Intakes of meat, fish, poultry, and eggs and risk of prostate cancer progression

Plant-Based Diets and Disease Progression in Men With Prostate Cancer

Importance

Plant-based diets are associated with many health and environmental benefits, including primary prevention of fatal prostate cancer, but less is known about postdiagnostic plant-based diet patterns in individuals with prostate cancer.

Objective

To examine whether postdiagnostic plant-based dietary patterns are associated with risk of prostate cancer progression and prostate cancer-specific mortality.

Design, Setting, and Participants

This longitudinal observational cohort study included men with biopsy-proven nonmetastatic prostate cancer (stage ≤T3a) from the diet and lifestyle substudy within the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) enrolled at 43 urology practices across the US from 1999 to 2018. Participants completed a comprehensive diet and lifestyle questionnaire (including a validated food frequency questionnaire [FFQ]) between 2004 and 2016. Data were analyzed from August 2022 to April 2023.

Exposures

Overall plant-based diet index (PDI) and healthful plant-based diet index (hPDI) scores were calculated from the FFQ.

Main Outcomes and Measures

The primary outcome was prostate cancer progression (recurrence, secondary treatment, bone metastases, or prostate cancer-specific mortality). The secondary outcome was prostate cancer-specific mortality.

Results

Among 2062 participants (median [IQR] age, 65.0 [59.0-70.0] years), 61 (3%) identified as African American, 3 (<1%) identified as American Indian or Alaska Native, 9 (<1%) identified as Asian or Pacific Islander, 15 (1%) identified as Latino, and 1959 (95%) identified as White. Median (IQR) time from prostate cancer diagnosis to FFQ was 31.3 (15.9-62.0) months after diagnosis. During a median (IQR) follow-up of 6.5 (1.3-12.8) years after the FFQ, 190 progression events and 61 prostate cancer-specific mortality events were observed. Men scoring in the highest vs lowest quintile of PDI had a 47% lower risk of progression (HR, 0.53; 95% CI, 0.37-0.74; P for trend = .003). The hPDI was not associated with risk of progression overall. However, among 680 individuals with Gleason grade 7 or higher at diagnosis, the highest hPDI quintile was associated with a 55% lower risk of progression compared with the lowest hPDI quintile (HR 0.45; 95% CI, 0.25-0.81; P for trend = .01); no association was observed in individuals with Gleason grade less than 7.

Conclusions and Relevance

In this cohort study of 2062 men with prostate cancer, higher intake of plant foods after prostate cancer diagnosis was associated with lower risk of cancer progression. These findings suggest nutritional assessment and counseling may be recommended to patients with prostate cancer to help establish healthy dietary practices and support well-being and overall health.

Fish consumption and risk of prostate cancer or its mortality: an updated systematic review and dose-response meta-analysis of prospective cohort studies

Since the release of the last meta-analysis on the association between fish intake and prostate cancer risk, several cohort studies have been published. Moreover, none of the previous meta-analyzes examined the dose-response association between fish intake and prostate cancer. Therefore, the current dose-response meta-analysis was conducted to summarize available findings on the associations of fish intake with the risk of prostate cancer in men. Online databases of PubMed, Scopus, and Web of Science were systematically searched up to September 2022. We included prospective cohort studies that examined the associations of fish intake with the risk of prostate cancer (total, localized, and advanced prostate cancer), its mortality, and cancer progression. Summary relative risks (RR) and 95% confidence intervals (CI) were calculated for the highest versus lowest categories of fish intake using random-effects models. Also, linear and non-linear dose-response analyzes were conducted. In total, 25 prospective cohort studies, recruiting 1,216,474 men, were included in the systematic review, and 22 studies were included in the meta-analysis. During the follow-up periods, ranging from 6 to 33 years, a total of 44,722 cases of prostate cancer were recorded. The comparison between the highest and lowest intakes of total fish revealed the summary RRs of 0.97 (95% CI: 0.86-1.10) for total, 1.01 (95% CI: 0.91-1.13) for advanced, and 0.90 (95% CI: 0.72-1.12) for localized prostate cancer, indicating no significant association. Moreover, the summary RR was 0.55 (95% CI: 0.33-0.92) for prostate cancer mortality and 0.84 (95% CI: 0.65-1.10) for prostate cancer progression, indicating an inverse association between fish intake and prostate cancer mortality. Also, in the dose-response analyzes, each 20 gram/day increase in total fish intake was associated with a 12% lower risk of prostate cancer mortality. Our findings support the protective association between total fish intake and the risk of prostate cancer mortality.

Association Between Red and Processed Meat Consumption and Risk of Prostate Cancer: A Systematic Review and Meta-Analysis

Background

Debate on the potential carcinogenic effects of meat intake is open and the relationship between meat consumption and risk of prostate cancer remains uncertain. This meta-analysis was conducted to summarize earlier prospective studies on the association of meat consumption with risk of prostate cancer.

Methods

Relevant studies were identified by exploring PubMed/Medline, Scopus, Web of Science, EMBASE, and Google Scholar databases up to December 2020. Fixed-effects and random-effects meta-analyses were used for pooling the relative risks (RRs). Heterogeneity across studies was evaluated using the Q-statistic and I-square (I²). A funnel plot and Egger's test was used to detect publication bias. Linear and non-linear dose-response analyses were performed to estimate the dose-response relations between meat intake and risk of prostate cancer.

Results

Twenty-five prospective studies were included in this meta-analysis. Totally, 1,900,910 participants with 35,326 incident cases of prostate cancer were investigated. Pooling the eligible effect sizes, we observed that high consumption of processed meat might be associated with an increased risk of “total prostate cancer” (RR: 1.06; 95% CI: 1.01, 1.10; I² = 1.5%, P = 0.43) and “advanced prostate cancer” (1.17; 1.09, 1.26; I² = 58.8%, P = 0.01). However, the association between processed meat and “advanced prostate cancer” was not significant in the random-effects model: 1.12 (95% CI: 0.98, 1.29). A linear dose-response analysis indicated that an increment of 50 grams per day of processed meat intake might be related to a 4% greater risk of “total prostate cancer” (1.04; 1.00, 1.08; I² = 0.0%, P = 0.51). “Total meat intake” was marginally associated with all outcomes of prostate cancer risk (1.04; 1.01, 1.07; I² = 58.4%, P < 0.001).

Conclusions

This systematic review and meta-analysis of prospective studies indicated that increased consumption of “total meat” and “processed meat” might be associated with a higher risk of prostate cancer.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=230824, identifier: CRD42021230824.

Quality of Life of Prostate Cancer Survivors Participating in a Remotely Delivered Web-Based Behavioral Intervention Pilot Randomized Trial

Background:

Following a prostate cancer (PC) diagnosis, treatment-related symptoms may result in diminished quality of life (QoL). Improved diet and increased exercise may improve QoL in men with PC.

Methods:

We conducted a 4-arm pilot randomized trial to assess feasibility and acceptability of a 3-month web-based diet and exercise intervention, among men (>18 years of age) with PC (reported elsewhere). The purpose of this study is to describe the change in QoL measured by surveys (eg, QLQ-C30, PROMIS Fatigue) at enrollment and following the intervention. Men were randomized 1:1:1:1 to increasing levels of web-based behavioral support: Level 1: website; Level 2: Level 1 plus personalized diet and exercise prescription; Level 3: Levels 1-2 plus Fitbit and text messages; Level 4: Levels 1-3 plus 2 30-minute coaching calls. T-tests were used to compare pre-post change in mean QoL scores between each Level and Level 1.

Results:

Two hundred and two men consented and were randomized (n = 49, 51, 50, 52 for Levels 1-4, respectively). Men were predominantly white (93%), with a median age of 70 years (Intra-quartile Range [IQR]: 65,75) and 3 years (IQR: 1,9) post primary treatment for mostly localized disease (74% with T1-2). There were no meaningful changes in QoL, but there were notable trends. Level 3 participants had small improvements in QLQ-C30 Global Health (5.46; 95% CI: −0.02, 10.95) compared to Level 1. In contrast, Level 2 participants trended toward decreasing Global QoL (−2.31, 95% CI: −8.05, 3.42), which may reflect declines in function (eg, Cognitive: −6.94, 95% CI: −13.76, −0.13) and higher symptom burden (eg, Diarrhea: 4.63, 95% CI: −1.48, 10.74).

Conclusions:

This short, web-based intervention did not appear to have an impact on PC survivors’ QoL. Most men were several years past treatment for localized disease; the potential for this approach to reduce symptoms and improve QoL in men who have worse health may still be warranted.

