Mediterranean diet: why would it be beneficial for the elderly?

Diet plays a crucial role in our overall and microbiological health, and older people are particularly vulnerable to age-related health complications that could be related to changes in their diet.

Unfortunately, aging is associated with inflammation and deterioration of several bodily systems that can lead to frailty. Frailty has also been linked to poor cognitive function, muscle loss, and chronic illnesses like diabetes.

Many older people have a restricted diet due to chewing and swallowing problems, reduced saliva production, or other health reasons that can lead to low microbial diversity in the composition of the gut microbiota, which is a marker of health.. On the other hand, adherence to a Mediterranean diet, which is mainly plant-based and emphasizes the abundance of vegetables, fruits, legumes, whole grains, nuts, olive oil and a balanced consumption of red meat and dairy products and saturated fat, has been associated with overall good health and beneficial changes in the gut microbiota, including an increase in bacteria that has been positively associated with decreased fragility and improved cognitive function in the elderly population.

Scientists from 8 different countries joined forces and studied how diet affects the gut microbiome and the frailty of an elderly European population. They analyzed the gut microbiota of 612 pre-fragile and non-fragile people aged 65 to 79 from different European countries (Poland, Netherlands, United Kingdom, France and Italy) before and after following a Mediterranean diet for 12 month. Frail and pre-fragile subjects were classified based on various criteria, including weight loss, low physical activity, and weakness.

Researchers found that following a Mediterranean diet had a positive impact on the gut microbiota, which was associated with decreased inflammation and frailty, and improved cognitive function.

Prior to adopting a Mediterranean diet, subjects exhibited marked differences in the composition of the gut microbiota, possibly due to differences in fiber, fat, vitamin, and mineral intake. However, after following a Mediterranean diet, the subjects showed similar gut microbiomes that had undergone marked changes, which the authors attribute to an increase in fiber, vitamin and mineral intake, compared to individuals from the control group whose changes were associated with increased fat. consumption.

Researchers found that following a Mediterranean diet had a positive impact on the gut microbiota, which was associated with decreased inflammation and frailty and improved cognitive function.

The Mediterranean diet group also had increased amounts of bacteria which produce the anti-inflammatory metabolite short chain fatty acids, and increased adherence to this diet was associated with greater microbial diversity. On the other hand, the control group showed higher levels of bacteria associated with colorectal cancer and type 2 diabetes and other inflammatory diseases as well as inflammatory metabolites derived from intestinal bacteria.

In conclusion, following a long-term Mediterranean diet, with plenty of plant-based foods, leads to a higher consumption of fiber, whole grains, polyunsaturated fats and vitamins and a decrease in the consumption of saturated fats, of alcohol, sodium and sugar which confer positive effects on the gut microbiome. One of the most remarkable positive changes in the composition of the gut microbiome after a Mediterranean diet for one year, including an increase in beneficial bacteria capable of producing anti-inflammatory metabolites.

While age, body mass index, and disease status do play a role in the formation of the gut microbiome, diet likely plays a major role in determining how these factors interact with each other. with others and affect health. Despite these promising results, it is important to note that adherence to a Mediterranean diet is not necessarily possible in all countries where certain key ingredients are not available or are not available all year round. In addition, it should be considered that this diet may not be a realistic option for elderly patients who have difficulty swallowing, reduced saliva production, or irritable bowel syndrome.

Overall, this study shows promising results for following a Mediterranean diet in the elderly population to ensure a healthy gut microbiome and to prevent frailty.

Reference:

Ghosh TS, Rampelli S, Jeffrey IB, et al, Mediterranean diet intervention alters the gut microbiome in older adults by reducing frailty and improving health status: 1 year NU-AGE diet intervention in five European countries. BMJ Gut; 2020: 69 (7).