Brain & memory

Memory, dementia and what keeps your brain healthy as you age.

97 answers, from 635 studies

Last updated: July 2026

Key questions

How much ashwagandha do you need per day?

For stress reduction, 240 to 500 mg per day already appears to have an effect; for safety, 600 mg per day has been studied for…

Yes · Moderate evidence

How many cups of green tea do you need per day?

For regular tea, three to five cups per day appears to be the best-supported amount for heart and brain benefits, though the…

Preliminary evidence

What does creatine do for people over sixty?

For people over sixty, creatine has reasonably well-supported benefits for muscle strength, muscle mass, and memory,…

Yes · Moderate evidence

Why does your memory work less well as you get older?

Memory loss with ageing is a normal biological process with multiple clearly demonstrated causes, but you can slow it down:…

Yes · Moderate evidence

Does learning a new language help keep your brain healthy?

Actively using two languages throughout your life is associated with a lower risk of dementia and a brain that continues to…

Moderate evidence

Can you prevent dementia with your lifestyle?

Lifestyle has a real but limited influence on dementia risk: quitting smoking, keeping blood pressure under control and…

Moderate evidence

What keeps your memory sharp in later life?

Getting good sleep, eating mindfully according to the MIND diet and engaging in targeted cognitive training have the strongest…

Moderate evidence

Does ergothioneine work as a longevity supplement?

Ergothioneine shows a positive signal in a small study of older adults with memory complaints, but it is too early for firm…

Preliminary evidence

Does years of insufficient sleep damage your brain?

Years of insufficient sleep damages the brain through multiple pathways at once, and some of that damage appears difficult or…

Yes · Moderate evidence

Does a low dose of lithium help protect the ageing brain?

There are preliminary indications that low doses of lithium may offer brain protection, but the evidence is still too thin and…

Preliminary evidence

Does lion's mane really work for your brain?

Lion's mane shows cautiously positive signals for attention and working memory in small studies, but the evidence is still too…

Preliminary evidence

Does methylene blue really work for your energy and brain?

Do not take this as a supplement. Methylene blue is a registered medicine and industrial dye, not a food, and not authorised…

Preliminary evidence

Does the Wim Hof Method really work?

The WHM shows positive effects in small studies in specific patient groups, but whether those benefits are unique to the…

Preliminary evidence

Is magnesium L-threonate better for your brain?

MgT has preliminary indications that it raises brain magnesium more effectively and may support cognition, but the evidence in…

Preliminary evidence

Is there a relationship between changing body odour and Alzheimer's disease?

Alzheimer's disease affects the patient's own sense of smell at an early stage, but whether people with Alzheimer's develop a…

How do I know whether my mood swings are hormonal or something else?

The cyclical pattern of your symptoms is the best distinguishing factor: if they occur only in the two weeks before your…

Can Magnetic Resonance Spectroscopy (MRS) detect Alzheimer's disease early?

MRS can detect early signs of Alzheimer's disease, even before a conventional brain scan shows abnormalities, but is most…

Yes · Moderate evidence

Can your gut flora influence your memory and concentration?

Your gut flora very likely does influence memory and concentration, but the evidence in humans is still limited. A varied diet…

Do I sleep worse if I am often alone or feel lonely?

Yes, loneliness is clearly associated with poorer sleep: you have more difficulty falling asleep, wake up more often during…

Why do some women suddenly experience anxiety symptoms after menopause?

Menopause increases the risk of anxiety symptoms through hormonal, physical and psychosocial factors that reinforce one…

Does loneliness accelerate your biological age?

Whether loneliness accelerates your biological age at the cellular level cannot be determined from the available studies.…

Is there a link between your hormones and the risk of dementia later in life?

There is solid evidence that thyroid hormones, sex hormones and stress hormones all play a role in dementia risk. The evidence…

What does poor air quality or fine particulate matter do to your memory in the long run?

Poor air quality, especially fine particulate matter, is consistently associated with worse cognitive performance and possibly…

What is the relationship between your thyroid and depressive symptoms?

