Dr Michelle Dickinson: nanotechnologist on how coffee can help protect your brain

If you’re holding a cup of coffee or tea right now, here’s a small piece of encouraging news.  A large study published in the journal JAMA suggests that people who drink two to three cups of caffeinated coffee or tea a day have about a 15-20 percent lower risk of developing dementia compared to people who avoid these drinks altogether.  The researchers analysed data from more than 130,000 men and women followed for up to 43 years as part of two major US health studies. Participants regularly reported what they ate and drank, whether they developed dementia, and how their cognitive abilities changed over time.  The people who drank the most caffeinated coffee or tea had an 18 percent lower risk of dementia compared to those who drank little or none. The benefit seemed to plateau at around two to three cups of coffee or one to two cups of tea per day.  Decaf coffee showed no clear link to reduced dementia risk.  Regular caffeine drinkers also reported slightly less cognitive decline and performed a bit better on some objective brain function tests.  Now we have to remember there may be other factors. It’s possible that people who drink tea and coffee differ in other ways, maybe they’re more socially engaged, more active, or have different sleep patterns. For example, people with poor sleep (which is linked to higher dementia risk) might avoid caffeine which could skew the results.  There are plausible biological reasons for the link. Tea and coffee contain caffeine and polyphenols, which may: Improve blood vessel health  Reduce inflammation Lower oxidative stress (damage caused by free radicals)  Improve metabolic health  Caffeine is also associated with lower rates of type 2 diabetes, which is itself a risk factor for dementia. But caffeine isn’t purely good. In some people it raises blood pressure, and high blood pressure is a major driver of dementia risk so more isn’t better.  Experts estimate that up to half of dementia cases worldwide could potentially be prevented or delayed by addressing known risk factors like high blood pressure, smoking, obesity, hearing loss, poor sleep, and lack of exercise.  So while your morning coffee might be part of a healthy pattern, it’s not a magic shield.  The real protective factors are the familiar ones: regular exercise, balanced nutrition, good sleep, social connection, and mental stimulation.  If anything, this research offers gentle reassurance. If you enjoy your daily coffee or tea, there’s no strong evidence here that you need to give it up for brain health  and there may even be a modest benefit.  LISTEN ABOVESee omnystudio.com/listener for privacy information.