This post is a companion to: Foods/Supplements-Vitamins: Choline.
The egg lady, Erin Richman, conducted two studies that warned men with PCa off eggs [1] & [2], & followed that up with a study that blamed the association on choline [3].
[1] (2010 - U.S.) Men in this study were participants in the Diet and Lifestyle substudy of CaPSURE.
"Most of the previous studies that examined ... eggs and risk of prostate cancer reported no association. However, risk factors for incidence of total prostate cancer may differ from risk factors for advanced or fatal disease and thus it is plausible that ... eggs may increase the risk of advanced prostate cancer or prostate cancer progression, but are not associated with risk of total prostate cancer ..."
Median weekly egg intake & PCa progression risk, by quartile of intake:
0.4 1.00 (reference)
1.0 1.17
3.0 1.06
5.5 2.02
Not exactly well-behaved.
"45% consumed ≤1 egg/wk, 41% consumed 3 eggs/wk, and 14% consumed >3 eggs/wk."
Not a whole lot of eggs.
I'm a bit suspicious of the numbers. Most eggs go to food companies that use eggs in their products. It has to be very difficult to account for eggs in baked goods, egg noodles, etc.
[2] (2011 - U.S.) Health Professionals Follow-up Study (HPFS).
"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 ..."
Median weekly egg intake & PCa progression risk, by quartile of intake:
< 0.5 1.00 (reference)
0.5–1.4 1.33
1.5–2.4 1.49
≥2.5 1.81
...
When I read the studies originally, it seemed absurd that one additional egg per week could have a measurable effect on aggressive disease or mortality. I wondered about associations ("bacon & egg", "sausage & egg", etc, or unhealthy baked goods containing eggs.)
[3] (2012 - U.S.) Health Professionals Follow-up Study (HPFS).
In this study median levels of choline were below adequate intake level for every quintile of intake.
...
It's hard to make sense of it all.
Using 147 mg choline for a large egg, here is the data shown above for [2], restated as daily choline intake from eggs. (Note that 1 egg/week = 21 mg choline/day:
< 10.5 mg 1.00 (reference)
10.5–29.4 1.33
31.5–50.4 mg 1.49
≥52.5 mg 1.81
With adequate intake for men being 550 mg/day, it's hard to see how such small incremental choline increases could explain the risk of eggs.
I have a very nice source of free range eggs. I have to be careful not to run the chickens over when I go to the farm to pick the eggs up. I don't eat eggs every day, but if I did, I wouldn't worry about a daily egg.
-Patrick
[1] ajcn.nutrition.org/content/...