There is a clear association between thyroid problems and depressive symptoms, although the precise direction of influence has…

Does regular sauna use protect your brain against decline?

Regular sauna use is associated with a notably lower risk of dementia, but the evidence comes from a single large…

Moderate evidence

Does watching a lot of television later in life affect your brain?

Watching more than 3.5 hours of television per day is associated with faster memory decline in people aged 50 and over,…

Yes · Moderate evidence

Why do damaged proteins accumulate in your cells as you age?

With age, the systems that clear damaged proteins become less and less efficient, while damage to proteins actually increases.…

Is it true that older people get less deep sleep, and what does that mean?

Older people demonstrably get less deep sleep, and this is associated with higher risks of dementia and lower growth hormone…

Yes · Strong evidence

What does high cholesterol do to your brain as you age?

High cholesterol in middle age likely increases the risk of dementia, but at older ages the relationship is less clear and…

Can thyroid problems worsen your memory and concentration?

Thyroid problems can cause memory complaints, but large-scale research shows barely any measurable effect at the group level…

Moderate evidence

What does alcohol do to your cells and DNA in the long term?

Prolonged alcohol use damages cells and DNA in multiple ways simultaneously, from oxidative stress in the liver to broken DNA…

Does drinking coffee really help against dementia, or is that a myth?

Drinking 2-3 cups of coffee daily is associated with a lower dementia risk in several large studies, but this is not yet a…

Moderate evidence

What does loneliness do to your immune system?

Loneliness disrupts your immune system in multiple ways simultaneously: more inflammation, reduced antiviral defence, and…

Do I sleep worse when I am stressed, and does that create a vicious cycle?

Stress worsens your sleep, and poor sleep in turn makes you more stressed and anxious. Improving sleep is therefore one of the…

Yes · Moderate evidence

What does long-term loneliness do to your brain?

Prolonged loneliness is associated with a higher risk of dementia and persistent low mood, and damages the stress system.…

Does frequent mobile phone use increase the risk of brain tumours?

Normal mobile phone use does not appear to increase the risk of brain tumours, but with more than ten years of intensive use…

Moderate evidence

Is reading every day good for your brain in the long run?

Daily reading is probably good for your brain, but the evidence is largely observational; a firm causal relationship in…

Yes · Preliminary evidence

What are the signs that your gut microbiome is out of balance?

A disrupted gut microbiome manifests as reduced bacterial diversity, mood complaints, skin problems, and a leaky gut wall, but…

Do your brains really shrink as you get older?

Your brain does indeed shrink measurably as you get older, but this far from always leads to noticeable cognitive decline.…

What does a vitamin D deficiency do to your brain?

A vitamin D deficiency is associated with multiple brain-related problems, from depression to MS and sleep disorders. Check…

Why are cells damaged when they receive too little oxygen?

Oxygen deprivation damages cells through multiple simultaneous pathways: energy deficit, toxic accumulation of calcium and…

Do you age faster if you sleep too little?

Sleep deprivation demonstrably disrupts the processes that keep the brain young, particularly the clearance of harmful…

Does green tea help improve your memory or concentration?

Green tea offers a modest but real benefit for concentration and working memory, primarily thanks to the combination of…

Yes · Moderate evidence

Does type 2 diabetes increase your risk of dementia?

Type 2 diabetes substantially increases the risk of dementia, and the younger you are at diagnosis, the greater that risk.…

Will my memory improve if I sleep more?

Getting enough sleep, and particularly the deep sleep phase, is an active part of how your brain retains new information. Too…

Yes · Moderate evidence

What is brain fog, really, and where does it come from?

Brain fog has multiple causes that each work differently, from temporary adenosine build-up due to sleep deprivation to…

What is the difference between REM sleep and deep sleep, and do I need both?

You need both sleep stages: deep sleep and REM sleep each do something different for your memory and brain, and getting a full…

Yes · Moderate evidence

Is there a link between depression and a higher risk of dementia?

Depression is strongly associated with a higher risk of dementia, though it remains uncertain whether depression causes…

Does fasting or eating less help your memory and concentration?

