Updated 06 June 2018

Can eating apples, bananas make your brain bigger?

A healthy diet may just be the key to bulk up your brain and make you smarter.

You go to the gym to make your muscles bigger, but what if you want to bulk up your brain to help you stay sharp? New research suggests you might want to head to the produce aisle..

"Adhering to an overall healthy diet supports brain health and might be a suitable preventive strategy to maintain and augment cognition in healthy older adults," said the study's senior author, Dr Meike Vernooij. She's a professor of population imaging at Erasmus University Medical Centre, in Rotterdam.

The study included more than 4 200 people aged 45 and older at the start. Average age was 66, the researchers said.

Study volunteers completed a survey about what types and how much food they ate over the past month. The survey included almost 400 food items.

What’s in a good diet?

The researchers looked at diet quality based on Dutch dietary guidelines. Diet quality was measured on a scale of zero to 14, with 14 the healthiest. The best diets contained lots of fruits and vegetables, nuts, whole grains, dairy and fish, and limited sugary beverages, the researchers said.

The average diet score was seven, the study found.

Participants also had MRI scans done to measure their brain size. Information was also collected about other factors that could affect brain size, such as high blood pressure, physical activity and smoking.

After adjusting the data to account for such factors, the researchers saw that a higher diet score was linked to larger brain volume. Folks with the healthiest diets had brains that were about 2ml larger than those who ate fewer healthy foods.

Could a 2ml difference in brain size actually translate to better thinking and memory skills? The researchers said yes, it seems to.

"It is known that the risk of cognitive decline increases with advancing age. Moreover, with increasing age our brain volume decreases," Vernooij said.

How does a good diet help the brain?

It's possible that good nutrition in youth – when the brain is developing and growing – may lead to a larger brain.

James Hendrix, director of global science initiatives at the Alzheimer's Association, said a healthy diet might lead to better blood flow.

"We think what's good for the heart is good for the brain. If your heart is working well and getting good blood flow to the brain, the brain will be working better," he said.

"One hypothesis of Alzheimer's is that amyloid and tau proteins build up because they're not being cleared properly. It may be that the brain needs good blood flow to clear out those proteins," he suggested.

Hendrix said it's important to note that there wasn't one healthy food that made a difference, but rather a healthy diet overall.

The findings were published online in the Neurology journal.

Image credit: iStock




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