I've worked in healthcare in Japan for nearly forty years. About thirty years ago, I was discussing Japanese longevity with clinicians and pathologists. Their take: traditional Japanese toilets. They noted that wealthier, more cosmopolitan Japanese people actually live shorter lives than poorer country people. Women squat five times a day or more, men once or twice. It keeps the legs strong — one of the major pillars of a long, healthy life. Western toilets, by contrast, put you in a seated position that kinks the colon and makes elimination harder, which may contribute to constipation and related problems. Perhaps part of the answer?
Thank you so much for sharing this perspective. That’s such an interesting aspect of longevity that I had never really thought about before. I don’t see the traditional Japanese-style squat toilets nearly as often in Japan anymore, so it’s interesting to think about whether that change could have any connection with physical strength and mobility. I can certainly see how regularly getting into a deep squat could help maintain leg strength over time. Thank you for bringing this perspective to the discussion!
Thank you for your thoughtful comment. I realise that my wording may have given the impression that I was recommending routine tumour-marker screening for all healthy people, and I’m sorry if that was misleading.
My intention was not to suggest that tumour-marker panels have been shown to extend life in healthy, asymptomatic people. Rather, I was describing one aspect of Japan’s health-check culture, where additional tests are sometimes offered and an abnormal result may lead to further investigation and, in some cases, earlier diagnosis.
I agree that this is very different from demonstrating a mortality benefit, and I think that distinction is important. The evidence for screening is quite specific to the individual test and the population being screened. For example, PSA screening has shown a reduction in prostate-cancer mortality in the ERSPC trial, although with important concerns about overdiagnosis.
So I appreciate you raising this point. I should have been more precise in the article about the distinction between detecting disease earlier and actually demonstrating an improvement in mortality.
How much impact does gut flora among populations have relative to this subject? Seems like it should be a lot, since diet heavily influences these outcomes. Thank you doctor.
Great question — and honestly one I wish I'd had room for in the article.
Gut flora is likely part of the story. Traditional Japanese diets — fermented foods, fiber, fish over red meat — are linked to a distinct gut microbiome, and that's associated with lower inflammation and better metabolic markers. But most of this is observational, so it's hard to say how much is the microbiome itself versus the diet driving it directly. Promising, not proven yet.
Funny enough, I actually had my own gut microbiome tested recently — and even being Japanese, mine wasn't great. A good reminder that "being Japanese" isn't a health plan on its own; the habits still have to be there.
I see your point, and I definitely understand where you’re coming from. I think the leap from “these long-lived populations eat a lot of salt” to “salt makes you live longer” is probably a bit too big, though.
At the same time, I don’t think we should ignore the other side either. Japan does have relatively high salt intake, and there’s strong evidence that excess sodium contributes to higher blood pressure, particularly in salt-sensitive people. So I’d be more comfortable saying too much salt can be harmful, especially for blood pressure, rather than saying that high-salt countries should necessarily have shorter lifespans.
And I agree with you that the fact that several high-salt countries have long life expectancies makes the relationship much more complicated than “salt = shorter life.” There are clearly many other factors at play.
my conclusion was a hyperbolic one with the intent to provoke people to think about the mainstream claim
Too much of anything cannot be good but the real question is what is too much and what is sufficient
Current guidelines are based on very questionable short term studies showing isolated results of lower blood pressure among people who already have high blood pressure. Say very little about long term effects and effects of healthy people
These recommendations alo ignore risks of low salt diet on other cardiovascular outcomes
Increased insulin resistance
Elevation of "bad" cholesterol and triglycerides
Activation of the renin-angiotensin-aldosterone system
Not to mention complete lack of understanding how low sodium diet affects other health aspects including nervous system, endocrine system, etc
Thank you for the reply, and yes I agree that finding the right balance is the important part. “Too much” and “enough” can mean very different things depending on the context, so I think that balance is often the real question.
