Mediterranean diet improves health and brain function of older people

More than ever, in the current climate of the COVID-19 pandemic, it is essential to shield the vulnerable and elderly but also to ensure the consumption of nutritious, well balanced meals to strengthen your immune system.

Right now, it might be challenging to find your comfort foods, but if you can and are able to change your routine you will grow good gut microbiota and increase the potential for a healthier life.  

A recent study in Gut, published by the British Medical Journal, reports on the health benefits of a Mediterranean diet (MedDiet) for older people. This study involved more than 600 people in five European countries, the UK, France, Netherlands, Italy and Poland. Consumption of the MedDiet, rich in Mediterranean foods, for 1 year resulted in gut microbiota changes which have the potential to promote healthy ageing.

Everything changes as you get older – your mind, your body and the way you view the world, even your gut bugs! It’s known that ageing is associated with the loss of body functions, mental health, muscle mass, increased inflammation and the onset of diseases such as diabetes. Frailty is also linked with changes in the bacteria found in your gut. This paper unravels the complex interplay of diet, microbiome and host health.

What is MedDiet?

A classic Mediterranean Diet includes increased amounts of vegetables, legumes, fruits, nuts, olive oil and fish and low amounts of red meat, dairy products and saturated fats.

It’s been widely reported that a MedDiet has significant health benefits, deriving from increased antioxidant activity, reduced incidences of several diseases, as well as reduced inflammation. More recently, the links between gut microbiome composition and better health have been noted.

However, a major challenge for elderly healthcare, especially those in long-term residential care, is the consumption of a varied diet that is associated with a diverse, healthy gut microbiome. Certainly, most elderly people do not consume a classic MedDiet.

Gut Microbiome Testing

In this study, stool samples of participants were profiled twice: a baseline reading taken at the start and one sample at the end of the year-long study.

MedDiet Gut Microbiome Profiles

After one year of eating a diet rich in Mediterranean foods the gut microbiome changed – for the better. Specific gut bacterial species including Faecalibacterium prausnitzii, Eubacterium and Roseburia came to dominate the guts of those eating the MedDiet. These bacteria have positive health associations including production of short chain fatty acids (SCFAs) that have anti-inflammatory properties and negative associations with diseases including type 2 diabetes and colorectal cancer.

In addition, the blood plasma was tested for bile acids molecules and it was found that bacteria were responsible for the enzymatic conversion of bile acids.

Patterns of gut bacterial associations were observed and can be used as health markers. Diet-positive bacteria were associated with lower levels of the inflammatory markers (hsCRP and IL-17) and measures of increased frailty (Fried Scores and Gait Speed Time). In contrast, they were positively associated with measures of improved cognitive function (e.g/ Constructional Praxis, BabCock Memory Score) and reduced frailty (Hand Grip Strength).

MedDiet vs Gut Microbiome

An important question is whether the change in the gut microbiome is responsible for the changes in these health scores or is it simply a consequence of the improved health of the study participants, in other words is it cause or effect?

Intriguingly it was found the health status of an individual is more strongly linked with the profile of the gut microbiome rather than the MedDiet by proxy. Therefore, the authors suggest that by protecting the ‘core’ gut microbial community, adherence to the diet could facilitate the retention of a stable community state in the microbiome, providing resilience and protecting from changes to alternative states that are found in unhealthy individuals.

So, once those gut microbiome changes have been made, and you know you have a healthy set of gut bacteria you only need to maintain those good bacteria to reap the health benefits. 

Health benefits of the MedDiet?

This study has shown that if you stick to a classic MedDiet for one year you can create the right internal environment for the growth of good intestinal bacteria. These gut bacteria collectively produce molecules which enhance your mental ability, increase memory and lower inflammation and in doing so, protect you against a range of diseases.

Anyone of any age should try this, give it a go and check your gut health with a microbiome profile test along the way!


This post has been written by the THBC team who are active researchers in infectious microbiology