As people live longer around the world, it is estimated that 75 million will be living with dementia by 2030.
To address this growing healthcare issue, researchers are trying to identify lifestyle and pharmacological interventions that appear to help slow dementia.
Diet is a big area of interest. Researchers from the University of Cincinnati College of Medicine recently looked at the effect following the MIND diet — the Mediterranean-DASH Intervention for Neurodegenerative Delay — had on a person's rate of cognitive decline in a racially diverse, nationwide study population. The MIND diet is a fusion of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets.
“Diet is one thing people can do that has an impact on whether they develop cognitive impairment or neurodegenerative diseases,” Russell Sawyer, corresponding author on the study, told TheDoctor.People who followed the MIND diet more closely had a slower rate of cognitive decline. The association between adherence to the diet and a slower rate of cognitive decline was even stronger among Black participants.
People need to make lifestyle changes as early as possible to slow rates of cognitive decline, Sawyer explained. Yes, we are living longer, but patients need not only more years, but healthier years. The effects of a good diet accumulate over time — or a lifetime, but they make a difference at any stage of life. Even though it is best if you make dietary changes in your 20s and 30s, there is plenty of evidence showing that improving your diet later in life can also slow the rate of cognitive decline.
“I tell my patients it is never too late to make a change like that,” said Sawyer, an assistant professor of clinical neurology and rehabilitation medicine at the University of Cincinnati. Data from more than 14,000 participants were analyzed for the current paper. The REGARDS study (REasons for Racial and Geographic Differences in Stroke) is an ongoing prospective study that assesses stroke mortality and cognitive function in Black and white adults.
Each person in the study completed a computer-assisted telephone interview and an in-home examination as they began participating. The telephone interview and in-home exam were repeated about ten years later. Participants also responded to a questionnaire about diet over the last year.
The MIND diet emphasizes green leafy vegetables, whole grains, olive oil, poultry, fish, beans and nuts. Participants' MIND diet scores were calculated based on their responses to the questionnaire.
One point was given for each of the following: three or more daily servings of whole grains; six or more weekly servings of green leafy vegetables; one or more daily servings of other vegetables; two or more weekly servings of berries; one or more weekly servings of fish; two or more weekly servings of poultry; three weekly servings of beans; five daily servings of nuts; four or fewer weekly servings of red meat; one or fewer weekly servings of fast or fried foods; one or more weekly servings of olive oil; and one or fewer tablespoons of butter or margarine daily; five or fewer weekly servings of pastries and sweets; and one glass per day of wine. The highest number of points possible was 12.
Participants were divided into three groups based on their diet score. The group with the lowest scores had an average diet score of five; the middle group had an average score of seven; and the highest group had an average score of nine.It is best to switch to a healthier diet in your 20s and 30s, but there is plenty of evidence showing that improving one's diet later in life can also slow the rate of cognitive decline.
During the 10-year study period, 12 percent of those with the lowest MIND diet scores developed some form of cognitive impairment. Eleven percent of those with a middle score and 10 percent of those with a high diet score developed cognitive impairment.
The differences may seem small, but those with the highest MIND diet scores had a four percent lower risk of developing cognitive impairment.
Women with the highest MIND diet scores had a six percent lower risk of developing cognitive impairment compared to women in the other two groups. No reduction in risk was seen in men.
People who followed the MIND diet more closely had a slower rate of cognitive decline. The association between adherence to the diet and a slower rate of cognitive decline was even stronger among Black participants.
“Preliminary data shows that better adherence to the MIND diet is associated with lower all-cause mortality and probably mortality due to things like Alzheimer's disease and dementia,” Sawyer said. He and his team plan to look at how adherence to the MIND diet affects plasma levels of biomarkers for neurodegeneration. Measuring levels of these biomarkers will give them an idea if someone is developing Alzheimer's disease.
The study is published in Neurology, the medical journal of the American Academy of Neurology.