Hello, I’m a French MD. French have a long history of being opinionated (文句が多い) and I will consolidate that ahaha. The automatic reaction from French docs, especially involved in communication on socials would be : “we salute your culture, and we should encourage cultural differences and exchange. But screening all around people without symptoms is a false positive cases factory”
So stating that screening is a root cause for longevity without solid data seem a bit bold to me. Sorry.
I think that’s really where the discussion lies — finding the right balance between the potential benefit of detecting something early and being able to intervene, versus the potential downsides of screening, such as false positives, overdiagnosis, unnecessary follow-up tests, and, depending on the modality, radiation exposure.
I don’t think screening is simply good or bad; it’s really about weighing the potential benefits against the risks and limitations for each type of screening.
I have to just skim past the "blue zone" talk. That's a scam where poor people with bad records inflated their age to get pensions or just didn't declare the death of a parent so they could keep the checks coming in.
We can get that regular check up in Canada. Typically it's on the patient to decide to start going in. I did at 40. I don't think any doctor is skipping "fasting glucose, LDL cholesterol, blood pressure", that's the basic starting point. From there I'm sure there's a few more that are pretty standard for everyone and then they will add more depending on the patient's health and more specific risks. A frustration I have is that this could be automated, instead it counts on me to decide I should go get checked. Most of preventative health care is counting on the patient to know what and when they should be screened for.
Thank you for sharing this! I’ve heard that regular health checkups are available in Canada as well, so it’s interesting to hear how the system works from your experience.
I can definitely see the difficulty in having the patient decide when they should start going for preventive screening. Even if the basic tests are straightforward, people may not necessarily know what they should be screened for or when they should start.
One thing I find interesting about Japan is that employees are generally required to have an annual health checkup through their workplace. If someone doesn’t complete it, the company will follow up, so the system doesn’t rely entirely on each individual remembering to arrange preventive care.
Of course, the Japanese system has its own limitations too, but I do think there is something valuable about making preventive health checks a regular part of life rather than something people have to think about only when they feel they need one.
I agree, an easy thing to automate. One example is the FIT test for initial colon cancer is mailed to you. Most other initial tests could be sent to you to determine who really needs to see a doctor.
I think Canadians would not like their work being that involved in their health. Much better if a doctors office sends automated reminders.
That’s definitely a great idea, and I completely understand your point about not wanting workplaces to be too involved in personal health information. I think automated reminders directly from a doctor’s office could be a really good solution.
I wish more Canadian doctors’ offices could automate that kind of preventive follow-up! I’ll have to ask a doctor from Canada about how feasible this would be within their system.
What is not good for the geese, can be good for the gander. High sodium in diets is bad for the Americans ( atleast often heard so), but doesn’t bother the Japanese. One could find similar contradicting findings between the two populations. The reason is culture and cuisine. The Japanese cuisine is one among the very ancient ones in the world, still flourishing and supporting the population admirably. Its basic nature has remained largely in tact. It means that over millanea, their metabolisms got fully tuned to high salt in take. It is not a minus point for them. On the contrary, the USA is a modern nation, has no legacy cuisine to fall back on and as a nation of largely immigrants, Europeans first, and from other continents, has its cuisine largely mish mash, still evolving and getting constantly churned by modern food science and even vested interests like food industry. For example, in a space of hundred years, the original animal fats were spurned in favour of seed oils for a few decades which are now being seen villainous. On the contrary, Japanese has always by tradition stuck with sesame oil, a seed oil. I am from India and I have often argued this point in several comments on postings on seed oils. Like Japan, our cuisine is ancient, largely in tact and is marked by the use of edible oils like mustard, peanuts, sesame, coconut, ghee etc, though oils like sunflower, palm and rice bran have made inroads in the last few decades. This w-6 centric platter has not harmed the population in any significant way, because our metabolisms are fully tuned to the downsides of w-6, compared to the unsettled metabolisms of the Americans with respect to w-6.
