If you want to protect your mind, be mindful of what you eat. Doctors say that a diet rich in fruits, vegetables and lean meats that includes a little wine can lower the risk of developing Alzheimer's disease.
The researchers have aptly named their diet the "MIND diet" — it is a hybrid of the Mediterranean diet and the DASH (Dietary Approaches to Stop Hypertension) diet. MIND stands for Mediterranean-DASH Intervention for Neurodegenerative Delay.
In a decade-long study of about 1,000 people, those who followed this diet reduced their risk of Alzheimer's disease by 53 percent, compared with people who did not follow it, according to the researchers. Even the people who only casually followed the diet had a lower risk of Alzheimer's, the researchers added.
The results appear online this month in the journal Alzheimer's & Dementia.
Alzheimer's disease, the most common form of dementia, affects more than 40 million people globally, according to Alzheimer's Disease International. Among developed nations, the prevalence rates tend to be highest in North America and northern Europe and lowest in Asia and the Mediterranean region. [6 Foods That Are Good for Your Brain]
Doctors believe that Alzheimer's disease is caused by a mix of genetic, environmental and lifestyle factors. Previous studies have found that Alzheimer's disease is associated with obesity, high blood pressure, high cholesterol, cardiovascular disease and diabetes.
A study published in the journal Neurology in 2011 found that people with diabetes were at least twice as likely to develop Alzheimer's disease, compared with people who don't have diabetes. In fact, researchers at Brown University have called Alzheimer's disease "Type 3 diabetes," given its connection to high blood-sugar levels and insulin resistance, hallmarks of Type 2 diabetes.
Alzheimer's disease rates are relatively low in Japan and in Italy, leading researchers to further ponder the connection between diet and loss of cognitive function among the elderly. In 2013, researchers in China found that the Japanese and Mediterranean diets may offer protection against Alzheimer's disease. These diets share an emphasis on fruits, vegetables, beans and fish, and include little red meat.
The latest study, conducted by researchers at Rush University Medical Center in Chicago, looked at the effects of a hybrid Mediterranean and DASH diet, the latter developed specifically to improve heart health. The study enlisted 923 participants, ages 58 to 98 years, and followed them for upward of 10 years.
The MIND diet emphasizes 15 dietary components, including 10 foods to eat daily — green leafy vegetables, other vegetables, nuts, berries, beans, whole grains, fish, poultry, olive oil and wine — and five foods to avoid: red meats, butter and stick margarine, cheese, pastries and sweets, and fried or fast food.
Lead author Martha Clare Morris, a nutritional epidemiologist at Rush, said her group focused on this mix of two well-known healthy diets because it would be easy for Americans to follow. The Mediterranean diet, for example, calls for much more fish consumption.
"We devised a diet and it worked in this Chicago study," Morris said. "The results need to be confirmed by other investigators in different populations and also through randomized trials."
Even those participants who didn't follow the diet perfectly had a 35 percent reduction in the risk of developing Alzheimer's disease. The longer and more consistently a person follows the MIND diet, the less risk that person will have of developing Alzheimer's disease, Morris added.
"[P]eople who eat this diet consistently over the years get the best protection," she said. "You'll be healthier if you've been doing the right thing for a long time."
Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science.