Adolescent carotenoid intake and benign breast disease

Tomatoes, Lycopene, and Prostate Cancer: What Have We Learned from Experimental Models?

Human epidemiology suggests a protective effect of tomatoes or tomato phytochemicals, such as lycopene, on prostate cancer risk. However, human epidemiology alone cannot reveal causal relations. Laboratory animal models of prostate cancer provide opportunities to investigate hypotheses regarding dietary components in precisely controlled, experimental systems, contributing to our understanding of diet and cancer risk relations. We review the published studies evaluating the impact of tomatoes and/or lycopene in preclinical models of prostate carcinogenesis and tumorigenesis. The feeding of tomatoes or tomato components demonstrates anti-prostate cancer activity in both transplantable xenograft models of tumorigenesis and models of chemically- and genetically-driven carcinogenesis. Feeding pure lycopene shows anticancer activity in most studies, although outcomes vary by model system, suggesting that the impact of pure lycopene can depend on dose, duration, and specific carcinogenic processes represented in different models. Nonetheless, studies with the transgenic adenocarcinoma of the mouse prostate (TRAMP) model of carcinogenesis typically demonstrate similar bioactivity to that of tomato feeding. In general, interventions that commence earlier in carcinogenesis and are sustained tend to be more efficacious. Accumulated data suggest that lycopene is one, but perhaps not the only, anticancer bioactive compound in tomatoes. Although it is clear that tomatoes and lycopene have anti-prostate cancer activity in rodent models, major knowledge gaps remain in understanding dose-response relations and molecular mechanisms of action. Published and future findings from rodent studies can provide guidance for translational scientists to design and execute informative human clinical trials of prostate cancer prevention or in support of therapy.

Physical activity and risk of benign proliferative epithelial disorders of the breast, in the Women's Health Initiative

BACKGROUND

Recreational physical activity (PA) has been shown to be inversely associated with breast cancer risk. However, the association of recreational PA with benign proliferative epithelial disorders (BPED) of the breast, conditions associated with increased risk of breast cancer, has not been adequately studied.

METHODS

We used data from an ancillary study of benign breast disease conducted among the 68 132 postmenopausal women (aged 50-79 at recruitment) participating in the Women's Health Initiative randomized clinical trials. All clinical trial participants underwent annual or biennial mammogram screening. During the follow-up, for women who reported breast biopsies but were cancer free, the associated histological sections were obtained and subjected to standardized central pathology review. Self-reported recreational PA at baseline (n = 61 684) and at 3 years of the follow-up (n = 55 923) were quantified as metabolic equivalents [MET]-h/week. There were 1624 confirmed BPED cases during an average follow-up time of 7.7 years. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Higher average PA over 4 years was associated with lower risk of non-atypical BPED (P-trend = 0.02). There was a 6% lower risk of non-atypical BPED for every 5 MET-h/week increase between baseline and year 3 (HR = 0.94, 95% CI 0.89-0.99). Compared with women who remained inactive (PAbaseline and PAyear3 <9 MET-h/week), those who became active (PAbaseline<9 MET-h/week to PAyear3 ≥9 MET-h/weekee), remained active (PAbaseline and PAyear3 ≥9 MET-h/week), or decreased activity (PAbaseline ≥9 MET-h/week to PAyear3 <9 MET-h/week) had lower BPED risk.

CONCLUSIONS

Recreational physical activity after menopause was associated with lower BPED risk among postmenopausal women.

Is There an Association between β-Carotene and Breast Cancer? A Systematic Review on Breast Cancer Risk

It is suspected that diet influences the risk of developing breast cancer. Several β-carotenoids have been inversely associated with breast cancer risk, but association by type of tumor and participant characteristics remain nuclear. The objective of this review of epidemiological studies is to investigate the relationship between β-carotenoids and breast cancer. This review covers the 2014-2020 period and was carried out using the PubMed and EMBASE databases. Only epidemiological studies carried out on β-carotenoids and breast cancer were included. The initial keyword search yielded 1559 results and finally a total of 28 studies were included. The quality of the articles and the risk of bias for each included article were assessed. The selected articles were subsequently classified according to their quality. The evidence from the included studies confirms that there is an association between β-carotenoids and breast cancer risk; the dietary intake of β-carotenoids may be beneficial in reducing the risk of developing breast cancer.

