Posts Tagged ‘lifestyle’
human longevity stuff: Blue Zones
The other day, I was talking to friends about human health and longevity and the claim, in a book I use for teaching English to NESB adults, that Okinawans are known for their longevity and that this is likely due to self-sufficiency, physical activity, diet and regular human interaction. While this was generally accepted in our discussion, I received some mild push-back to the effect that this had been exaggerated somewhat, and that the concept of ‘blue zones’, which I’d never heard of, had been largely debunked. So, let me look into this.
A December 2025 article in The Gerontologist, also published in the National Library of Medicine, entitled ‘The validity of Blue Zones demography: a response to critiques’, and which has two named authors, opens with these remarks in its abstract:
Blue Zones are geographically and temporally defined areas with a history of disproportionately high concentrations of nonagenarians and centenarians. Nearly two decades ago, these zones gained international attention when the Blue Zone term was introduced in seminal articles published in Experimental Gerontology and National Geographic. Since then, numerous scientific papers have extracted valuable insights into human health from investigating the long-lived people who live there. However recently, validity of the ages of people living in the Blue Zones has been questioned. Here, we address these concerns by describing in detail the age validation process undertaken in Blue Zones and comparing it to the prevailing standards in gerontological demography.
The abstract goes on to point out what is fairly obvious, that ‘most self-reported claims of exceptional longevity are false’, and of course I remember reading in the Bible about 969-year-old Methuselah and his remarkable rellies. Well, at least their god is real, en it? Anyway, the abstract ends with the claim that ‘cross-checking multiple independent documentary sources’ has effectively minimised or eliminated ‘errors due to fraud, honest mistakes, poor memory, or identity switches, especially between homonymous [identically – or near identically-named] siblings’. And this, it’s claimed, leaves us with Blue Zones that are ‘valid and reliable’.
Reading on, the paper states that Japan has been accurately found to be the longest-lived country for at least the last century, but more importantly for this little essay, it highlights the work of a 19th century pioneering demographer and folklorist (he apparently coined the term ‘folklore’), William Thoms, who proposed these steps for verifying longevity claims:
(i) search for official birth records; (ii) check the records for other individuals with the same name; (iii) corroborate the birth record with additional forms of evidence; and (iv) if the person is still alive, verify as much as possible by quizzing the person about things such as public events that can be cross-checked with additional data sources.
These are a start; in the 21st century we generally have more effective record-keeping, at least in the ‘first world’. In those countries where, unsurprisingly, records aren’t so well kept, credulous investigators can be duped. This happened when National Geographic sent a Harvard physician, Alexander Leaf, to various soi-disant ‘longevity hotspots’, in Equador, Pakistan and the region now known as Azerbaijan, in the early 1970s. Leaf’s report, apparently, was a monument to credulity, and was soon invalidated by more experienced analysts, but it all eventually led to what became the ‘Blue Zone’ disputes. The term is explained in the Gerontologist article, referenced below.
When one of us … in 1999 presented for the first time data suggesting the existence of exceptionally long-lived communities in the central area of the Mediterranean island of Sardinia, where the proportion of centenarians was demonstrably higher than in the rest of the island (Pes, 1999), most demographers reacted with skepticism. From 2001 to 2019, a collaboration with the Belgian demographer Michel Poulain was able to demonstrate that Sardinian longevity in these areas was genuine. For instance, it was determined that people born in this longevity hotspot between 1880 and 1900 were nearly three times as likely to live to the age of 100 years as Sardinians living outside the area. The area was dubbed a Blue Zone because of the blue marker used to indicate the area on a map. The first scientific article mentioning this term was published in Experimental Gerontology in 2004 (Poulain et al., 2004).