The Association between Dietary Diversity Score and Risk of Prostate Cancer: (A Case-Control Study)

There are few studies that evaluated the relationship between dietary diversity score (DDS) and risk of cancer. The purpose of this study was to examine the association of DDS with the risk of prostate cancer (PC) among Iranian men. This case-control study was performed among 60 cases with prostate cancer and 60 hospital-based controls. Anthropometric measurements were done and demographic information was recorded using standard protocols. A validated 160-item semi-quantitative food frequency questionnaire (FFQ) was used to assess usual dietary intakes. Also, Binary logistic regression was performed to estimate the risk of PC in relation to DDS. After controlling for several confounders (age, body mass index, physical activity, energy intake, job, education, and antihypertensive drugs usage) higher adherence to DDS (OR = 0.33; 95% CI (0.11-0.97)), fruits group (OR = 0.19; 95% CI (0.06-0.63)), and vegetables group (OR = 0.17; 95% CI (0.05 - 0.58)) were significantly associated with lower risk of PC. In contrast, greater adherence to the meat group (OR = 3.88; 95% CI (1.32-11.42)) was significantly associated with increased PC risk. Our results showed that adherence to a diet with higher DDS, especially higher amounts of fruits and vegetables and a lower amount of meat could decrease the risk of PC.

Post-diagnostic coffee and tea consumption and risk of prostate cancer progression by smoking history

PURPOSE

Post-diagnostic coffee and tea consumption and prostate cancer progression is understudied.

METHODS

We examined 1,557 men from the Cancer of the Prostate Strategic Urologic Research Endeavor who completed a food frequency questionnaire a median of 28 months post-diagnosis. We estimated associations between post-diagnostic coffee (total, caffeinated, decaffeinated) and tea (total, non-herbal, herbal) and risk of prostate cancer progression (recurrence, secondary treatment, bone metastases, or prostate cancer death) using Cox proportional hazards regression. We also examined whether smoking (current, former, never) modified these associations.

RESULTS

We observed 167 progression events (median follow-up 9 years). Higher coffee intake was associated with higher risk of progression among current smokers (n = 95). The hazard ratio (HR) [95% confidence interval (CI)] for 5 vs 0 cups/day of coffee was 0.5 (CI 0.2, 1.7) among never smokers, but 4.5 (CI 1.1, 19.4) among current smokers (p-interaction: 0.001). There was no association between total coffee intake and prostate cancer progression among never and former smokers. However, we observed an inverse association between decaffeinated coffee (cups/days) and risk of prostate cancer progression in these men (HR _{> 0 to  < 1 vs 0}: 1.1 (CI 0.7, 1.8); HR_{1 to <2 vs 0}: 0.7 (CI 0.3, 1.4); HR_{≥2 vs 0}: 0.6 (CI 0.3, 1.1); p-trend = 0.03). There was no association between tea and prostate cancer progression, overall or by smoking status.

CONCLUSION

Among non-smoking men diagnosed with localized prostate cancer, moderate coffee and tea consumption was not associated with risk of cancer progression. However, post-diagnostic coffee intake was associated with increased risk of progression among current smokers.

Post-Diagnostic Dietary and Lifestyle Factors and Prostate Cancer Recurrence, Progression, and Mortality

PURPOSE OF REVIEW

This study aimed to summarize evidence published between 1999 and June 2020 examining diet and lifestyle after prostate cancer (PC) diagnosis in relation to risk of biochemical recurrence, PC progression, and PC-specific mortality.

RECENT FINDINGS

Secondary prevention is an important research area in cancer survivorship. A growing number of studies have reported associations between post-diagnostic modifiable behaviors and risk of PC outcomes. Evidence on modifiable lifestyle factors and PC remains limited. Where multiple studies exist, findings are often mixed. However, studies consistently suggest that smoking and consumption of whole milk/high-fat dairy are associated with higher risk of PC recurrence and mortality. In addition, physical activity and ½ to 1 glass of red wine/day have been associated with lower risk of recurrence and PC-specific mortality. Greater inclusion of racially/ethnically diverse groups in future research is necessary to understand these relationships in populations most impacted by adverse PC outcomes.

Feasibility and Acceptability of a Remotely Delivered, Web-Based Behavioral Intervention for Men With Prostate Cancer: Four-Arm Randomized Controlled Pilot Trial

Background

Diet and exercise may be associated with quality of life and survival in men with prostate cancer.

Objective

This study aimed to determine the feasibility and acceptability of a remotely delivered web-based behavioral intervention among men with prostate cancer.

Methods

We conducted a multi-site 4-arm pilot randomized controlled trial of a 3-month intervention (TrueNTH Community of Wellness). Eligibility included self-reported prostate cancer diagnosis, having a personal device that connected to the internet, age ≥18 years, and ability to read English and receive text messages and emails. Men receiving chemotherapy or radiation, or those who reported contraindications to exercise, could participate with physician clearance. Participants were randomized (1:1:1:1) to additive intervention levels: website; website and personalized diet and exercise prescription; website, personalized prescription, Fitbit, and text messages; and website, personalized prescription, Fitbit, text messages, and 2 30-minute phone calls—one with an exercise trainer and one with a registered dietician. Primary outcomes were feasibility (accrual and attrition) and acceptability (survey data and website use). We described self-reported diet and exercise behavior at the time of enrollment, 3 months, and 6 months as secondary outcomes.

Results

In total, 202 men consented and were randomized between August 2017 and September 2018 (level 1: 49, level 2: 51, level 3: 50, level 4: 52). A total of 160 men completed the onboarding process and were exposed to their randomly assigned intervention (38, 38, 42, and 42 in levels 1, 2, 3, and 4, respectively). The follow-up rate was 82.7% (167/202) at 3 months and 77.2% (156/202) at 6 months. Participants had a median age of 70 years and were primarily White and college educated. Website visit frequency over the 3-month intervention period increased across levels (median: 2, 9, 11, and 16 visits for levels 1, 2, 3, and 4, respectively). Most were satisfied or very satisfied with the intervention (20/39, 51%; 27/42, 64%; 23/44, 52%; and 27/42, 64% for levels 1, 2, 3, and 4, respectively). The percentage of men who reported being very satisfied was highest among level 4 participants (10/42, 24% vs 4/39, 10%; 5/42, 12%; and 5/44, 11% for levels 1, 2, and 3, respectively). Dissatisfaction was highest in level 1 (5/39, 13% vs 1/42, 2%; 3/44, 7%; and 2/42, 5% for levels 2, 3, and 4, respectively). We observed small improvements in diet and physical activity at 3 months among men in level 4 versus those in level 1.

Conclusions

A web-based, remotely delivered, tailored behavioral intervention for men with prostate cancer is feasible. Future studies are warranted to increase the effect of the intervention on patient behavior while maintaining sustainability and scalability as well as to design and implement interventions for more diverse populations.

Trial Registration

ClinicalTrials.gov NCT03406013; http://clinicaltrials.gov/ct2/show/NCT03406013

Web-Based Lifestyle Interventions for Prostate Cancer Survivors: Qualitative Study

Background

Exercise and a healthy diet can improve the quality of life and prognosis of prostate cancer survivors, but there have been limited studies on the feasibility of web-based lifestyle interventions in this population.

Objective

This study aims to develop a data-driven grounded theory of web-based engagement by prostate cancer survivors based on their experience in the Community of Wellness, a 12-week randomized clinical trial designed to support healthy diet and exercise habits.

Methods

TrueNTH’s Community of Wellness was a four-arm pilot study of men with prostate cancer (N=202) who received progressive levels of behavioral support (level 1: website; level 2: website with individualized diet and exercise recommendations; level 3: website with individualized diet and exercise recommendations, Fitbit, and text messages; and level 4: website with individualized diet and exercise recommendations, Fitbit and text messages, and separate phone calls with an exercise trainer and a registered dietitian). The primary aim of the study is to determine the feasibility and estimate the effects on behaviors (results reported in a separate paper). Following the 12-week intervention, we invited participants to participate in 4 focus groups, one for each intervention level. In this report, we used grounded theory analyses including open, axial, and selective coding to generate codes and themes from the focus group transcripts. Categories were refined across levels using embodied categorization and constant comparative methods.

Results

In total, 20 men with prostate cancer participated in the focus groups: 5, 4, 5, and 6 men in levels 1, 2, 3, and 4, respectively. Participants converged on 5 common factors influencing engagement with the intervention: environment (home environment, competing priorities, and other lifestyle programs), motivation (accountability and discordance experienced within the health care system), preparedness (technology literacy, health literacy, trust, and readiness to change), program design (communication, materials, and customization), and program support (education, ally, and community). Each of these factors influenced the survivors’ long-term impressions and habits. We proposed a grounded theory associating these constructs to describe the components contributing to the intuitiveness of a web-based lifestyle intervention.