This is an important attribute of populations of old cultures and food vs health guidelines should never miss it.
Thank you for sharing such a thoughtful perspective. I have mostly been thinking about the direct effects of things like salt intake itself, but your point about the role of culture, traditional dietary patterns, and population differences is certainly an interesting one and adds another dimension to the discussion.
It’s a perspective I hadn’t considered as much before, and it’s a good reminder that nutrition is often more complex than looking at individual nutrients alone. Thank you very much!
Thanks Dr for your prompt, appreciative words. I have offered this perspective in comments to quite a few expert posts on food vs health parameters. One or two accepted my premise. Beyond writing in contexts like this, I have no means pushing this perspective into main stream thinking. Actually where old populations exist and where such anecdotes can be found, it is incumbent on the part of those governments and their nutrition/medical bodies to issue locally appropriate guidelines derived from their own population studies and back up research. It doesn’t seem to be happening. Every one clings to inappropriate guidelines.
Whether it is salt intake or w-6 intake (edible oils), the biology is old and universal. Their downsides in excess are real. But what is excess is not universal. If the universal guideline now ( read American), for example, is 10 gm salt max per day, the Japanese could have been taking 15 gms a day for generations. Comfortably. If they were to switch to 10 gm max guideline now, their metabolisms could face conditions of salt deficiency. Am I right ? As I see it, we are under the influence of dozens of health guidelines in our daily lives. Some qualifying as preventive indicators and many related to our labelled conditions. Some could be universal, but many would have to be reset against our cultural practices passing down from generation to generation. Would modern medical science recognise this need ?
Thank you again for sharing this perspective. I think your point about the importance of considering cultural and population differences is very interesting. I had mostly been thinking about the direct effects of salt intake on health, but I had not really considered the question of whether the definition of “excess” should be different depending on a population’s long-term dietary patterns.
I would be a little cautious about saying that reducing salt intake from 15 g to 10 g would necessarily cause salt deficiency, since the body has quite effective mechanisms for maintaining sodium balance, and the optimal intake is not simply determined by what a population has historically consumed. But I do agree that applying the same nutritional threshold to every population without considering their diet, lifestyle, genetics, and existing health data may be an oversimplification.
I think this is where population-specific research becomes particularly important. Rather than assuming that one country’s guideline should automatically apply everywhere, it would be interesting to see more guidelines developed from long-term data on the populations they are actually intended for.
Your broader point about modern medicine needing to distinguish between truly universal principles and recommendations that may need cultural or population-specific adjustment is something I hadn’t really thought about before. Thank you for giving me that perspective!
The salt intake example was just hypothetical. Considering the view that Japanese salt consumption is higher than American or present norm. I am not a medical doctor, nor a nutritionist. But I would differ from what you say of substantially lower consumption of salt than what is the body adjusted to. Yes, it has mechanisms for balancing, but need not be for all. Salt deficiency is a well reported condition. Some would react to lower intakes, on a consistent basis especially.
The other point is that population scale permanent readjustment of metabolic needs can happen, hypothetically Japanese average from the present assumed 15 gm of daily salt can settle down to 8 gms if there is a change in the food scene. But that readjustment would be a several generations process, even with some hick ups for the first few generations. If the present level is a 2000 year old legacy, the change can be a legacy only another 2000 years down the line. Anyway, thanks for this engaging conversation. I am long retired, home bound and out of physical contact with the professional world. People like you have the opportunity to seed this relevant perspective into mainstream thinking. Best wishes.
I see your point. Perhaps the bigger question is not just how long we live, but how we live — and whether we can pursue healthier, longer lives in a way that is also more sustainable for the planet.
I live in the US and I have a yearly health exam. What’s unusual about that? It’s part of my Medicare coverage. When I was on work insurance, I had a “well woman” exam every year.
Thank you for your comment! And that’s great to hear.