So the Blue Zone concept has been extended to other regions based on careful research (I cannot, of course, confirm this, but the article goes to great lengths to present and justify its methodology – in fact that’s the article’s entire purpose, so all skeptics should read it). Four areas, in particular, have been confirmed, and are ‘generally accepted by the international scientific community’, along with the Blue Zone concept: Okinawa, Japan; Sardinia, Italy; Ikaria, Greece; and Nicoya, in north-western Costa Rica. These regions are separately dealt with in detail in the article, so I would be hard put to provide a summary here. The article also points out that Blue Zones can come and go, or weaken or strengthen, due to immigration, emigration, westernisation or other factors. Okinawa, for example, has recently been in dispute regarding its status due to some of these factors, as has the Nicoya zone.
Finally, I’ll just quote the age verification processes used:
… it requires: (i) identifying potential high-longevity target areas based on public demographic databases; (ii) accurately counting the number of people born in the target area, categorised by sex and year of birth; (iii) identifying and confirming the age, using additional data sources, of individuals who have reached a preset threshold age (e.g., 90 years); and (iv) calculating the ratio of the 90+ population to total births recorded during the same time interval. This ratio reflects the probability of people born in the target area to reach the threshold age. The process is designed to minimise the likelihood of false positives (type I errors) and ensure accurate identification of Blue Zones.
And I’ll just finish by mentioning a few points. The first-described Blue Zone, in Sardinia, as mentioned, doesn’t include the whole island, but ‘six villages located in the hills of a rural region in east central Sardinia called Ogliastra containing about 12,000 people’. The percentage of centenarians there…
was approximately five times as high as the percentage of centenarians throughout Europe and nearly three times the percentage in Sardinia as a whole. Equally surprising, although worldwide there are roughly three times as many female as male centenarians—in the Sardinian Blue Zone there were approximately equal numbers of male and female centenarians (Poulain et al., 2004). Since that original analysis, the proportion of centenarians in this Blue Zone has increased (Poulain & Herm, 2025).
That is really fascinating, as it brings to mind the general question of female longevity in comparison to that of males. Something for another post, perhaps. It also, of course, raises the question of why only one area of Sardinia qualifies as a Blue Zone. No answer is provided or attempted. And, to be fair, the article’s purpose is to validate the existence of Blue Zones, not to explain why they exist.
The Blue Zone in Nicoya, Costa Rica, has, on re-investigation, shrunk to about a quarter of its size compared to earlier studies, but ‘a new Blue Zone had emerged in three provinces in northern Costa Rica near the Nicaraguan border’. The Blue Zone on the mountainous Greek Island of Ikaria, which has a population of about 8,000, has been validated between 2008 and 2009, with details provided. And while there is evidence of false claims regarding centenarians in Japan, the data from Okinawa has been validated.
Of course there is speculation as to why these Blue Zones exist, and why they tend to occur in ‘under-developed’ regions. Often under-developed regions have high crime rates, and lower life expectancies, but more isolated and self-sustaining regions appear not to have experienced these problems. It does seem to be the case that community support and connection, physical activity, as well as some genetic elements as yet uncovered, are an important part of the answer.
Reference
how to tackle obesity
A little over a year and a half ago I started getting worried about weight gain. I didn’t like the way I looked, I hated seeing photos highlighting my tubbiness, but I loved food, cooking and eating it, especially the latter. I also preferred to take a fatalist line. Both my parents were slim in youth, especially my mother, and then developed a middle-aged spread. It was inevitable, you got older, your metabolism slowed, you slowed, you didn’t do the sporty outdoor things you used to, and you developed a sophisticated interest in and love of food that, in spite of the extra bulk and the gastric ailments, made life so much more je ne sais quoi than in your tenderfoot days. Genetics and the Zeitgeist are against you, so relax and just roll with the fat.
And yet, vanity was prevailing upon me to cut a more dashing figure before it was too late, and I was certainly keen to live longer. My weight had gotten up to 83.5 kgs, and I’m a shorty, at around 167-168cms, so according to that rough guide, the BMI, I was about half a kilo below being officially obese. So I decided to cut down on eating so much. No planned or organised diet, just plain old calorie restriction. I wanted to get down to under 80kgs at least, in the short term, and after that, well, just one day at a time as the cliché has it. if I could get my weight down to the mid-seventies that would be fantastic, but difficult, and unlikely.