Fasting can improve memory and concentration in older adults with insulin resistance, but the effect disappears when fasting…

Preliminary evidence

Is irritable bowel syndrome a real condition, or is it all in your head?

IBS is a recognised physical condition with measurable biological abnormalities, not a figment of the imagination. If you are…

What does excess weight do to your brain in the long run?

Excess weight harms your brain in multiple ways at once: less brain tissue, weaker connections and a higher risk of dementia.…

What does your estrogen level do to your memory and concentration?

Oestrogen has a measurable influence on memory and concentration, and the decline during perimenopause is accompanied by…

Can stress really make your gut sick?

Stress disrupts your gut microbiome and increases the risk of gut complaints such as irritable bowel syndrome, but the precise…

Can high blood pressure in your 40s cause dementia later in life?

High blood pressure in your forties demonstrably increases your risk of dementia later in life, and early treatment appears to…

Does olive oil protect your brain against decline?

Extra virgin olive oil as part of the Mediterranean diet has been associated with less cognitive decline in multiple studies,…

Yes · Moderate evidence

What does smoking do to your brain as you age?

Smoking accelerates brain ageing and increases the risk of dementia. Quitting smoking is one of the best-supported steps you…

Does your brain age faster than the rest of your body?

Whether your brain ages faster than the rest of your body varies from person to person, but the consequences are significant:…

Why do I dream so much, and is that good or bad?

Simply dreaming a lot is normal and need not be a cause for concern. However, persistent nightmares or dreams that you…

Moderate evidence

Is it bad for your brain if you don't get enough exercise for years on end?

Years of insufficient physical activity are associated with a considerably higher risk of dementia and cognitive decline,…

Yes · Moderate evidence

What does cortisol do to your body in the long run when you are chronically stressed?

Chronic stress noticeably dysregulates your cortisol system: your daily rhythm flattens, your immune function, sleep and…

What does caffeine do to your memory and concentration in the long run?

Caffeine makes you temporarily more alert, but does not structurally improve your long-term memory. Use it in moderation and…

Does metformin lower your risk of cancer or dementia?

In people with diabetes there are indications that metformin lowers overall cancer risk, but the evidence varies or is absent…

Moderate evidence

What does NAD+ do for your brain?

NAD+ is biologically crucial for your brain and declines with age, but whether supplementation via NMN or other means…

Does creatine affect dopamine levels?

In healthy people, creatine has no demonstrable effect on dopamine in the blood. Positive signals so far come exclusively from…

How does creatine improve mood and well-being?

Creatine shows early signals of mood improvement, particularly in women with depressive symptoms, but is officially not…

Does creatine supplementation reduce brain fog?

Creatine may relieve cognitive complaints, but the effect depends strongly on your situation: people with chronic fatigue,…

Moderate evidence

Does gratitude or optimism help your health and longevity?

Keeping a gratitude journal regularly probably helps with mood and possibly with sleep, but the evidence is too thin to make…

Moderate evidence

Does creatine also help with memory and concentration?

Creatine has the strongest evidence for a memory effect in older adults aged 66 and over. In younger, healthy adults, the best…

Moderate evidence

Is sleeping in on the weekend beneficial, or does it fail to make up for sleep deprivation?

Sleeping in on the weekend temporarily relieves fatigue but does not genuinely make up for sleep deprivation: cognition,…

No · Moderate evidence

Does my sleep change as I get older, and is that normal?

Your sleep genuinely changes with age: feeling tired earlier, sleeping more lightly and for shorter periods, and waking more…

Yes · Strong evidence

What does alcohol do to your brain in the long term?

Alcohol harms the brain in multiple ways: from temporary memory blackouts with acute use to lasting cognitive damage from…

What does prolonged stress do to your memory?

Prolonged stress harms memory through measurable changes in the brain, and early-life stress increases the risk of memory…

Does the MIND diet help against dementia and cognitive decline?

Large observational studies link the MIND diet to a lower risk of dementia, but the only large controlled study found no…

Moderate evidence

Does a mentally stimulating life, such as studying or complex work, protect against dementia?

