What are Blue Zones?

The term ‘Blue Zone’ is used to describe the regions of the world where people live longer and healthier lives than average. The zones are also defined as a limited and homogeneous geographical area in which the population shares the same lifestyle and environment. The term was chosen because the authors used a blue pen on a map to mark villages with long-lived populations [Poulain et al. 2004, Buettner & Skemp 2016, Poulain et al. 2013].

Currently, these regions are considered ‘Blue Zones’:

Okinawa (Japan)
Sardinia (Italy)
Nicoya Peninsula (Costa Rica)
Ikaria (Greece)

All five regions have certain cultural similarities that are used as an explanation for a long and healthy life. These include

a plant-based diet
moderate calorie intake
low tobacco and alcohol consumption
regular physical activity
strong social ties

The ‘Blue Zones’ concept is commercialised by Buettner and his marketing company Blue Zones LLC.

Criticism of the ‘Blue Zones’ concept

The Blue Zones concept has been criticised [Amigo 2024]. It is criticised that the data on life expectancy and health in these regions is not always reliable or well documented. It is also criticised that the ‘Blue Zone’ diet is not significantly different from the Mediterranean diet and that commercial interests are behind the reporting on the ‘Blue Zones’ [Hall, 2021].

In addition, life expectancy on the island of Okinawa is now lower than on the Japanese mainland. Researchers attribute this to the increasingly Westernised diet on the island [Gavirolova & Gavrilov, 2012].

What is scientifically verified?

However, despite the criticism of the Blue Zone concept, some of the factors described there can be demonstrated relatively well in basic research on model organisms with regard to their positive influence on life expectancy - and have been shown for a long time and independently of the Blue Zone concept (see also How to stay healthy in old age?).

For example, a balanced diet plays a role in life expectancy, which has been scientifically demonstrated in many model organisms. A gut-healthy diet with sufficient fibre and pre/probiotics can increase the bacterial microbiome in the gut [Heiman & Greenway, 2016]. A higher diversity of the gut microbiome has been shown to lead to a longer lifespan in model organisms such as killifish [Smith et al., 2017].

Dieting causes epigenetic changes during ageing

April 18, 2017

In mice, dietary restrictions can lead to changes in lipid metabolism, thus increasing the animals' lifespans more

Caloric restriction can also extend lifespan under research conditions in various model organisms [Green et al. 2021]. However, it should be noted that such measures are not directly transferable to humans - many personal factors play a role here. In model organisms, for example, the positive effect depends heavily on genetic factors, biological sex and the extent of calorie reduction and can also be reversed [Mitchell et al. 2016].