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

Quantifying the Contributions of Environmental Factors to Prostate Cancer and Detecting Risk-Related Diet Metrics and Racial Disparities

The relevance of nongenetic factors to prostate cancer (PCa) has been elusive. We aimed to quantify the contributions of environmental factors to PCa and identify risk-related diet metrics and relevant racial disparities. We performed a unique analysis of the Diet History Questionnaire data of 41 830 European Americans (EAs) and 1282 African Americans (AAs) in the PLCO project. The independent variables in the regression models consisted of age at trial entry, race, family history of prostate cancer (PCa-fh), diabetes history, body mass index (BMI), lifestyle (smoking and coffee consumption), marital status, and a specific nutrient/food factor (X). P < .05 and a 95% confidence interval excluding zero were adopted as the criteria for determining a significant difference (effect). We established a priority ranking among PCa risk-related genetic and environmental factors according to the deviances explained by them in the multivariate Cox-PH regression analysis: age > PCa-fh > diabetes ⩾ race > lifestyle ⩾marital-status ⩾BMI > X. We confirmed previous studies showing that (1) high protein and saturated fat levels in diet were related to increased PCa risk, (2) high-level supplementary selenium intake was harmful rather than beneficial for preventing PCa, and (3) supplementary vitamin B6 was beneficial for preventing benign PCa. We obtained the following novel findings: high-level organ meat intake was an independent predictor for increased aggressive PCa risk; supplementary iron, copper and magnesium increased benign PCa risk; and the AA diet was "healthy" in terms of the relatively lower protein and fat levels and was "unhealthy" in that it more commonly contained organ meat. In conclusion, we established a priority ranking among the contributing factors for PCa and identified several risk-related diet metrics and the racial disparities. Our findings suggested some new approaches to prevent PCa such as restriction of organ meat intake and supplementary microminerals.

8-Geranyloxycarbostyril as a potent 15-LOX-1 inhibitor showed great anti-tumor effects against prostate cancer

Carbostyrils are quinolone derivatives, with possible growth inhibition properties on cancer cells. Unlike many tumors, 15-Lipoxygenase-1 (15-LOX-1) is highly expressed in prostate cancer (PCa) cells and has oncogenic properties. Here, with the hypothesis that 6-, 7- and 8-geranyloxycarbostyril (GQ) have inhibitory properties on 15-LOX-1, their effects were assessed on PCa cells. Their cytotoxic effects were evaluated by MTT assay and mechanism of cell death was investigated using annexin V/PI staining. Finally, the anti-tumor properties of 8-GQ were assessed in immunocompromised C57BL/6 mice bearing human PCa cells. Accordingly, these compounds could effectively inhibit 15-LOX activity in PCa cells. MTT and flow cytometry tests confirmed their toxic effects on PCa cells, with no significant toxicity on normal cells, and apoptosis was the main mechanism of cell death. In vivo results indicated that use of 8-GQ at 50 mg/kg had stronger anti-tumor effects than 5 mg/kg cisplatin, with fewer side effects on normal tissues. Therefore, 8-GQ can be introduced as a potential drug candidate with 15-LOX-1 inhibitory potency, which can be effective in treatment of prostate cancer, and should be considered for further drug screening investigations.

Dietary Factors and Prostate Cancer Development, Progression, and Reduction

Due to the constantly increasing number of cases, prostate cancer has become one of the most important health problems of modern societies. This review presents the current knowledge regarding the role of nutrients and foodstuff consumption in the etiology and development of prostate malignancies, including the potential mechanisms of action. The results of several in vivo and in vitro laboratory experiments as well as those reported by the clinical and epidemiological research studies carried out around the world were analyzed. The outcomes of these studies clearly show the influence of both nutrients and food products on the etiology and prevention of prostate cancer. Consumption of certain nutrients (saturated and trans fatty acids) and food products (e.g., processed meat products) leads to the disruption of prostate hormonal regulation, induction of oxidative stress and inflammation, and alteration of growth factor signaling and lipid metabolism, which all contribute to prostate carcinogenesis. On the other hand, a high consumption of vegetables, fruits, fish, and whole grain products exerts protective and/or therapeutic effects. Special bioactive functions are assigned to compounds such as flavonoids, stilbenes, and lycopene. Since the influence of nutrients and dietary pattern is a modifiable risk factor in the development and prevention of prostate cancer, awareness of the beneficial and harmful effects of individual food ingredients is of great importance in the global strategy against prostate cancer.

