Monday, June 16, 2008

Activator X

Activator X, the almost-mythical vitamin discovered and characterized by Weston Price, has been identified! For those of you who are familiar with Weston Price's book 'Nutrition and Physical Degeneration', you know what I'm talking about. For the rest of you, allow me to explain.

Weston Price was a dentist and scientist in the early part of the 20th century. Practicing dentistry in Cleveland, he was amazed at the poor state of his patients' teeth and the suffering it inflicted. At the time, dental health was even worse than it is today, with some children in their teens already being fitted for dentures. Being a religious man, he could not bring himself to believe that 'physical degeneration' was what God intended for mankind. He traveled throughout the world looking for cultures that did not have crooked teeth or dental decay, and that also exhibited general health and well-being. And he found them. A lot of them.

These cultures were all considered 'primitive' at the time, and were not subject to the lifestyles or food choices of the Western world. He documented, numerically and with photographs, the near-absence of dental cavities and crooked teeth in a number of different cultures throughout the world. He showed that like all animals, humans are healthy and robust when occupying the right ecological niche. Price had a deep respect for the nutritional knowledge these cultures curated.

He also documented the result when these same cultures were exposed to Western diets of white flour, sugar and other industrially processed foods: they developed rampant cavities, their children grew with crooked teeth due to narrow dental arches, as well as a number of other strikingly familiar health problems. I think it's worth mentioning that Price's findings were universally corroborated by doctors in contact with the same cultures at the time. They are also corroborated by the archaeological record. Many of his findings were published in respected peer-reviewed journals. 'Nutrition and Physical Degeneration' is required reading for anyone interested in the relationship between nutrition and health.

Naturally, Price wanted to understand what healthy diets had in common besides the absence of white flour and sugar. Having studied cultures as diverse as the carnivorous Inuit, the dairy-eating Masai and agricultural groups in the Andes, he realized that humans are capable of thriving on very diverse foods. However, he did find one thing in common: they all ate some amount of fat-soluble, animal-derived vitamins. Even the near-vegetarian groups ate insects or small animals that were rich in these vitamins. He looked for, but did not find, a single group that was entirely vegetarian and had the teeth and health of the groups he described in 'Nutrition and Physical Degeneration'.

There were three vitamins he found abundantly in the diets of healthy non-industrialized people: A, D, and an unknown substance he called 'activator X'. He considered them all to be synergistic and critical for proper mineral metabolism (tooth and bone formation and maintenance) and general health. He had a chemical test for activator X, but he didn't know its chemical structure and so it remained unidentified. He found activator X most abundantly in grass-fed butter (but not grain fed!), organ meats, shellfish, insects, and fish eggs. Many of these foods were fed preferentially to pregnant or reproductive-age women in the groups he studied.

Price used extracts from grass-fed butter (activator X), in combination with high-vitamin cod liver oil (A and D), to prevent and reverse dental cavities in many of his patients. 'Nutrition and Physical Degeneration' contains X-rays of case studies showing re-calcification of severe cavities using this combination.

After reading his book, I wasn't sure what to make of activator X. If it's so important, why hasn't it been identified in the 60+ years since he described it? I'm happy to say, it finally has. In the summer of 2007, Chris Masterjohn wrote an article for the Weston Price foundation website, in which he identified Weston Price's mystery vitamin: it's vitamin K2, specifically the MK-4 isoform (menatetrenone).

It occurs exactly where Weston Price described it, and research is beginning to find that it's also critical for mineral metabolism, bone and tooth formation and maintenance. Its function is synergistic with vitamins A and D. To illustrate the point, where do A, D and K2 MK-4 all occur together in nature? Eggs and milk, the very foods that are designed to feed a growing animal. This is true from sea urchins to humans, confirming the ubiquitous and critical role of these nutrients. K2 has not yet been recognized as such by the mainstream, but it is every bit as important to health as A and D. The scientific cutting edge is beginning to catch on, however, due to some very tantalizing studies.

In the next post, I'll go into more detail about K2, what the science is telling us and where to get it.


Anonymous said...

Well, mercifully, I happen to love raw fish eggs (especially salmon roe). Back when I was in college I did a summer gill netting salmon in Alaska. Our diet during the week consisted of peanut butter on sourdough bread, fresh king salmon backed in the small oven, and gobs of fresh roe right out of the fish. After we really developed the taste, we didn't even wash it.

Oh, and Rainier Beer... :)

Stephan Guyenet said...


Amazing. I could definitely see myself feasting on raw salmon roe. The dried stuff just isn't as good.

Debs said...

It's lucky that mainstream nutritionists pay attention to vitamins; they might actually pay attention to this one, even though K-2 MK4 is found in the kinds of deliciously fatty foods they love to hate.

Nice post, and exciting information. I ate a big old chunk of grass-fed butter to celebrate the news.

Stephan Guyenet said...

Those in the know are paying very close attention to K2. I feel like I have an unfair advantage, having read NPD.

Christopher Robbins said...

Several months ago I saw a study about lowfat dairy and dairy products causing a certain cancer (Can't remember which). The studay also noted that whole fat dairy did not cause this cancer. I haven't been able to find the study since. Have you seen it? Have a link to it?


Anonymous said...

I know you're planning a follow-up post, but I'm wondering if pasteurization or cooking destroys K2. I am aware of the benefits of raw milk, but it is not available where I live. I can get eggs from pastured hens and pasteurized grass-fed cheese from Australia plus some locally made pasteurized cheese from cows fed a mixed diet of feed and pasture.

The Japanese, especially the Okinawans, have exceptional longevity, yet their traditional diet includes no dairy products. I'm guessing they derive K2 from eggs and possibly other animal foods.

