If you don't want dementia then a daily orange juice may help

A study published late last year in the journal Neurology has found that Middle-aged men who consume orange juice on a daily basis may be lowering their chances of cognitive decline.

The Harvard University study involved almost 28,000 men whose diets were tracked for 20 years, starting when they were aged 51.

They found the men who drank a small glass of orange juice were 47 per cent less likely to have difficulty remembering, following instructions or navigating familiar areas.

Memory lapses, difficulty understanding situations and periods of confusion can be early signs of brain decline which can ultimately lead on to dementia.

Based on the results of mental tests which were carried out every four years, the researchers also found that by their later 70s, men who had regularly consumed the most vegetables over the previous decades were 17 per cent less likely to have moderate cognitive problems and 34 per cent less likely to have 'extensive' cognitive issues.

Of those who drank orange juice daily only 6.9 per cent of people who went on to have poor cognitive function compared with 8.4 per cent in men who drank orange juice less than once a month.

The study's lead author, Changzheng Yuan, said: "The protective role of regular consumption of fruit juice was mainly observed among the oldest men. Since fruit juice is usually high in calories from concentrated fruit sugars, it's generally best to consume no more than a small glass (four to six ounces) per day."

"Fruit and vegetable consumption may be a piece of the puzzle to maintaining cognitive health and should be viewed in conjunction with other behaviours believed to support cognitive health."

The researchers sorted the men into five groups based on their intake of fruit and veg and the cognitive tests asked things such as whether the men could remember recent events or items on shopping lists.