A diet designed specifically for the mind can significantly reduce brain ageing, a study has found.
The eating plan, known by the acronym MIND, can reduce brain ageing by almost eight years.
It slows cognitive decline among ageing adults, even when the person is not at risk of developing Alzheimer's disease, according to researchers.
The 'Mediterranean-DASH Intervention for Neurodegenerative Delay' (MIND) diet includes at least three daily servings of wholegrains, a green leafy vegetable and one other vegetable every day.
A diet designed specifically for the mind, which involves eating plenty of wholegrains, salad, vegetables, lean meat, fish and nuts, can significantly reduce brain ageing, a study has found
It also includes a daily glass of wine and recommends snacking on nuts, beans every other day, eating poultry and berries at least twice a week and fish at least once a week.
It advises people to avoid foods such as red meat, butter and stick margarine, whole fat cheese, pastries and sweets, and fried or fast food.
To arrive at their conclusions, the researchers at the Rush University Medical Center in Chicago studied 960 adults over 4.7 years who were free of dementia when they enrolled.
They were around 81.4 years in age, and were part of the Rush Memory and Aging Project, a study of residents of more than 40 retirement communities and senior public housing units in the Chicago area.
During the study they received annual tests for cognitive ability, including tests for long and short term memory, the ability to perceive the spatial relationship between objects and testing for quickly comparing letters, numbers, objects, pictures, or patterns.
They also completed food questionnaires every year, allowing the researchers to compare how their adherence to the MIND diet was linked with changes in their thinking abilities.
The study found that people who followed the diet more rigorously showed an equivalent of being 7.5 years younger cognitively than those who followed the diet the least strictly.
The same study found that the MIND diet may halve a person's risk in developing Alzheimer's disease.
The MIND diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets.
Both diets have been found to reduce the risk of cardiovascular conditions, like high blood pressure, heart attack and stroke.
Older adults who stuck rigidly to the diet had brains on average 7.5 years younger than those who didn't stick to it, according to the research (file photo)
Dr Martha Morris, of the Rush University Medical Centre, who developed the diet, said: 'Everyone experiences decline with ageing; and Alzheimer's disease is now the sixth leading cause of death in the US, which accounts for 60 to 80 per cent of dementia cases.
'Therefore, prevention of cognitive decline, the defining feature of dementia, is now more important than ever.
'Delaying dementia's onset by just five years can reduce the cost and prevalence by nearly half.'
The results were published in the journal Alzheimer's & Dementia.
Commenting on the research, Dr Clare Walton, of the Alzheimer’s Society’s said: 'This research reinforces what we already know about the importance of maintaining a healthy and balanced diet to keep your brain healthy.
'Previous research suggests that the MIND diet can reduce the risk of developing dementia and now we see it could also slow down the cognitive decline normally seen with age.
'It’s important that people realise there are several steps you can take to reduce your risk of dementia, in addition to a healthy balanced diet, including being physically and mentally active and not smoking.'