Well, fast forward to the present, and my weight fluctuates daily between 68.5 and 69 kgs, and I’ve moved completely out of the overweight category to normal. Digestive and gastric problems almost completely gone, more energy, and above all a level of pride at my self-discipline that’s beyond price. It was a long slow road, but a fascinating one, and it was nothing but calorie restriction, and a daily handful of exercises out of the CSIRO heart book that did it. You watch, I’ll be struck down by a heart attack or bowel cancer tomorrow.
Anyhow, considering my pretty well seamless experience of gradual weight loss, I’m interested in an article in the most recent Skeptical Inquirer magazine which takes a look at the obesity issue and asks the question – is ‘energy balance’ really the problem, and the solution?
Don’t worry, I’m not talking about new-age energy derived from crystals or pyramids, I’m talking about the balance between calories consumed and calories burned off. Basically, the prevailing wisdom is that we eat too much (especially of the wrong kind of food) and exercise too little, and this imbalance causes obesity. It’s a prevailing wisdom that’s worked for me – though it’s difficult, as I’m now constantly at myself to forgo that piece of food and to get up and move around more. And there will be no end to that vigilance, till the day I die or give up caring.
Even so, I would be very sceptical of a silver bullet approach to this problem, though of course I recognise that calorie restriction just doesn’t seem to work for a lot of people, mainly because they just aren’t able to permanently change their behaviour. And of course many would argue that cutting down their food intake drastically would reduce their quality of life too much. The Skeptic’s Guide folks were saying in their last episode that their late mate Perry would probably prefer to die at twenty, scoffing down a hamburger, than live on 1600 cals a day. That’s a bit extreme, but you get the drift.
I’m not a calorie counter, and I’ve no idea of my basal metabolic rate, but I’d roughly guess that around 1600 cals a day is what I’m down to, and I’d also guess that the reason I’ve been able to change my behaviour is because it wasn’t so ingrained in me in the first place. I was a really skinny kid who was an almost unmanageably finicky eater. I hated almost all vegetables, and many different kinds of meat, and my mother had a terrible time, apparently, trying to find nutritious foods that I would eat. As I got into my teens I was pretty active and sporty and I really didn’t think about food much, though my childhood sensitivities about the stuff gradually faded. What spoiled me – though some would look at it very differently – was a job I took on in my early twenties as a kitchen hand in a prestigious French restaurant. The alimentation there was to die for, and the experience h my attitude to food, and the cooking thereof, for better or worse. Add to that the inevitable slow-down as sporty youth has been left behind, and my working life, such as it’s been, has tended more towards the sedentary.
So it’s a far cry from the battle facing the childhood obese, who’ve laid down heavy neural pathways connecting fatty, sugary foods with well-being and pleasure, or so I imagine. Or had them laid down by their nasty fatty parents. I seem to have recovered psychologically something of the more active spirit of my youth, actually managing to keep, largely, to a regimen of simple exercises – no gym fees – and some not-brisk-enough walking (I really do seem to have laid down an abundance of neural pathways for dawdling), as well as managing to switch off, largely, the lazy snacking-grazing habits of my latter years.
But to return to the article ‘Obesity:what does the science really say?’. There’s some argy-bargy, but it doesn’t really contradict the energy balance approach, as I see it, it just supplements and modifies it with more detailed knowledge about hormones, sweeteners, refined foods and the like.
Okay, the sugar issue has become a major bone of contention. Here’s a quote:
Pediatric endocrinologist Robert Lustig (2012) agrees that adiposity is a hormonal predicament. In his new book, Fat Chance, the child obesity expert indicts simple, super-sweet sugars as the chief culprits, arguing that sucrose and high-fructose corn syrup corrupt our biochemistry and render us helplessly hungry and lethargic in ways fat and protein do not. In other words, Lustig insists that sugar-induced hormonal imbalances cause self-destructive behaviours, not the other way round.
