Research Reveals a Surprising Anti-Alzheimer’s Effect of Eggs

A recent study looked at links between different environmental exposures and Alzheimer’s risk, based on a sample of around 500,000 people in the UK. Oddly, consuming eggs had one of the strongest protective effects out of everything covered in the study. But is this just an odd result, or does something as simple as eating eggs really have a protective effect?

Eggs Consistently Reduce Alzheimer’s Risk in Studies

Based on available research, it really does seem like egg consumption is associated with a reduced risk of Alzheimer's and cognitive decline. Firstly, the UK-based study had a huge sample size, so it’s pretty compelling on its own, suggesting a 76% increase in risk for people who never ate eggs.

But that is far from the only result:

• A 2024 study followed 1,024 older adults over 6.7 years on average, and analysed their risk based on their egg consumption at baseline. The results showed that consuming more than one egg per week was associated with a reduced risk of Alzheimer’s, 47% lower than people who ate less than one egg per week.

• A 2026 study used a large cohort of Seventh-day Adventists in the US, looking at a sample of 39,498 people (who were aged 65 or older during follow-up) over an average of 15.3 years. Risks decreased with greater egg consumption. For instance, there was a 17% reduction in risk for people who ate eggs once a month to once a week, and a 27% reduction for people who ate eggs five or more times a week, compared to people who never or rarely consumed eggs.

• A meta-analysis looking at 13 longitudinal and 8 cross-sectional studies on egg consumption found that consuming 1 egg per day was associated with a 9% decrease in the risk of cognitive decline. More precisely, the benefits peaked at 50 to 60 g of egg per day.

Why Are Eggs Good for Your Brain?

As well as containing omega-3 fatty acids, lutein, tryptophan, vitamin B12 and other potentially beneficial ingredients, many authors point to choline as a key factor. This essential nutrient is a precursor to acetylcholine, which is crucial for memory and synaptic function. Choline levels in the body have been independently linked to changes in cognitive function with aging and Alzheimer’s disease – so there are also other options if you don’t like eggs!

New Stem Cell Therapy for Parkinson's 💉

I had a senior recently return from this year's BioJapan forum, essentially a bio-industry partnering event, and he shared with us some interesting cases/studies/products being developed. Given that iPSC technology, which won the 2012 Nobel Prize, was first developed in Japan, this was no surprise.

Japan remains at the forefront of regenerative medicine. This year, Japan authorized the world's first two commercial induced pluripotent stem cell (iPSC)-based cell therapies:

One of them is for Parkinson's Disease, where allogeneic iPSC-derived dopaminergic neural progenitor cells are transplanted into the brain to restore dopamine generation.

This comes as a surprise for us who have tinkered with iPSC: 🤔❓

1. They are injecting the progenitor cells, not the final derived product > basically injecting Tomato instead of Ketchup situation

2. It is not personalised therapy > iPSC was always presumed to eventually have great breakthroughs with personalised cells. Thank goodness because the price of ¥55,306,737 is already steep.

💉 Injections to the putamen/striatum, report improvements in motor skills at the end of their 2 year trial. This is also the first clinical trial using iPSC cells confirming that iPS-cell-derived progenitors can survive without forming tumours and produce neurons in the putamen of patients with Parkinson's.

Nevertheless, I'm excited to see what comes next: 🚶 During this 7-year window, Sumitomo Pharma is required to conduct mandatory Phase IV post-marketing surveillance and collect additional safety and efficacy data before full, permanent approval can be considered.

If you live alone, getting a pet can slow cognitive decline

Interesting UK cohort study: Pet Ownership, Living Alone, and Cognitive Decline Among Adults 50 Years and Older.

It found that pet ownership is linked to slower decline in "composite verbal cognition (a combined score for memory and word production), memory, and word fluency" (credo summary).

There was only a difference for people who lived alone. I.e. if you live with other humans, having a pet wasn't associated with better outcomes. But among those living alone, those with pets were better off.

Another reason to get a pet!

The “Physical Activity Paradox” in Dementia Risk Revealed in New Study

A new study has revealed a so-called “physical activity paradox” in dementia risk. In a nutshell, even though physical activity is generally considered to be protective, in some cases it can actually increase your risk. Just looking at “physical activity” as a single factor misses a lot of crucial detail.

The Different Types of Physical Activity  

The researchers identify four different types of physical activity: leisure-time, occupational, household and commuting activity. They’re basically pointing out that having a physically-demanding occupation is different from doing chores around the house or cycling to the office.

However, much of the evidence focuses on leisure time physical activity, which only represents 12% of all physical activity around the world.

The Study: Reviewing the Evidence on Different Types of Physical Activity

The researchers basically wanted to update a previous review they published in 2022, adding evidence from the intervening years and performing the analysis for different types of activity separately. The new paper [1] uses the 57 studies included in that review, and adds 17 new cohort and case-control studies published between the start of 2021 and May 2026. This led to a combined sample of over 4.2 million participants.