Breast Cancer Primary Prevention and Diet: An Umbrella Review

Introduction: Many studies have been published, but none have pooled the useful evidence available in the literature to produce guidelines and health policies promoting healthy eating styles to prevent breast cancer (BC). The present study aimed to summarize the evidence produced to date, taking a judicious, critical approach to the quality of the studies analyzed. Methods: An umbrella review method was adopted, which is a systematic review of second-level studies, meta-analyses and literature reviews. Results: In all, 48 studies were considered: 32 meta-analyses, 4 pooled analyses, 5 systematic reviews, and 7 qualitative reviews. A higher intake of total meat, or red or processed meats, or foods with a high glycemic index, or eggs would seem to be associated with a higher risk of BC. Some foods, such as vegetables, would seem instead to have an inverse association with BC risk. One meta-analysis revealed an inverse association between citrus fruit and mushroom consumption and BC. Some nutrients, such as calcium, folate, vitamin D, lignans and carotenoids, also seem to be inversely associated with BC risk. The evidence is still conflicting as concerns exposure to other dietary elements (e.g., polyunsaturated fatty acids, dairy foods). Conclusion: Nutrition is one of the most modifiable aspects of people’s lifestyles and dietary choices can affect health and the risk of cancer. Overall, adhering to a healthy eating style may be associated with a significant reduction in the risk of BC.

Dietary patterns and relative expression levels of PPAR-γ, VEGF-A and HIF-1α genes in benign breast diseases: case-control and consecutive case-series designs

We aimed to study dietary patterns in association with the relative expression levels of PPAR-γ, vascular endothelial growth factor-A (VEGF-A) and hypoxia-inducible factor-1α (HIF-1α) in women with benign breast disease (BBD). The study design was combinative, included a case-series and case-control compartments. Initially, eligible BBD patients (n 77, aged 19-52 years old) were recruited at Nour-Nejat hospital, Tabriz, Iran (2012-2014). A hospital-based group of healthy controls was matched for age (n 231, aged 20-63 years old) and sex. Dietary data were collected using a valid 136-item FFQ. Principal component analysis generated two main components (Kaiser-Meyer-Olkin = 0·684), including a Healthy pattern (whole bread, fruits, vegetables, vegetable oils, legumes, spices, seafood, low-fat meat, skinless poultry, low-fat dairy products, nuts and seeds) and a Western pattern (starchy foods, high-fat meat and poultry, high-fat dairy products, hydrogenated fat, fast food, salt and sweets). High adherence to the Western pattern increased the risk of BBD (ORadj 5·59; 95 % CI 2·06, 15·10; P < 0·01), whereas high intake of the Healthy pattern was associated with a 74 % lower risk of BBD (95 % CI 0·08, 0·81; P < 0·05). In the BBD population, the Western pattern was correlated with over-expression of HIF-1α (radj 0·309, P < 0·05). There were inverse correlations between the Healthy pattern and expressions of PPAR-γ (radj -0·338, P < 0·05), HIF-1α (radj -0·340, P < 0·05) and VEGF-A (radj -0·286, P < 0·05). In conclusion, new findings suggested that the Healthy pattern was associated inversely with the risk of BBD, and this could be correlated with down-regulation of PPAR-γ, VEGF-A and HIF-1α genes, which might hold promise to preclude BBD of malignant pathological transformation.

Dairy consumption during adolescence and endometriosis risk

BACKGROUND

Modifiable risk factors such as diet may be important in both the etiology and progression of endometriosis as well as the prevalence of pain symptoms and infertility associated with this condition. In adults, higher intake of dairy has been associated with a lower risk of endometriosis diagnosis. There is currently no literature on whether dairy intake during adolescence, a potentially critical window of exposure, influences endometriosis risk.

OBJECTIVE

The objectige of the study was to evaluate the association between consumption of dairy foods in adolescence and the risk of laparoscopically confirmed endometriosis.

STUDY DESIGN

This was a prospective cohort study, the Nurses' Health Study II, which has prospectively collected data since 1989. In 1998, when participants were aged 34-51 years, they completed a 124 item food frequency questionnaire about their high school diet. Cases were defined as those who self-reported laparoscopically confirmed endometriosis. Cox proportional hazard models were used to calculate hazard ratios and 95% confidence intervals for the association between dairy foods and laparoscopically confirmed endometriosis.

