Fish from the Med, good for the head?

Think back to the last time you dipped sourdough into balsamic, mixed with a gleaming pool of olive oil. Extra virgin, please. As the world of nutrition science continues to shift our perceptions between food ideals, a new study has come to light featuring the sunny, olive oil lifestyle. The paper, published in the online journal Neurology, has shown that those who sustain themselves on a Mediterranean diet retain more brain volume than those who don’t. There is however, one key and slightly unusual exception – the amount of fish consumed, regardless of how much other meat is eaten, fails to make an overall difference. This particular finding contrasts with earlier studies looking into health benefits of a Mediterranean diet. So why is it so healthy for us, even without the fish?

Looking at it in the big picture, the Mediterranean diet is full of fruits, vegetables, beans, cereal grains like rice, and legumes, as well as copious amounts of olive oil. Dairy, fish and wine (of course) are consumed in moderate amounts, with limited intake of red meat and poultry. Researchers in this study gathered data on eating habits from almost a thousand Scottish people, all aged around 70, who did not have dementia. Participants all differed in how closely their dietary habits followed that of a Mediterranean lifestyle. MRI scans showed that those who followed the diet more closely over a period of three years were less likely to lose brain volume than those who didn’t. In fact, dietary difference alone explained 0.5% difference in brain volume. This doesn’t sound like much, but is a significant proportion when taking into account that the total brain volume lost is solely due to to the process of ageing. And how do we know that this difference really is completely attributed only to diet?

Researchers went a step further by testing other possible confounding factors such as age, gender, weight, education, high blood pressure, or having a history of diabetes or obesity. Results nevertheless remained the same. The main, unusual takeaway was that fish or meat consumption did not make a significant difference to brain health. It is important to note, following the study, that results could be attributed to specific components of the Mediterranean diet. Perhaps it was just the regular consumption of butter beans or two kilos of kale per week that did the trick.

Study author Michelle Luciano, PhD, of the University of Edinburgh says, “As we age, the brain shrinks and we lose brain cells which can affect learning and memory. This study adds to the body of evidence that suggests the Mediterranean diet has a positive impact on brain health.”