Adding 0.1% to 0.2% taurine to the feed of laying hens reduces cholesterol in their egg yolks by 15–20% and increases the levels of omega-3 and omega-6 fatty acids.
Mechanism
Synthesis from 1 study
Taurine tells the liver to make less cholesterol and get rid of more of it through bile and storage, so less ends up in the egg yolk. At the same time, it increases the production of certain healthy fats in the liver, which get put into the yolk during egg formation.
Most probable mechanism
Taurine changes how the liver handles fats: it slows down cholesterol production, pushes more cholesterol out through bile, and stores excess cholesterol as esters, which together lowers the amount of cholesterol available for egg yolks. At the same time, taurine boosts the production of certain healthy fats in the liver, which get packed into the egg yolk during its formation.
Taurine enters hepatocytes and suppresses the expression of SREBP2, a master regulator of cholesterol synthesis
Reduced SREBP2 decreases expression of HMGCR, the rate-limiting enzyme in cholesterol biosynthesis, lowering hepatic cholesterol production
Taurine upregulates ABCG5, increasing the transport of cholesterol from hepatocytes into bile for excretion
Taurine increases ACAT2 expression, converting free cholesterol into cholesteryl esters for storage or lipoprotein packaging, reducing free cholesterol availability
At higher doses, taurine upregulates CYP7A1, accelerating the conversion of cholesterol into bile acids for elimination
The combined reduction in hepatic cholesterol synthesis and increased excretion and storage lowers circulating cholesterol, limiting its delivery to the ovary for yolk deposition
Taurine enhances hepatic production or preservation of polyunsaturated fatty acids C18-3n and C18-2n, increasing their concentration in circulation
During vitellogenesis, circulating polyunsaturated fatty acids bind to vitellogenin and are incorporated into the developing yolk
Evidence from Studies
Supporting (1)
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Effects of dietary taurine supplementation on polyunsaturated fatty acids, cholesterol, and egg quality of egg of hens
Contradicting (0)
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Gold Standard Evidence Needed
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