Studies were excluded if they had a follow-up of less than a year, if diagnoses were based on self-report or cause of death data, if people had dementia or mild cognitive impairment at baseline, or any research focusing specifically on people with a diagnosed disease.

What They Found: Leisure Time Activity Protects, Occupational Activity Doesn’t

The analysis found that leisure time physical activity was associated with a 24% lower chance of all-cause dementia, while occupational activity increased risk by around 20%. These were the two areas with the most research, but less reliable findings also suggest that household activity reduces risk by 15% and commuting activity increases it by 10%.

Limitations to Keep in Mind

As always, there are issues to keep in mind. Firstly, physical activity was based on self-reporting, which is open to bias, and secondly, the type of studies included make it hard to rule out reverse causation. Notably, 93% of studies came from high income countries, so the evidence base is not very representative of the world. The results broadly held for specific types of dementia, but vascular dementia wasn’t as well covered. 

However, the core findings generally seem robust.

Shingles Vaccine Protects Against Dementia

A flagship study came out in Nature in 2025 that solidified a long observed finding, that the Shingles (Herpes Zoster) vaccine can protect against dementia.

Previous studies were classic observational cohort designs which can fail to show causation or account for confounding factors. This 2021 study found "a combined analysis estimated a 31% lower risk" and indicated the need for stronger research.

In comes the 2025 Nature study, this time a natural experiment arose:

To provide causal as opposed to correlational evidence, we take advantage of the fact that, in Wales, eligibility for the zoster vaccine was determined on the basis of an individual’s exact date of birth. Those born before 2 September 1933 were ineligible and remained ineligible for life, whereas those born on or after 2 September 1933 were eligible for at least 1 year to receive the vaccine.

The finding:

We show that receiving the zoster vaccine reduced the probability of a new dementia diagnosis over a follow-up period of 7 years by 3.5 percentage points (95% confidence interval (CI) = 0.6–7.1, P = 0.019), corresponding to a 20.0% (95% CI = 6.5–33.4) relative reduction. This protective effect was stronger among women than men.

Interestingly, the newer recombinant vaccines seem to be ever more effective than the live-attenuated vaccines (the ones tested in the Nature experiment), though more studies are in the pipeline to deepen this finding.

The mechanism for why the protective effect happens is still TBD, though some hypothesize that detrimental impact of getting Shingles on the brain may cause long term damage that leads to dementia.

Either way, the impacts seem clear, the Shingles vaccine seems like a must-get in a full range defense against dementia.

Does Socialisation Reduce Cognitive Decline? A New Study Says Yes

For people who don’t already have dementia, but are worried about it, learning about protective factors and risk factors for cognitive decline is one of the only steps you can take. A common piece of advice is to remain socially active, but does it really make a difference?

A new study [1] looked into this and found a very clear correlation between higher levels of social engagement and better cognitive performance.

Why Researching the Impact of Social Engagement is Difficult

Defining social engagement isn’t as easy as you might think. As a paper tackling this issue points out, researchers tend to use many different, overlapping terms. For example, social participation, social connectedness and community engagement are all used, and other studies may focus instead on social isolation. The paper points out that the subtle distinctions between these methods makes it difficult to interpret the evidence as a whole.

What the New Study Adds

The new research [1] used a composite measure called the Social Engagement Index, which covers specific things like whether you live with other people, whether you went out for fun in the past month, whether you visited friends or family, whether you’re married, employed and more. The idea is to cover many metrics of social engagement and use all of them to produce the final score.

They used data from the National Health and Aging Trends Study from 2011 to 2019, which covers Americans aged 65 or older enrolled in Medicare, and discounted anyone likely to have dementia at the start of the study. They found that higher social engagement (at baseline) was associated with a reduced decline in memory, orientation (i.e. what day is it? Who is the vice president?) and executive function. This was also incremental: the more engaged, the better the outcome.

Does Social Engagement Reduce Cognitive Decline?

The overall picture isn’t as clear as we might like. A “systematic review of reviews” covered this issue (section 4.1 for a summary) and despite emphasizing that low social engagement increases your risk, concluded that the data on the presumed protective effect is inconsistent. That said, the difference between a protective effect and avoiding an increase in risk seems more of a philosophical issue than a practical one.

As the new study also suggests, it certainly seems better to be socially engaged than to not be.

New Study Suggests Blood Pressure Variability is What Matters for Cognitive Decline

A new study has found a new insight on the relationship between blood pressure and cognitive decline. Since hypertension is a well-established – and controllable – risk factor for cognitive decline, scientists assumed that reducing it is the best strategy. But this seems to be missing a crucial piece of the puzzle.

