How do you keep your brain healthy as you age?
Combining more physical activity 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, interesting developments to follow rather than actionable advice.
Regular physical activity is by far the best-supported thing you can do for your brain. Moderate to vigorous exercise helps both cognitively healthy older adults and people at higher risk of decline. People who move more also have a lower risk of dementia, including Alzheimer's disease. The effects depend on the type of exercise and how long you keep it up, but the consistency across many large studies makes this the strongest lever we currently have.
Your brain adapts as you get older. It switches to alternative 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 spent a lifetime studying, doing challenging work, or staying mentally engaged appear to be more resilient against brain problems later in life.
What you eat matters too, although these findings come mainly from studies that tracked people over time rather than studies that prove cause and effect. Large amounts of simple sugars, such as those found in soft drinks and sweets, are associated with poorer cognitive performance and brain changes also seen in Alzheimer's disease. Complex carbohydrates from wholegrains and vegetables are linked to better memory scores. Omega-3 fatty acids from oily fish are positively associated with memory, while saturated fats are associated with the opposite.
Spermidine, a substance found in wheat germ, legumes, and cheese, has barely been studied in people yet. In animal studies and one small study in people, there was a positive effect on cognitive functioning. Large-scale studies are still missing, so this is something to keep an eye on rather than established advice.
Fundamental research shows how the brain removes waste products through tiny channels in the membranes surrounding it. In mouse studies, deterioration of that system led to greater build-up of the Alzheimer's-associated protein amyloid beta and to cognitive decline. A study examining nearly 1.3 million brain cells also found activity patterns in brain support cells that are linked to cognitive resilience in Alzheimer's disease. Fascinating, but still far from practical applications.
The claims are based on many studies combined and large reviews, as well as studies that track people over time and basic lab and animal research. The strength of the evidence ranges from strong (exercise and dementia risk) to limited (spermidine, the brain's waste-clearance system). Nutritional findings are largely based on patterns seen across groups of people, not proven causes.
What do immune cells in your brain do during ageing?
Microglia play an active role in brain ageing through fat build-up and energy shortage, but most of the evidence still comes from animal studies. There are no human treatments yet, so if you have concerns about memory problems, discuss them with your doctor.
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.
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.
Do your brains really shrink as you get older?
Your brain does indeed shrink with age, particularly in areas involved in memory and planning. High blood pressure accelerates that process, while exercise and cognitive effort strengthen your brain's compensatory activity.
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 support for protecting your memory in later life. Some factors, such as the UV-skin link, are still too preliminary to act on.