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 healthy people is still lacking, so reading is a sensible habit, not a proven treatment.
Brain scans show that reading engages a broad network of brain regions simultaneously: visual areas at the back of the brain, language areas on the left side of the cortex, and the cerebellum. That makes it one of the richer cognitive activities you can do on a daily basis, although this does not yet say anything directly about long-term effects.
People who engaged in many cognitively enriching activities early in life, including reading, appear to be more resilient against cognitive decline in later life. This has been studied in people with multiple sclerosis, a condition in which brain damage occurs from a young age. Those who had a large vocabulary and were intellectually active continued to function well for longer despite considerable brain damage. This is explained through the concept of 'cognitive reserve': the brain is better able to compensate for damage if it was used intensively earlier in life. However, this is observational evidence: people who read a lot differ from people who do not in more ways than one, and a direct causal relationship has not yet been established.
In people who already have dementia, reading is mentioned in a review article in JAMA as a non-pharmacological approach that may help to alleviate symptoms or slow progression. This is a recommendation within a review, not a randomised study that tested reading as a specific intervention. The supporting evidence is therefore limited.
In summary: daily reading activates many brain regions simultaneously and is associated in observational research with less cognitive decline, but a proven causal effect in healthy people over the long term has not yet been firmly established. The indications are encouraging, not conclusive.
Three sources: one neuroimaging review (PMID 9448259), one review on cognitive reserve in MS (PMID 23897894), one clinical review article on dementia in JAMA (PMID 31638686). No randomised trials that have tested reading as a specific daily intervention in healthy people.
Is it bad for your brain if you don't get enough exercise for years on end?
Years of too little exercise is associated with a clearly elevated risk of memory problems and dementia. Moving more, even lightly, is the most concrete form of protection you can build in.
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 function well for longer, but learning a language as an adult does not yet provide comparable protection. If you want the benefits, it comes down to years of active use, not learning alone.
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. Exercise combined with diet appears to be able to partly reverse this, so losing weight is good for your brain too.
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 alcohol do to your brain in the long term?
Long-term heavy drinking demonstrably damages the brain, in part irreversibly. Stopping helps, but after years of heavy use it should always be done under medical supervision.
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.