From the Pacific Ocean, to the Caribbean, to the Aegean Sea, there are islands where the locals seem to live much longer than the rest of the world. Science now calls them Blue Zones, and research into these enclaves has only expanded our understanding of diet and lifestyle
We’ve been hearing, and reading, about Blue Zones for 20 years now. They are real places but also somewhat mythical – regions of the Earth where humans live to an unusually old age, in unlikely numbers and in uncommonly good health. Much less widely known is why they’re called Blue Zones. Dr Giovanni Pes is best qualified to explain.
By his own account, he invented the term while researching clusters of centenarians on his home island of Sardinia in the year 2000. “At that time I had no computer,” says Dr Pes today. “Only a map of the island. Every time we discovered a village where the number of centenarians exceeded a certain threshold, I used a blue marker to put a dot on the map.
“After six months, a cloud of these dots was visible, so it was very natural to refer to them as ‘Blue Zones’. I never imagined that the term would become famous, but it was later used by other demographers to indicate populations anywhere in the world charaterised by a high proportion of long-lived people.” Since Pes published his first articles on the data from Sardinia, other Blue Zones have been identified on the islands of Okinawa, Japan, and Ikaria, Greece, and on the Nicoya peninsula of Costa Rica.
In each case there are certain similarities among the oldest residents. A diet high in whole foods, low in animal fats and rich in antioxidants; a lifestyle that favours habitual or “mindless” exercise (whereby people burn calories without having to think about it); a surrounding social system that fosters strong bonds between families and communities.
These factors have since been duly listed and codified by the American author, explorer and researcher Dan Buettner, who worked with Pes and others on related studies and continues to make a big thing of Blue Zones as vectors for how we might live better and longer. He’d rather not go into detail, but Dr Pes makes clear that there is not exactly consensus among the various data-gatherers, many of whom have since gone their own ways, and drawn their own conclusions. Working out of the Department of Clinical and Experimental Medicine at Sardinia’s University of Sassari, Pes himself is scientifically bound to be sceptical of subsequent claims for Blue Zones in Martinique, or in Galicia, Spain.
“I cannot recognise them [as such] until I can personally verify the data.” Demographic changes of the last quarter century have also made it trickier to remain so sure about the status of existing Blue Zones. On tiny Ikaria, for example, the population is simply too small to test the findings any further. Recent surveys on Okinawa, meanwhile, “show clearly that the generation born after the Second World War are not behaving like their parents”.
“They are not following the traditional diet, the lifestyle in general. And as they start the ageing process, they will lose the benefits of that lifestyle.” Here we come to the crux – Dr Pes’ work has been based around centenarians and “super-centenarians” (those who reach ages of over 110), or nonogenarians where he can’t find enough of their elders. All these people were born in a different time, a different world, and when they pass away it seems more than possible that these statistical outposts will disappear, too.
Looking back toward his home ground of Sardinia, Dr Pes has come to believe that “some Blue Zones will die, but others will emerge”. Across the mountain villages that constituted his original field of study, the number of centenarians is still increasing for now, though he notes, too, that fewer of the younger residents are following their fathers and grandfathers into the particular farming tradition that helped ensure their longevity.
Dr Pes’s research yielded what he called “the shepherd hypothesis”, proposing certain routines and circumstances as a kind of elixir of life in that area. “I interviewed centenarians who told me they covered at least 30 kilometres on foot every day, walking up and down hilly terrain that gave them extra stimulus in terms of energy expenditure. This is why they were so much fitter from a respiratory and cardiovascular point of view. Stronger, more capable of resisting the onset of age-related and metabolic diseases.”
It’s tempting to think that we all might live so long if we just dropped everything, moved to the mountains and started eating only farmhouse dishes rich in root veg and goat’s cheese. “We can’t really imitate Blue Zoners, because they’re so different from how we exist now in post-modern societies. You can’t just live like an old Sardinian shepherd. But what you can do is select some specific aspect of his lifestyle, and adapt it to yours.”
“If you do more physical exercise, avoid the use of cars or elevators, this should be enough to help. Or if you start eating better … ”
Dr Pes himself has taken this to heart. “I have no garden, I can’t produce my own food, so all I can do is pay more attention to the labels of what I buy in the supermarket. Avoid junk, replace pasta with legumes or bread with vegetables. I’ve never been very fond of meat, now I have it maybe once a month.”
Considering his own longevity, he might take comfort from the fact that his great uncle lived to 110, and his mother is still going at age 99. But one irony of his work has been the discovery that genetics don’t help that much. In the early days, many observers assumed that Sardinia’s particular gene pool – as distinct from other European populations – would explain its odd gerontology. In the years since, no specific feature of the native DNA has proven this out, and experts now estimate the “heritability” of lifespan at 10 per cent or less.
“In a way that’s good news, because it means at least 90 per cent is due to other, non-genetic factors.” In any case, suggests Dr Pes, we should all be more focused on what some now call “healthspan”, and “mindspan”. “The point is not just to have a longer life, and personally I would prefer it to be shorter, but healthier. I’m a big believer in the idea of successful ageing, which means maintaining a healthy body, and mind, as long as we can. We don’t need Blue Zones for that. Any physician or nutritionist will tell you the same thing.”