From what I’ve heard from people in the U.S., the annual health exam is often relatively basic—checking vital signs, reviewing medical history, doing a physical examination, and ordering basic blood work.
In Japan, health checkups can be much more extensive. In addition to basic blood tests and a physical examination, they may include chest X-rays, ECGs, abdominal ultrasound, and various cancer screenings depending on your age and the type of checkup. More advanced tests such as CT and MRI can also be added.
So I think the difference is less about whether people have an annual health exam, and more about the breadth and detail of the testing that is routinely available through employers or private health checkup programs in Japan. Access to tests such as MRI can also be relatively quick and considerably less expensive than in the U.S., although this varies by facility and insurance coverage.
Well, I had an echocardiogram yesterday, as a follow-up to my annual exam. My heart is healthy, but I have an anomaly in my heartbeat.
Ordering X-rays or a CT scan for no reason — just to see what’s there — is irresponsible, since that is exposure to radiation. And an MRI for nothing? What is it going to show?
An annual exam here is basic blood panel and physical (pelvic exam for women), with referral to imaging or further tests *if symptoms or history warrant deeper examination.*
I wouldn't be too worried about the radiation. Motorcycle racers are some of the most x-rayed people in the world and don't seem to have a higher risk from it. It is a waste of resources that everyone has to pay for one way or another.
Thank you for your perspective! I agree that the radiation exposure from a medically necessary scan is generally quite small, and the benefits can certainly outweigh the risks when there is a reasonable chance of finding something early and treating it.
I think the discussion is really about that balance: the potential benefit of detecting a condition early or being able to intervene, versus the small additional risk associated with radiation exposure. For routine diagnostic imaging, the doses are generally far below the levels associated with tissue damage, although repeated exposure can contribute to a small cumulative lifetime cancer risk.
So I don’t think the message should be “radiation is dangerous, so we should avoid CT,” but rather that CT and other X-ray-based tests should have a clear clinical reason, with the lowest reasonable dose used. That way, we can capture the potential benefits without exposing people unnecessarily.
Thank you for your reply, and I’m glad to hear that your heart is healthy and that you were able to have an echocardiogram.
And I completely agree that imaging shouldn’t be ordered simply for the sake of looking for something, especially when radiation is involved. In Japan as well, imaging and further tests are generally recommended based on symptoms, medical history, risk factors, or findings from an initial examination.
I think the main difference with the Japanese health checkup system is that some people have access to a wider range of screening options, but that doesn’t necessarily mean every test is appropriate or necessary for everyone.
I fully agree with this. After 18 months living in Tokyo, seeing the amount of drinking and smoking, I was baffled. And then my employer sent notice about the Ningen Dock. I was stunned by the comprehensive testing that happens every year. It’s truly impressive (and this from a Canadian and UK citizen whose countries think they have good public free health care!)
Thank you so much for your comment! And yes, although smoking in Japan has been decreasing quite a lot compared with the past, partly because of the rising price of cigarettes, drinking is still very much part of social and work culture here.
It’s a little ironic, though, that when Ningen Dock season comes around, people often start cutting back on alcohol and even avoiding things like ramen for a week or so beforehand. Of course, it would be better not to drink at all, but I suppose at least they’re making an effort before their health check.
Thank you so much for the comment! I’m really glad to hear that it resonated with you, especially since it’s something you’ve been thinking about for a long time!
I've worked in healthcare in Japan for nearly forty years. About thirty years ago, I was discussing Japanese longevity with clinicians and pathologists. Their take: traditional Japanese toilets. They noted that wealthier, more cosmopolitan Japanese people actually live shorter lives than poorer country people. Women squat five times a day or more, men once or twice. It keeps the legs strong — one of the major pillars of a long, healthy life. Western toilets, by contrast, put you in a seated position that kinks the colon and makes elimination harder, which may contribute to constipation and related problems. Perhaps part of the answer?
