By Chiamaka Egwu
Following the MIND diet more closely may slow brain shrinkage and delay some structural signs of brain ageing by about 2.5 years, a new study has found.
The long-running study of 1,647 middle-aged and older adults found that people with greater adherence to the MIND diet experienced slower loss of brain tissue, particularly grey matter, and less enlargement of the brain’s ventricles, fluid-filled spaces that tend to expand as brain tissue shrinks.
The findings, published online in the Journal of Neurology, Neurosurgery & Psychiatry, add to previous research linking the MIND diet with better cognitive health.
The MIND diet, short for Mediterranean-DASH Diet Intervention for Neurodegenerative Delay, combines elements of the Mediterranean diet and the Dietary Approaches to Stop Hypertension, DASH, diet.
It emphasises green leafy vegetables, other vegetables, berries, nuts, whole grains, fish, beans, olive oil and poultry, while limiting butter and margarine, cheese, red meat, pastries and sweets, and fried fast foods.
Researchers from the Framingham Heart Study Offspring cohort followed participants for an average of 12 years. Their average age at the beginning of the study was 60.
Participants underwent regular health assessments and repeated MRI brain scans between 1999 and 2019, allowing researchers to track changes in brain structure over time.
As expected, participants experienced age-related reductions in total brain, grey matter, white matter and hippocampal volumes, while cerebrospinal fluid and ventricular volumes increased.
However, those with higher MIND diet scores showed slower loss of grey matter.
According to the researchers, every three-point increase in MIND diet score was associated with a slower rate of grey matter loss of 0.279 cubic centimetres per year — equivalent to about 20 per cent less age-related decline and approximately 2.5 years of delayed brain ageing.
A similar association was observed in ventricular enlargement. Every three-point increase in MIND score was associated with slower ventricular expansion, corresponding to about eight per cent less tissue loss and roughly one year of delayed brain ageing.
Berries, poultry stand out
Some individual foods appeared to have stronger associations with healthier brain changes.
Higher consumption of berries was associated with slower increases in ventricular volume, while poultry intake was linked to slower ventricular enlargement and slower grey matter loss.
In contrast, greater consumption of sweets was associated with faster ventricular enlargement and greater loss of hippocampal volume.
Fried fast foods were also associated with a greater decline in hippocampal volume.
The researchers suggested that foods rich in antioxidants, such as berries, could help reduce oxidative stress, while protein sources such as poultry may help limit neuronal damage.
They also suggested that fried fast foods, which can contain unhealthy fats and compounds associated with inflammation, could contribute to inflammation and vascular damage.
However, the researchers reported some unexpected findings.
Higher whole-grain consumption was associated with several unfavourable structural changes, including faster grey matter and hippocampal volume loss and faster ventricular enlargement.
Cheese, meanwhile, showed the opposite pattern, with greater consumption associated with slower declines in grey matter and hippocampal volume, less ventricular enlargement and fewer white matter hyperintensities.
The researchers cautioned that these individual food associations should not be interpreted in isolation.
Stronger effect in older adults
The overall relationship between MIND diet adherence and brain structure remained consistent in additional analyses and appeared stronger among older participants.
Stronger associations were also observed among participants who were more physically active and those who were not overweight or obese.
The researchers said the findings could indicate that combining a brain-healthy diet with other healthy lifestyle habits may be relevant to reducing the risk of neurodegenerative disease.
However, the study does not prove that the MIND diet itself causes slower brain ageing.
Because it was an observational study, the researchers could identify associations but could not establish cause and effect. They also noted limitations including reliance on participants’ recall of their food intake, possible changes in diet over time and the inability to completely rule out other factors, including genetic risks.
The participants were predominantly White, meaning the findings may not apply equally to all ethnic populations.
Despite the limitations, the researchers concluded: “These findings reinforce the potential of the MIND diet as a brain-healthy dietary pattern and support its role in strategies aimed at slowing neurodegeneration in aging populations.”
