These 2 activities can help you raise smarter kids, says brain study: They're ‘associated with improved cognition'

Parents who want to raise smarter kids should sign them up for organized sports, put down the video games and pick up a book, a new study suggests.

Neuroscientists at the University of Eastern Finland spent two years studying 504 children between the ages of 6 and 9, in a recently published peer-reviewed study. The children who spent more time reading and playing on sports teams developed better thinking skills than those who focused on other activities, from unsupervised computer to unstructured free play, researchers found.

The best results came when children combined increased sports and reading time with a healthy diet, which the researchers defined as a traditional Nordic diet featuring low-fat dairy products and less red meat or sausage.

"Improved diet quality and increased organized sports and reading were associated with improved cognition," the neuroscientists wrote.

One particular part of the study's findings stands out: the suggestion that structured physical activity, like organized sports, can improve kids' cognitive skills. The finding builds on past research, which showed a clear link between increased physical activity and improved brain function, including memory and learning ability.

Kids who play youth sports often have higher self-esteem and lower rates of anxiety and depression than their peers, according to the National Institutes of Health. Team sports especially offer a mental health boost by blending physical activity with social development.

Still, experts often recommend a healthy mix of structured and unstructured play for children: The former can provide more targeted learning, while the latter can help foster creativity and self-motivation.

Books versus video games

The study's findings around reading and screen time are less surprising.

Reading for pleasure is linked with better mental health, creativity and reasoning skills in kids, a University of Cambridge study found earlier this year. Children who spend more time reading score higher on cognitive tests than kids who replace that reading time with screen time, according to past studies by the Cincinnati Children's Hospital.

It's not all bad news for screens. Video games offer some benefits to children's development, boosting memory, spatial awareness and — when played in groups — social skills, the American Psychological Association says.

But that cognitive development is hindered when the child's screen time is completely unsupervised, the University of Eastern Finland neuroscientists found. Toxic behavior and harassment are more common in social video gaming when children are not supervised, other researchers note.

If you're not sure how to encourage your children to spend less on video games and more time with books or sports, take a gentle and transparent approach, experts say.

Avoid phrases like "because I said so" when encouraging new behavior in your children, clinical neuroscientist Dr. Caroline Leaf told CNBC Make It last month. Instead, take the opportunity to explain to them how activities like team sports or reading could boost their brain power in the long run.

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