A new Annals of Neurology study headed by Nikolaos Scarmeas of the Columbia University Medical Center in New York has found that people who followed a Mediterranean-style diet were up to 40% less likely than those who largely avoided it to develop Alzheimer’s during the course of the research study. Previous posts on Alzheimer’s research are here.
The study evaluated about 2,200 elderly residents of northern Manhattan every 18 months for signs of dementia over a four years period. None showed any dementia at the start of the study, but by the end of the study, 262 had developed Alzheimer’s. The researchers gave each participant a score of zero to nine on a scale that measured how closely they adhered to a Mediterranean-style diet. Compared to those showing the lowest adherence, those who scored four or five on the diet scale showed 15% to 25% less risk of developing Alzheimer’s during the study and those with higher scores had about 40% less risk. Prior research suggested that certain components of the Mediterranean diet can reduce the risk of developing Alzheimer’s, but the research focused on specific nutrients (such as vitamin C) or foods such as fish. By incorporating an entire diet, the new study addresses possible interactions between specific foods and nutrients.
The diet tested in the study included primarily vegetables, legumes, fruits, cereals and fish, while limiting intake of meat and dairy products. The diet also included drinking moderate amounts of alcohol and emphasizing monounsaturated fats, such as in olive oil, over saturated fats. Previous research has suggested that such an approach also reduces the risk of heart disease, and the new study is additional evidence that certain conditions that are associated with heart disease — high cholesterol, high blood pressure, obesity, smoking and uncontrolled diabetes — may also contribute to Alzheimer’s.