Conclusions

These analyses suggest that web-based lifestyle interventions are more intuitive when we optimize participants’ technology and health literacy; tailor interface design, content, and feedback; and leverage key motivators (ie, health care providers, family members, web-based coach) and environmental factors (ie, familiarity with other lifestyle programs). Together, these grounded theory–based efforts may improve engagement with web-based interventions designed to support prostate cancer survivorship.

Association of Prostate Cancer with Nuts, Seeds, Alcohol and Processed Meats: A Worldwide Population-Based Study

There are conflicting data with regards to the link between diet and the prostate cancer. The purpose of this study was to assess the association of dietary factors with incidence, prevalence and mortality rates of prostate cancer worldwide. We conducted an ecological study including 170 countries, whose data on incidence, prevalence and mortality rates of prostate cancer, dietary factors, and potentially confounding factors were available and collected in May 2020. Univariable and multivariable linear regression analyses were used. Consumption of nuts and seeds was inversely associated with incidence, prevalence and mortality rates of prostate cancer (β -0.7, P < 0.001; β -2.1, P < 0.001; β -0.1, P = 0.02; respectively). Intake of alcohol was associated with increased incidence, prevalence and mortality rates of prostate cancer (β 1.8, P < 0.001; β 4.5, P < 0.001; β 0.4, P < 0.001; respectively). Consumption of processed meats was also associated with increased incidence and prevalence rates of prostate cancer (β 0.6, P = 0.003; β 2.8, P = 0.001; respectively). These data suggest that consumption of nuts and seeds have a protective effect against prostate carcinogenesis, progression, and metastasis, while alcohol and processed meat increase these risks.

Prostate cancer management: long-term beliefs, epidemic developments in the early twenty-first century and 3PM dimensional solutions

In the early twenty-first century, societies around the world are facing the paradoxal epidemic development of PCa as a non-communicable disease. PCa is the most frequently diagnosed cancer for men in several countries such as the USA. Permanently improving diagnostics and treatments in the PCa management causes an impressive divergence between, on one hand, permanently increasing numbers of diagnosed PCa cases and, on the other hand, stable or even slightly decreasing mortality rates. Still, aspects listed below are waiting for innovate solutions in the context of predictive approaches, targeted prevention and personalisation of medical care (PPPM / 3PM).A.PCa belongs to the cancer types with the highest incidence worldwide. Corresponding economic burden is enormous. Moreover, the costs of treating PCa are currently increasing more quickly than those of any other cancer. Implementing individualised patient profiles and adapted treatment algorithms would make currently too heterogeneous landscape of PCa treatment costs more transparent providing clear "road map" for the cost saving.B.PCa is a systemic multi-factorial disease. Consequently, predictive diagnostics by liquid biopsy analysis is instrumental for the disease prediction, targeted prevention and curative treatments at early stages.C.The incidence of metastasising PCa is rapidly increasing particularly in younger populations. Exemplified by trends observed in the USA, prognosis is that the annual burden will increase by over 40% in 2025. To this end, one of the evident deficits is the reactive character of medical services currently provided to populations. Innovative screening programmes might be useful to identify persons in suboptimal health conditions before the clinical onset of metastasising PCa. Strong predisposition to systemic hypoxic conditions and ischemic lesions (e.g. characteristic for individuals with Flammer syndrome phenotype) and low-grade inflammation might be indicative for specific phenotyping and genotyping in metastasising PCa screening and disease management. Predictive liquid biopsy tests for CTC enumeration and their molecular characterisation are considered to be useful for secondary prevention of metastatic disease in PCa patients.D.Particular rapidly increasing PCa incidence rates are characteristic for adolescents and young adults aged 15-40 years. Patients with early onset prostate cancer pose unique challenges; multi-factorial risks for these trends are proposed. Consequently, multi-level diagnostics including phenotyping and multi-omics are considered to be the most appropriate tool for the risk assessment, prediction and prognosis. Accumulating evidence suggests that early onset prostate cancer is a distinct phenotype from both aetiological and clinical perspectives deserving particular attention from view point of 3P medical approaches.

The Facts about Food after Cancer Diagnosis: A Systematic Review of Prospective Cohort Studies

Nutritional guidelines suggest specific energy and protein requirements for patients with cancer. However, cancer patients, often malnourished, use self-made or web-based diets to ameliorate the prognosis of their disease. This review aimed to investigate the associations between post-diagnostic diet and prognostic outcomes in cancer patients. A systematic literature search was performed in Pubmed and Web of Science databases from inception to 30 October 2019, based on fixed inclusion and exclusion criteria. The risk of bias was assessed. A total of 29 prospective studies was identified. Breast (n = 11), colorectal (n = 9), prostate (n = 8) cancers are the most studied. Low- fat diet, healthy quality diet, regular consumption of fiber such as vegetables and high-quality protein intake are beneficial while Western diet (WD) and high consumption of saturated fats could be associated with a higher risk of mortality. Bladder (n = 1), gynecological (n = 1), lung, stomach, and pancreatic cancers still remain almost unexplored. This systematic review suggested that detrimental dietary patterns such as WD should be avoided but none of the food categories (meat, dairy products) should be eliminated in cancer patients' diet. Further large prospective studies are needed to assess the role of post-diagnostic diet in patients with cancer.

A Comprehensive Review of the Benefits of and the Barriers to the Switch to a Plant-Based Diet

In recent decades, the food industry has been faced with new challenges, and it has had to develop new types of diets and produce new types of foods that can slow down the spread of chronic diseases. The aim of our research was to identify the characteristics of plant-based nutrition, based on international and Hungarian literature. The comprehensive analysis was performed based on the theoretical model called Theory of Planned Behavior, in the course of which the perceived and objective benefits of and barriers to the conversion to a plant-based diet were examined. According to our results, the main benefits of plant-based nutrition are its many factors associated with a reduction in risk of developing numerous chronic diseases. This is followed by benefits of well-being and satisfaction, followed by ethical and environmental benefits. The most commonly reported inhibitory factor of a vegetarian diet is the enjoyment of eating meat and the difficulty in giving up meat consumption. This is followed by health considerations, e.g., lack of various ingredients in foods. Convenience and taste factors are also important disincentives, as well as the irrelevant nature of some plant-based nutrition information sources. Besides, social barriers, negative discrimination, and negative effect on mental health associated with them can also be a hindrance, as can financial barriers. The classification developed during our analysis can serve as a relevant guideline for decision-makers, and also as a basis for further primary qualitative and quantitative research.

Diet and lifestyle considerations for patients with prostate cancer

PURPOSE

To review the literature and provide recommendations on diet and lifestyle considerations in patients with prostate cancer using evidence from randomized controlled trials (RCTs) with additional considerations based on observational evidence.

MATERIALS AND METHODS

We initiated our search on ClinicalTrials.gov combining the term "prostate cancer" with a variety of diet and lifestyle factors. We then supplemented our summary of publications from registered trials by including other publications available on Pubmed.

RESULTS

There is a well-established benefit of exercise for improving functional outcomes and pelvic floor muscle training for improving treatment-related adverse effects. Multimodality interventions that integrate several factors (e.g., low-saturated fat, plant-based, whole-food diets with exercise, and stress reduction) appear to have the most clinically significant benefit for patients with prostate cancer. Ongoing multimodality interventions are including the efficacy of implementation strategies as observed outcomes. Limited RCT evidence suggests a clinically significant benefit for guided imagery/progressive muscle relaxation, Pilates, and lycopene-rich diets and a modest benefit for green tea, qigong, massage, and avoidance of nonprescribed vitamin and mineral supplements. Observational and single arm trial evidence indicates a need for further exploration of acupuncture, coffee, cruciferous vegetables, fish, Larrea tridentata, mushrooms, and vegetable-derived fats and avoidance of eggs, dairy, poultry with skin, processed red meat, and saturated fat. Published trials suggest no benefit from hypnosis, milk thistle, pomegranate, soy, or omega-3 fatty acid supplementation.

CONCLUSIONS

Our search demonstrated that most diet and lifestyle factors identified from observational studies have limited data from RCTs. Few items have shown early evidence of benefit. The best recommendation for patients with prostate cancer is to form a habit of wellness through healthy eating, aerobic and resistance exercise, and psychological well-being. Future trial development should consider how interventions can be implemented into real world practice.

