Eating up to three eggs a day for a month doesn't seem to raise levels of a blood chemical linked to heart disease, even though eggs contain a nutrient called choline. This suggests that the choline in eggs doesn't turn into that harmful chemical in healthy young people.

We analyzed the available evidence on whether eggs raise TMAO levels in healthy young adults, and what we’ve found so far suggests that eating up to three eggs a day for a month does not appear to increase levels of this blood chemical, even though eggs contain choline — a nutrient that can be converted into TMAO under certain conditions [1]. The evidence we’ve reviewed includes 46 assertions that support this finding, with no studies or claims contradicting it. This means that, in healthy young adults, the choline from eggs may not follow the same metabolic path that leads to TMAO production. TMAO is a compound some studies have linked to heart health concerns, but its formation depends on gut bacteria and other individual factors, which may vary widely. Our analysis does not show that eggs cause TMAO to rise in this group, but we also can’t say this applies to everyone — age, gut microbiome, and overall diet could change the outcome. What we’ve found so far is limited to healthy young adults over a one-month period, and longer-term or broader population effects remain unclear. For now, if you’re a healthy young adult eating eggs regularly, the evidence doesn’t point to a spike in TMAO from consuming up to three eggs daily. But if you have other health conditions or are older, this may not tell the whole story.