Blue zones refer to areas in the world where researchers have observed a relatively large proportion of the population displaying exceptional longevity, that is, they had a disproportionately high number of people living to a 100 or more. They identified five regions worldwide: Loma Linda, California (US), Nicoya (Costa Rica), Nuoro Province, Sardegna (Italy), Ikarya (Greece) and Okinawa (Japan).

The purpose of studying these populations was to try and identify factors that may extend longevity, and therefore hopefully emulate this in other populations with the purpose of extending life.

While genetics, a non-modifiable factor, plays a significant role in survival to advanced age, researchers identified several modifiable lifestyle factors that were associated with increased lifespan, many of which are a reflection of lifestyle principles which are known to have a positive effect on healthspan and lifespan.

So what can we learn from these populations, and what can we all do to live longer, healthier lives? Exercise, diet and sleep are arguably the three most important lifestyle factors, which are the foundation of longevity.

Blue zone inhabitants were shown to be physically active in their everyday lives, such as walking to get around and partaking in physical chores and/or manual labour. Being physically active is one of the most important things you can do to positively influence your long-term health.

In terms of diet, the vast majority of inhabitants tended to have a plant-based diet, meaning a large proportion of their diet was from plants (beans, legumes, vegetables, fruit and wholegrains). This would, therefore suggest a high-fibre diet, something that has time and again been shown to be conducive to counteracting the chronic diseases of ageing.

Additionally, it was observed that these inhabitants tend to go by the 80% rule − eating till they were 80% full. This means they ate slowly and did not overeat, which is an effective strategy to reduce calorie intake, the positive effects of which are very well-studied and documented. Overconsumption of calories is the cause of obesity, which is the root cause of many of the chronic diseases of ageing, as discussed previously.

Exercise, diet and sleep are arguably the three most important lifestyle factors

The consumption of wine was also observed to be common to the majority of these populations. This is not to say that alcohol consumption of any kind, be it red wine or anything else, is going to increase our lifespan. Alcohol is a proven toxin, and it is only when consumed in low to moderate amounts that its benefits, as an aid to socialising, for example, outweigh any of the toxic effects alcohol has.

Though sleep was not directly identified as one of the lifestyle commonalities in these blue zones, residents did incorporate daily stress relief practices, had a sense of purpose and motivation, as well as fostered meaningful relationships, all of which help keep the various forms of stress at bay, which indirectly promotes better sleep.

Chronic stress, in its various forms − psychological, mental, emotional − is detrimental to our health in many ways and increases our risk of all-cause mortality. By having daily downtime, we help keep chronic stress at bay which, in turn, allows better quality sleep, which feeds back to being less stressed, among other far-reaching, positive effects on our health.

Also feeding into this is the power of social connectedness and surrounding yourself with the right ‘tribe’. As is often stated, you are the sum of the people you surround yourself with. Surrounding yourself with individuals who practise healthy lifestyle behaviours reinforces positive lifestyle choices.

These lifestyle principles, which appear to be common to these so-called blue zones, form the guidelines outlined by the researchers. These guidelines are based on observed characteristics and behaviours of these populations. They are characteristics and behaviours which together correlate, but do not cause, extended lifespan. They do not provide some sort of magic formula to living well into old age but do demonstrate that adopting a healthy lifestyle contributes to reduced mortality risk.

As has been proven time and again, consistently practising healthy habits throughout our lives with regard to nutrition, exercise, sleep, stress management, social connectedness and avoidance of harmful substances is key to longevity.

Philip Borg is a longevity medicine specialist, as well as a consultant interventional radiologist. He leads The Longevity Clinic at St James Hospital.