Mediterranean diet: counteracts brain atrophy and rejuvenates it by 5 years

The benefits of the Mediterranean diet are not only for the cardiovascular system, diabetes or obesity. According to a new study, following a diet rich in fruits,vegetables, fish, legumes and low in meat could also hinder brain atrophy and cognitive aging, in the elderly. Indeed, consumption of the foods typical of the Mediterranean diet is associated with greater brain volume, equal to that of a brain 5 years younger, than that of individuals who do not adhere to this dietary regimen.

The research, published in Neurology the medical journal of the American Academy of Neurology, was conducted by researchers at Columbia University in New York, USA.

The characteristics of the Mediterranean diet 

The Mediterranean nutritional model is inspired by the food traditions of countries bordering the Mediterranean Sea, mainly Italy, Greece, Spain and Morocco. The traditional Mediterranean diet favors the consumption of plant-based foods and is characterized by an abundance of vegetables, cereals, legumes, fish, fruits, dried fruits, and olive oil as the primary source of fats.  

Instead, it provides for moderate consumption of meat, dairy products and eggs, and modest consumption of wine with meals. A dietary regimen, therefore, marked by a low content of saturated fatty acids, rich in carbohydrates and fiber, and a high content of fatty acids important for their anti-inflammatory function. 

The Mediterranean diet is not just a set of foods, but includes the choice of fresh produce, selected according to seasonality and local availability. This style of eating promotes the use of typical products and protects local culinary traditions. In recent years, the Mediterranean diet has been much studied in relation to its many health benefits, particularly for the prevention of chronic diseases. 

In fact, a Mediterranean-style diet exerts a protective action on the heart, reducing the risk of cardiovascular disease, and counteracts obesity, diabetes, high cholesterol and hypertension. According to recent studies it would also help to counter some neurological diseases such as Alzheimer's, and the decline in cognitive abilities typical of the aging process.

Eat more fish and less meat for less brain shrinkage

The aim of the Columbia University researchers, led by Yian Gu, was to test whether increased adherence to the Mediterranean diet was related to brain size and the maintenance of brain size during the aging process. According to the researchers, adherence to the Mediterranean diet had to meet at least five characteristics out of the nine that describe that diet. Studying elderly subjects, the team showed that those who followed a Mediterranean style had larger brains than those who did not adhere to it, with a difference equivalent to five years of aging. 

Specifically, gray matter and white matter volumes in the brain were 5 and 6 milliliters greater, respectively, than those measured in subjects who did not adhere to the Mediterranean diet. The Mediterranean diet considered in this study, included a high intake of grains, vegetables, legumes, fruits, nuts, olive oil, and a low consumption of foods of animal origin except fish, an important component of this type of diet. 

In the test subjects, consumption of at least 100-150 grams of fish each week, and no more than 100 grams of meat per day, caused a significant reduction in brain cell loss, quantifiable in about three to four years of aging. Increasing the amount of fish and reducing meat consumption could be the 2 key nutritional elements to which the benefits of the Mediterranean diet on brain structure are due.

Some details of a complex work

The study involved 674 people with an average age of 80, not suffering from dementia, who filled out food questionnaires about the diet they followed during the previous year. The researchers' team then scanned, via MRI, the brains of more than 650 of the selected people. The participants were divided into two groups based on how closely or not their eating habits were akin to the principles of the Mediterranean diet. The subjects who had followed the Mediterranean eating style more closely showed a total brain volume 13.11 milliliters greater than the subjects in the other group. As Dr. Gu noted, the study does not directly prove that the Mediterranean diet prevents brain shrinkage but shows the existence of an association that will still need to be studied.

More Mediterranean foods, less aging

In conclusion, these results show that in older adults, adherence to the Mediterranean diet is associated with less atrophy and less brain volume loss, making these individuals "younger" by 5 years than those of the same age who do not follow the Mediterranean diet. According to the researchers, these results are exciting, as they hypothesize the possibility that brain shrinkage and the effects of aging can be slowed simply by following a healthy diet rich in fruits, vegetables and fish. 

Source: Yian Gu, et al. "Mediterranean diet and brain structure in a multiethnic elderly cohort" Published online before print October 21, 2015 Neurology .