Thank you so much for sharing this perspective. That’s such an interesting aspect of longevity that I had never really thought about before. I don’t see the traditional Japanese-style squat toilets nearly as often in Japan anymore, so it’s interesting to think about whether that change could have any connection with physical strength and mobility. I can certainly see how regularly getting into a deep squat could help maintain leg strength over time. Thank you for bringing this perspective to the discussion!
Well man checks have been subjected to trials and show no benefit. I would suggest trialing unhealthy man checks instead
Thank you for your thoughtful comment. I realise that my wording may have given the impression that I was recommending routine tumour-marker screening for all healthy people, and I’m sorry if that was misleading.
My intention was not to suggest that tumour-marker panels have been shown to extend life in healthy, asymptomatic people. Rather, I was describing one aspect of Japan’s health-check culture, where additional tests are sometimes offered and an abnormal result may lead to further investigation and, in some cases, earlier diagnosis.
I agree that this is very different from demonstrating a mortality benefit, and I think that distinction is important. The evidence for screening is quite specific to the individual test and the population being screened. For example, PSA screening has shown a reduction in prostate-cancer mortality in the ERSPC trial, although with important concerns about overdiagnosis.
So I appreciate you raising this point. I should have been more precise in the article about the distinction between detecting disease earlier and actually demonstrating an improvement in mortality.
How much impact does gut flora among populations have relative to this subject? Seems like it should be a lot, since diet heavily influences these outcomes. Thank you doctor.
Great question — and honestly one I wish I'd had room for in the article.
Gut flora is likely part of the story. Traditional Japanese diets — fermented foods, fiber, fish over red meat — are linked to a distinct gut microbiome, and that's associated with lower inflammation and better metabolic markers. But most of this is observational, so it's hard to say how much is the microbiome itself versus the diet driving it directly. Promising, not proven yet.
Funny enough, I actually had my own gut microbiome tested recently — and even being Japanese, mine wasn't great. A good reminder that "being Japanese" isn't a health plan on its own; the habits still have to be there.
the low sodium (salt) argument was always obviously wrong
Not only that Japan has high salt intake but most other blue zones and countries with longer lifespans
Greek food is very salty (feta and other cheeses, olives, salted fish, meat seasoning, ...)
Italian food is salty (Prosciutto and cured meats, anchovies, capers, Baccala, Ricotta Salata and other cheeses like Pecorino )
Icelandic food is very salty (Harðfiskur, Saltfiskur, Hangikjöt, Söltuð Síld, even deserts Salmiak Lakkrís)
Singaporean food is very salty as well (almost all dishes)
If anything can be concluded from this is that salty food make one live longer
Thank you for your comment!
I see your point, and I definitely understand where you’re coming from. I think the leap from “these long-lived populations eat a lot of salt” to “salt makes you live longer” is probably a bit too big, though.
At the same time, I don’t think we should ignore the other side either. Japan does have relatively high salt intake, and there’s strong evidence that excess sodium contributes to higher blood pressure, particularly in salt-sensitive people. So I’d be more comfortable saying too much salt can be harmful, especially for blood pressure, rather than saying that high-salt countries should necessarily have shorter lifespans.
And I agree with you that the fact that several high-salt countries have long life expectancies makes the relationship much more complicated than “salt = shorter life.” There are clearly many other factors at play.
my conclusion was a hyperbolic one with the intent to provoke people to think about the mainstream claim
Too much of anything cannot be good but the real question is what is too much and what is sufficient
Current guidelines are based on very questionable short term studies showing isolated results of lower blood pressure among people who already have high blood pressure. Say very little about long term effects and effects of healthy people
These recommendations alo ignore risks of low salt diet on other cardiovascular outcomes
Increased insulin resistance
Elevation of "bad" cholesterol and triglycerides
Activation of the renin-angiotensin-aldosterone system
Not to mention complete lack of understanding how low sodium diet affects other health aspects including nervous system, endocrine system, etc
Thank you for the reply, and yes I agree that finding the right balance is the important part. “Too much” and “enough” can mean very different things depending on the context, so I think that balance is often the real question.