The Problem: Mixed Results on Lowering Blood Pressure

The new paper points out that different studies disagree about the cognitive benefits of interventions to reduce blood pressure.  

The SPRINT-MIND study recruited people with hypertension but not diabetes. It found a reduced risk of mild cognitive impairment for people on a more intensive blood pressure reduction regimen, but no difference in probable dementia.

Conversely, the ACCORD-MIND trial focused on people with type 2 diabetes and included a similar comparison of a more intensive vs. less intensive blood pressure reduction regimen. In this case, though, there was no difference in cognitive function.

What the New Study Did

The new research [1] pooled data from both of these trials, and analyzed the data again at participant-level. The paper notes that blood pressure variability (BPV) is linked to both cardiovascular events and cognitive decline, and tends to be higher in people with diabetes.

To test whether this is the important factor, researchers looked at BPV between each visit in the original studies. The original researchers used varying cognitive tests, but the authors identified two essentially equivalent measures of psychomotor processing speed among them. They used these to compare results across both studies.

What They Found: Higher Variability, Greater Decline

People with more variability in their blood pressure saw greater cognitive decline over the study period. In particular, those in the highest third of BPV had a faster rate of decline than those in lower thirds. The relationship seemed to be linear: each 10% increment of BPV led to consistently higher levels of decline.

What the Study is Missing

The study only focused on one measure of cognitive decline, rather than a global score. All participants also had a high cardiovascular risk, so the results might not carry over to other populations.

 What Doctors Can Do

One thing the study suggests is optimizing drug selection and timing to reduce BPV where possible. Doctors can also try novel interventions specifically designed to bring down BPV.

🩸Can a Blood Test Tell How Fast Your Brain Is Aging?

What if a blood sample could reveal which parts of your body are aging the fastest, and even predict your risk of developing diseases years before symptoms appear? 🤔❓

A new study published by Stanford researchers analyzed blood plasma proteins with nearly 3,000 proteins across 44,498 UK Biobank participants for organ aging, and 7,000+ proteins in 60,542 individuals for cell-type-specific aging.

Using Machine Learning, the scientists figured out how much composite protein “signature” represented each organ and let the models assign biological ages to 11 organ systems and 40+ cell types.

😮 Turns out one-third of us have at least one organ that's aging dramatically faster or slower than the rest.

They discovered that aging is far from uniform. Instead, different cells and organs age at different rates, meaning two people of the same chronological age can have very different biological aging profiles, where 1 in 4 participants had multiple extremely aged or youthful organs; 20–25% showed accelerated aging in a single cell type, while 1–3% had >10 rapidly aging cell types.

In the study, they claim that cellular aging signatures were uniquely associated with disease status:

• 🧠Astrocytes (brain support cells): Extreme astrocyte aging demonstrated a 12.59-fold increased risk of incident Alzheimer’s disease (AD).

• 💪🏻Skeletal muscle cells: People with aged muscle cells had a 12.7× higher risk of amyotrophic lateral sclerosis (ALS), detectable three years before symptoms appear.

• 🫁 Respiratory cells: Smokers with aged lung epithelial cells faced 58% higher lung cancer risk than smoking alone would predict.

🍀Interestingly, new findings on Alzheimer’s disease offer hopeful news for carriers of the APOE4 gene that has long been linked to Alzheimer’s.

1. The predictive power of astrocyte aging (HR = 5.16) was comparable to APOE4 carrier status itself (HR = 5.30).

2. APOE4 gene + aged astrocytes three times higher risk compared to an average APOE carrier.

3. In contrast, APOE4 carriers with youthful astrocytes appeared to neutralise the genetic risk completely as none of their 23 APOE4/4 carriers developed Alzheimer's.

4. Youthful astrocytes reduced overall AD risk by over 60%

Side Note: ♀️ Women seemed to be more vulnerable to the harmful associations in both APOE4 gene and aged astrocyes.

🧬The researchers also identified an inverse pattern via biological age quantification from blood for the APOE gene variants:

• APOE4 → astrocytes age faster, macrophages age slower

• APOE2 (the protective variant) → the exact opposite: younger astrocytes, older macrophages

Together, these findings highlight a shift in how we understand aging. Chronological age is merely one measure, and this algorithm may provide a more precise picture of one's health trajectories by decoding cellular aging signatures from blood.

✨ Check out the these links for a deeper read:

1. More on the APOE Gene 🧬

2. Stanford Medicine Newsletter: Biological age of our organs and cell types within them predict our disease risk, longevity.

😴 Sleep Is More Than Just Rest: The Hidden Link Between Sleep Disorders and Dementia 💤

Most of us know that a bad night's sleep makes us feel tired, irritable, and unable to concentrate the next day. But growing scientific evidence suggests that POOR SLEEP may have much more serious long-term consequences, increasing the risk of developing dementia and Alzheimer's disease (AD).

