclusion of these foods in dietary assessment methods may improve future intake estimates and the distributions on which breast cancer survival analyses are based.

Soy, Soy Foods and Their Role in Vegetarian Diets

Soy is a basic food ingredient of traditional Asian cuisine used for thousands of years. In Western countries, soybeans have been introduced about a hundred years ago and recently they are mainly used for surrogate foods production. Soy and soy foods are common nutritional solutions for vegetarians, due to their high protein content and versatility in the production of meat analogues and milk substitutes. However, there are some doubts about the potential effects on health, such as the effectiveness on cardiovascular risk reduction or, conversely, on the possible disruption of thyroid function and sexual hormones. The soy components that have stimulated the most research interest are isoflavones, which are polyphenols with estrogenic properties highly contained in soybeans. In this review, we discuss the characteristics of soy and soy foods, focusing on their nutrient content, including phytoestrogens and other bioactive substances that are noteworthy for vegetarians, the largest soy consumers in the Western countries. The safety of use will also be discussed, given the growing trend in adoption of vegetarian styles and the new soy-based foods availability.

Dietary Patterns in Puerto Rican and Mexican-American Breast Cancer Survivors: A Pilot Study

Breast cancer is the leading cause of cancer death among Hispanic women. Certain dietary factors have been associated with the risk of breast cancer recurrence, but data in Hispanic survivors is scarce.

OBJECTIVE

to examine dietary patterns and diet quality in two groups of Hispanic breast cancer survivors.

METHODS

23 Mexican-American (MA) and 22 Puerto Rican (PR) female breast cancer survivors completed a culturally adapted validated food frequency questionnaire. Intake was standardized per 1000 kcal and compared to US Dietary Guidelines and the DASH-style diet adherence score was calculated.

RESULTS

Overweight/obese was 70 % in MA and 91 % in PR. PR consumed diets rich in fruit/100 % fruit juices and beans, while MA diets were high in vegetables, beans, and total grains. Both groups consumed high amounts of starchy vegetables, refined grains, animal protein and calories from solid fats and added sugars but low intakes of whole grains, dairy products and nuts and seeds. DASH scores were relatively low.

CONCLUSION

MA and PR female breast cancer survivors have different dietary patterns but both groups had relatively low diet quality. These groups could benefit from culturally tailored interventions to improve diet quality, which could potentially reduce cancer recurrence. ClinicalTrials.gov Identifier NCT01504789.

The Impacts of Genistein and Daidzein on Estrogen Conjugations in Human Breast Cancer Cells: A Targeted Metabolomics Approach

The beneficial effect of dietary soy food intake, especially for women diagnosed with breast cancer, is controversial, as in vitro data has shown that the soy isoflavones genistein and daidzein may even stimulate the proliferation of estrogen-receptor alpha positive (ERα+) breast cancer cells at low concentrations. As genistein and daidzein are known to inhibit key enzymes in the steroid metabolism pathway, and thus may influence levels of active estrogens, we investigated the impacts of genistein and daidzein on the formation of estrogen metabolites, namely 17β-estradiol (E2), 17β-estradiol-3-(β-D-glucuronide) (E2-G), 17β-estradiol-3-sulfate (E2-S) and estrone-3-sulfate (E1-S) in estrogen-dependent ERα+ MCF-7 cells. We found that both isoflavones were potent inhibitors of E1 and E2 sulfation (85–95% inhibition at 10 μM), but impeded E2 glucuronidation to a lesser extent (55–60% inhibition at 10 μM). The stronger inhibition of E1 and E2 sulfation compared with E2 glucuronidation was more evident for genistein, as indicated by significantly lower inhibition constants for genistein [K_is: E2-S (0.32 μM) < E1-S (0.76 μM) < E2-G (6.01 μM)] when compared with those for daidzein [K_is: E2-S (0.48 μM) < E1-S (1.64 μM) < E2-G (7.31 μM)]. Concomitant with the suppression of E1 and E2 conjugation, we observed a minor but statistically significant increase in E2 concentration of approximately 20%. As the content of genistein and daidzein in soy food is relatively low, an increased risk of breast cancer development and progression in women may only be observed following consumption of high-dose isoflavone supplements. Further long-term human studies monitoring free estrogens and their conjugates are therefore highly warranted to evaluate the potential side effects of high-dose genistein and daidzein, especially in patients diagnosed with ERα+ breast cancer.

Cancer Related to Herbs and Dietary Supplements: Online Table of Case Reports. Part 5 of 5

A current listing of potentially life-threatening, cancer-related dietary supplements (DSs; includes herbs) based on PubMed case reports was summarized in online tables that can now be updated continually to forewarn United States consumers, clinicians, and DS companies. Documented PubMed case reports were used to create a "Toxic Table" related to cancer (1966 to April 2016, and cross-referencing). Keywords included "herb" or "dietary supplement" combined with "cancer" as well as the specific herb "name" combined with "cancer" and sometimes "toxicity." Excluded were herb combinations (some exceptions), Chinese herb mixtures, teas of mixed herb contents, fungi (mycotoxins from molds and mushrooms), poisonous plants, self-harm, excessive doses (except vitamins/minerals), legal or illegal drugs, drug-herb interactions, and confounders of drugs or diseases related to cancer. Also included were a few foods related to cancer. Over the past 50+ years, PubMed case reports revealed an increased risk of cancer related to approximately one herb (guang fang ji), no dietary supplements (except those containing guang fang ji or aristolochic acid), and two foods (bracken fern, which is sometimes sold as an herbal supplement, and hot maté). This online "Toxic Table" can now be continually updated to assist researchers and clinicians in preventing serious adverse events from DSs related to cancer.

Dietary Natural Products for Prevention and Treatment of Breast Cancer

Breast cancer is the most common cancer among females worldwide. Several epidemiological studies suggested the inverse correlation between the intake of vegetables and fruits and the incidence of breast cancer. Substantial experimental studies indicated that many dietary natural products could affect the development and progression of breast cancer, such as soy, pomegranate, mangosteen, citrus fruits, apple, grape, mango, cruciferous vegetables, ginger, garlic, black cumin, edible macro-fungi, and cereals. Their anti-breast cancer effects involve various mechanisms of action, such as downregulating ER-α expression and activity, inhibiting proliferation, migration, metastasis and angiogenesis of breast tumor cells, inducing apoptosis and cell cycle arrest, and sensitizing breast tumor cells to radiotherapy and chemotherapy. This review summarizes the potential role of dietary natural products and their major bioactive components in prevention and treatment of breast cancer, and special attention was paid to the mechanisms of action.

Health impact of childhood and adolescent soy consumption

Soyfoods have been intensely researched, primarily because they provide such abundant amounts of isoflavones. Isoflavones are classified as both plant estrogens and selective estrogen receptor modulators. Evidence suggests that these soybean constituents are protective against a number of chronic diseases, but they are not without controversy. In fact, because soyfoods contain such large amounts of isoflavones, concerns have arisen that these foods may cause untoward effects in some individuals. There is particular interest in understanding the effects of isoflavones in young people. Relatively few studies involving children have been conducted, and many of those that have are small in size. While the data are limited, evidence suggests that soy does not exert adverse hormonal effects in children or affect pubertal development. On the other hand, there is intriguing evidence indicating that when soy is consumed during childhood and/or adolescence, risk of developing breast cancer is markedly reduced. Relatively few children are allergic to soy protein, and most of those who initially are outgrow their soy allergy by 10 years of age. The totality of the available evidence indicates that soyfoods can be healthful additions to the diets of children, but more research is required to allow definitive conclusions to be made.