RESULTS

Among women who completed the questionnaire about their high school diet in 1998, 581 cases of laparoscopically confirmed endometriosis were diagnosed among 32,868 premenopausal women from 1998 to 2013. Women who consumed more than 4 servings per day of dairy foods during adolescence had a 32% lower risk of laparoscopically confirmed endometriosis during adulthood (95% confidence interval, 0.47-0.96; P_trend = .04) compared with women consuming 1 or fewer servings per day. The association was similar for low-fat and high-fat dairy foods. Yogurt and ice cream consumption, specifically, were associated with a lower risk of endometriosis. Those who consumed 2 or more servings of yogurt per week as an adolescent had a 29% lower risk of endometriosis diagnosis (95% confidence interval, 0.52-0.97; P_trend = .02) compared with those consuming less than 1 serving per week. In addition, women who consumed 1 or more servings per day of ice cream per day during adolescence had a 38% lower risk of endometriosis diagnosis (95% confidence interval, 0.40-0.94; P_trend = .20) compared with those consuming less than 1 serving per week.

CONCLUSION

Our findings suggest that dairy consumption, specifically yogurt and ice cream intake, in adolescence may reduce the risk of subsequent endometriosis diagnosis. Future studies in adolescent populations are needed to confirm these results.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Psychosocial stress is associated with benign breast disease in young Chinese women: results from Project ELEFANT

PURPOSE

Psychosocial stress, including bereavement and work-related stress, is associated with the risk of breast cancer. However, it is unknown whether it may also be linked with increased risk of benign breast disease (BBD).

METHODS

Our study leveraged 61,907 women aged 17-55 years old from the Project ELEFANT study. BBD was diagnosed by clinician. Self-reported data on psychosocial stress over a 10-year period was retrospectively collected from questionnaires and categorised by cause (work, social and economic) and severity (none, low and high). Odd ratios (ORs) for the development of BBD were estimated using logistic regression. The model was adjusted for age, BMI, TSH levels, smoking, alcohol consumption, family history, age of menarche, oral contraceptive usage, education and occupation.

RESULTS

Within our study, 8% (4,914) of participants were diagnosed with BBD. Work-related stress [OR 1.57, 95% confidence interval (CI) 1.46-1.69] and financial stress (OR 1.34, 95% CI 1.24-1.44) were significantly associated with BBD incidence, with a smaller but still significant association with social stress (OR 1.11, 95% CI 1.01-1.21). The associations remained significant after exclusion of participants with first- and second-degree family history of breast disease. The presence of multiple forms of stress did not synergistically increase risk. The neutrophil-lymphocyte ratio (NLR), a marker of systemic inflammation and prognostic marker for breast cancer, was not associated with BBD.

CONCLUSIONS

Psychosocial stress, particularly work-related and financial stress, is associated with increased risk of benign breast disease among young Chinese women.

Exploring the Valuable Carotenoids for the Large-Scale Production by Marine Microorganisms

Carotenoids are among the most abundant natural pigments available in nature. These pigments have received considerable attention because of their biotechnological applications and, more importantly, due to their potential beneficial uses in human healthcare, food processing, pharmaceuticals and cosmetics. These bioactive compounds are in high demand throughout the world; Europe and the USA are the markets where the demand for carotenoids is the highest. The in vitro synthesis of carotenoids has sustained their large-scale production so far. However, the emerging modern standards for a healthy lifestyle and environment-friendly practices have given rise to a search for natural biocompounds as alternatives to synthetic ones. Therefore, nowadays, biomass (vegetables, fruits, yeast and microorganisms) is being used to obtain naturally-available carotenoids with high antioxidant capacity and strong color, on a large scale. This is an alternative to the in vitro synthesis of carotenoids, which is expensive and generates a large number of residues, and the compounds synthesized are sometimes not active biologically. In this context, marine biomass has recently emerged as a natural source for both common and uncommon valuable carotenoids. Besides, the cultivation of marine microorganisms, as well as the downstream processes, which are used to isolate the carotenoids from these microorganisms, offer several advantages over the other approaches that have been explored previously. This review summarizes the general properties of the most-abundant carotenoids produced by marine microorganisms, focusing on the genuine/rare carotenoids that exhibit interesting features useful for potential applications in biotechnology, pharmaceuticals, cosmetics and medicine.

