People who ate eggs regularly had a lower risk of developing Alzheimer’s disease than people who almost never touched them. That’s the headline from a large new study making the rounds on Hacker News, where the finding pulled a score of 180 and landed squarely in the research category. The effect wasn’t small, and it held up even after researchers stripped out the usual confounders.
What stands out here is the size and length of the dataset. This isn’t a two-week lab experiment with 40 volunteers.
What the researchers did
The team pulled data from the Adventist Health Study-2, a big prospective cohort of U.S. Seventh-day Adventists, and linked it to Medicare records to catch actual Alzheimer’s diagnoses. Diet came from a validated food frequency questionnaire, with egg intake sorted into buckets from “never or rarely” up to “five or more times per week.”
The numbers behind it:
- 39,498 participants
- 15.3 years average follow-up
- 2,858 diagnosed with Alzheimer’s over that window
They ran multivariable-adjusted Cox proportional hazards models, controlling for demographics, lifestyle, other food groups, and existing health conditions. A restricted cubic spline analysis let them look at egg intake as a continuous measure rather than just rough categories.
The results, laid out
Compared with people who never or rarely ate eggs, every level of egg consumption came with lower risk. Here are the hazard ratios (below 1.0 means lower risk):
- 1 to 3 times per month: 0.83
- Once per week: 0.83
- 2 to 4 times per week: 0.80
- 5 or more times per week: 0.73
That top group, the frequent egg eaters, showed a 27% lower risk. The spline model told a matching story from the other direction: eating zero eggs carried a hazard ratio of 1.22 versus a modest 10 grams a day, so cutting eggs out entirely tracked with 22% higher risk.
Why might eggs help? They’re dense in choline, which supports the brain chemical acetylcholine, plus omega-3s, lutein, and B vitamins tied to cognitive health. The researchers frame the effect as a “potential neuroprotective benefit of nutrients found in eggs when consumed as part of a balanced diet.”
Why it matters
Diet is one of the few Alzheimer’s risk factors you actually control. There’s no cure and no reliable drug that reverses the disease, so anything modifiable gets attention fast. An effect this consistent, across a huge sample followed for over 15 years, is worth noting even if it doesn’t rewrite anyone’s meal plan overnight.
The practical read for most people is simple: moderate egg consumption showed the benefit. This wasn’t a case where more is always dramatically better. A few eggs a week already put participants well below the never-eat-eggs group, and the jump from “once a week” to “five plus times” was real but modest.
The limits worth remembering
This is where discipline matters. The study shows correlation, not causation. It can’t prove eggs prevent Alzheimer’s, only that egg eaters got diagnosed less often.
A few specific caveats:
- The population was Seventh-day Adventists, a health-conscious group with lots of vegetarians and few smokers or heavy drinkers. That’s great for isolating diet, but it means the results may not transfer cleanly to the general public.
- Diet was self-reported through a questionnaire, which always carries some fuzziness.
- Egg eaters could differ in unmeasured ways the adjustments didn’t fully catch.
The authors flag the health-conscious population themselves, so they’re not overselling it.
My take: this is a genuinely useful data point, not a prescription. If you already eat eggs, this is reassuring, especially given how long eggs spent on the dietary blacklist over cholesterol worries that have since softened. If you avoid them, it’s not a reason to panic-buy a dozen. It’s one more brick in the wall of evidence that ordinary, whole foods do quiet work for the brain.
Expect follow-up research to test whether choline specifically is doing the heavy lifting, and whether the pattern holds in less health-conscious populations. Full methodology and the complete hazard ratio breakdown are available at the original source.