Can eggs prevent Alzheimer's?

According to a new study, just one egg a week cuts the risk of Alzheimer's disease considerably.

A new study in the July issue of the Journal of Nutrition points to the important role of dietary choline in brain health during aging.

Can Eggs Prevent Alzheimer’s?

The study included more than 1,000 adults with an average age of 81 years. Over the course of the study (average of 6.7 years), 27% were clinically diagnosed with Alzheimer's disease. Those who ate eggs on a weekly basis (more than one or two eggs per week) were half as likely to develop Alzheimer's disease.

The researchers then looked at the brain autopsies of nearly 600 of the deceased study participants. The results showed that those who regularly ate eggs also had a lower risk of having Alzheimer's pathology in the brain.

They then determined that 39% of the effect of egg consumption was due to the dietary choline provided by eggs. Eggs are the most important food source of choline in most people's diets, and choline is the precursor to the neurotransmitter acetylcholine. Choline is also a component of the cell membrane.

My skeptical side:
Seeing that large of a risk reduction made me immediately start “what about-ing”. Does this mean that eggs prevent Alzheimer's? Or is there some other connection? Did everyone else in the study group eat Pop-Tarts and Fruit Loops or drink Ensure for breakfast? Who doesn't eat at least one egg a week? Are they eating eggs from free-range chickens running around on a big pasture in Montana? Or the sad-looking cheap eggs from the store?

And if eating just a few eggs a week cuts your risk of Alzheimer's in half, why has the government been telling us not to eat eggs for decades?

Let's take a look at what's known about choline and brain function in aging.

Prior studies on choline and/or egg consumption:

Other studies have also shown that egg consumption is associated with better cognitive function in older adults.

• A study of 2800 adults over the age of 60 showed that 57% consumed eggs on a weekly basis and egg eating was associated with higher cognitive scores.[ref]

• Another study of more than 3000 older adults found that participants who ate eggs (up to 6 eggs a week) had an 18% lower risk of cognitive impairment.[ref]

• Another study of 470 older participants also found that verbal test scores were better in people who ate more than half an egg a week.[ref]

• However, a study in China found no statistical significance in cognitive function scores among egg eaters. This study points out that socioeconomics and demographics were more likely to come into play.[ref]

• A study in Finland looked at choline intake in middle age and then followed up 22 years later. They found that those who consumed higher levels of choline had a ~30% reduced risk of dementia. This study included all dietary sources of choline and found that both total choline and phosphatidylcholine intake were associated with better brain health. APOE type did not play a role in the association.[ref]

Enough about the epidemiological studies. What about clinical trials?

• A randomized, double-blind, placebo-controlled, parallel-group trial in adults aged 60-80 years compared the use of a choline supplement containing egg yolk choline with a placebo made from egg yolks with the choline removed. After 12 weeks, there was a significant increase in verbal memory scores in the group receiving 300 mg/day of egg yolk choline.[ref]

300 mg/day of choline is equivalent to eating 2 eggs per day.

Why would eggs - or choline - reduce the risk of Alzheimer’s?

Choline, acetylcholine, and Alzheimer’s

Acetylcholine is a neurotransmitter and neuromodulator in the brain. Acetylcholine acts on cholinergic neurons to modulate excitability. It also plays an important role in learning and memory.

Low levels of acetylcholine in the brain are associated with Alzheimer's disease. And long-term use of anticholinergic drugs, such as Benadryl, may increase the risk of dementia.[ref]

Acetylcholine is broken down (switched off) by acetylcholine esterase, and inhibiting acetylcholinesterase can increase acetylcholine levels. One of the mainstays of Alzheimer's medication is acetylcholinesterase inhibitors.[ref]

Adding supplemental choline to an acetylcholinesterase inhibitor helps with cognitive improvements in people with Alzheimer’s disease.[ref]

Which type of choline?

Trials are underway with α-GPC choline to see if it stops mild cognitive impairment, and it seems to be the preferred form of choline for improving cognitive function. Alpha-GPC is a supplemental form of choline that is thought to be more bioavailable than other forms. It is a semi-synthetic derivative of lecithin that is converted to phosphatidylcholine in the body[ref].ref]

Previous trials using α-GPC plus donepezil showed that it helped improve outcomes and one trial showed that α-GPC alone improves outcomes in patients with neurological conditions associated with cerebrovascular injury.[ref]

There are lots of brands that sell alpha GPC supplements. ConsumerLab.com is an independent supplement testing company, and they show the Double Wood alpha GPC and Swanson alpha GPC as approved, meaning they contain the claimed amount and form of choline and don’t contain heavy metals. You can get both on Amazon: Double Wood Alpha GPC ($19.85/300 mg/ 60 capsules) or Swanson Alpha-Gpc ($24.89 / 300 mg / 60 capsules).

Caution with alpha-GPC? A recent study on supplemental choline, alpha-GPC, found that there was a correlation between the relative risk of stroke and taking alpha-GPC.[ref] If you are at an elevated stroke risk, you may want to be cautious with alpha GPC. However, I would like to see more on this to understand why supplementing with alpha-GPC could increase the relative risk of stroke.

Do you even need to take a supplement?
The epidemiological research shows that simply eating eggs seems to be as beneficial. If you like to eat eggs, two eggs provide around 300 mg of choline.

Eggs for breakfast every morning can get a bit boring, so if you are looking for more egg recipe ideas, check out TooManyEggs.com. There you’ll find a recipe book with 800 egg recipes (free as a .pdf, or buy it as a hardcopy).

I took time out from writing this newsletter to snap a pic of my source of eggs for this morning’s breakfast. This particular hen is also an escape artist and not where she is supposed to be this morning…

Enjoying Longevity Lifehacks? Consider supporting this substack as a paid subscriber.