Early Life Exposures and Adult Cancer Risk

Very little is known about the influence of early life exposures on adult cancer risk. The purpose of this narrative review was to summarize the epidemiologic evidence relating early life tobacco use, obesity, diet, and physical activity to adult cancer risk; describe relevant theoretical frameworks and methodological strategies for studying early life exposures; and discuss policies and research initiatives focused on early life. Our findings suggest that in utero exposures may indirectly influence cancer risk by modifying biological pathways associated with carcinogenesis; however, more research is needed to firmly establish these associations. Initiation of exposures during childhood and adolescence may impact cancer risk by increasing duration and lifetime exposure to carcinogens and/or by acting during critical developmental periods. To expand the evidence base, we encourage the use of life course frameworks, causal inference methods such as Mendelian randomization, and statistical approaches such as group-based trajectory modeling in future studies. Further, we emphasize the need for objective exposure biomarkers and valid surrogate endpoints to reduce misclassification. With the exception of tobacco use, there is insufficient evidence to support the development of new cancer prevention policies; however, we highlight existing policies that may reduce the burden of these modifiable risk factors in early life.

Physical activity, sedentary behaviour, diet, and cancer: an update and emerging new evidence

The lifestyle factors of physical activity, sedentary behaviour, and diet are increasingly being studied for their associations with cancer. Physical activity is inversely associated with and sedentary behaviour is positively (and independently) associated with an increased risk of more than ten types of cancer, including colorectal cancer (and advanced adenomas), endometrial cancers, and breast cancer. The most consistent dietary risk factor for premalignant and invasive breast cancer is alcohol, whether consumed during early or late adult life, even at low levels. Epidemiological studies show that the inclusion of wholegrain, fibre, fruits, and vegetables within diets are associated with reduced cancer risk, with diet during early life (age <8 years) having the strongest apparent association with cancer incidence. However, randomised controlled trials of diet-related factors have not yet shown any conclusive associations between diet and cancer incidence. Obesity is a key contributory factor associated with cancer risk and mortality, including in dose-response associations in endometrial and post-menopausal breast cancer, and in degree and duration of fatty liver disease-related hepatocellular carcinoma. Obesity produces an inflammatory state, characterised by macrophages clustered around enlarged hypertrophied, dead, and dying adipocytes, forming crown-like structures. Increased concentrations of aromatase and interleukin 6 in inflamed breast tissue and an increased number of macrophages, compared with healthy tissue, are also observed in women with normal body mass index, suggesting a metabolic obesity state. Emerging randomised controlled trials of physical activity and dietary factors and mechanistic studies of immunity, inflammation, extracellular matrix mechanics, epigenetic or transcriptional regulation, protein translation, circadian disruption, and interactions of the multibiome with lifestyle factors will be crucial to advance this field.

Plasma carotenoids and the risk of premalignant breast disease in women aged 50 and younger: a nested case-control study

PURPOSE

To examine the association of plasma carotenoids, micronutrients in fruits, and vegetables, with risk of premalignant breast disease (PBD) in younger women.

METHODS

Blood samples were collected at the Siteman Cancer Center between 2008 and 2012 from 3537 women aged 50 or younger with no history of cancer or PBD. The analysis included 147 participants diagnosed with benign breast disease or breast carcinoma in situ during a 27-month follow-up and 293 controls. Cases and controls were matched on age, race/ethnicity, and date of and fasting status at blood draw. Plasma carotenoids were quantified. We used logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) and linear regression to assess racial differences in plasma carotenoids.

RESULTS

The risk reduction between the highest and lowest tertiles varied by carotenoid, with β-cryptoxanthin having the greatest reduction (OR 0.62; 95% CI, 0.62-1.09; P _trend = 0.056) and total carotenoids the least (OR 0.83; 95% CI, 0.48-1.44; P _trend = 0.12). We observed an inverse association between plasma carotenoids and risk of PBD in obese women (BMI ≥ 30 kg/m²; 61 cases and 115 controls) but not lean women (BMI < 25 kg/m²; 54 cases and 79 controls), although the interaction was not statistically significant. Compared to white women, black women had lower levels of α and β-carotene and higher levels of β-cryptoxanthin and lutein/zeaxanthin.

