Nutrition & Brain Health The Egg Study

Nutrition and Brain Health: The Egg Study

A study published this week in The Journal of Nutrition found that older adults who ate eggs at least five times a week had a 27% lower risk of being diagnosed with Alzheimer’s disease. The research came from scientists at Loma Linda University in California, who analyzed data from nearly 40,000 U.S. adults over age 65. It’s the kind of headline that makes people want to scramble a dozen eggs immediately. But as with most nutrition research, the details matter more than the number.

What the study found

The researchers drew from the Adventist Health Study-2, a large cohort study linked with Medicare claims data. That linkage let them track real Alzheimer’s diagnoses rather than relying on cognitive tests alone. Over an average follow-up of about 15 years, 2,858 participants developed Alzheimer’s.

The dose-response pattern was interesting. Compared to people who never ate eggs:

• Eating eggs 1 to 3 times per month was associated with a 17% lower risk.
• Eating eggs 2 to 4 times per week: 20% lower risk.
• Five or more times per week: 27% lower risk.

The study also compared “visible” eggs (scrambled, fried, boiled) with “hidden” eggs, the kind baked into goods and packaged foods. No meaningful difference emerged based on form of consumption.

Those numbers look compelling. But a 27% relative risk reduction does not mean eggs will prevent Alzheimer’s in 27 out of 100 people. It means that within this specific population, the group eating eggs most frequently had that degree of lower risk compared to non-consumers. Big difference.

Why eggs might matter for the aging brain

Choline — the nutrient essential for making acetylcholine, a neurotransmitter that drives memory and learning — shows up in few foods as abundantly as it does in egg yolks. Most Americans don’t get enough choline. The recommended adequate intake is 550 mg per day for men and 425 mg for women, and one large egg contains roughly 150 mg.

Eggs also contain lutein and zeaxanthin, antioxidant carotenoids that accumulate in brain tissue. They have vitamin B12, omega-3 fatty acids including DHA, and high-quality protein with tryptophan (a serotonin precursor). None of this is exotic. It’s just a lot of relevant compounds packed into a cheap, widely available food.

This is not proof that eggs prevent Alzheimer’s

Let me be blunt: this study cannot prove that eggs prevent Alzheimer’s disease. It’s observational. The researchers watched what people ate and what happened to them over time. They did not randomly assign half the group to eat eggs and half to avoid them. That distinction matters enormously.

The study population, Seventh-day Adventists, tends to smoke less, drink less alcohol, and eat more plants than the average American. They have lower baseline rates of obesity and cardiovascular disease. These are people who were already doing a lot right. When you see that egg intake correlates with lower Alzheimer’s risk in this group, you’re seeing what happens when eggs get added to an already protective dietary pattern. Not to a diet built on fast food and soda.

Dr. Joel Salinas, a behavioral neurologist at NYU Langone, called the study “reasonably well-designed” but noted it’s “more directional rather than definitive.” Dietitian Michelle Routhenstein made a sharper observation: “My first reaction was, well what else are they eating?” It’s a question that carries more weight than you’d think.

And there’s this: the study was supported by an investigator-initiated grant from the American Egg Board. That doesn’t automatically invalidate the findings. But industry funding of nutrition research has a well-documented pattern of producing results favorable to the funder, and you should know about it before you reorganize your breakfast.

Cholesterol concerns

For years, eggs were dietary villains because of their cholesterol content. One large egg has about 186 mg. The 2020–2025 Dietary Guidelines for Americans stepped back from setting a strict daily cholesterol cap, and accumulating evidence shows that for most people, dietary cholesterol from eggs doesn’t meaningfully raise blood cholesterol levels.

But “most people” isn’t everyone. Some individuals are cholesterol hyper-responders, meaning egg yolks can bump their LDL more than average. If you have elevated cardiovascular risk or your lipid panel runs high, talk to your doctor before doubling your egg intake based on a headline.

Practical advice

If you like eggs and tolerate them, keep eating them a few times a week as part of a varied diet. That’s the boring answer. It’s the right one.

Here’s what the evidence supports right now:

• Eggs are nutrient-dense and contain specific compounds relevant to brain health.
• Moderate consumption, roughly 3 to 7 eggs per week, appears safe and potentially beneficial for most healthy adults.
• What you eat eggs with matters as much as the eggs themselves. Eggs alongside vegetables and whole grains are a very different meal from eggs next to processed sausage and white toast.

If you don’t eat eggs for ethical or dietary reasons, the same brain-supportive nutrients are available elsewhere. Choline shows up in soy, kidney beans, and quinoa. Lutein and zeaxanthin are abundant in dark leafy greens like kale and spinach. Omega-3s and B12 may need supplementation on a fully plant-based diet, ideally guided by lab work.

The broader picture on Alzheimer’s prevention involves a mix of habits: physical activity, blood pressure and blood sugar management, sleep quality, social engagement, and a thoughtful diet. No single food does the heavy lifting. The pattern does.

This is a promising study. It adds to a growing body of evidence that what we eat matters for our brains as we age. But promising isn’t proven, and the American Egg Board’s fingerprints on the funding should temper some of the enthusiasm. The question nobody has answered yet is whether a randomized trial, one that could establish causation rather than association, will ever be conducted. Given that eggs cost about 30 cents each and can’t be patented, probably not.