Think of blueberries as a brain's best friend. A new study from the Rush University Medical Center found that sticking to what is known as the MIND diet can slow cognitive decline and may reduce a person's risk of developing Alzheimer's disease. The diet essentially follows a Mediterranean diet, said a press release on the study.
The study found that older adults who followed the program rigorously showed an equivalent of being 7.5 years younger cognitively than those who followed the diet least. The results of the study were published in the online journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
The National Institute of Aging-funded study evaluated cognitive change among 960 older adults (average age was 81.4 years) who were free of dementia at the study's start. The subjects were followed for 4.7 years. During the study, they received annual, standardized testing for cognitive ability in five areas. The study group also completed annual food frequency questionnaires, allowing the researchers to compare participants' reported adherence to the MIND diet with changes in their cognitive abilities as measured by the tests.
The MIND diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. Both diets have been found to reduce the risk of cardiovascular conditions, like hypertension, heart attack and stroke.
"Everyone experiences decline with aging; and Alzheimer's disease is now the sixth leading cause of death in the U.S., which accounts for 60 to 80 percent of dementia cases. Therefore, prevention of cognitive decline, the defining feature of dementia, is now more important than ever," said researcher Martha Clare Morris, ScD, a nutritional epidemiologist who, with colleagues, developed the diet. "Delaying dementia's onset by just five years can reduce the cost and prevalence by nearly half," she said in a press release.
The MIND diet has 10 brain-healthy food groups and five unhealthy groups -- red meat, butter and stick margarine, cheese, pastries and sweets, and fried or fast food.
To benefit from the MIND diet, a person must eat at least three servings of whole grains, a green leafy vegetable and one other vegetable every day, a glass of wine; snack most days on nuts, have beans every other day or so, eat poultry and berries at least twice a week and fish at least once a week. In addition, the study found that to have a real shot at avoiding the devastating effects of cognitive decline, he or she must limit intake of the designated unhealthy foods, especially butter (less than 1 tablespoon a day), sweets and pastries, whole fat cheese, and fried or fast food (less than a serving a week for any of the three).
Berries were the only fruit specifically to be included in the MIND diet. "Blueberries are one of the more potent foods in terms of protecting the brain," Morris said. Strawberries also have performed well in past studies of the effect of food on cognitive function.
Another study from the Salk Institute for Biological Studies found that fisetin, a flavonol found in strawberries, mangoes, cucumber, and other fruits and vegetables, may protect the brain against Alzheimer’s, dementia, and age-related memory loss. That study, however, was performed on mice.
What you eat and how that impacts your cognitive abilities long-term has been a ripe topic for scientists. Multiple studies have connected eating strawberries and blueberries with slowing age-related mental decline. Regular consumption of the fruits were found to slow cognitive aging by up to 2.5 years, according to a Harvard study.