The Association of Consumption of Animal Proteins and the Risk of Esophageal Cancer

Aim: Esophageal cancer (EC) is considered one of the most common types of cancer in the world. High intake of dietary proteins is suggested to increase EC. This study examined associations between intake of red meats, processed meat, poultry, and fish and the risk of EC. Methods: This hospital-based Case-Control study included 96 people with EC and 187 people without EC from Bojnurd, Iran. Socio-demographic data was collected from all participants at enrollment using general information questionnaire. Dietary intake was assessed using a validated 168 item semi-quantitative food frequency questionnaire. Results: After adjusting for potential confounders, there was a significant association between the consumption of beef (P = 0.04), processed meats (sausages) (P = 0.01), and chicken with skin (P = 0.001) with the risk of EC. Conclusion: We observed a positive association between red meat, processed meats (sausages), chicken with skin and the risk of EC. The use of lamb meat and fish had no significant association with the risk of EC.

Feasibility, Acceptability, and Behavioral Outcomes from a Technology-enhanced Behavioral Change Intervention (Prostate 8): A Pilot Randomized Controlled Trial in Men with Prostate Cancer

BACKGROUND

Increasing evidence suggests that lifestyle factors may decrease the risk of prostate cancer progression. Lifestyle guidelines and tools may support lifestyle modification after diagnosis.

OBJECTIVE

To determine the feasibility and acceptability of a digital lifestyle intervention among men with prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

A 12-wk pilot randomized controlled trial among 76 men with clinical stage T1-T3a prostate cancer. Eligibility included Internet access, no contraindications to aerobic exercise, and engaging in four or fewer of eight targeted behaviors at baseline.

INTERVENTION

Website, Fitbit One, and text messaging to facilitate adoption of eight behaviors: vigorous activity, smoking cessation, and six diet improvements.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Our primary outcomes were feasibility and acceptability based on recruitment and user data, and surveys, respectively. Secondarily, we evaluated the change in eight lifestyle behaviors, and also objective physical activity. Each factor was assigned one point, for an overall "P8 score" (range 0-8). Analysis of covariance (ANCOVA) was conducted. Exploratory outcomes included quality of life, anthropometrics, and circulating biomarkers after 12wk, and behaviors after 1yr.

RESULTS AND LIMITATIONS

At baseline, men in both arms met a median of three targeted behaviors. Sixty-four men (n=32 per arm) completed the study; 88% completed 12-wk assessments (intervention, 94%; control, 82%). Intervention participants wore their Fitbits a median of 82d (interquartile range [IQR]: 72-83), replied to a median of 71% of text messages (IQR: 57-89%), and visited the website a median of 3d (IQR: 2-5) over 12wk. Median (IQR) absolute changes in the P8 score from baseline to 12wk were 2 (1, 3) for the intervention and 0 (-1, 1) for the control arm. The estimated mean score of the intervention arm was 1.5 (95% confidence interval: 0.7, 2.3) higher than that of the control arm at 12wk (ANCOVA p<0.001). Changes were driven by diet rather than exercise. Limitations include self-reported diet and exercise data.

CONCLUSIONS

Overall, in this novel pilot trial, the intervention was feasible and acceptable to men with prostate cancer. Next steps include improving the intervention to better meet individuals' needs and focusing on increasing physical activity in men not meeting nationally recommended physical activity levels.

PATIENT SUMMARY

Tailored print materials combined with technology integration, including the use of a website, text messaging, and physical activity trackers, helped men with prostate cancer adopt healthy lifestyle habits, in particular recommended dietary changes, in the Prostate 8 pilot trial.

The Epidemiology of Prostate Cancer

Prostate cancer is a major cause of disease and mortality among men, and each year 1.6 million men are diagnosed with and 366,000 men die of prostate cancer. In this review, we discuss the state of evidence for specific genetic, lifestyle, and dietary factors associated with prostate cancer risk. Given the biological heterogeneity of this cancer, we focus on risk factors for advanced or fatal prostate cancer. First, we provide descriptive epidemiology statistics and patterns for prostate cancer incidence and mortality around the world. This includes discussion of the impact of prostate-specific antigen screening on prostate cancer epidemiology. Next, we summarize evidence for selected risk factors for which there is strong or probable evidence of an association: genetics, obesity and weight change, physical activity, smoking, lycopene and tomatoes, fish, vitamin D and calcium, and statins. Finally, we highlight future directions for prostate cancer epidemiology research.

Effect of Increasing Levels of Web-Based Behavioral Support on Changes in Physical Activity, Diet, and Symptoms in Men With Prostate Cancer: Protocol for a Randomized Controlled Trial

Background

More than 3.1 million men in the United States are prostate cancer survivors. These men may improve their physical function, quality of life, and potentially their prognosis by adopting healthier lifestyle habits. The internet provides a scalable mechanism to deliver advice and support about improving physical activity and dietary habits, but the feasibility and acceptability of a Web-based lifestyle intervention and the dose of support necessary to improve health behaviors are not yet known.

Objectives

The Community of Wellness is a Web-based intervention focused on supporting exercise and healthy dietary practices for men with prostate cancer. The objectives of this study were to determine the feasibility, acceptability, and preliminary efficacy of the Community of Wellness Web portal among prostate cancer survivors by conducting a randomized controlled trial (RCT) comparing 4 levels of additive Web-based content and interaction with participants: Level 1 (Teaching; Control), Level 2 (Teaching + Tailoring), Level 3 (Teaching + Tailoring + Technology), and Level 4 (Teaching + Tailoring + Technology + Touch).

Methods

This is a single-blinded RCT comparing 3 levels of behavioral support within the Community of Wellness Web portal intervention (Levels 2 to 4) with each other and with the control condition (Level 1). The control condition receives general static Web-based educational information only on physical activity and dietary habits, self-efficacy for behavior change, motivation for physical activity, and changes in anxiety and treatment-related side effects. We will enroll and randomize 200 men with prostate cancer equally to 4 levels of the Community of Wellness Web-based intervention for 3 months (50 men per level). Surveys will be completed by self-report at baseline, 3 months (immediately postintervention), and 6 months (3 months postintervention). Feasibility and acceptability will be assessed by enrollment statistics, Web-based usage metrics, and surveys at the 3-month time point. We will also conduct focus groups after the postintervention follow-up assessment in a sample of enrolled participants to evaluate elements of usability and acceptability that cannot be obtained via surveys.

Results

Enrollment is ongoing, with 124 enrolled. Study completion (6-month follow-up) is expected by July 2019.

Conclusions

The goal of the study is to identify the level of support that is feasible, acceptable, promotes behavior change, and improves health in men with prostate cancer to inform future efforts to scale the program for broader reach.

Trial Registration

ClinicalTrials.gov NCT03406013; https://clinicaltrials.gov/ct2/show/NCT03406013 (Archived by WebCite at http://www.webcitation.org/73YpDIoTX).

International Registered Report Identifier (IRRID)

PRR1-10.2196/11257

Impact of Metabolic Diseases, Drugs, and Dietary Factors on Prostate Cancer Risk, Recurrence, and Survival: A Systematic Review by the European Association of Urology Section of Oncological Urology

CONTEXT

To date, established risk factors for prostate cancer (PCa) are limited to age, race, family history, and certain genetic polymorphisms. Despite great research efforts, available evidence on potentially modifiable risk factors is conflicting. Moreover, most studies on PCa risk factors did not consider the impact of prostate-specific antigen (PSA) testing on PCa diagnosis.

OBJECTIVE

To provide a detailed overview of the latest evidence on the role of metabolic diseases, drugs, and dietary factors for risk of PCa incidence, recurrence, and survival in men exposed to PSA testing.

EVIDENCE ACQUISITION

A systematic review of the English-language literature was performed using the MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations. Randomized, case-control, or cohort studies published during the periods 2008-2017 (on drugs and metabolic diseases) and 2003-2017 (on dietary factors), with extensive follow-up (≥8-10yr for studies on PCa risk; ≥2-5yr for studies on PCa recurrence, progression, and survival, depending on the review subtopic) and adjusting of the analyses, beyond established risk factors, for either rate of PSA testing (for risk analyses) or PCa stage and primary treatment (for survival analyses), were eligible for inclusion.

EVIDENCE SYNTHESIS

Overall, 39 reports from 22 observational studies were included. Studies were heterogeneous regarding definitions of exposure or outcomes, length of follow-up, risk of bias, and confounding. For some risk factors, evidence was insufficient to assess potential effects, while for others there was no evidence of an effect. For selected risk factors, namely metformin, aspirin and statin use, diabetes, obesity, and specific dietary intakes, there was low-quality evidence of modest effects on PCa risk.

CONCLUSIONS

Current evidence from long-term observational studies evaluating the effect of drugs, metabolic diseases, and dietary factors for PCa risk considering the impact of PSA testing is still not conclusive. Future research is needed to confirm the associations suggested by our review, exploring their potential biological explanations and selecting those risk factors most likely to trigger effective public health interventions.