CONCLUSIONS

We observed suggestive inverse associations between plasma carotenoids and risk of PBD in younger women, consistent with inverse associations reported for invasive breast cancer. Carotenoids may play a role early in breast cancer development.

Breast Cancer Research in the Nurses' Health Studies: Exposures Across the Life Course

OBJECTIVES

To review the contribution of the Nurses' Heath Study (NHS) and the NHS II in identifying risk and protective factors for breast cancer incidence and survival.

METHODS

We conducted a narrative review of NHS and NHS II articles on breast cancer incidence and survival published from 1976 to 2016, with a focus on exogenous and endogenous hormones; lifestyle factors, including diet, physical activity, and aspirin use; intermediate markers of risk; and genetic factors.

RESULTS

With the investigation of individual risk factors, as well as their incorporation into risk prediction models, the NHS has contributed to the identification of ways in which women may reduce breast cancer risk, including limiting alcohol consumption, reducing the duration of postmenopausal estrogen-plus-progestin use, avoiding weight gain, and increasing vegetable consumption. In addition, the NHS has helped elucidate the roles of several biomarkers and contributed to the identification of risk alleles.

CONCLUSIONS

The NHS has contributed to our understanding of lifestyle, hormonal, and genetic risk factors for breast cancer, highlighting the importance of exposures across the life course, and has helped identify lifestyle changes that may reduce risk and improve survival after a diagnosis of breast cancer.

Intakes of fat and micronutrients between ages 13 and 18 years and the incidence of proliferative benign breast disease

PURPOSE

Dietary exposures during adolescence may exert important effects on breast development and future breast cancer risk. This study evaluated the associations between high school intakes of fat and micronutrients and the incidence of proliferative benign breast disease (BBD), a marker of increased breast cancer risk.

METHODS

29,480 women (mean age 43.3 years, range 33.6-52.9) completed a high school food frequency questionnaire in 1998 in the Nurses' Health Study II. Between 1991 and 2001, 682 women (follow-up time: 259,828 person-years) were diagnosed with proliferative BBD whose biopsy slides were reviewed and confirmed by the study pathologists.

RESULTS

In multivariate Cox proportional hazards models, high school intakes of total fat and types of fat were not associated with proliferative BBD. Women in the highest quintile of total retinol activity equivalents (RAEs), which incorporate retinol, α- and β-carotene, and β-cryptoxanthin intakes, had a 17 % lower risk of proliferative BBD than those in the lowest quintile [multivariate hazard ratio (HR) 95 % CI 0.83 (0.64, 1.07), p trend = 0.01]; however, additional adjustment for high school dietary factors (vitamin D, nuts, and fiber) rendered the association nonsignificant [0.99 (0.73, 1.34), p trend = 0.32]. Results were similar with additional adjustment for adult RAE intake. Intakes of vitamin E and individual carotenoids were not associated with proliferative BBD, although an inverse association cannot be ruled out.

CONCLUSIONS

In this study, adolescent fat and micronutrient intakes were not associated with risk of proliferative BBD.

Breast cancer risk accumulation starts early: prevention must also

Nearly one in four breast cancers is diagnosed before the age of 50, and many early-stage premalignant lesions are present but not yet diagnosed. Therefore, we review evidence to support the strategy that breast cancer prevention efforts must begin early in life. This study follows the literature review methods and format. Exposures during childhood and adolescence affect a woman's long-term risk of breast cancer, but have received far less research attention than exposures that occur later in life. Breast tissue undergoes rapid cellular proliferation between menarche and first full-term pregnancy, and risk accumulates rapidly until the terminal differentiation that accompanies first pregnancy. Evidence on childhood diet and growth in height, and adolescent alcohol intake, among other adolescent factors is related to breast cancer risk and risk of premalignant proliferative benign lesions. Breast cancer prevention efforts will have the greatest effect when initiated at an early age and continued over a lifetime. Gaps in knowledge are identified and deserve increase attention to inform prevention.