Switch to Mediterranean diet boosts good bacteria, curbs harmful ones, even if you’ve been on a bad diet all your life

An experiment in which a group of elderly subjects swapped a bland, restricted diet for a Mediterranean one showed why it is beneficial – it changes the gut

Production of microbes linked to better brain function rises, while that of microbes linked to increased frailty falls

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The Mediterranean diet is rich in fresh vegetables and fruit, and fish, and switching to it at any time in life can have health benefits, researchers say.

Published: 1:17pm, 19 Feb 2020Updated: 5:29am, 20 Feb 2020

Switching in old age from a bland, unvaried diet to a Mediterranean mix of fresh vegetables, fruit and fish restores a balance of intestinal bacteria linked to good health, researchers say.

In a clinical trial with 612 volunteers aged 65 to 79 across five European countries, those who adopted a typical Mediterranean diet for a year showed more “good” microbes linked to better brain function, and a net drop in gut flora thought to trigger inflammation and increased frailty.

The results held true regardless of age or weight, both of which influence the community of bacteria species – numbering up to 1,000 – that make up the human microbiome, the scientists reported in the journal Gut.

“This diet might act on gut bacteria in such a way as to help curb the advance of physical frailty and cognitive decline in older age,” said lead author Paul O’Toole, head of the School of Microbiology at University College Cork in Ireland.

If you’ve been eating food like this most of your life, you could have killed off some of the “good” microbes that promote brain function. The sooner you switch to a Mediterranean diet, the better, even if you’re 65 already – you’ll see the benefits. Photo: Shutterstock

In the later stages of life there is a natural decline of bodily functions and a tendency for the immune system to overreact, leading to a clinical condition known as frailty.

“In an older person, the immune system is striking at shadows,” O’Toole explained. “It is constantly turned on and firing into deep space.”