Hello, I’m a French MD. French have a long history of being opinionated (文句が多い) and I will consolidate that ahaha. The automatic reaction from French docs, especially involved in communication on socials would be : “we salute your culture, and we should encourage cultural differences and exchange. But screening all around people without symptoms is a false positive cases factory”
So stating that screening is a root cause for longevity without solid data seem a bit bold to me. Sorry.
Thank you very much for the comment!
I think that’s really where the discussion lies — finding the right balance between the potential benefit of detecting something early and being able to intervene, versus the potential downsides of screening, such as false positives, overdiagnosis, unnecessary follow-up tests, and, depending on the modality, radiation exposure.
I don’t think screening is simply good or bad; it’s really about weighing the potential benefits against the risks and limitations for each type of screening.
I have to just skim past the "blue zone" talk. That's a scam where poor people with bad records inflated their age to get pensions or just didn't declare the death of a parent so they could keep the checks coming in.
We can get that regular check up in Canada. Typically it's on the patient to decide to start going in. I did at 40. I don't think any doctor is skipping "fasting glucose, LDL cholesterol, blood pressure", that's the basic starting point. From there I'm sure there's a few more that are pretty standard for everyone and then they will add more depending on the patient's health and more specific risks. A frustration I have is that this could be automated, instead it counts on me to decide I should go get checked. Most of preventative health care is counting on the patient to know what and when they should be screened for.
Thank you for sharing this! I’ve heard that regular health checkups are available in Canada as well, so it’s interesting to hear how the system works from your experience.
I can definitely see the difficulty in having the patient decide when they should start going for preventive screening. Even if the basic tests are straightforward, people may not necessarily know what they should be screened for or when they should start.
One thing I find interesting about Japan is that employees are generally required to have an annual health checkup through their workplace. If someone doesn’t complete it, the company will follow up, so the system doesn’t rely entirely on each individual remembering to arrange preventive care.
Of course, the Japanese system has its own limitations too, but I do think there is something valuable about making preventive health checks a regular part of life rather than something people have to think about only when they feel they need one.
I agree, an easy thing to automate. One example is the FIT test for initial colon cancer is mailed to you. Most other initial tests could be sent to you to determine who really needs to see a doctor.
I think Canadians would not like their work being that involved in their health. Much better if a doctors office sends automated reminders.
That’s definitely a great idea, and I completely understand your point about not wanting workplaces to be too involved in personal health information. I think automated reminders directly from a doctor’s office could be a really good solution.
I wish more Canadian doctors’ offices could automate that kind of preventive follow-up! I’ll have to ask a doctor from Canada about how feasible this would be within their system.
What is not good for the geese, can be good for the gander. High sodium in diets is bad for the Americans ( atleast often heard so), but doesn’t bother the Japanese. One could find similar contradicting findings between the two populations. The reason is culture and cuisine. The Japanese cuisine is one among the very ancient ones in the world, still flourishing and supporting the population admirably. Its basic nature has remained largely in tact. It means that over millanea, their metabolisms got fully tuned to high salt in take. It is not a minus point for them. On the contrary, the USA is a modern nation, has no legacy cuisine to fall back on and as a nation of largely immigrants, Europeans first, and from other continents, has its cuisine largely mish mash, still evolving and getting constantly churned by modern food science and even vested interests like food industry. For example, in a space of hundred years, the original animal fats were spurned in favour of seed oils for a few decades which are now being seen villainous. On the contrary, Japanese has always by tradition stuck with sesame oil, a seed oil. I am from India and I have often argued this point in several comments on postings on seed oils. Like Japan, our cuisine is ancient, largely in tact and is marked by the use of edible oils like mustard, peanuts, sesame, coconut, ghee etc, though oils like sunflower, palm and rice bran have made inroads in the last few decades. This w-6 centric platter has not harmed the population in any significant way, because our metabolisms are fully tuned to the downsides of w-6, compared to the unsettled metabolisms of the Americans with respect to w-6.