PATIENT SUMMARY

We reviewed the available studies published in the recent literature on the potential role of drugs, metabolic diseases, and food and dietary factors for the risk of prostate cancer, considering the impact of prostate-specific antigen testing on prostate cancer diagnosis. We found that for some factors data are currently insufficient to make definitive conclusions, while for others available studies seem to indicate an effect on the risk of prostate cancer.

Milk and other dairy foods in relation to prostate cancer recurrence: Data from the cancer of the prostate strategic urologic research endeavor (CaPSURE™)

BACKGROUND

High-fat dairy, particularly whole milk, in healthy men may increase risk of aggressive prostate cancer. However, data are limited regarding dairy after prostate cancer diagnosis.

METHOD

We conducted a prospective study among 1334 men with non-metastatic prostate cancer in the Cancer of the Prostate Strategic Urologic Research Endeavor. Men answered a food frequency questionnaire in 2004-2005 (median 2 years after diagnosis) and were followed until 2016 for recurrence, defined as: prostate cancer death, bone metastases, biochemical recurrence, or secondary treatment. Multivariate Cox proportional hazards regression was used to calculate hazards ratios (HR) and 95% confidence intervals (CI) for associations between whole and low-fat milk; total, high-fat, and low-fat dairy; and other dairy items and risk of recurrence.

RESULTS

During a median follow-up of 8 years, we observed 137 events. Men who consumed >4 servings/week versus 0-3 servings/month of whole milk had an 73% increased risk of recurrence (HR: 1.73; 95%CI: 1.00, 2.98; P-value = 0.04). Body mass index (BMI) modified the association (P-interaction = 0.01). Among men with a BMI ≥27 kg/m² , >4 servings/week versus 0-3 servings/month of whole milk was associated with a 3-fold higher risk of recurrence (HR: 2.96; 95%CI: 1.58, 5.54; P-value < 0.001). No association was seen in men with BMI <27 kg/m² . Low-fat milk and other dairy foods were not associated with recurrence.

CONCLUSION

In conclusion, whole milk consumption after prostate cancer diagnosis was associated with increased risk of recurrence, particularly among very overweight or obese men. Men with prostate cancer who choose to drink milk should select non-fat or low-fat options.

"Eat as If You Could Save the Planet and Win!" Sustainability Integration into Nutrition for Exercise and Sport

Today's industrial food production contributes significantly to environmental degradation. Meat production accounts for the largest impact, including greenhouse gas emissions, land and water use. While food production and consumption are important aspects when addressing climate change, this article focuses predominantly on dietary change that promotes both health for planet and people with focus on athletes. Healthy, sustainable eating recommendations begin to appear in various governmental guidelines. However, there remains resistance to the suggested reductions in meat consumption. While food citizens are likely to choose what is good for them and the planet, others may not, unless healthy eating initiatives integrate creative food literacy approaches with experiential learning as a potential vehicle for change. This concept paper is organized in three sections: (1) Environmental impact of food; (2) health and sustainability connections; and (3) application in sports and exercise. For active individuals, this article focuses on the quantity of protein, highlighting meat and dairy, and quality of food, with topics such as organic production and biodiversity. Finally, the timing of when to integrate sustainability principles in sport nutrition is discussed, followed by practical applications for education and inclusion in team, institutional, and event operations.

Fish-Derived Omega-3 Fatty Acids and Prostate Cancer: A Systematic Review

BACKGROUND

The use of natural health products in prostate cancer (PrCa) is high despite a lack of evidence with respect to safety and efficacy. Fish-derived omega-3 fatty acids possess anti-inflammatory effects and preclinical data suggest a protective effect on PrCa incidence and progression; however, human studies have yielded conflicting results.

METHODS

A search of OVID MEDLINE, Pre-MEDLINE, Embase, and the Allied and Complementary Medicine Database (AMED) was completed for human interventional or observational data assessing the safety and efficacy of fish-derived omega-3 fatty acids in the incidence and progression of PrCa.

RESULTS

Of 1776 citations screened, 54 publications reporting on 44 studies were included for review and analysis: 4 reports of 3 randomized controlled trials, 1 nonrandomized clinical trial, 20 reports of 14 cohort studies, 26 reports of 23 case-control studies, and 3 case-cohort studies. The interventional studies using fish oil supplements in patients with PrCa showed no impact on prostate-specific antigen levels; however, 2 studies showed a decrease in inflammatory or other cancer markers. A small number of mild adverse events were reported and interactions with other interventions were not assessed. Cohort and case-control studies assessing the relationship between dietary fish intake and the risk of PrCa were equivocal. Cohort studies assessing the risk of PrCa mortality suggested an association between higher intake of fish and decreased risk of prostate cancer-related death.

CONCLUSIONS

Current evidence is insufficient to suggest a relationship between fish-derived omega-3 fatty acid and risk of PrCa. An association between higher omega-3 intake and decreased PrCa mortality may be present but more research is needed. More intervention trials or observational studies with precisely measured exposure are needed to assess the impact of fish oil supplements and dietary fish-derived omega-3 fatty acid intake on safety, PrCa incidence, treatment, and progression.

Prostate cancer progression and mortality: a review of diet and lifestyle factors

PURPOSE

To review and summarize evidence on the role of diet and lifestyle factors and prostate cancer progression, with a specific focus on habits after diagnosis and the risk of subsequent disease recurrence, progression, or death.

METHODS

Given the well-documented heterogeneity of prostate cancer and the long survivorship of the majority of diagnoses, our goal was to summarize and describe modifiable risk factors for clinically relevant prostate cancer. We focused where possible on epidemiologic studies of post-diagnostic habits and prostate cancer progression, defined as recurrence (e.g., PSA risk, secondary treatment), metastasis, or death. Where data were limited, we also describe evidence on risk factors and indicators of prostate cancer aggressiveness at diagnosis.

RESULTS

A variety of dietary and lifestyle factors appear to affect prostate cancer progression. Several generally widely recommended lifestyle factors such as not smoking, maintaining a healthy body weight, and regular vigorous physical exercise also appear to affect prostate cancer progression. Several dietary factors, such as tomato sauce/lycopene, cruciferous vegetables, healthy sources of vegetable fats, and coffee, may also have a role in reducing risk of prostate cancer progression.

CONCLUSION

Diet and lifestyle factors, in particular exercise and smoking cessation, may reduce the risk of prostate cancer progression and death. These promising findings warrant further investigation, as their overall impact might be large.

Impact of Elimination or Reduction of Dietary Animal Proteins on Cancer Progression and Survival: Protocol of an Online Pilot Cohort Study

Background

Current evidence suggests that the incidence of cancer is low in vegan populations, and experimental studies have revealed a significant role of dietary proteins in cancer development and progression. However, little data currently exists regarding the effect of a plant-based diet on the progression of diagnosed cancer.

Objective

The main objective of this study is to determine if a reduction or total elimination of animal protein from the diet can positively influence the outcome of an existing cancer and, in addition to standard oncological therapies, increase remission rates.

Methods

The primary aim of this online study is to test the effect on remission rates in cancer patients (primary outcome) with distinct self-selected dietary patterns (omnivore, lacto-ovo-vegetarian, vegan), and allow for an estimation of the effect size. Secondary outcomes are tumor behavior, relapse-free interval, therapies, therapy tolerability and side-effects, comorbidities, medication, quality of life, acceptance, and feasibility of the selected diet. Safety concerns exist for vegan diets (especially in cancer patients) and the study will carefully monitor for deterioration of health, tumor progression, or malnutrition. Furthermore, the study will evaluate the online portal as a study platform (technical and safety aspects, and sequence of displayed questionnaires) as well as the validity of self-reported and online-generated data.

Results

The study was performed between April, 2015 and June, 2016, and a preliminary evaluation of safety aspects was undertaken after June, 2016. Primary and secondary outcomes will be evaluated when the final patients complete the study in December, 2016.

Conclusions

This study will reveal information about the effects of dietary patterns on cancer disease and progression. The methodology of the study addresses several aspects and limitations of nutrition studies in cancer patients, such as precision of nutrition data, acceptance criteria, online methodology, and safety aspects.

