Apart from following a diet rich in oily fish, wholegrains and fruit and vegetables, some other foods should be avoided, according to experts.

Fizzy drinks

Neurologist Dr Shaheen Lakhan told HuffPost that because of the high sugar content in fizzy drinks, soda can be among the worst foods.

“Soda is one of the worst foods for brain health due to the high concentration of simple sugars, which damage the blood vessels supplying the brain,” he said.

“Over time, this starves the brain from the very fuels it needs to function, leading to premature dementia and strokes. Acutely, sugar also causes brain inflammation, irritability, poor mood and sleep disturbances.”

Margarine

A lot of people assume that real butter is the worst option for your health, and though butter is high in fats, margarine contains trans fats, which raise ‘bad’ cholesterol.

“We often hear that trans fats aren’t good for your heart and blood vessels. The same applies to the vessels of the brain,” said Dr Shae Datta.

“A study from the journal Neurology found that older adults who had the highest levels of elaidic acid (a common type of trans fat) in their blood were more likely to develop dementia. Better to stick to olive oil and real butter.”

French fries

While everyone enjoys French fries as a treat, Dr Pedram Navab has explained that foods high in fat can cause damage to blood vessels.

“A diet that incorporates fatty foods like French fries can damage blood vessels that supply the brain, causing cognitive impairment,” he said.

“It reduces the blood-brain barrier (BBB) integrity and leads to neuronal damage of the hippocampus, a part of the brain that is instrumental for learning and memory.”