This is an important attribute of populations of old cultures and food vs health guidelines should never miss it.
Thank you for sharing such a thoughtful perspective. I have mostly been thinking about the direct effects of things like salt intake itself, but your point about the role of culture, traditional dietary patterns, and population differences is certainly an interesting one and adds another dimension to the discussion.
It’s a perspective I hadn’t considered as much before, and it’s a good reminder that nutrition is often more complex than looking at individual nutrients alone. Thank you very much!
Thanks Dr for your prompt, appreciative words. I have offered this perspective in comments to quite a few expert posts on food vs health parameters. One or two accepted my premise. Beyond writing in contexts like this, I have no means pushing this perspective into main stream thinking. Actually where old populations exist and where such anecdotes can be found, it is incumbent on the part of those governments and their nutrition/medical bodies to issue locally appropriate guidelines derived from their own population studies and back up research. It doesn’t seem to be happening. Every one clings to inappropriate guidelines.
Whether it is salt intake or w-6 intake (edible oils), the biology is old and universal. Their downsides in excess are real. But what is excess is not universal. If the universal guideline now ( read American), for example, is 10 gm salt max per day, the Japanese could have been taking 15 gms a day for generations. Comfortably. If they were to switch to 10 gm max guideline now, their metabolisms could face conditions of salt deficiency. Am I right ? As I see it, we are under the influence of dozens of health guidelines in our daily lives. Some qualifying as preventive indicators and many related to our labelled conditions. Some could be universal, but many would have to be reset against our cultural practices passing down from generation to generation. Would modern medical science recognise this need ?
Thank you again for sharing this perspective. I think your point about the importance of considering cultural and population differences is very interesting. I had mostly been thinking about the direct effects of salt intake on health, but I had not really considered the question of whether the definition of “excess” should be different depending on a population’s long-term dietary patterns.
I would be a little cautious about saying that reducing salt intake from 15 g to 10 g would necessarily cause salt deficiency, since the body has quite effective mechanisms for maintaining sodium balance, and the optimal intake is not simply determined by what a population has historically consumed. But I do agree that applying the same nutritional threshold to every population without considering their diet, lifestyle, genetics, and existing health data may be an oversimplification.
I think this is where population-specific research becomes particularly important. Rather than assuming that one country’s guideline should automatically apply everywhere, it would be interesting to see more guidelines developed from long-term data on the populations they are actually intended for.
Your broader point about modern medicine needing to distinguish between truly universal principles and recommendations that may need cultural or population-specific adjustment is something I hadn’t really thought about before. Thank you for giving me that perspective!
The salt intake example was just hypothetical. Considering the view that Japanese salt consumption is higher than American or present norm. I am not a medical doctor, nor a nutritionist. But I would differ from what you say of substantially lower consumption of salt than what is the body adjusted to. Yes, it has mechanisms for balancing, but need not be for all. Salt deficiency is a well reported condition. Some would react to lower intakes, on a consistent basis especially.
The other point is that population scale permanent readjustment of metabolic needs can happen, hypothetically Japanese average from the present assumed 15 gm of daily salt can settle down to 8 gms if there is a change in the food scene. But that readjustment would be a several generations process, even with some hick ups for the first few generations. If the present level is a 2000 year old legacy, the change can be a legacy only another 2000 years down the line. Anyway, thanks for this engaging conversation. I am long retired, home bound and out of physical contact with the professional world. People like you have the opportunity to seed this relevant perspective into mainstream thinking. Best wishes.
What is your evidence that checking tumour markers in healthy people improves life expectancy, as you suggest?