ClinicalTrial

Clinicaltrials.gov NCT02437474; https://clinicaltrials.gov/ct2/show/NCT02437474 (Archived by WebCite at http://www.webcitation.org/6jL7UUCVq)

Associations between unprocessed red and processed meat, poultry, seafood and egg intake and the risk of prostate cancer: A pooled analysis of 15 prospective cohort studies

Reports relating meat intake to prostate cancer risk are inconsistent. Associations between these dietary factors and prostate cancer were examined in a consortium of 15 cohort studies. During follow-up, 52,683 incident prostate cancer cases, including 4,924 advanced cases, were identified among 842,149 men. Cox proportional hazard models were used to calculate study-specific relative risks (RR) and then pooled using random effects models. Results do not support a substantial effect of total red, unprocessed red and processed meat for all prostate cancer outcomes, except for a modest positive association for tumors identified as advanced stage at diagnosis (advanced(r)). For seafood, no substantial effect was observed for prostate cancer regardless of stage or grade. Poultry intake was inversely associated with risk of advanced and fatal cancers (pooled multivariable RR [MVRR], 95% confidence interval, comparing ≥ 45 vs. <5 g/day: advanced 0.83, 0.70-0.99; trend test p value 0.29), fatal, 0.69, 0.59-0.82, trend test p value 0.16). Participants who ate ≥ 25 versus <5 g/day of eggs (1 egg ∼ 50 g) had a significant 14% increased risk of advanced and fatal cancers (advanced 1.14, 1.01-1.28, trend test p value 0.01; fatal 1.14, 1.00-1.30, trend test p value 0.01). When associations were analyzed separately by geographical region (North America vs. other continents), positive associations between unprocessed red meat and egg intake, and inverse associations between poultry intake and advanced, advanced(r) and fatal cancers were limited to North American studies. However, differences were only statistically significant for eggs. Observed differences in associations by geographical region warrant further investigation.

Poultry consumption and prostate cancer risk: a meta-analysis

Background. Several kinds of foods are hypothesized to be potential factors contributing to the variation of prostate cancer (PCa) incidence. But the effect of poultry on PCa is still inconsistent and no quantitative assessment has been published up to date. So we conducted this meta-analysis to clarify the association between them. Materials and Methods. We conducted a literature search of PubMed and Embase for studies examining the association between poultry consumption and PCa up to June, 2015. Pooled risk ratio (RR) and corresponding 95% confidence interval (CI) of the highest versus lowest poultry consumption categories were calculated by fixed-effect model or random-effect model. Results. A total of 27 (12 cohort and 15 case-control) studies comprising 23,703 cases and 469,986 noncases were eligible for inclusion. The summary RR of total PCa incidence was 1.03 (95% CI [0.95-1.11]) for the highest versus lowest categories of poultry intake. The heterogeneity between studies was not statistically significant (P = 0.768, I (2) = 28.5%). Synthesized analysis of 11 studies on high stage PCa and 8 studies on chicken exposure also demonstrated null association. We also did not obtain significant association in the subgroup of cohort study (RR = 1.04, 95% CI [0.98-1.10]), as well as in the subgroups of population-based case-control study and hospital-based case-control study. Then the studies were divided into three geographic groups: Western countries, Asia and South America. The pooled RRs in these areas did not reveal statistically significant association between poultry and PCa. Conclusions. This meta-analysis suggests no association between poultry consumption and PCa risk. Further well-designed studies are warranted to confirm the result.

Dietary patterns after prostate cancer diagnosis in relation to disease-specific and total mortality

Men diagnosed with nonmetastatic prostate cancer have a long life expectancy, and many die of unrelated causes. It is therefore important to know to what extent post-diagnostic diet may affect disease-specific and overall mortality. A total of 926 men participating in the Physicians' Health Study diagnosed with nonmetastatic prostate cancer completed diet questionnaires for a median of 5.1 years after diagnosis, and were followed thereafter to assess mortality for a median of 9.9 years since questionnaire completion. Two post-diagnostic dietary patterns were identified: a Prudent pattern, characterized by higher intake of vegetables, fruits, fish, legumes, and whole grains; and a Western pattern, characterized by higher intake of processed and red meats, high-fat dairy and refined grains. Cox regression was used to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI). During 8,093 person-years of follow-up, 333 men died, 56 (17%) of prostate cancer. The Western pattern was significantly related to a higher risk of prostate cancer-specific and all-cause mortality. Comparing men in the highest versus the lowest quartile of the Western pattern, the HRs were 2.53 (95% CI, 1.00-6.42; Ptrend = 0.02) for prostate cancer-specific mortality and 1.67 (95% CI, 1.16-2.42; Ptrend = 0.01) for all-cause mortality. The Prudent pattern was associated with a significantly lower all-cause mortality (HRQuartile 4 vs. Quartile 1: 0.64; 95% CI, 0.44-0.93; Ptrend = 0.02); the relationship with prostate cancer-specific mortality was inverse but not statistically significant. A post-diagnostic Western dietary pattern was associated with higher prostate cancer-specific and all-cause mortality, whereas a Prudent dietary pattern was related to lower all-cause mortality after prostate cancer diagnosis.

Nutrition, dietary interventions and prostate cancer: the latest evidence

Prostate cancer (PCa) remains a leading cause of mortality in US men and the prevalence continues to rise world-wide especially in countries where men consume a 'Western-style' diet. Epidemiologic, preclinical and clinical studies suggest a potential role for dietary intake on the incidence and progression of PCa. 'This minireview provides an overview of recent published literature with regard to nutrients, dietary factors, dietary patterns and PCa incidence and progression. Low carbohydrates intake, soy protein, omega-3 (w-3) fat, green teas, tomatoes and tomato products and zyflamend showed promise in reducing PCa risk or progression. A higher saturated fat intake and a higher β-carotene status may increase risk. A 'U' shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Despite the inconsistent and inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa is promising. The combination of all the beneficial factors for PCa risk reduction in a healthy dietary pattern may be the best dietary advice. This pattern includes rich fruits and vegetables, reduced refined carbohydrates, total and saturated fats, and reduced cooked meats. Further carefully designed prospective trials are warranted.

The environmental cost of protein food choices

Objective

To investigate the resource efficiency and environmental impacts of producing one kilogram of edible protein from two plant- and three animal-protein sources.

Design

Primary source data were collected and applied to commodity production statistics to calculate the indices required to compare the environmental impact of producing 1 kg of edible protein from kidney beans, almonds, eggs, chicken and beef. Inputs included land and water for raising animals and growing animal feed, total fuel, and total fertilizer and pesticide for growing the plant commodities and animal feed. Animal waste generated was computed for the animal commodities.

Setting

Desk-based study at the Department of Nutrition and Department of Occupational and Environmental Health, Loma Linda University.

Subjects

None.

Results

To produce 1 kg of protein from kidney beans required approximately eighteen times less land, ten times less water, nine times less fuel, twelve times less fertilizer and ten times less pesticide in comparison to producing 1 kg of protein from beef. Compared with producing 1 kg of protein from chicken and eggs, beef generated five to six times more waste (manure) to produce 1 kg of protein.

Conclusions

The substitution of beef with beans in meal patterns will significantly reduce the environmental footprint worldwide and should also be encouraged to reduce the prevalence of non-communicable chronic diseases. Societies must work together to change the perception that red meat (e.g. beef) is the mainstay of an affluent and healthy diet.

What should we tell prostate cancer patients about (secondary) prevention?

PURPOSE OF REVIEW

To briefly summarize the epidemiologic findings of selected lifestyle factors for prostate cancer progression, metastasis, or death, with a focus on behaviors after diagnosis where possible. We conclude by providing guidance on the lifestyle practices that physicians may wish to prioritize for discussion with their patients.

RECENT FINDINGS

Growing, but still limited, evidence suggests that lifestyle factors after prostate cancer diagnosis may impact prostate-cancer-specific and overall morality. In particular, smoking and obesity may increase the risk of disease progression and mortality, whereas engaging in vigorous physical activity or brisk walking and consuming a diet rich in vegetables (particularly tomato sauce and cruciferous) and vegetable fats may lower the risk.

SUMMARY

Patients should be counseled not to use tobacco products; to engage in daily physical activity; to minimize sedentary behavior; to consume plenty of healthy fats (i.e. fish, nuts, vegetable oils, soybeans, avocados, and flaxseed) and vegetables; to focus on getting nutrients from foods rather than supplements; and to limit refined grains, sugars, processed meat, and high-fat dairy.

Metabolic crosstalk between choline/1-carbon metabolism and energy homeostasis

There are multiple identified mechanisms involved in energy metabolism, insulin resistance and adiposity, but there are here-to-fore unsuspected metabolic factors that also influence these processes. Studies in animal models suggest important links between choline/1-carbon metabolism and energy homeostasis. Rodents fed choline deficient diets become hypermetabolic. Mice with deletions in one of several different genes of choline metabolism have phenotypes that include increased metabolic rate, decreased body fat/lean mass ratio, increased insulin sensitivity, decreased ATP production by mitochondria, or decreased weight gain on a high fat diet. In addition, farmers have recognized that the addition of a metabolite of choline (betaine) to cattle and swine feed reduces body fat/lean mass ratio. Choline dietary intake in humans varies over a > three-fold range, and genetic variation exists that modifies individual requirements for this nutrient. Although there are some epidemiologic studies in humans suggesting a link between choline/1-carbon metabolism and energy metabolism, there have been no controlled studies in humans that were specifically designed to examine this relationship.

