I hated eggs for most of my life. A few years ago, I discovered through trial-and-error that it was the whites I really hated because I had an allergy. I started eating the yolks a couple of years ago. Since getting my chickens, I now eat around ten egg yolks a week. I have them as yolk cakes or a fat bomb omelette (see recipes).
The main reason I took the plunge with yolks was the information I read on the importance of choline for human health. It was discovered in the 1800s, but classified as an essential nutrient in the late ’90s. Although sometimes classified as a vitamin, it is, in fact, an amino acid derivative. Our bodies produce choline in small amounts, but not enough of it for optimum health.
Why is it Important?
- Cell membranes – Choline is essential to the synthesis of phosphatidylcholine and sphingomyelin; these are the structural components of cell membranes. Choline is found in all cell membranes.
- Brain function – Choline aids in the synthesis of acetylcholine, a key neurotransmitter. It may combat cognitive decline.
- Fat transport – Choline aids in transporting lipids and cholesterol around the body and getting both to the cells that need them.
- Cardiovascular Health – Choline may help convert homocysteine to methionine. High levels of the former are associated with cardiovascular disease.
How much Choline?
As we grow, the more we need. According to the Institute of Medicine. Food and Nutrition Board we need the following amounts of choline dependent on age:
|Birth to 6 months||125 mg/day||125 mg/day|
|7–12 months||150 mg/day||150 mg/day|
|1–3 years||200 mg/day||200 mg/day|
|4–8 years||250 mg/day||250 mg/day|
|9–13 years||375 mg/day||375 mg/day|
|14–18 years||550 mg/day||400 mg/day||450 mg/day||550 mg/day|
|19+ years||550 mg/day||425 mg/day||450 mg/day||550 mg/day|
Choline Rich Foods
Well eggs obviously; four of them will give you your daily requirement. But beef liver, cod, Brussels sprouts, broccoli and tuna are all good sources as well. A more detailed breakdown of foods can be found here. Of course, a lot of these foods are verboten for paleos and ketos.
Dangers of Choline Deficiency
Most people are not consuming enough choline. That said, very few people will develop complications unless they are completely deficient. Worse case scenarios: muscle damage, fatty liver disease and liver damage.
Dangers of Excessive Choline
Most people are not going to scarf down ten eggs a day every day which would push you past maximum tolerance. It seems that the danger of too much choline would be for those who take it as a supplement. Problems include: fishy body odour, vomiting, excessive sweating and salivation, hypotension, liver toxicity and cardiovascular problems.
Choline and Cancer
During my research I came across some studies that suggest a link between choline and the development and progression of prostate cancer. Apparently poultry and egg consumption significantly increased the chance of prostate progression. Still this same study concluded that “w]hile the link between choline and fatal prostate cancer is becoming clear, the risk-benefit analysis remains murky. Choline is an essential nutrient and is associated with a number of positive health effects, including possibly preventing fatty liver disease and cognitive decline in the elderly. We cannot and probably should not put all of our patients on choline-free diets.”
To confound the layman further, I found this meta-study which concluded that “choline and betaine consumption possesses the ability to lower cancer risk.” It added, however, that “these results should be considered with caution on account of the considerable heterogeneity, the potential biases and confounding factors.” Another study concluded that “[i]ndividuals with high plasma concentrations of methionine, choline, and betaine may be at reduced risk of CRC [colorectal cancer].” This was another statistical meta-study.
Talk about damned if you do, damned if you don’t! None of these cancer studies are able to explain why choline may lead to prostate cancer or protect one from CRC and other cancers. They speculate but don’t prove. Is this a classic correlation does not prove causation scenario for both sides of the cancer coin? Clearly more research is needed when it comes to choline’s links to cancer as a preventive and a cause.
Given my diet, I’m probably still a little below optimum choline consumption. However, given the information I found on prostate cancer, I think I’ll keep it that way until new data emerges. On balance, the benefits outweigh the risks for me. Chickens, get laying!