Actually we shouldn’t be living long, isnt it ? Its a disgrace to the Planet, the way we dwell.
I see your point. Perhaps the bigger question is not just how long we live, but how we live — and whether we can pursue healthier, longer lives in a way that is also more sustainable for the planet.
I live in the US and I have a yearly health exam. What’s unusual about that? It’s part of my Medicare coverage. When I was on work insurance, I had a “well woman” exam every year.
Thank you for your comment! And that’s great to hear.
From what I’ve heard from people in the U.S., the annual health exam is often relatively basic—checking vital signs, reviewing medical history, doing a physical examination, and ordering basic blood work.
In Japan, health checkups can be much more extensive. In addition to basic blood tests and a physical examination, they may include chest X-rays, ECGs, abdominal ultrasound, and various cancer screenings depending on your age and the type of checkup. More advanced tests such as CT and MRI can also be added.
So I think the difference is less about whether people have an annual health exam, and more about the breadth and detail of the testing that is routinely available through employers or private health checkup programs in Japan. Access to tests such as MRI can also be relatively quick and considerably less expensive than in the U.S., although this varies by facility and insurance coverage.
Thank you again for sharing your experience!
Well, I had an echocardiogram yesterday, as a follow-up to my annual exam. My heart is healthy, but I have an anomaly in my heartbeat.
Ordering X-rays or a CT scan for no reason — just to see what’s there — is irresponsible, since that is exposure to radiation. And an MRI for nothing? What is it going to show?
An annual exam here is basic blood panel and physical (pelvic exam for women), with referral to imaging or further tests *if symptoms or history warrant deeper examination.*
I wouldn't be too worried about the radiation. Motorcycle racers are some of the most x-rayed people in the world and don't seem to have a higher risk from it. It is a waste of resources that everyone has to pay for one way or another.
Thank you for your perspective! I agree that the radiation exposure from a medically necessary scan is generally quite small, and the benefits can certainly outweigh the risks when there is a reasonable chance of finding something early and treating it.
I think the discussion is really about that balance: the potential benefit of detecting a condition early or being able to intervene, versus the small additional risk associated with radiation exposure. For routine diagnostic imaging, the doses are generally far below the levels associated with tissue damage, although repeated exposure can contribute to a small cumulative lifetime cancer risk.
So I don’t think the message should be “radiation is dangerous, so we should avoid CT,” but rather that CT and other X-ray-based tests should have a clear clinical reason, with the lowest reasonable dose used. That way, we can capture the potential benefits without exposing people unnecessarily.
Thank you for your reply, and I’m glad to hear that your heart is healthy and that you were able to have an echocardiogram.
And I completely agree that imaging shouldn’t be ordered simply for the sake of looking for something, especially when radiation is involved. In Japan as well, imaging and further tests are generally recommended based on symptoms, medical history, risk factors, or findings from an initial examination.
I think the main difference with the Japanese health checkup system is that some people have access to a wider range of screening options, but that doesn’t necessarily mean every test is appropriate or necessary for everyone.
I fully agree with this. After 18 months living in Tokyo, seeing the amount of drinking and smoking, I was baffled. And then my employer sent notice about the Ningen Dock. I was stunned by the comprehensive testing that happens every year. It’s truly impressive (and this from a Canadian and UK citizen whose countries think they have good public free health care!)
Thank you so much for your comment! And yes, although smoking in Japan has been decreasing quite a lot compared with the past, partly because of the rising price of cigarettes, drinking is still very much part of social and work culture here.
It’s a little ironic, though, that when Ningen Dock season comes around, people often start cutting back on alcohol and even avoiding things like ramen for a week or so beforehand. Of course, it would be better not to drink at all, but I suppose at least they’re making an effort before their health check.
This is something I’ve been thinking about for so long!!! Nice article ♥️
Thank you so much for the comment! I’m really glad to hear that it resonated with you, especially since it’s something you’ve been thinking about for a long time!