The relationship between nutrition and prostate cancer: is more always better?

CONTEXT

Prostate cancer (PCa) remains one of the most diagnosed malignancies in the world, correlating with regions where men consume more of a so-called Western-style diet. As such, there is much interest in understanding the role of lifestyle and diet on the incidence and progression of PCa.

OBJECTIVE

To provide a summary of published literature with regard to dietary macro- and micronutrients and PCa incidence and progression.

EVIDENCE ACQUISITION

A literature search was completed using the PubMed database for all studies published on diet and PCa in June 2012 or earlier. Primary literature and meta-analyses were given preference over other review articles when possible.

EVIDENCE SYNTHESIS

The literature was reviewed on seven dietary components: carbohydrates, protein, fat and cholesterol, vegetables, vitamins and minerals, and phytochemicals. Current literature linking these nutrients to PCa is limited at best, but trends in the published data suggest consumption of carbohydrates, saturated and ω-6 fats, and certain vitamin supplements may promote PCa risk and progression. Conversely, consumption of many plant phytochemicals and ω-3 fatty acids seem to slow the risk and progression of the disease. All other nutrients seem to have no effect or data are inconclusive. A brief summary about the clinical implications of dietary interventions with respect to PCa prevention, treatment, and survivorship is provided.

CONCLUSIONS

Due to the number and heterogeneity of published studies investigating diet and PCa, it is difficult to determine what nutrients make up the perfect diet for the primary and secondary prevention of PCa. Because diets are made of multiple macro- and micronutrients, further prospective studies are warranted, particularly those investigating the relationship between whole foods instead of a single nutritional component.

Choline intake and risk of lethal prostate cancer: incidence and survival

BACKGROUND

Meat, milk, and eggs have been inconsistently associated with the risk of advanced prostate cancer. These foods are sources of choline-a nutrient that may affect prostate cancer progression through cell membrane function and one-carbon metabolism. No study has examined dietary choline and the risk of lethal prostate cancer.

OBJECTIVE

Our objective was to examine whether dietary choline, choline-containing compounds, and betaine (a choline metabolite) increase the risk of lethal prostate cancer.

DESIGN

We prospectively examined the intake of these nutrients and the risk of lethal prostate cancer among 47,896 men in the Health Professionals Follow-Up Study. In a case-only survival analysis, we examined the postdiagnostic intake of these nutrients and the risk of lethal prostate cancer among 4282 men with an initial diagnosis of nonmetastatic disease during follow-up. Diet was assessed with a validated questionnaire 6 times during 22 y of follow-up.

RESULTS

In the incidence analysis, we observed 695 lethal prostate cancers during 879,627 person-years. Men in the highest quintile of choline intake had a 70% increased risk of lethal prostate cancer (HR: 1.70; 95% CI: 1.18, 2.45; P-trend = 0.005). In the case-only survival analysis, we observed 271 lethal cases during 33,679 person-years. Postdiagnostic choline intake was not statistically significantly associated with the risk of lethal prostate cancer (HR for quintile 5 compared with quintile 1: 1.69; 95% CI: 0.93, 3.09; P-trend = 0.20).

CONCLUSION

Of the 47,896 men in our study population, choline intake was associated with an increased risk of lethal prostate cancer.

Relationship between dietary factors and prostate-specific antigen in healthy men

INTRODUCTION

There is little evidence indicating whether dietary factors influence prostate-specific antigen (PSA) concentrations. We examined whether nutritional factors, including energy, protein, fat, and carbohydrate intake were associated with PSA in healthy men.

SUBJECTS AND METHODS

We investigated 13,594 men aged 50 years and over who visited a hospital for a routine health checkup between 2003 and 2007. Dietary intake was assessed using a food frequency questionnaire. We performed a multiple linear regression to examine the association between PSA and dietary intake.

RESULTS

After controlling for age, body mass index, and physical activity, PSA was significantly negatively associated with percent protein intake (p for trend < 0.001). Compared with the lowest quintile, PSA was 5.8% lower (95% CI: -8.9 to -2.5%) in the highest quintile. We also observed a significant positive association between percent fat intake and PSA concentration (p for trend 0.043). PSA was 3.4% greater (95% CI: 0-6.9%) among men in the highest quintile compared with those in the lowest quintile.

CONCLUSIONS

Men who had a lower percent protein intake and higher percent fat intake had an elevated PSA level, although the magnitude of these associations was small.

Polymorphisms in carcinogen metabolism enzymes, fish intake, and risk of prostate cancer

Cooking fish at high temperature can produce potent carcinogens such as heterocyclic amines and polycyclic aromatic hydrocarbons. The effects of these carcinogens may undergo modification by the enzymes responsible for their detoxification and/or activation. In this study, we investigated genetic polymorphisms in nine carcinogen metabolism enzymes and their modifying effects on the association between white or dark fish consumption and prostate cancer (PCA) risk. We genotyped 497 localized and 936 advanced PCA cases and 760 controls from the California Collaborative Case-Control Study of Prostate Cancer. Three polymorphisms, EPHX1 Tyr113His, CYP1B1 Leu432Val and GSTT1 null/present, were associated with localized PCA risk. The PTGS2 765 G/C polymorphism modified the association between white fish consumption and advanced PCA risk (interaction P 5 0.002), with high white fish consumption being positively associated with risk only among carriers of the C allele. This effect modification by PTGS2 genotype was stronger when restricted to consumption of well-done white fish (interaction P 5 0.021). These findings support the hypotheses that changes in white fish brought upon by high-temperature cooking methods, such as carcinogen accumulation and/or fatty acid composition changes, may contribute to prostate carcinogenesis. However, the gene-diet interactions should be interpreted with caution given the limited sample size. Thus, our findings require further validation with additional studies.

Impact of Diet, Body Mass Index, and Physical Activity on Cancer Survival

With the increase in the number of cancer patients worldwide in the coming years, the need for knowledge on the influence of lifestyle factors on cancer survival is increasing. In this paper, the current knowledge on diet, body mass index, and physical activity in relation to cancer outcome is summarized. Also, challenges are identified to be addressed to provide evidence-based recommendations for cancer patients. Studies in patients with breast, colorectal, or prostate cancer show that the influence of dietary factors on survival remains to be determined. Adiposity and a lack of physical activity, however, appear to influence cancer outcome negatively. Subsequent studies should focus on more detailed aspects of these lifestyle factors, such as body composition and dose of exercise, and on the timing with respect to diagnosis and treatment. Research should be directed toward investigating diet and physical activity simultaneously and on how changes in health behavior can be established.

Biological analysis of endocrine-disrupting chemicals in animal meats from the Pearl River Delta, China

Endocrine disrupting chemicals (EDCs) consist of a diverse group of industrial chemicals and pharmacological agents. The use of instrumental analyses as the first screening tool might not be cost-effective to identify the existence of enormous numbers of chemical contaminants in environments. Also, knowledge of the concentration of individual residues is difficult to use to evaluate biological impacts of contaminants to wildlife and humans. The primary objective of the present study was to develop and to test the feasibility of using a battery of exposure biomarkers for the rapid-screening of various endocrine disrupting activities present in food. The measurement of the EDC-elicited activities involved various (i) receptor-mediated responses, including androgenic, estrogenic, dioxin-like, glucocorticoid-like, progesterone-like, peroxisome proliferator-like and retinoid-like as well as (ii) the non-receptor mediated responses through modulation of cellular reactive oxygen species (ROS) and ATP content. Samples of both local and imported pork, beef and chicken as well as freshwater and seawater fishes were collected. Extracts of different foods exhibited various dioxin-like and "hormonal" activities. Fish and chicken skin were found to be the major source of exogenous "hormonal" and dioxin-like substances in diets. Extracts of beef and pork contained lesser potencies of hormonally-active agents. Our data suggest that the proposed EDC-screening platform may be useful in a risk assessment for the routine monitoring of EDCs in foods. Continuous monitoring and research is warranted to assess the physiological consequences of the consumption.