Association of Total Dietary Intake of Sugars with Prostate-Specific Antigen (PSA) Concentrations: Evidence from the National Health and Nutrition Examination Survey (NHANES), 2003-2010

BACKGROUND

There is increasing evidence that dietary intake of sugars may be a risk factor for prostate cancer (PCa) and elevate the concentration of serum prostate-specific antigen (PSA). However, there is limited evidence of the correlation between total dietary intake of sugars and serum PSA concentrations for adult American males. Herein, we evaluated the association between total dietary intake of sugars and serum PSA concentrations in men without a malignant tumor diagnosis in the United States (US) National Health and Nutrition Examination Survey (NHANES) database. Material and Methods. In this secondary data analysis, a total of 6,403 men aged ≥40 years and without malignant tumor history were included from 2003 to 2010. The independent variable of this study was the total dietary intake of sugars, and the dependent variable was serum PSA concentrations. Covariates included dietary, comorbidity, physical examination, and demographic data.

RESULTS

The average age of participants included in this study was 58.1 years (±13.6). After adjusting for the dietary, comorbidity, physical examination, and demographic data, we observed that a dietary intake increase of one gram of total dietary intake of sugars was associated with an increase of serum PSA concentrations by 0.003 ng/mL (after log2 transformed, 95% CI: 0.001 to 0.005) with a P value for trend less than 0.05. Sensitivity analysis using the generalized additive model (GAM) supported the linear association between total dietary intake of sugars and serum PSA concentrations.

CONCLUSION

The total dietary intake of sugars is independently and positively associated with serum PSA concentrations in adult American males who are without a personal history of malignant tumors.

The Impact of African Ancestry on Prostate Cancer Disparities in the Era of Precision Medicine

Prostate cancer disproportionately affects men of African ancestry at nearly twice the rate of men of European ancestry despite the advancement of treatment strategies and prevention. In this review, we discuss the underlying causes of these disparities including genetics, environmental/behavioral, and social determinants of health while highlighting the implications and challenges that contribute to the stark underrepresentation of men of African ancestry in clinical trials and genetic research studies. Reducing prostate cancer disparities through the development of personalized medicine approaches based on genetics will require a holistic understanding of the complex interplay of non-genetic factors that disproportionately exacerbate the observed disparity between men of African and European ancestries.

Influence of Diet and Nutrition on Prostate Cancer

The incidence of prostate cancer (PCa) displays widespread regional differences, probably owing to differences in dietary habits. Nutrients, including fat, protein, carbohydrates, vitamins (vitamin A, D, and E), and polyphenols, potentially affect PCa pathogenesis and progression, as previously reported using animal models; however, clinical studies have reported controversial results for almost all nutrients. The effects of these nutrients may be manifested through various mechanisms including inflammation, antioxidant effects, and the action of sex hormones. Dietary patterns including the Western and Prudent patterns also influence the risk of PCa. Recent studies reported that the gut microbiota contribute to tumorigenesis in some organs. Diet composition and lifestyle have a direct and profound effect on the gut bacteria. Human studies reported an increase in the abundance of specific gut bacteria in PCa patients. Although there are few studies concerning their relationship, diet and nutrition could influence PCa, and this could be mediated by gut microbiota. An intervention of dietary patterns could contribute to the prevention of PCa. An intervention targeting dietary patterns may thus help prevent PCa.

Dietary fatty acid quality affects systemic parameters and promotes prostatitis and pre-neoplastic lesions

