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.
Staying cognitively active is one of the most thoroughly studied protective habits. Older adults who regularly read, play board games, play a musical instrument, or dance had a 7% lower dementia risk per step up on the activity scale in a cohort study of people aged 75 and over. This effect held up after people with early, not-yet-diagnosed dementia were removed from the analysis. This is an observational finding, not proof of cause and effect, but the association is strikingly consistent.
What you eat also appears to matter. The MIND diet, a combination of the Mediterranean and DASH dietary patterns specifically focused on brain nutrition, was associated in observational research with cognitive performance comparable to that of people who were on average 7.5 years younger, measured over nearly five years. The pattern is rich in vegetables, nuts, fish, and olive oil, and low in red meat and processed products. The combination appears to work more strongly than either diet individually. Direct causality has not yet been demonstrated in large randomised trials.
Exercise likely protects the brain through several pathways simultaneously: it helps clear harmful proteins, suppresses inflammation, stimulates growth factors for nerve cells, and improves blood flow to the brain. Notably, in one randomised trial involving one hundred people with mild memory complaints, six months of intensive resistance training protected specific brain regions that normally shrink rapidly in Alzheimer's disease. That protective effect was still measurable even one year after training had stopped. Pure aerobic exercise or cognitive computer games alone did not produce that long-term effect in the same study. The study is too small for firm conclusions, but the result is worth keeping in mind.
In one cohort study of people aged 75 and over, greater physical activity on its own was not measurably associated with a lower dementia risk. This is noteworthy, but it is likely a methodological artefact: the study was not specifically designed for this purpose and the participants were already relatively old and not very active. Broader reviews do describe exercise as a recognised protective factor, so this single negative result is not a reason to remain inactive.
Herbal supplements and medicinal plant extracts are sometimes promoted as a supplement for cognitive decline. Research in this area consists largely of small or preclinical studies. Large, well-designed clinical trials are lacking, and concrete recommendations cannot be made on the basis of the available evidence.
Sources include one randomised trial (n=100, resistance training in MCI), one systematic review, several narrative reviews, and two cohort studies. No meta-analyses. Causal evidence is limited; most findings are associational.
Can you prevent dementia with your lifestyle?
Lifestyle does meaningfully influence your risk of dementia: one third of all cases are linked to modifiable factors such as physical activity, blood pressure and smoking. Especially if you already have an elevated risk, tackling several things at once is worthwhile.
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.
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 impossible to reverse. Make sure you consistently get enough sleep, and have sleep apnoea treated if you have symptoms of it.
What does air pollution do to your brain in the long term?
Long-term exposure to air pollution, and fine particulate matter in particular, is associated with an increased risk of dementia and faster memory decline. The associations have been demonstrated in multiple human studies, but a direct cause-and-effect relationship has not yet been conclusively proven.
Does regular sauna use protect your brain against decline?
There are indications that very frequent sauna use (four to seven times per week) is associated with lower rates of dementia, but the evidence is observational and has not yet been confirmed in women or other groups. It is an interesting lifestyle factor to watch, but not a proven form of protection.
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, but whether olive oil itself is the protective factor has not been proven. Anyone wishing to support their brain health would do well to follow the complete dietary pattern, not just the olive oil.