According to a new study a Mediterranean style diet that’s rich in fish, olive oil and vegetables can help keep dementia at bay and people who are already suffering from mild dementia could have reduced chances of transitioning to Alzheimer’s disease. 

Nikolaos Scarmeas, assistant professor of clinical neurology at the Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Medical Center said, "We know from previous research that a healthy diet like this is protective for cardiovascular risk factors like cholesterol, hypertension and diabetes. Now this current study shows it may help brain function too."

The researchers believe that individual components of the diet could be responsible for the effect. "For example, potentially beneficial effects for mild cognitive impairment or mild cognitive impairment conversion to Alzheimer's disease have been reported for alcohol, fish, polyunsaturated fatty acids and lower levels of saturated fatty acids," the researchers added.

A typical Mediterranean diet contains lots of fish, vegetables, fruits and cereals, as well as low levels of dairy, meat and saturated fats, and limited amounts of alcohol. "Among behavioural traits, diet may play an important role in the cause and prevention of Alzheimer's disease," said the study authors.

The study by Dr Nikolaos Scarmeas and his team, from Columbia University, New York screened 1,393 people who had healthy brain functions and 482 patients who had mild cognitive impairment. The participants were all questioned about their dietary habits and given a score for how closely their diet resembled a typical Mediterranean diet.

The researchers followed the participants for an average of 41/2 years and found that out of the 1,393 people without any cognitive impairment 275 developed the condition. The found the participants who had reported to consume a Mediterranean diet that was rich in vegetables, fish, olive oil and legumes and low in fat meat and dairy had a 28 % lower risk of developing mild cognitive impairment as compared to those whose diet was least like the Mediterranean diet. The one third participants in the middle group had a 17 % lower risk of developing mild cognitive impairment.

The 482 participants who had mild cognitive impairment at the beginning of the study, at the end of 4 years roughly 106 of them developed Alzheimer’s disease and the one third of the participants who had the highest adherence to the Mediterranean diet were found to have a 48 % lower risk of developing Alzheimer’s as compared to those with the least adherence to the diet.

Rebecca Wood, chief executive of the Alzheimer's Research Trust, said: "Diet almost certainly plays a part in every person's Alzheimer's risk – and diet remains a magnet for research because it could offer a relatively inexpensive way to fight a disease that ruins countless lives.

"By reducing salt and saturated fat intake and adding oily fish and lots of fruit and vegetables to our shopping baskets, we can help reduce the risk of developing dementia as well as reaping the countless other benefits of living a healthy lifestyle."

Duke University Medical Center aging expert Murali Doraiswamy said, "Since Alzheimer's changes may start in the brain decades before memory loss occurs, what you eat starting in your midlife may be crucial."

The results of the study are published in the Archives of Neurology journal.  (Harkiran contributed to this report)