The MIND diet, a brain-healthy diet that focuses on plant-based foods like whole grains, green leafy vegetables, fruits, and nuts, only has a short-term impact on enhancing your memory and other cognitive abilities which are not last-longing, new research has revealed.

Results from the study, published in The New England Journal of Medicine, showed that within a three-year period, there was no significant statistical difference in change in cognition for participants in the MIND diet group compared to the usual diet control group.

"The benefits within the new study’s three-year clinical trial weren’t as impressive as we’ve seen with the MIND diet observational studies in the past, but there were improvements in cognition in the short-term, consistent with the longer-term observational data," said lead study author Lisa Barnes, associate director of the Alzheimer’s Disease Research Center at Rush University Medical Center in the US.

Both study groups were coached to reduce calories by 250 kilocalories per day. But there was a significant improvement during the first two years of the study.

"What we saw was an improvement in cognition in both groups, but the MIND diet intervention group had a slightly better improvement in cognition, although not significantly better," Barnes added.

Both groups lost approximately 5 kg over three years, suggesting that it could have been weight loss that benefited cognition in this trial, she mentioned.

The MIND diet has been ranked among the top five diets by the US News & World Report annually for the last six years. The latest trial of the MIND diet enrolled 604 people who were overweight and had a suboptimal diet and a family history of Alzheimer’s disease.

The trial compared two different diet interventions, both of which included dietary counselling with a mild calorie restriction of 250 calories per day for weight loss.

"The good news is that this helped all participants improve on average, but unfortunately hindered the ability to detect significant differences between the two groups in this relatively short period of time," said Barnes.

The MIND diet has 14 dietary components, including nine “brain-healthy food groups” – such as chicken and fish, green leafy vegetables and berries, and nuts – and five unhealthy groups: red meat, butter and stick margarine, full-fat cheese, pastries and sweets, and fried foods.