Australia’s fabulous Cosmos magazine had a headline article, ‘Toxic sugar’, late last year which particularly targeted the previously under-rated fructose as a major public health hazard. Obviously, if Cosmos is featuring this view, it must be right, though the article was nuanced and highlighted the debate as much as any particular position. Anyway, think fructose, think fruit, right? Well, yes and no. Fructose, of course, is found in sweet fruit, but how many kids gorge on sweet fruit these days, when they can drink litres of soft drink instead? High fructose corn syrup (HFCS), used in soft drink and many other products, is the major source of fructose in modern western diets – particularly in the US. It’s this intake that’s led to the huge rise in a particular type of liver disease, non-alcoholic steatohepatitis, as well as childhood diabetes. Fructose is ‘sweeter’ than glucose, and is added to many products because it makes them sell.
Fructose differs from glucose in that it doesn’t stimulate a direct insulin response from the liver. Lustig contends that understanding insulin is a major key to understanding obesity and a host of ailments which together constitute ‘metabolic syndrome’. Table sugar is made up of both fructose and glucose, though the fructose can go largely undetected, because it’s only glucose that we measure when we check blood sugar levels.
But really, how complicated and debated all this stuff is. Other researchers point out that, though teenagers might drink copious quantities of HFCS-laced soft drink, most adult intake of fructose is not enough to be problematic. In my own case, I don’t eat as much fruit as I’m supposed to (which is how much?), and I haven’t had a sweet tooth since childhood. In the sugar bowl in my kitchen, the raw sugar has turned hard as a rock for lack of use (I don’t get many visitors), and the same goes for the big jar of sugar in my cupboard. Still, the last time (in fact the only time) I had my general blood chemistry checked out – 18 months ago, when my weight was at its highest – my triglyceride levels, and my LDL cholesterol levels, were slightly raised. I suspect most of my sugars were obtained from starchy foods, particularly bread, which I’ve cut down on quite a bit. Carbohydrates such as bread, potatoes and pasta – all favourite foods of mine, but all of which I’ve cut down on sharply in the last 18 months – are made up of complex glucose-containing molecules, which are broken up by the digestive system to allow glucose to enter the bloodstream.
In any case, it’s easy for me to say how I tackled obesity, or the threat of it. My approach was fairly casual. I ate less, really quite a lot less, but particularly targeted carbohydrates and processed foods. Processed foods are a worry in two ways – they take up far less energy to consume, and they come with added sugar. As one researcher puts it, we just don’t require any extra sugar in our diet, our bodies produce enough of it for all our requirements. I’ve never really measured calories, I’ve just gone on gut feeling, pun intended. I have no way of objectively measuring my health – I don’t have the technology available to me. It’s funny, your body is like a ‘black box’. I’ve no idea right now of my blood sugar levels, my levels of insulin, leptin, cortisol and other vital hormones mentioned in the material I’ve been reading. I don’t know how my electrolytes are faring or whether there’s too much fat accumulating around my organs. All I’m able to measure is my weight. Even my greater feelings of well-being are entirely subjective. I could well be fooling myself. Still, in spite of the debates among dieticians and obesity researchers, the consensus is clear, and it seems they’re arguing more and more about less and less. Avoid fatty foods and sugary foods, perhaps especially the latter, because they play havoc with your hormonal system, creating addictive behaviours and insulin resistance. Generally eat less, and enjoy what you eat more, and keep up with moderate, regular exercise. An active life, both physically and intellectually, will help break the habit of psychological dependence on food. Try to get your ‘rushes’ and to feed your ‘satisfaction centres’ from some other source than food. Not very scientific, I know, but it worked for me – he added with a smug little smirk.