For years, doctors have said that there’s little that can be done to prevent Alzheimer’s disease and other types of dementia, and to just hope for a pharmaceutical cure. Research is finding that just like the rest of your body, your brain needs a nutritious diet to operate at its best. Focusing on fresh fruit and vegetables, lean protein, and healthy fats may be the best way to stave off Alzheimer’s and dementia.
In 2006, Claudia Kawas from the Institute for Brain Aging and Dementia at the University of California, Irvine, reviewed a number existing studies on the Mediterranean diet and its impact on AD. Kawas noticed better cognitive performance and a reduced risk of Alzheimer’s disease (AD) in persons who consumed the Mediterranean diet, with significant amounts of fruits, vegetables, fish, and olive oil on a regular basis.
Another study by investigators at Columbia University Medical Center in New York followed more than 2,200 individuals over 4 years, tracking the development of AD. The results suggested that those who had the highest adherence to the Mediterranean diet had a 40% reduced risk of developing the disease, whereas those more modestly adhering to this diet had only a 20% risk reduction. The beneficial effect of the Mediterranean diet is due to the complex nutritional components contained in the foods, which are rich in antioxidants and high in unsaturated fatty acids.
Part of the reason that the Mediterranean diet reduces the risk of AD is because of the many beneficial fats associated with it. Scientists have devoted a great deal of resources into studying how certain dietary fats increase the risk of AD, while others reduce it.
A study at the Rush Institute for Healthy Aging in Chicago discovered an association between healthy fats and brain health. The researchers speculated that a diet high in vegetable fats and low in trans fat (found in margarine and other processed foods) appears to slow the brain deterioration that leads to AD. The researchers recruited 815 adults aged 65 and older. All passed mental function tests showing them to be free of the symptoms of AD, and each completed a questionnaire designed to assess their usual eating habits. The researchers were looking for a connection between the amount and kinds of fat in the participants’ diets and the risk of developing AD.
Four years later, the participants again completed the mental function tests, at which time 131 showed signs of AD. After examining the findings, the researchers concluded that those who ate the most polyunsaturated fat from vegetable sources such as corn oil and safflower oil were much less likely than others in the study to have symptoms of AD. Conversely, those who consumed the most trans fat from sources like hydrogenated vegetable oil were more likely than others to develop the disease.
Other studies have also noted that a high intake of saturated fat and cholesterol and a low intake of polyunsaturated fatty acids increase the risk of AD. In large population studies, high dietary intake of fat and calories has been associated with an increased risk for the disease, whereas high intake of fish was associated with a decreased risk.
Researchers at the Karolinska Institutet in Stockholm determined that saturated fat increased the risk of dementia and AD by 73%. After examining the fat intake of 1,449 people aged 65-80 years over a 21 year period, researchers determined that moderate intake of polyunsaturated fat at midlife decreased the risk of dementia whereas saturated fat intake was associated with an increased risk.