Archive for the ‘longevity’ Category
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
three things: IQ and longevity, the Taliban and Americans, the real World Cup
Nerissa: …. superfluity comes sooner by white hairs, but competency lives longer
The Merchant of Venice, Act 1 , scene 2
Thing one
I don’t know what my IQ is, having never knowingly sat a test, but I assume it’s a number just short of infinity. So it was interesting to read, in Carl Zimmer’s book on genetics, She has her mother’s laugh, that IQ is highly correlated to longevity. Not that there’s a genetic link, at least not directly, but it stands to reason. The higher your IQ, the quicker it takes for you to ‘get’ things. This was more or less confirmed by a simple, ingenious brain processing test. Subjects were shown simple shapes flashing very briefly on a computer screen – two vertical lines spaced apart with a horizontal line sitting on top. The participants had to guess which of the two vertical lines was the longest each time. Researchers had worked out that if the images were flashed too briefly, the participants just resorted to guesswork. It required approximately 0.1 seconds for people, on average, to perceive the shape correctly. The key, though, lay in the variation of that perception. It ranged from 0.02 seconds to 0.136 seconds, and researchers found a pretty reliable correlation between accurate perception time and intelligence (presumably measured by IQ – Zimmer doesn’t say). Unfortunately it’s not quite reliable enough, apparently, for us to do away with those pesky, long-winded IQ tests and replace them snappy shape tests, but as mentioned, it does seem to confirm the intuition that intelligence has to do with sharpness and quick-wittedness. Which brings me back to longevity. Some work done in Scotland, which has turned out to be accidentally longitudinal, provides interesting evidence. In 1932 the Scottish government conducted a massive testing program of nearly 90,000 eleven-year-old students – just about the whole of the country’s kids of that age. They were all given a 71-question exam involving decoding, analogising and arithmetic among other things. Over time this ‘experiment’, or what you will, was forgotten, but the records were unearthed in 1997, and then researchers tried to get in touch, some 65 years later, with the ‘kids’ who’d been tested. They managed to gather together 101 elderly citizens in an Aberdeen hall to resit the gruelling test. They found that the score on the original test was a pretty good indicator – 73% – of the score second time around. But there was another interesting finding – the percentage of the test-takers who had scored well and were still alive in 1997 was considerably higher than those who’d scored poorly. Some 70% of the women in the top quarter of scores were still alive, compared to 45% in the bottom quarter:
Children who scored higher, in other words, tended to live longer. Each extra 15 IQ points, researchers have since found, translates into a 24% drop in the risk of death.
Carl Zimmer, She has her mother’s laugh, p296
Why is this so? Smarter people generally know what to do, and are quicker to learn what to do, to live longer, to make more, financially and otherwise, of the circumstances they find themselves in, to be safer, healthier and the like. Stands to reason.
Thing two
A huge fuss is being made of allegations, probably true, of Putin offering and paying bounties to the Taliban to kill American soldiers in Afghanistan. My first reaction to this news was – surely the fervently anti-American and anti-western Taliban were already hell-bent on killing infidel foreigners, and many of the purest ideologues among them would be insulted by the offer of bribes to do so? Then again, many of them would’ve been laughing up their ample sleeves at the thought of being paid by the Russkies, whom they likely consider only slightly less odious and infidelious than the Yanks, to do what they were already heaven-bent on doing. For this reason, it would surely be impossible to prove that any deaths of Americans, or their coalition partners – including Australians – at the hands of the Taliban, could be sheeted home to Putin and his fellow thugs. Even if money traced to Russia appeared in Taliban bank accounts after some atrocity or other, this doesn’t exclude the possibility that the atrocity would’ve occurred in any case. Win-win for the Taliban.
Thing 3
The announcement that the real World Cup will take place in Australia and New Zealand in 2023 makes life a little more bearable, though it’s three years away and I’m not getting any younger. This competition combines two of the most life-affirming enities in life, for me at least – women and soccer. Hopefully we’ll have learned many lessons from Covid-19 by then haha, and at least some of today’s thuggish political leaders will have been placed where they can do no more harm, and we can get on with the more exciting stuff of life, like having fun.