What is the current scientific consensus regarding these questions?


I am sincerely wanting to understand this concept from a scientific (not anecdotal) perspective. What does “interlocked” mean? How does increasing sodium ensure that potassium concentrations in muscles and nerves is adequate? What does ketosis have to do with this — especially since it seems to make it harder for the body to retain fluids and along with it — I’d presume— minerals?

(Old Baconian) #22

Well, for one thing, if you lack sodium, the body tries to balance the pH of the blood by pulling potassium and magnesium out of the cells and into the blood, and the same is true, mutatis mutandis, of the other electrolytes.

The only relevance of ketosis to this is the following: insulin interferes with the kidneys’ ability to excrete sodium, and excessive glucose, stored as glycogen, causes water retention, which also interferes with the excretion of sodium. So when we go onto a ketogenic diet, the excess glycogen gets used, and the lowered insulin allows the kidneys to return to their normal, faster rate of excreting sodium. This simply means that on a ketogenic diet we need to work a bit harder to ensure that we are getting enough sodium. (The symptoms known colloquially as the keto “flu” are actually symptoms of a lack of sodium.)

Additionally, two studies, released a few years ago, confirm that the healthiest people are those whose sodium intake is in the range of 4-6 g/day, which is the equivalent of 10-15 grams of sodium chloride. There is a lecture on YouTube by Dr. Andrew Mente, one of the researchers on the PURE Study, detailing this particular finding.

People on a ketogenic diet probably need a bit more than that, but how much more would be anybody’s guess. Fortunately, the body has feedback mechanisms, such as craving salt or finding it to taste terrible, that keep us within the right range, if we listen.

(Michael - When reality fails to meet expectations, the problem is not reality.) #23

Other factors are food choices and individual variability. Most food contains sodium, some foods lots of it. If you’re eating those sodium-rich foods your need to supplement will be much less or even null. Additionally, some of us seem to hold onto sodium moreso than others. So just because the metabolic state of ketosis returns our metabolism to normal water throughput, we’re not thereby automagically condemned to supplement sodium. Or anything else. My own n=1 experience: I did not supplement sodium when I started keto, never experienced carb withdrawal symptoms (aka ‘keto flu’) and only later started to supplement sodium, potassium and magnesium to try to lessen leg muscle cramps I had suffered for decades prior to keto. I doubt that I’m unusual.


They didn’t publish 3 years results last time I’ve checked. Or have I missed it?

The silence after 2 years worries me. Were the stats so bad after 3 years that they didn’t want to publish?


Ok, I get that a sodium deficiency can deplete potassium, but why shouldn’t I be concerned about meeting the potassium requirement as well as sodium? I am truly shocked at how little potassium I am getting in my diet, especially since cutting out avocado — which I’ve since added back. I plan to focus for the next month or so on getting a balanced amount of potassium with sodium to see if this helps with muscle and nerve symptoms (pain, tingling and weakness).

(Central Florida Bob ) #26

Sorry I missed this a few days ago, but speaking of centenarians…

One of my most favorite studies I’ve ever found came from Mark Sisson at Primal Blueprint in August of '19. According to this study, the thing that populations with the most people living well past 100 years old had in common was living in areas without good birth certificates and good birth records.

Quoting Mark - what factors account for the long lifespans?

Red wine consumption didn’t predict supercentenarianism.

Legume consumption didn’t predict it.

The presence of hills didn’t predict it.

It turns out that a strong predictor of super-longevity is the absence of detailed birth records.

In the United States, whenever a state introduced birth certificates, supercentenarianism miraculously dropped by 69-82%. A full 82% of all supercentenarians on record in the U.S. were “born” before birth certificates were used. Only 18% have birth certificates; only 18% of American supercentenarians can actually be verified. Oops.

In Okinawa, Sardinia, and Ikaria, the strongest predictor for regions with high reported supercentenarianism was high crime, low income, and low life expectancy relative to the national average. Ninety-nine percent of male Italian centenarians smoke. Hundreds of thousands of Japanese centenarians are actually dead or missing. These aren’t what you’d expect. Oops again.

Emphasis added by me.

Gee, the strongest predictor of longevity is living in high crime, low income and low life expectancy areas compared to the rest of the nation? That seems completely backwards from everything we know about poverty being a substantial health risk. And that’s not even touching 99% of Italian centenarians smoking.

The conclusion of the paper is that the primary causes of reported supercentenarianism in these countries are pension fraud and reporting error.

One study doesn’t prove anything. Several studies might if they’re done well. But this one actually made me laugh out loud.


The study is about “super-centenarians” (living to 110, which is a more questionable achievement), and it’s looking at data from 1880-1900. By 1915 — where I live (Northeast US), birth registration had been well established. We have documentation for the ages of my immediate relatives. I can’t speak for Okinawa or Italy, but in the US — in the year 2021 — there is no question that the numbers of people reaching their 90s and 100 are increasing. It will be interesting to see what happens to the trend as those born in mid-twentieth century age. My guess is that extremes of unhealthy lifestyle habits associated with this era are likely to catch up.

(Edith) #28

I would want to know percentages. There may be more people reaching their 90s and up just because there are more people. If we went back and counted the percentage of the population, would it still be more today. An is that a fair comparison?

We have vaccinations, antibiotics (for now), amazing surgical interventions, less manual labor, more modern conveniences, etc… I really don’t know if we can truly compare life expectancies of the past and now.


The link is per million but it’s a fair point that the population is aging. Still, adjusting for age is not going to explain the huge increase.

I don’t know what you mean by “fair”. I think the reason to look at these patterns is to stimulate thinking about why. The examples you gave are obvious factors. It’s interesting to also think about dietary factors and how much they might have played a role. Or not?

(Doug) #30

It’s hard to get a total grasp of the numbers; I tried yesterday, thinking about @Fangs’ 93 year old mother. :slightly_smiling_face:

For some years, a search gives straightforward results right away, i.e. “Of people born in that year, this percentage are still alive.” I was looking for 1928 (assuming she was born then) and didn’t get anything.

My wife has an aunt who was born in 1933, and one website, as of January 2020, said that 39% of those born then were still alive. Surprisingly high, IMO, but I don’t know any differently. Would have been people 86-87 years old at that point.

Things really change as we look at different times. In the past, a sadly significant number of people died in their first year. Controlling for that shows a considerably higher average lifespan. Likewise, if somebody makes it to 65 (for example) then their odds of making it to 85 or 90 are substantial.

Using World Bank figures and data from The Society of Actuaries as of two years ago, for the United States:

65 year old man, average health = 55% chance of getting to 85, 30% chance of getting to 90.

65 year old woman, average health = 65% chance of getting to 85, 46% chance of getting to 90.

With excellent health, 65 year old man = 43% chance of seeing 90.

" " " 65 year old woman = 54% chance of seeing 90.

Women, excellent health at age 65, 1/3 of them will be alive at age 95.

Men, excellent health at age 65, 1/4 of them will be alive at age 95.


Longevity calculator for a given person at a given age, rated for everall health, smokes or does not smoke.