Group two received the same questions and advice, plus access to a website the research team developed. The site offered automated behavioral support for doing brain exercises and guidance on following a healthy lifestyle.

Group three got everything group two had, plus two brief appointments, phone calls or emails with a facilitator — typically a nurse — to encourage continued use of the website.

A year later, everyone retook the Baddeley test.

What the researchers found

All three groups improved. The biggest surprise came from group one, the comparison group. After 12 months, 28% of its participants no longer showed signs of cognitive impairment. In group two, just under 33% reversed their decline; in group three, around 32% did.

Groups two and three also posted small additional gains in their Baddeley scores relative to the comparison group. Group three, which had the extra human support, saw an 8% drop in the number of people with mild cognitive impairment compared with group one. Among participants who began the study with impairment, group three showed an 18% reduction in severe cognitive impairment relative to the comparison group.

Because participants already ate fairly healthy diets and stayed physically active throughout the study, the researchers attribute the improvements mainly to people doing more brain-stimulating activities — essentially, more puzzles, reading and socializing.

Important caveats

The findings come with limitations the authors themselves stress.

First, the study lacked a true control group. Group one received advice, had cognitive testing, and answered questions about brain-stimulating activities — and this appears to have changed their behavior. A classical control group receives no intervention at all, which lets researchers isolate a treatment's effect by comparing it with untreated peers. That comparison was not possible here, which means the overall improvement across all groups may partly reflect the attention and advice everyone received.

Second, the team has not yet run a formal process analysis — a detailed statistical examination of which variables actually predicted the observed changes. A longer follow-up is also needed to determine whether these activities deliver lasting benefits, including any effect on the development of dementia.

Why it still matters

The study is not the first to show that brain training and lifestyle changes can improve cognitive health. But it is the first large trial to examine what even small daily activities can achieve — and it suggests that simply advising people and pointing them toward accessible activities can have a real impact.

The core message, the researchers say, is encouraging: the brain remains malleable well into older age. Even the small things you do each day can make a difference in countering cognitive decline.