While it also has high levels of protein, which provides the raw materials to make neurotransmitters and other brain chemicals.
"It's a true brain superfood," says Ms Barns.
PUMPKIN SEEDS
These nutritious seeds are one of our best natural sources of zinc, which is vital for cognitive function - our ability to think, learn and reason.
They're also high in magnesium, which helps nerve signals travel around the body, including to and from the brain, as well as essential fatty acids and protein.
EGGS
Eggs are a fantastic food for many reasons - not least for your brain.
The yolks are rich in choline, a vitamin-like substance that's needed for the myelin sheath that surrounds nerve fibres, including in the brain.
Choline can also be used to make the neurotransmitter acetylcholine, which is vital for learning and memory.
And eggs are also a good source of B vitamins and iron, which support the nervous system and cognitive function.
SEAWEED
A staple food in Japan, seaweed is well known for its content of health-boosting minerals, particularly iodine.
Like magnesium, iodine plays an important role in the health of our nervous system and brain and, like zinc, supports cognitive function.