Let's look at some meta-analyses, published seven years apart, provide compelling evidence linking sleep disorders with dementia.

In Shi et al., 2017 (247,000 people): With 18 longitudinal studies - consolidated that sleep disturbances are an independent risk factor, not merely an early symptom of dementia.

• Insomnia was mainly linked to a higher risk of AD.

• Obstructive Sleep Apnea (OSA) was associated with increased risk of all-cause dementia, AD, and vascular dementia (VasD).

❓However, evidence was limited, with most studies relying on self-reported sleep.

In Ungvari et al., 2025 : Analysed 39 studies

• Insomnia raises all-cause dementia risk by 36%, AD by 49%, and VasD by 59%.

• OSA raises risk by 33% in all-cause dementia and 45% in AD.

In Zhang et al., 2025 : Analysed 76 studies

• Excessive Daytime Sleepiness (EDS): +41% in all-cause and +85% in VasD

• Sleep-Related Movement Disorders: +153% VasD (showing restless legs/periodic limb movements are primarily vascular risk factors).

💊 Ungvari et al., 2025 raises the question of whether treating sleep disorders can mitigate dementia risk and states that it remains an important avenue for future research, particularly mentioning:

• CPAP (Continuous Positive Airway Pressure) for Obstructive Sleep Apnea (OSA).

  • Has been found to improve cognitive performance, particularly in executive function and memory

• Cognitive Behavioral Therapy for Insomnia (CBT-I)

🧠 Why might poor sleep affect the brain?

During deep sleep, the brain activates the glymphatic system, a specialised waste-clearance pathway that removes metabolic waste products, including amyloid-beta proteins associated with Alzheimer's disease.

Poor or fragmented sleep may reduce this nightly "brain cleaning" process, allowing harmful proteins to accumulate. Sleep disorders may also contribute through:

• 🫀 Reduced oxygen supply to the brain (particularly in sleep apnea)

• 🩸 Increased inflammation

• ❤️ Higher blood pressure and cardiovascular disease

• 🧠 Greater oxidative stress

• 🔄 Disruption of normal circadian rhythms

All of these factors have independently been linked to cognitive decline and neurodegeneration.

💡 A Note for Caution: Remember that these factors are links / associations and not a direct cause.

They are more of an INDICATOR of things that often go hand-in-hand and have have a bilateral relationship, for example: People with dementia may experience increased daytime sleepiness and cognitive impairment.

While improving sleep cannot guarantee prevention of dementia, taking sleep seriously may be one of the most accessible ways to protect brain health as we age.

• 🧠 Your brain works hard all day. Give it the sleep it needs to repair, recover, and protect itself for the future.

Does the MIND Diet Really Prevent Neurodegenerative Disease?

Diet gets a lot of attention when it comes to preventing neurodegenerative disease, because improving it is one of the few simple, preventative actions we can all take.

This is exactly what motivated some researchers to devise what’s called the “MIND” diet, which was specifically designed to protect against cognitive decline and neurodegenerative diseases. But does it really work?

Developing the MIND Diet

The full name of the MIND diet is the Mediterranean-DASH Diet Intervention for Neurodegenerative Delay. Combining elements from the popular Mediterranean diet and the blood pressure focused DASH diet, it also incorporates other foods that evidence suggests help with dementia.

Broadly, it suggests eating:

• Vegetables, especially leafy greens

• Berries

• Whole grains

• Beans and legumes

• Nuts

• Poultry

• Non-fried fish

• Extra virgin olive oil

Initial research scored participants on how well their diet matched the MIND diet, and found a link between MIND diet score and reduced cognitive decline with age.

Testing the MIND Diet

The same research group also tested how the MIND diet impacted Alzheimer’s risk. The methodology and cohort were basically the same – based in Chicago, n = 923, mainly white and non-Hispanic – except they used the participants’ annual Alzheimer’s assessment instead of their global cognitive score. As in the previous study, they compared the MIND diet with the Mediterranean and DASH diets.

The study suggested strong adherence to all of these diets reduced Alzheimer’s risk, but MIND outperformed the others for people who only partially followed the recommendations.  

However, a randomized controlled trial of the MIND diet came to a conflicting conclusion. The test pitted the MIND diet against a control diet (n = 604) with a mild calorie restriction, and found that both diets improved global cognition scores. People following MIND scored a little better, but the difference wasn’t statistically significant.

Does the MIND Diet Really Work?

The best answer to this question comes from a meta-analysis focusing on dementia in general . The authors combined three studies for a cohort analysis (n = 18,136) and 11 studies for the meta-analysis (n = 224,049). Both analyses found that the mind diet is associated with lower dementia risk in older adults.

More evidence is still needed – especially for non-Western populations and specific types of dementia – but overall, it does seem effective.