Originally published 6/10/2023
Several published research articles on eggs and prostate cancer point to choline, a nutrient primarily in egg yolks, as a possible culprit in causing prostate cancer (PCa). A 2022 Cleveland Clinic study[i] found that, “Men with increased choline … had almost twice the risk of lethal prostate cancer as controls,” according to a medical news story. Choline is an important nutrient, but overdoing it by consuming egg yolks may increase PCa risk.
In Africa, however, a totally different kind of egg—one that is not eaten—can directly cause PCa. A specific parasitic worm called Schistosoma haematobium can be picked up from activities in or use of infested waters. This species is found in Africa and the middle east, and it affects the urogenital system in both men and women. The larvae in the water penetrate the skin and enter the body. When the females become adults, they lay eggs in the person’s blood. In men, these find their way into the prostate gland, where they can lodge and cause …” inflammation that may play a major role in prostate carcinogenesis,” meaning the beginning of prostate cancer.[ii]
According to the World Health Organization, at least 251.4 million people required prevention against this or other forms of the parasite. More research is needed to determine the exact pathways by which the eggs contribute to the onset of PCa.
How do you like your eggs? Scrambled, soft-boiled, over easy, poached? No matter how you cook them, you may want to think twice about how often you consume them. It seems that there is a powerful link between eggs and lethal prostate cancer (PCa). Humpty Dumpty may indeed have a “great fall”—at least in the number of eggs men eat—if the results of an important study are taken seriously.
Why should we take the 2011 study by Richman, et al. to heart? For one thing, its authors hail from three venerable institutions, Harvard School of Public Health, Brigham and Women’s Hospital and Harvard Medical School, and University of California/San Francisco. For another, the study’s authors are authoritative when it comes to academic research and science. Finally, the study data was drawn from the huge, ongoing Health Professionals Follow-up Study (HPFS). Before breaking the bad news about eggs, a few words about the HPFS.
The HPFS was launched in 1986, and initially over 50,000 men in various health-related professions (dentists, doctors, optometrists, podiatrists and even veterinarians) enrolled. Initial information was gathered. As the Richman study explains:
Participants completed a baseline questionnaire on medical diagnoses, physical activity, weight, medications, and smoking, as well as a semi-quantitative food frequency questionnaire (FFQ) (7). Information on medical diagnoses, physical activity, weight, medications, and smoking is updated every two years, and dietary information is updated every four years. The average questionnaire response rate exceeds 94%.[iii]
The Richman study
The Richman study focused on dietary meat and eggs, including processed and unprocessed red meat; beef, pork and lamb as main dish, mixed dish or sandwich; total red meat; total poultry with or without skin; chicken or turkey hot dogs or sandwiches; and eggs. Their primary outcome was “… lethal prostate cancer, defined as distant organ metastases due to prostate cancer (TNM stage: M1) or prostate cancer death that occurred during the follow-up period of 1994–2008.” After identifying and amassing data from the HPFS, they conducted standard statistical analyses, including correlating numerous factors, and filtering out possible confounders. In short, they performed a massive statistical calculation.
They noted the following trends, which may not surprise you:
Men who consumed more red meat and eggs had a higher average BMI [body mass index]; engaged in less vigorous activity; were more likely to be current smokers, have a history of type II diabetes, and have a family history of prostate cancer; and tended to eat less poultry and fish and more dairy compared to men who consumed the least red meat or eggs. In contrast, men who consumed more poultry engaged in more vigorous activity, were less likely to be current smokers, and tended to eat less red meat, dairy, and coffee, and more fish compared to men who consumed the least poultry.[iv]
What might be surprising is that they did not find a statistically significant link between the various meat groups, including red meat, and the development of lethal prostate cancer after adjusting for variables. However, when it comes to lethal PCa and eggs, the connection they discovered may deter you from ever cracking another egg—or at least, eating them only occasionally. According to the published paper, “Men who consumed 2.5 or more eggs per week had a 81% increased risk of lethal prostate cancer compared to men who consumed less than half an egg per week.”
What is it about eggs in particular that fosters PCa aggression? As PCa cells, which are rich in cholesterol, metabolize it for their development and fuel, it plays a complex role “…in supporting cancer progression and suppressing immune responses.”[v] Blood concentrations of cholesterol have been linked with advanced cancers.
The authors conducted a separate dietary analysis of participants who were diagnosed with local or regional (but not metastatic) PCa during the follow-up period. While they found “suggestive” links between total red meat or poultry and progression into lethal PCa, none were of statistical significance. Therefore, they theorize that “… egg intake affects risk of lethal prostate cancer early in the natural history of the disease.” In short, if you are ever diagnosed with PCa, your cumulative history of eating eggs may be an influence on the cell line and activity of your disease.
Thus, the work of Richman, et al. presents us with a cautionary tale, and it is up to each of us to make wise nutritional choices accordingly.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
[i] Reichard CA, Naelitz BD, Wang Z, Jia X, et al. Gut Microbiome-Dependent Metabolic Pathways and Risk of Lethal Prostate Cancer: Prospective Analysis of a PLCO Cancer Screening Trial Cohort. Cancer Epidemiol Biomarkers Prev. 2022 Jan;31(1):192-199.
[ii] Choto ET, Mduluza T, Sibanda EN, Mutapi F, Chimbari MJ. Possible association and co-existence of schistosome infection and prostate cancer: A systematic review. Afr J Reprod Health. 2020 Dec;24(4):185-197.
[iii] Richman EL, Kenfield SA, Stampfer MJ, Giovannnucci EL, Chan JM. Egg, red meat, and poultry intake and risk of lethal prostate cancer in the prostate-specific antigen-era: incidence and survival. Cancer Prev Res (Phila). 2011 Dec;4(12):2110-21.
[v] Huang, B., Song, Bl. & Xu, C. Cholesterol metabolism in cancer: mechanisms and therapeutic opportunities. Nat Metab. 2020;2:132–141.