Eating eggs may increase men's risk of developing the more lethal form of prostate cancer, concluded US researchers in a study published recently in the journal Cancer Prevention Research, a journal of the American Association for Cancer Research.
First author Erin L. Richman from the department of Epidemiology and Biostatistics at the University of California, San Francisco (UCSF) and colleagues, write that we already know red and processed meat may increase risk of advanced prostate cancer, and although post-diagnostic data on diet and prostate cancer is "sparse", there have been suggestions that eating poultry with skin and eggs may hasten the progress of the disease.
So they decided to do a study using dietary data from 27,607 men who had been followed from 1994 to 2008 and who had no cancer at the start of the period. This group included men who developed prostate cancer that spread to other organs and also who died from the disease, enabling the researchers to examine total, unprocessed and processed red meat, poultry and egg intake in relation to risk of lethal prostate cancer.
The researchers report that for the risk analysis, they noted there were 199 observed events over 306,715 person years (when you multiply the number of people observed by the number of years each was followed for and compare this to the number of events you are interested in observing, you get a sense of how populated the "map" of available data points for analysis is).
They found that men who ate 2.5 eggs or more a week had a significant 81% higher risk of developing lethal prostate cancer compared to men who ate fewer than 0.5 eggs a week on average. For the case-only survival analysis, they observed 123 events during 19,354 person-years. From these data points they found a suggestion, but this was not statistically significant, that eating poultry and processed red meat after a diagnosis of localized prostate cancer was linked to progression to lethal disease.
The researchers conclude that "consumption of eggs may increase risk of developing a lethal form of prostate cancer among healthy men".