Environmental and nutritional factors, including fatty acids (FA), are associated with prostatitis, benign prostate hyperplasia and prostate cancer. We hypothesized that different FA in normolipidic diets (7%) affect prostate physiology, increasing the susceptibility to prostate disorders. Thus, we fed male C57/BL6 mice with normolipidic diets based on linseed oil, soybean oil or lard (varying saturated and unsaturated FA contents and ω-3/ω-6 ratios) for 12 or 32 weeks after weaning and examined structural and functional parameters of the ventral prostate (VP) in the systemic metabolic context. Mongolian gerbils were included because they present a metabolic detour for low water consumption (i.e., oxidize FA to produce metabolic water). A linseed oil-based diet (LO, 67.4% PUFAs, ω-3/ω-6 = 3.70) resulted in a thermogenic profile, while a soybean oil-based diet (SO, 52.7% PUFAs, ω-3/ω-6 = 0.11) increased body growth and adiposity. Mice fed lard (PF, 13.1% PUFA, ω-3/ω-6 = 0.07) depicted a biphasic growth, resulting in decreased adiposity in adulthood. SO and PF resulted in hepatic steatosis and steatohepatitis, respectively. PF and SO increased prostate epithelial volume, and lard resulted in epithelial hyperplasia. Animals in the LO group had smaller prostates with predominant atrophic epithelia and inflammatory loci. Inflammatory cells were frequent in the VP of PF mice (predominantly stromal) and LO mice (predominantly luminal). RNAseq after 12 weeks revealed good predictors of a later-onset inflammation. The transcriptome unveiled ontologies related to ER stress after 32 weeks on PF diets. In conclusion, different FA qualities result in different metabolic phenotypes and differentially impact prostate size, epithelial volume, inflammation and gene expression.

Higher baseline dietary fat and fatty acid intake is associated with increased risk of incident prostate cancer in the SABOR study

BACKGROUND

To study the association of nutrient intake measured by baseline food frequency questionnaire and risk of subsequent prostate cancer (PCa) in the SABOR (San Antonio Biomarkers of Risk) cohort study.

METHODS

After IRB approval, more than 1903 men enrolled in a prospective cohort from 2000 to 2010 as part of the SABOR clinical validation site for the National Cancer Institute Early Detection Research Network. Food and nutrient intakes were calculated using a Food Frequency Questionnaire. Cox proportional hazards modeling and covariate-balanced propensity scores were used to assess the associations between all nutrients and PCa.

RESULTS

A total of 229 men were diagnosed with PCa by prostate biopsy. Among all nutrients, increased risk of PCa was associated with intake of dietary fat scaled by the total caloric intake, particularly saturated fatty acid (SFA) [HR 1.19; 95% CI, 1.07-1.32), P value < 0.001, False discovery rate (FDR) 0.047] and trans fatty acid (TFA) [HR per quintile 1.21; (95% CI) (1.08-1.35), P < 0.001, FDR 0.039]. There was an increased risk of PCa with increasing intake of monounsaturated fatty acid (MUFA) (HR per quintile 1.14; 95% CI 1.03-1.27, P = 0.01, FDR 0.15) and cholesterol [HR per quintile 1.13; 95% confidence interval (95% CI) (1.02-1.26), P-value 0.02, FDR 0.19].

CONCLUSION

After examining a large, population-based cohort for PCa diagnosis, we identified dietary total fat and certain fatty acids as associated with increased risk of PCa. We found no factors that were protective from PCa. Dietary modification of fatty acid intake may reduce risk of PCa.

Dietary patterns and prostate cancer risk in Japanese: the Japan Public Health Center-based Prospective Study (JPHC Study)

PURPOSE

The development of prostate cancer may be impacted by environmental factors, including diet. The aim of this study was to evaluate the association between dietary patterns and risk of prostate cancer in a large prospective cohort study among Japanese men.

METHODS

A total of 43,469 men who participated in the Japan Public Health Center-based Prospective Study were followed from 1995 to 1998 to the end of 2012, during which 1,156 cases of prostate cancer were newly identified. Dietary intake was assessed using a validated food frequency questionnaire in the 5-year follow-up survey.

RESULTS

Three major dietary patterns were derived using exploratory factors analysis: prudent, westernized, and traditional dietary patterns. The westernized dietary pattern was associated with a higher risk of total prostate cancer (HR: 1.22; 95% CI 1.00-1.49; p trend = 0.021), localized cancer (HR: 1.24; 95% CI 0.97-1.57; p trend = 0.045), and advanced cancer (HR: 1.23; 95% CI 0.82-1.84; p trend = 0.233). The prudent dietary pattern was associated with a lower risk of total and localized prostate cancer, with respective multivariable HRs for the highest and lowest quintiles of 0.71 (95% CI 0.50-1.02; p trend = 0.037) and 0.63 (95% CI 0.38-1.03; p trend = 0.048) among subjects detected by subjective symptoms. No association was found between the traditional dietary pattern and prostate cancer risk among our subjects.

