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 currently gives you the best chance of a healthy brain. Spermidine and new insights into how the brain cleans itself are, for now, only interesting to follow.
Regular exercise is by far the best-supported thing you can do for your brain. Moderate to vigorous training helps both cognitively healthy older adults and people at elevated risk of decline. Those who exercise more also have a lower risk of dementia, including Alzheimer's disease. The effects depend on the type of training and how long you keep it up, but the consistency across multiple large studies makes this the most solid handle we currently have1,2.
Your brain adapts as you age. It switches to alternative neural circuits to compensate for early decline. Both exercise and staying mentally active strengthen that adaptability. This is linked to what researchers call 'cognitive reserve': people who have studied throughout their lives, done cognitively demanding work, or stayed mentally active appear to be more resilient against brain problems in later life3,4.
What you eat also matters, although these findings come mainly from observational research rather than proven causal relationships. High intakes of simple sugars, such as those in soft drinks and sweets, are associated with poorer cognitive performance and brain changes also seen in Alzheimer's disease. Complex carbohydrates from whole grains and vegetables, on the other hand, are associated with better memory scores. Omega-3 fatty acids from fatty fish are positively associated with memory; saturated fats are associated negatively5,6.
Spermidine, a compound found in wheat germ, legumes, and cheese, has barely been studied in humans. In animal studies and one small human study, there was a positive effect on cognitive functioning. However, large-scale studies are still lacking, so this is something to keep an eye on rather than an established recommendation.
Fundamental research shows how the brain removes waste products through small channels in the meninges. In mouse studies, deterioration of that system led to greater accumulation of the Alzheimer's protein amyloid-beta and cognitive decline. Research involving nearly 1.3 million brain cells also found activity patterns in brain support cells that are associated with cognitive resilience in Alzheimer's disease7,8. Fascinating, but still far from concrete applications.
The claims are based on systematic reviews and meta-analyses (PMID 38811309, 31095081), conceptual and observational studies (PMID 19035823, 30222945, 34139473, 33053376), and fundamental and preclinical research (PMID 30046111, 39048816). The strength of evidence ranges from strong (exercise and dementia risk) to limited (spermidine, the brain's waste-clearance system). Nutritional findings are largely associational.
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: a biologically old brain increases the risk of Alzheimer's more than threefold. Keep an eye on your blood pressure, sleep and lifestyle, as these have the most demonstrable influence on brain ageing.
Which lifestyle habits protect your brain health over the long term?
Cognitive activities, a plant-based dietary pattern, and regular exercise, preferably in combination, offer the best-supported protection for your brain over the long term. Hard cause-and-effect evidence is still lacking, but the associations are broad and consistent enough to take seriously.
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. Alzheimer's blood tests are only meaningful in the presence of genuine memory or cognitive complaints, and always under the supervision of a specialist.
What can I concretely do to prevent dementia?
Various lifestyle choices demonstrably lower your risk, but no single approach guarantees that you will prevent dementia. Regulating blood pressure, exercising, not smoking and staying mentally active are the best-supported steps you can take.
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 best-supported approach: 45 to 60 minutes of moderate exertion per session, several times a week.
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 can take to keep your brain healthy for as long as possible.