No Association between Egg Intake and Prostate Cancer Risk: A Meta-analysis

Abstract

Asian Pacific J Cancer Prev, 13 (9), 4677-4681 IntroductionProstate cancer is the most common cancer among men in United States. It is also one of the leading causes of cancer death among men of all races (Siegel et al., 2012). Although age and family history have been established as strong risk factors for prostate cancer, the role of individual dietary factors is not well understood. The large variation in incidence across countries may also suggest the role of lifestyle and dietary factors in its cause (Yu et al., 1991). Eggs are frequently consumed worldwide, supply substantial portions of protein, fat, retinal, riboflavin and iron. Eggs are also unique among foods, given their relatively high content of several substances, such as cholesterol, choline, biotin, and avidin. There is evidence pointing to a possible role of eggs consumption on cancer etiology. A positive association has been observed between eggs consumption and risk of colorectal cancer (Steinmetz et al., 1994). For other cancer sites, there is no established association with eggs. Several studies considered the relation between eggs intake and prostate cancer. Though most of them reported no association, results were often inconsistent. With the aim to investigate the relationship between prostate cancer and eggs consumption, we carried out a meta-analysis of epidemiological studies published up to July 2012. Materials and MethodsA systematic literature search was carried out in the AbstractObjective: Egg consumption has been suggested to increase the risk of colorectal and some other cancers. The present study summarized and quantified the current evidence relating dietary intake of eggs and prostate cancer. Materials and methods: Literature searches were conducted to identify peer-reviewed manuscripts published up to July 2012. Twenty manuscripts from nine cohort studies and 11 case-control studies were identified. Summary risk estimates with 95% confidence intervals (CIs) were calculated for case-control and cohort studies separately. Results: Neither the case-control not the cohort studies showed any association of prostate cancer incidence with egg consumption (case-control studies: odds ratio 1.09, 95% CI 0.86-1.31; cohort studies: relative risk 0.97, 95% CI 0.97-1.07). The results were consistent in subgroup analysis. Furthermore, no association was observed between egg consumption and prostate cancer-specific mortality. Conclusions: Our analyses provided no evidence of a significant influence of egg consumption on prostate cancer incidence and mortality. However, more studies, particularly large prospective studies, are needed.

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

“…A recent meta-analysis suggested no association with risk of prostate cancer (overall or prostate cancer-specific mortality) [16]. In the HPFS, men who consumed ≥2.5 eggs per week had a 1.8-fold increased risk of developing lethal prostate cancer compared with men who consumed <0.5 eggs per week [17].…”

Fruit and Vegetable Intake in Relation to Prostate Cancer in Iranian Men: A Case-Control Study

“…It is also one of the leading causes of cancer death among men of all races (XIE and HE, 2013). Literature reviews of PCa epidemiol¬ogy have reported high incidence in Western countries, with lower but typically increasing incidence in less developed countries (Baade et al, 2009;Mohagheghi et al, 2010;Zhang et al, 2011;Center et al, 2012).…”

Egg intake and cancers of the breast, ovary and prostate: a dose–response meta-analysis of prospective observational studies

“…Indeed, several meta-analyses of observational studies have assessed the potential harm of egg intake on such cancers and found a positive association with the risk of breast ( 18 ) and ovarian ( 19 ) cancers, suggested some association with an increased risk of endometrial ( 20 ) and fatal prostate ( 21 ) cancers, but found no association with the risk of total prostate cancer ( 21 ) . However, given that the distribution of egg intake differs across studies, previous meta-analyses ( 19 – 21 ) that pooled RR comparing the highest with the lowest category of egg intake have limited interpretability in terms of the dose–response relationship.…”