CONCLUSION

Our results suggest that a western-style diet may lead to a higher risk of prostate cancer in the total population, whereas the prudent diet contributes to a lower risk among subjects detected by subjective symptoms.

Age-specific Serum Prostate Specific Antigen Ranges Among Apparently Healthy Nigerian Men Without Clinical Evidence of Prostate Cancer

INTRODUCTION

Serum prostate specific antigen (PSA) levels increase with age and varies among different races and communities. The study was aimed at defining the age-specific reference ranges of serum PSA in our environment.

METHODS

We evaluated the relationship between age and serum PSA levels and the age-specific reference ranges of serum PSA among civil servants in Lagos, who underwent routine medical checkups. Criteria for inclusion were men who have no lower urinary tract symptoms, normal digital rectal examination and serum PSA ≤ 20 ng/ml. SPSS Statistic 21 was used for data evaluation and the mean, median, 95(th) percentile PSA levels were estimated. Pearson's correlation was used to examine the relationship, and P < 0.05 was considered significant.

RESULTS

4032 men met the criteria for inclusion in the evaluation. The mean age was 51.6 (range 40-70) years, and there was a strong correlation between serum PSA levels and age (r = 0.097, P < 0.001). PSA ranges of 0-2.5, >2.5-4.0, >4.0-10, and >10 ng/ml were found in 3218 (80%), 481 (12%), 284 (7%), and 52 (1%) men, respectively. The mean, median and the 95(th) percentile PSA for the overall group were 1.84, 1.33, and 5.2 ng/ml respectively. However the 95(th) percentile PSA levels for men aged 40-49, 50-59, and 60-70 years were 4.78, 5.47, and 8.93 ng/ml respectively.

CONCLUSION

The age-specific PSA levels among Nigerian men for each age group is higher than what was described for men in the Western world. These reference ranges of serum PSA should be considered for men aged ≥40 years in our environment.

An investigation into the association between DNA damage and dietary fatty acid in men with prostate cancer

Prostate cancer is a growing problem in New Zealand and worldwide, as populations adopt a Western style dietary pattern. In particular, dietary fat is believed to be associated with oxidative stress, which in turn may be associated with cancer risk and development. In addition, DNA damage is associated with the risk of various cancers, and is regarded as an ideal biomarker for the assessment of the influence of foods on cancer. In the study presented here, 20 men with prostate cancer adhered to a modified Mediterranean style diet for three months. Dietary records, blood fatty acid levels, prostate specific antigen, C-reactive protein and DNA damage were assessed pre- and post-intervention. DNA damage was inversely correlated with dietary adherence (p = 0.013) and whole blood monounsaturated fatty acids (p = 0.009) and oleic acid (p = 0.020). DNA damage was positively correlated with the intake of dairy products (p = 0.043), red meat (p = 0.007) and whole blood omega-6 polyunsaturated fatty acids (p = 0.015). Both the source and type of dietary fat changed significantly over the course of the dietary intervention. Levels of DNA damage were correlated with various dietary fat sources and types of dietary fat.

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.

Association of diet with prostate specific antigen and prostate volume

Background:

Prostate is an important male reproductive system gland and its disorders can affect men's quality of life and health. Prostatitis, benign prostatic hyperplasia (BPH), and prostate adenocarcinoma are major disorders that can be found in all men in different ages.

Objectives:

The aim of this study was to investigate the association of diet with serum prostate specific antigen (PSA) level as well as prostate volume.

Patients and Methods:

In this cross-sectional study, 950 men older than 40 years of age who had attended our clinic for a screening program for prostate cancer were enrolled. Data was extracted from the program database. The eligible cases included all noncancerous subjects with available data concerning serum PSA level and prostate volume; the patients had completed a 50-item self-administered food frequency questionnaire about their diet during the preceding two year.

Results:

No overall association was found between the consumption of foods and prostate volume as well as serum PSA level. There was a significant correlations between age and serum PSA level (r = 0.24) as well as with prostate volume (r = 0.22) (P < 0.001). In addition, there was a significant correlation between serum PSA level and prostate volume (r = 0.41 and P < 0.001).

Conclusions:

The results of this study confirmed the previous reports regarding the serum PSA level correlation with prostate volume. There was no evidence that dietary patterns might have any important effect on prostate volume and serum PSA in this Iranian population.