Longitudinal studies consistently show that mental challenge lowers the risk of dementia, but this is an association, not a…

Yes · Moderate evidence

Can you still reverse early-onset forgetfulness with your lifestyle?

Fully reversing forgetfulness is rarely achievable, but exercise, blood pressure treatment and good blood sugar control can…

Preliminary evidence

Does heading the ball frequently in football, or sustaining a concussion, increase my risk of dementia later in life?

Professional footballers who head the ball frequently have a considerably higher risk of dementia than goalkeepers or people…

Yes · Moderate evidence

Is it normal to forget names more often around age 50, or should I be worried?

Forgetting names around age 50 is normal and biologically explainable. It is not a reason for immediate concern, but exercise…

Yes · Moderate evidence

Can you tell someone's biological age from their face?

Your face does emit biological signals, but it is too limited and too variable to measure your biological age accurately. Take…

Is there a real connection between your gut microbiome and your mood or brain?

There is a biologically plausible and, in animal research, robustly supported connection between your gut microbiome and your…

Do B vitamins (folate, B6) benefit your heart and brain?

Folic acid reduces stroke risk by approximately 16%, but probably only if you have a deficiency. For broader cardiovascular…

Moderate evidence

Does exercise really help with depression and anxiety?

Yes, exercise genuinely works: for mild to moderate depression it is as effective as medication, for anxiety disorders it is…

Yes · Strong evidence

Do brain-training games help prevent cognitive decline?

Cognitive training has a demonstrable, albeit modest, benefit for people with Alzheimer's disease or mild dementia, but does…

Moderate evidence

Can I test my risk of Alzheimer's with a blood test (p-tau217)?

The p-tau217 blood test is an accurate tool if you have memory or cognitive complaints and a doctor is supervising you. As a…

Yes · Moderate evidence

Does poor sleep cause dementia sooner?

Poor sleep probably increases your risk of dementia, but ordinary insomnia does not make dementia inevitable. One exception:…

Yes · Moderate evidence

When should I be concerned about memory problems?

Not every instance of memory loss is worrying, but certain signs deserve prompt medical attention: sudden deterioration, the…

Moderate evidence

What can I do to keep my brain healthy as I age?

Combining more exercise with staying mentally active and eating a diet low in sugar and higher in omega-3 fatty acids…

Moderate evidence

Which blood values should I have checked to age healthily?

Blood sugar, blood lipids and inflammatory markers are the best-supported measurements if you want to age healthily.…

Preliminary evidence

How healthy are blueberries and other red/blue fruits for your brain?

Eating blueberries daily or taking them as a supplement appears worthwhile if you are middle-aged or older with mild memory…

Does a second language or music help protect the brain against ageing?

Speaking two or more languages daily appears to protect the brain in later life, with the strongest evidence for people who…

Yes · Moderate evidence

Does staying socially and physically active protect against dementia?

Staying socially and physically active is probably your best lifestyle investment against dementia. The strongest results come…

Yes · Moderate evidence

Does exercise keep my brain sharp?

Regular exercise demonstrably keeps your brain sharper, as long as serious cognitive decline has not yet set in. The…

Yes · Strong evidence

Does poor hearing increase my risk of developing dementia?

Poor hearing is associated with a modest but real increased risk of dementia. Have hearing loss assessed and treated promptly,…

Does deep sleep flush waste products from your brain?

Yes, your brain cleanses itself largely during sleep, and deep sleep appears to play the most important role in this.…

Do fish oil pills keep my memory sharp?

Fish oil pills probably do not keep your memory sharp. Multiple human studies, including systematic reviews and randomised…

No · Moderate evidence

What can I concretely do to prevent dementia?

A combined approach, including regular physical activity, blood pressure and diabetes management, not smoking, maintaining…

Moderate evidence

I have APOE4 -- how serious is that, and what can I do about it?

APOE4 substantially increases your risk of Alzheimer's disease, but at younger ages lifestyle factors such as blood pressure,…

Yes · Moderate evidence

How healthy is meditating, and what exactly does it do for you?

For depression, anxiety, and pain perception, daily meditation offers a modest but consistent benefit, best used as a…

Yes · Strong evidence

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