MIND Diet: The Fifteen Food Groups, the Rush Studies and the 2023 Trial

MIND stands for Mediterranean-DASH Intervention for Neurodegenerative Delay. It is a scoring system of fifteen food groups, ten to eat and five to limit, drawn up in 2015 by researchers at Rush University in Chicago from the Mediterranean diet and the DASH diet. The figure that matters most is from its only randomised trial: among 604 older adults followed for three years, thinking scores on the MIND diet did not differ significantly from those on a control diet. This entry belongs to NNWA's handbook of diets.

What is the MIND diet?

It is a hybrid of two older patterns, adjusted towards foods that earlier studies had linked to brain health. Its authors kept the plant-based core of both parents and the limits on animal and high saturated fat foods. They then made changes: the MIND diet names green leafy vegetables and berries as groups of their own, and it does not ask for high fruit intake, high dairy intake, potatoes or more than one fish meal a week. The scoring was fixed before the authors tested it on their study data.

The ten food groups to eat and five to limit

Each group earns 0, 0.5 or 1, and the fifteen are added up, so a perfect score is 15. The table gives the level that earns the full point in the 2015 papers. The third column is this page's reading for an Indian kitchen and is not part of the published score.

Two rows need care. The berry point rested on one questionnaire item about strawberries, and the supporting research was on blueberries and strawberries, so counting jamun fruit, phalsa or amla is a guess, not a finding. And the olive oil point was a single yes or no about the oil usually used at home; nothing in the studies says whether mustard, groundnut or sesame oil would earn it.

What did the Rush studies find?

They found that people with higher MIND scores did better over time, in two reports from one cohort of older people in retirement communities around Chicago. In the first, 923 people aged 58 to 98 were followed for an average of 4.5 years. Those in the top third of scores had a hazard ratio for Alzheimer's disease of 0.47 against the bottom third, and the middle third had 0.65. NIA, the US government's institute for research on ageing, describes the first figure as a 53 per cent reduced rate.

In the second report, 960 participants were tested for an average of 4.7 years. The gap in the rate of decline between the top and bottom thirds was put as equivalent to being 7.5 years younger. The people studied were on average 81.4 years old and 75 per cent were women; their scores averaged 7.4 and ran from 2.5 to 12.5, so nobody reached 15.

These are observational results, and the authors say so. Diet was recorded with a food frequency questionnaire and nobody was assigned to eat anything. Those with the highest scores also had more education, more physical and mental activity and fewer cardiovascular conditions. The papers state that the findings cannot be read as cause and effect, that the sample was old and largely non-Hispanic white, and that a trial was needed.

What did the 2023 trial find?

It found no significant benefit. The trial, published in the New England Journal of Medicine, screened 1,929 people and assigned 604 older adults at two sites to the MIND diet or a control diet for three years. All were free of cognitive impairment, had a family history of dementia, a body mass index above 25 and a diet judged suboptimal on a 14-item questionnaire. Both groups were given mild calorie restriction, counselling and support to lose weight, and 93.4 per cent completed the trial.

Global cognition scores improved in both groups: by 0.205 standardised units on the MIND diet and 0.170 on the control diet. The difference of 0.035 units had a 95 per cent confidence interval from -0.022 to 0.092 and a P value of 0.23, which means chance could account for it. Brain scans told the same story, with white-matter changes, hippocampal volume and grey- and white-matter volumes similar in the two groups.

How limited is the evidence?

Very. The whole case for MIND as a brain diet rests on observational studies, and the single randomised trial did not confirm them. No trial has shown that the diet prevents dementia or Alzheimer's disease; the 2023 trial measured test scores and scans over three years, not diagnoses. NIA calls the evidence for the Mediterranean and MIND diets mixed, and says there is so far no evidence that eating or avoiding a specific food can prevent Alzheimer's or age-related cognitive decline.

The trial does not prove the diet useless either. Its comparison was demanding: the control group also cut calories, was counselled and improved. It cannot say what a longer period, or people with a poorer diet at the start, would show. And none of the research was done in India or on Indian food. The fair summary is that MIND is a sensible way to eat whose specific promise for the brain is unproven.

