[Healthy Aging at 100] Dementia Prevention: Follow the 3·3·3 Rule Instead of Medication

Recently, clinical research results on the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet for dementia prevention were published in the New England Journal of Medicine, one of the most prestigious medical journals. The MIND diet is an acronym for Mediterranean-DASH (Dietary Approaches to Stop Hypertension) Intervention for Neurodegenerative Delay, a dietary regimen first introduced by American nutritional epidemiologist Morris and his team in 2015.

The research team observed that people following the Mediterranean diet and DASH diet, especially those consuming foods like green leafy vegetables, nuts, and berries, showed better cognitive function. Based on this, they devised the MIND diet, which, like the Mediterranean and DASH diets, emphasizes intake of whole grains, vegetables, nuts, poultry, and fish proteins, while limiting red or processed meats, sweets, fried foods, butter, and margarine. Particular emphasis is placed on consuming green leafy vegetables, berries, nuts, and olive oil. The study published in NEJM tracked 604 individuals aged 65 and older with no prior cognitive decline but with a family history of dementia over three years. When comparing the group following the MIND diet with mild calorie restriction (about 250 kcal less per day) to the control group, no difference was found in the increase of cognitive function scores.

Another recent observational study tracking 18,136 people over 5 to 13 years (median) reported that the MIND diet reduced dementia incidence by 19%. The authors of the NEJM study explained that the shorter follow-up period and the fact that the control group also received dietary guidance for calorie restriction might have contributed to the lack of difference between the two groups. Most previous studies supporting the MIND diet’s role in dementia prevention were observational, so more rigorously designed clinical trials are needed; this paper represents such an attempt. Reading this paper reminded me of patients who occasionally visit the clinic requesting prescriptions for dementia prevention drugs, prompting me to discuss methods for preventing dementia.

First, the Central Dementia Center recommends dementia prevention rules summarized as 3 dos, 3 don’ts, and 3 must-dos. The recommended dos are walking at least three times a week, eating a balanced diet including fish and vegetables, and diligently reading and writing. The don’ts include quitting smoking, drinking alcohol sparingly, and being careful to avoid head injuries. The must-dos are regularly undergoing health check-ups to monitor and manage blood pressure, blood sugar, and cholesterol; frequently contacting and communicating with family and friends; and receiving annual early dementia screening. Dementia screening tests are available free of charge at public health centers for those aged 60 and above.

Additionally, the World Health Organization (WHO) recommends for dementia prevention at least 150 minutes of moderate-intensity or 75 minutes of high-intensity exercise per week, smoking cessation, a Mediterranean or healthy balanced diet, moderate alcohol consumption, management of hypertension, diabetes, and hyperlipidemia, obesity control, and cognitive training. Although evidence is weak that treating depression and hearing loss (e.g., with hearing aids) prevents dementia, both depression and hearing loss are known risk factors for dementia. Since treatment also provides other health benefits, screening and treatment are recommended if depression or hearing loss is suspected in older adults. Vitamin B, vitamin E, and multivitamin supplementation lack evidence and are not recommended as dementia prevention therapies.

Currently, no medication has been proven effective in preventing dementia in people without dementia. If medications are taken, managing blood pressure, blood sugar, and cholesterol with appropriate drugs in cases of hypertension, diabetes, or hyperlipidemia, along with practicing the dementia prevention rules mentioned above (e.g., the Central Dementia Center’s 3 dos, 3 don’ts, and 3 must-dos), may be helpful.

Jo In-Young, Professor, Department of Family Medicine, Samsung Seoul Hospital