Christopher Robbins said...

The Japanese have Natto a fermented product that contains considerable k2.

Stephan Guyenet said...

Sonagi and Chris,

K2 is heat-stable, thankfully. You don't have to eat dairy products to get it, although grass-fed dairy is a good source.

The K2 in natto is not activator X. X is the MK-4 isoform; natto contains mostly MK-7 and no MK-4. MK-7 is showing some of the same benefits as MK-4 in preliminary trials, but at this point I would not trust it as an adequate substitute. It doesn't seem to behave quite the same in the body, and it is not the form that mammals synthesize from K1 for use in their own tissues.

Stephan Guyenet said...

Hi Chris,

I'm not familiar with the study, sorry.

Debs said...

Is it this study about prostate cancer?

Anonymous said...

Hi Stephan,

Thanks for the excellent post.

I came across your article after watching Dr. Pete Peterson's interview with Project Camelot.

My question is where can I obtain Activator X? Is is sold over the counter?



Unknown said...


I came accross an interview with Dr. Pete Peterson and in it he mentioned Activator X. He stated that the oil from a bottom feeder fish would be the best source. Would you know which fish he may have been referring to and if not what in your opinion is the best source of Activator X. Also where do you buy it.



Tom said...

Stephan, similar to Andre Heath, I too have recently seen Dr Petersons interview in which he states that this particular vitamin is found in the highest concentrations in Ratfish Liver Oil (Which does not appear to be available as a supplement anywhere) What are your personal experiences of this and can you shed some more light on the topic?


Tom said...

Stephan, similar to Andre Heath, I too have recently seen Dr Petersons interview in which he states that this particular vitamin is found in the highest concentrations in Ratfish Liver Oil (Which does not appear to be available as a supplement anywhere) What are your personal experiences of this and can you shed some more light on the topic?


Stephan Guyenet said...

Andre health and klu06tm,

Activator X is vitamin K2 MK-4. You can buy supplements, but you can also get it from pastured butter, eggs, chicken and organs. I haven't seen any evidence that ratfish liver oil contains significant K2 MK-4.

Unknown said...

Is Shark Liver oil perhaps the oil he is referring to? It does contain squalene, which is used in vaccine adjuvant to distribute antibodies; however I am not sure squalene is antioxidant.

Please see discussion on the following thread:

Unknown said...

After further investigation on the sites below, I am even more convinced that Squalene is indeed the oil that has all the beneficial characteristics.

It is an anti-oxidant (against oxidation, rejuvenates with oxygen, transports oxygen through the body very fast), it has Vitamin A, boosts the immune system, and many other positive characteristics.

See the following 2 websites:

davew said...


the rat fish he is speaking of is the skate fish.

the theory of activator x is K2 has not been proven in a lab. i have tried. i think there should be room for discussion that activator x is in fact something different than any of the mk/k2's. i do believe that sometime in the future it will be shown to be something different

Anonymous said...

This guy talks about Active X and he says it comes from a bottom feeding fish in the ocean and tells you how to separate the oil so that it has absolutely no fishy smell or taste and no reduction in effectiveness.
but he does not say what kind of fish it is? why I'm NOT SURE? Must be top secret!

Anonymous said...

the fish that dr. pete peterson did not mention is the ratfish, at david wilcock's website he tells us this, wilcock is the blond haired blue shirted man who was interviewing dr. peterson in the youtube video that "someone who cares" gave us the link to

made2order said...

I think it would be important to listen to the interview of Dr. Pete Peterson, here is the link:
Great revelations of science & technology here, well worth th time to listen to.

Unknown said...

Skate Liver Oil is what Dr. Peterson is referring to. It is related to the ratfish and shark family.

Here is more info:

Unknown said...

The fish, Dr. Peterson is referring to, is a slate fish. It is in the ratfish and shark family.

Here is more info:

GoodVibesEnergy said...

To purchase Activator X, I suggest trying Aside from being great for our physical health it also opens our psychic Pineal Gland which usually functions by shielding off the interior area from all electromagnetic field activity. This causes an "inversion" so that time/space, the mirror inverse of space/time can flow through via the information field. Sound crazy? So does Quantum Physics.

Pieris said...

The fish known as skate is VERY different from the ratfish. I can tell you that he meant ratfish not skate fish. The ratfish is a very special fish which was highly revered by the Vikings and MUCH MORE so than the cod liver oil, which was much more easily obtained. He states in the interview that ratfish is not the real name. That is correct too. The real name is Chimaera Monstrosa Linnaeus. Ratfish is the nickname because of its rat-like appearance (rodent like teeth and a very long eel-like tail).

Many blogs confuse it with skatefish liver oil, and assume that fermented skatefish liver oil is the same thing. But the skate is VERY different from the ratfish. Any marine biologist will tell you this. Those that know about the Chimaera Monstrosa will also tell you that its oily liver constitutes approximately 60% of its total body weight. Actually, the oil he mentions in the interview has no strong taste whatsoever. Ratfish liver oil actually has a very mild taste. Fermented oils have a very strong taste and smell, and are produced by the "rotting process" (you can learn more about this process from old scientific papers which also describe the original pre-industrial rotting process, which has been conveniently called fermentation by some: it appears that someone is trying to sell their skatefish oil).

There is absolutely no conclusive scientific evidence that MK4, or K2 for the matter, is activator X. It could be a host of other substances, even a complex.

tom said...

i tried to find the Chris Masterjohn article mentioned as being at the weston price website-- but it is no longer available there. is it available anywhere else on-line?