Why does dementia matter in India?

Because the number of older Indians is large and the condition is common among them. A national study that tested adults aged 60 and over between 2018 and 2020 estimated that 7.4 per cent have dementia, about 8.8 million people, with higher rates among women and in rural areas. WHO counted 57 million people living with dementia worldwide in 2021, over 60 per cent of them in low- and middle-income countries, and says it is not an inevitable part of ageing.

WHO's list of things that raise the risk includes high blood pressure, high blood sugar, overweight, smoking, harmful alcohol use, physical inactivity, social isolation and hearing loss. Its list of actions includes a healthy, balanced diet beside being active, not smoking and managing blood pressure, cholesterol and blood sugar. Diet is one item on that list, which is a better guide to its weight than any single headline. The handbook's entry on insulin and insulin resistance covers the blood sugar side.

An Indian MIND day

The day below is an illustration, not a prescription, and it is vegetarian with a fish option. Portions follow ICMR-NIN's My Plate for the Day for about 2,000 kcal, which allots 400 g of vegetables including leafy ones, 85 g of pulses, 35 g of nuts and seeds and 27 g of oil. An older adult usually needs less than that, so check your own figure on the calorie calculator and scale the grains and oil.

The green leafy vegetable tables list what is in season, and strawberries are the one berry the Rush questionnaire asked about. The day leaves out wine and gives no olive oil point; neither omission is a flaw.

A worked example: scoring one week

This is an illustrative case, not a real person. Take a 63-year-old retired bank clerk in Chennai, vegetarian and a non-drinker, whose mother had dementia. He cooks in sesame and groundnut oil. He scores his usual week using the three levels printed in the 2015 paper.

How does MIND compare with ICMR-NIN's guideline?

Most of it is already Indian advice. ICMR-NIN's Dietary Guidelines for Indians ask for 400 g of vegetables a day including green leafy vegetables, 35 g of nuts and seeds, pulses daily, about 200 g of marine fish a week for those who eat it, and ghee or butter limited to one or two teaspoons a day. They also tell readers to minimise fast foods and bakery foods. The differences are the berry group, which the Indian guideline does not single out, and wine.

Indian habits meet some groups and miss others. In NFHS-5, 52 per cent of women and 51.5 per cent of men aged 15 to 49 ate dark green leafy vegetables daily and about half ate pulses daily, which would earn full MIND points. Against that, 7.4 per cent of women ate fried foods daily and a further 35.6 per cent weekly.

Who is the MIND diet not for, and who should see a doctor?

People on the blood thinner warfarin should not raise leafy vegetables to six or more servings a week on their own. The US National Library of Medicine's guidance says to keep vitamin K foods consistent from week to week, not to eat large amounts of leafy green vegetables, and to speak to the doctor before changing the diet. People with kidney disease, diabetes or a nut allergy also need their treating team's advice on pulses, nuts and portions.

Three further cautions apply. The wine point should be ignored: WHO states that no level of alcohol consumption is safe for health, and lists harmful alcohol use as a dementia risk. The trial's calorie restriction was for people with a body mass index above 25; an older adult who is thin or losing weight without trying needs a medical review, not a diet. And forgetfulness that is new or getting worse needs a doctor's assessment. The MIND diet is not a treatment for memory loss and does not replace any prescribed medicine.

Common myths and mistakes

The second mistake is to shop for a miracle food. NIA names blueberries, leafy greens and curcumin, the compound in turmeric, as foods studied for the brain, and concludes that none has been shown to prevent Alzheimer's. The handbook's entry on curcumin looks at that evidence. Imported blueberries are not required by anything in the research.

Learning this with NNWA

NNWA is a private skill academy based in Kolkata, with online teaching in English and Hindi. Its Geriatric Nutrition course and its wider programmes prepare people to plan food for healthy older adults and to refer anyone with memory symptoms or a medical condition to a doctor. No NNWA course is a degree or a dietitian qualification.