According to a newly released five-country study published in the journal Gut, diets that are high in whole grains, fruit, veg, legumes, beans, and olive oil can have a positive impact on gut bacteria, increasing diversity and helping to ward off the advances of old age.
Shown to be effective against everything from physical frailty through to cognitive decline, researchers noted a strong link against poor and restrictive diets in ageing populations and a premature onset of frailty.
In addition, they found that the issue of reduced gut bacteria diversity was particularly prevalent among those in longer-term residential care, with these individuals ageing at a noticeably advanced rate.
A Mediterranean diet and its impact on the microbiome
One of the goals of the team behind the study was to observe whether a Mediterranean diet – one high in fruit, veg, and olive oil – would be effective in improving and maintaining the microbiome in elderly people’s guts, and whether this would have an impact on their ageing.
The year-long study, conducted across Europe, evaluated the gut microbiome of 612 people between the ages of 65 and 79, at both the beginning and the end of the 12-month period. Of these individuals, 289 were encouraged to eat their regular diet, while 323 were asked to adopt a traditional Mediterranean diet, complete with fruit and veg, legumes, nuts, fish, and olive oil.
Those who took part were based across five countries – France, Italy, the Netherlands, Poland, and the UK – with 28 of them considered to be frail, 151 verging on frailty, and 433 in good health at the start of the study.
Interestingly, researchers found that their theory was proved right and that adopting a Mediterranean diet helped to bring about significant and positive changes to the gut microbiome. Over the course of a year, such increases were associated with healthy ageing and a reduction in the sort of harmful inflammation that’s often seem among an elderly population.
How it works
Speaking on the results of their research, the scientists suggested that a Mediterranean diet is beneficial because it can help to prevent the loss of bacterial diversity, while also increasing bacteria associated with indicators of good health, such as handgrip strength, walking speed, memory, and reduced levels of inflammation.
They concluded that: “The interplay of diet, microbiome, and host health is a complex phenomenon influenced by several factors.”
Delving into their results further, the researchers explained that these changes in microbiome likely triggered a rise in the type of bacteria that creates beneficial short-chain fatty acids, while also decreasing the bacteria that produces bile acids, and which is linked to bowel cancer, fatty liver, insulin resistance, and cell damage.
These changes in the microbiome were largely due to an uplift in dietary fibre, minerals, and vitamins – in particular, vitamin C, copper, iron, magnesium, manganese, and potassium.
What’s interesting is that these same results were found irrespective of body mass index or age, showing a strong causal link between a Mediterranean diet and healthy ageing.
Another factor that did not seem to have an impact was a person’s country of origin, with similar responses to a Mediterranean diet seen amongst all participants, irrespective of where they hailed from.
As the study’s authors point out: “Notably, in spite of country-specific microbiome composition differences at baseline and different dietary adherences, the diet-responsive taxa identified across the entire cohort were largely shared across the different nationalities – that is, their association with diet was not specific for any country.”
While they added that additional factors may have an impact on ageing, such as body mass index, disease status, and initial dietary patterns, the researchers nonetheless concluded that a Mediterranean diet had a clear beneficial impact on those who ingested it – a trend unlikely to be reserved for the elderly.
Source: Gut – 17th February 2020
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