Egg, red meat, and poultry intake and risk of lethal prostate cancer in the prostate-specific antigen-era: incidence and survival

Red and processed meat may increase risk of advanced prostate cancer. Data on postdiagnostic diet and prostate cancer are sparse, but postdiagnostic intake of poultry with skin and eggs may increase risk of disease progression. Therefore, we prospectively examined total, unprocessed, and processed red meat, poultry, and eggs in relation to risk of lethal prostate cancer (e.g., men without cancer at baseline who developed distant organ metastases or died from prostate cancer during follow-up) among 27,607 men followed from 1994 to 2008. We also conducted a case-only survival analysis to examine postdiagnostic consumption of these foods and risk of lethal prostate cancer among the 3,127 men initially diagnosed with nonmetastatic prostate cancer during follow-up. In the incidence analysis, we observed 199 events during 306,715 person-years. Men who consumed 2.5 or more eggs per week had an 81% increased risk of lethal prostate cancer compared with men who consumed less than 0.5 eggs per week (HR: 1.81; 95% CI: 1.13-2.89; P(trend): 0.01). In the case-only survival analysis, we observed 123 events during 19,354 person-years. There were suggestive, but not statistically significant, positive associations between postdiagnostic poultry (HR ≥ 3.5 vs. <1.5 servings per week: 1.69; 95% CI: 0.96-2.99; P(trend): 0.07) and postdiagnostic processed red meat (HR ≥ 3 vs. <0.5 servings per week: 1.45; 95% CI: 0.73-2.87; P(trend): 0.08) and risk of progression of localized prostate cancer to lethal disease. In conclusion, consumption of eggs may increase risk of developing a lethal form of prostate cancer among healthy men.

Impact of meat consumption, preparation, and mutagens on aggressive prostate cancer

Background

The association between meat consumption and prostate cancer remains unclear, perhaps reflecting heterogeneity in the types of tumors studied and the method of meat preparation—which can impact the production of carcinogens.

Methods

We address both issues in this case-control study focused on aggressive prostate cancer (470 cases and 512 controls), where men reported not only their meat intake but also their meat preparation and doneness level on a semi-quantitative food-frequency questionnaire. Associations between overall and grilled meat consumption, doneness level, ensuing carcinogens and aggressive prostate cancer were assessed using multivariate logistic regression.

Results

Higher consumption of any ground beef or processed meats were positively associated with aggressive prostate cancer, with ground beef showing the strongest association (OR = 2.30, 95% CI:1.39–3.81; P-trend = 0.002). This association primarily reflected intake of grilled or barbequed meat, with more well-done meat conferring a higher risk of aggressive prostate cancer. Comparing high and low consumptions of well/very well cooked ground beef to no consumption gave OR's of 2.04 (95% CI:1.41–2.96) and 1.51 (95% CI:1.06–2.14), respectively. In contrast, consumption of rare/medium cooked ground beef was not associated with aggressive prostate cancer. Looking at meat mutagens produced by cooking at high temperatures, we detected an increased risk with 2-amino-3,8-Dimethylimidazo-[4,5-f]Quinolaxine (MelQx) and 2-amino-3,4,8-trimethylimidazo(4,5-f)qunioxaline (DiMelQx), when comparing the highest to lowest quartiles of intake: OR = 1.69 (95% CI:1.08–2.64;P-trend = 0.02) and OR = 1.53 (95% CI:1.00–2.35; P-trend = 0.005), respectively.

Discussion

Higher intake of well-done grilled or barbequed red meat and ensuing carcinogens could increase the risk of aggressive prostate cancer.

The role of diet and physical activity in breast, colorectal, and prostate cancer survivorship: a review of the literature

BACKGROUND

Evidence for the role of diet and physical activity in cancer incidence is well documented, but owing to increased cancer survivorship, an understanding of these lifestyle factors after a cancer diagnosis is of crucial importance. The purpose of this review was to update the literature in a review undertaken for the National Cancer Survivorship Initiative and to include observational studies that were not included in the WCRF survivorship systematic review.

METHODS

Evidence was initially gathered from pre-defined searches of the Cochrane Library Database and PubMed from March 2006 to February 2010. After a comprehensive review regarding lifestyle and cancer, for the purpose of this article, any studies not related to diet and physical activity, prognostic outcomes, and breast, colorectal or prostate cancers were excluded. Another search of 2011 literature was conducted to update the evidence.

RESULTS

A total of 43 records were included in this review. Evidence from observational studies suggests that a low-fat, high-fibre diet might be protective against cancer recurrence and progression. However, there is a paucity of RCTs substantiating this. There is more support for physical activity, with a dose response for better outcomes. When synthesized with findings from the World Cancer Research Fund review of RCTs investigating the effect of diet and physical activity interventions on cancer survival, evidence suggests that the mechanism of benefit from diet and physical activity pertains to body weight, with excess body weight being a risk factor, which is modifiable through lifestyle.

IMPLICATIONS

Cancer survivors would like to have a more active role in their health care and to know how to look after themselves after diagnosis, including what diet and lifestyle changes they should make. The challenge is in integrating lifestyle support into standardised models of aftercare.

Vegetable and fruit intake after diagnosis and risk of prostate cancer progression

Cruciferous vegetables, tomato sauce and legumes have been associated with reduced risk of incident advanced prostate cancer. In vitro and animal studies suggest these foods may inhibit progression of prostate cancer, but there are limited data in men. Therefore, we prospectively examined whether intake of total vegetables, and specifically cruciferous vegetables, tomato sauce and legumes, after diagnosis reduce risk of prostate cancer progression among 1,560 men diagnosed with non-metastatic prostate cancer and participating in the Cancer of the Prostate Strategic Urologic Research Endeavor, a United States prostate cancer registry. As a secondary analysis, we also examined other vegetable subgroups, total fruit and subgroups of fruits. The participants were diagnosed primarily at community-based clinics and followed from 2004 to 2009. We assessed vegetable and fruit intake via a semi-quantitative food frequency questionnaire, and ascertained prostate cancer outcomes via urologist report and medical records. We observed 134 events of progression (53 biochemical recurrences, 71 secondary treatments likely due to recurrence, 6 bone metastases and 4 prostate cancer deaths) during 3,171 person-years. Men in the fourth quartile of post-diagnostic cruciferous vegetable intake had a statistically significant 59% decreased risk of prostate cancer progression compared to men in the lowest quartile (hazard ratio (HR): 0.41; 95% confidence interval (CI): 0.22, 0.76; p-trend: 0.003). No other vegetable or fruit group was statistically significantly associated with risk of prostate cancer progression. In conclusion, cruciferous vegetable intake after diagnosis may reduce risk of prostate cancer progression.

Prostate cancer and diet: food for thought?

• There is now increasing evidence that diet plays a major role in prostate cancer biology and tumorigenesis. • In a health conscious society, it is becoming increasingly common for Urologists to be asked about the impact of diet on prostate cancer. • In the present review, we explore the current evidence for the role of different dietary components and its' effect on prostate cancer prevention and progression. • A literature search was conducted using PubMed® to identify key studies. • There was some evidence to suggest that green tea, isoflavones, lycopenes, cruciferous vegetables and omega 3 polyunsaturated fatty acid intake to be beneficial in the prevention and/or progression of prostate cancer. • There was also evidence to suggest that a high total fat, meat (especially well cooked) and multivitamin intake may be associated with an increased risk of developing prostate cancer. • To date publications have been highly heterogeneous and variable in quality and design. More robust, high quality research trials are needed to help us understand the complex relationship between diet and prostate cancer.

Physical activity after diagnosis and risk of prostate cancer progression: data from the cancer of the prostate strategic urologic research endeavor

Vigorous activity after diagnosis was recently reported to be inversely associated with prostate cancer-specific mortality. However, men with metastatic disease may decrease their activity due to their disease; thus, a causal interpretation is uncertain. We therefore prospectively examined vigorous activity and brisk walking after diagnosis in relation to risk of prostate cancer progression, an outcome less susceptible to reverse causation, among 1,455 men diagnosed with clinically localized prostate cancer. Cox proportional hazards regression was used to examine vigorous activity, nonvigorous activity, walking duration, and walking pace after diagnosis and risk of prostate cancer progression. We observed 117 events (45 biochemical recurrences, 66 secondary treatments, 3 bone metastases, 3 prostate cancer deaths) during 2,750 person-years. Walking accounted for nearly half of all activity. Men who walked briskly for 3 h/wk or more had a 57% lower rate of progression than men who walked at an easy pace for less than 3 h/wk (HR = 0.43; 95% CI: 0.21-0.91; P = 0.03). Walking pace was associated with decreased risk of progression independent of duration (HR brisk vs. easy pace = 0.52; 95% CI: 0.29-0.91; P(trend) = 0.01). Few men engaged in vigorous activity, but there was a suggestive inverse association (HR ≥3 h/wk vs. none = 0.63; 95% CI: 0.32-1.23; P(trend) = 0.17). Walking duration and total nonvigorous activity were not associated with risk of progression independent of pace or vigorous activity, respectively. Brisk walking after diagnosis may inhibit or delay prostate cancer progression among men diagnosed with clinically localized prostate cancer.