Why internet use can actually lower your dementia risk

This is the 86th instalment in a series on dementia, including the research into its causes and treatment, advice for carers, and stories of hope. I was startled by a comment from a friend recently: she told me that she almost never uses the internet. I work, cook, shop and walk listening to podcasts. I read the news online each morning. I use the internet to research, find supper recipes, search for new books to read and download the latest episodes of favourite radio shows. The trace of smugness in my friend’s tone made me worry: what effect was this constant connectivity having on my well-being? My concern deepened after watching part of a report on 60 Minutes Australia titled “Brain Drain”, about kids’ screen time and their brain health. The findings were sobering. Research has found that young people who do not exercise much and spend hours on their screens – playing games, watching YouTube, scrolling through Instagram – show brain changes similar to those that doctors see on the scans of elderly people with Alzheimer’s disease. This phenomenon, dubbed “digital dementia” by researchers, suggests that excessive time online may be making children less smart. Cognitive neuroscientist Dr Mark Williams at Macquarie University in Australia has been studying these effects on the developing brain. “Preschoolers and kids who use devices regularly have abnormal development of their white matter tracks,” he says. These are the fibres that go from left to right in the brain and from front to back, supporting healthy brain messaging. He believes being on a device and online too much could be causing a rise in early-onset dementia symptoms, even among 25- to 35-year-olds. While the term “digital dementia” describes cognitive deficits caused by lifestyle rather than disease, Williams notes a 400 per cent increase in young adults seeking treatment for these issues. The youngest patient he references is just 19, whose cognitive decline – driven by extreme screen time – mirrors the brain scans of much older patients. At the same time, evidence suggests that internet use could actually be good for the brains of older people. In a large US study conducted at New York University’s School of Global Public Health, 18,000 adults aged 50 to 65 were followed for about eight years. The study, published in the Journal of the American Geriatrics Society, found that regular internet users had about half the risk of dementia compared with non-users. Part of this value is about remaining relevant. Unless you can manage the internet, you are thwarted in many areas, such as online banking, making flight reservations, or keeping up with grandchildren via FaceTime. However, the NYU researchers noted the effect is “dose-dependent”, presenting as a U-shaped curve. No use at all was as damaging as too much. There is a “sweet spot” where the internet serves as a cognitive tool rather than a sedentary trap. Building cognitive reserve That spot depends on what you are doing online. You need to be living life in the real world – getting out to move and meet real people. Being online often means being sedentary, which is not good for the brain or body. Not all internet use is created equal, either. Scrolling mindlessly through Instagram is not as cognitively stimulating as responding to an email, updating a budget or searching for information. Even online games have varying values. If you do Wordle every day and find it easy, it is time to change it up. To build “cognitive reserve”, you must ensure the games are stretching you. The worrying “brain rot” associated with some young people occurs because they are not using their brains while online; they are getting “dumber” on their smartphones. Healthy internet use is about using devices as a tool – for connection, learning or admin – rather than as a default background habit. How to use the internet while still using your brain Set clear online jobs Go online with a clear purpose: paying bills, emailing, making a reservation for something, learning, connecting with friends or family. Try to limit it to a couple of hours a day, suggests the Washington-based Information Technology and Innovation Foundation. It notes that regular internet usage by older adults is a key factor in reducing dementia risk, provided it remains purposeful. Prioritise active, social and learning uses Engage in video calls, language learning or reading news from trusted outlets. Anything that engages memory, planning and social cognition supports brain health. Limit passive scrolling Decide in advance to limit yourself to 20 to 30 minutes of social media. The American Psychiatric Association suggests turning off notifications to regain control over your attention. Research in the Journal of Social and Clinical Psychology highlights that limiting social media can significantly decrease loneliness and depression. Safeguard sleep Many experts and expert bodies, including the American Academy of Sleep Medicine, encourage people to disconnect from devices at least 30 minutes before going to bed as they are known to disrupt healthy sleep, mainly because of bright screens and stimulation. Keep the phone out of the bedroom or across the room at night. Bradley Zicherman, a psychiatrist at Stanford University in California, says this helps keep people from reaching for their phone first thing in the morning. Ending that habit, he says, may also help you reach for your phone less frequently during the day. Look after your body while online The American Optometric Association recommends the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds. Additionally, stand and move every 30 to 40 minutes to counteract the sedentary nature of screen time. Curate your feeds for mood UC Davis Health, of the University of California, Davis, warns of social media’s impact on mental health. Mute or unfollow accounts that upset you. Intentionally follow accounts that inspire new ideas, and step away entirely some days. Do things that do not require being online Maintain at least one fully offline hobby, such as hiking or gardening. Research from Utah State University emphasises that hobbies improve mental health through real-world engagement. Use the internet to support these, such as route trackers or to find groups or tutorials, not to replace them. Watch for red flags A handy checklist on problematic internet use from Australia’s Victoria State government suggests you are online too often if you feel empty after browsing, stay up later than intended to scroll, or find that relationships and exercise are being displaced. I still use the internet every day, but I no longer feel concerned when I am using it as a tool. As for my “offline” friend? She might be missing out on the cognitive boost of a well-placed Google search, but she certainly has the “moving in the real world” part right. The goal for the rest of us is to find that sweet spot in between. Like what you read? Follow SCMP Lifestyle on Facebook, X and Instagram. You can also sign up for our eNewsletter here.

Why internet use can actually lower your dementia risk

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}While excessive screen time can harm young brains, a study finds that using the internet wisely can boost cognitive health in older adults

While excessive screen time can harm young brains, a study finds that using the internet wisely can boost cognitive health in older adults