Anti-Inflammatory Diet

All health care starts with diet. My recommendations for a healthy diet are here:
Anti-Inflammatory Diet and Lifestyle.
There are over 190 articles on diet, inflammation and disease on this blog
(find topics using search [upper left] or index [lower right]), and
more articles by Prof. Ayers on Suite101 .

Wednesday, December 9, 2009

Humans vs. Naked Mole Rats

Blood Sugar, Insulin, Superoxide, Couch Potatoes

(Thanks to my loyal readers for the inspiration for this article.)
There is a lot to be learned by sticking one's head in the sand.  Mole rats of East African deserts are just as naked as humans, but beyond the lack of hair and complex social structures, we are as different as night and day.  These differences explain some of our unusual physiological characteristics.  Maybe our health problems are linked to our sweaty skin, predatory nature and our need to run, just as the naked mole rats (NMRs) are adapted to their dark, high carb, climate-controlled burrows.

Mole Rats:
  • low metabolic rate controlled by eating
  • live in low oxygen burrows
  • poor temperature regulation
  • live in the tubers that they eat -- sweet potatoes with legs
  • no insulin or superoxide dismutase
  • vitamin C and D production (in darkness)?
  • no pain sensors in skin, no stress, no sweat
  • mostly vegetarian, starch

Humans:
  • high metabolic rate controlled by physical activity
  • live in high oxygen
  • temperature regulation by sweating
  • hunters, runners, farmers
  • no vitamin C production, vitamin D via sunlight
  • insulin used to regulate blood sugar, insulin resistance by superoxide
  • oxidative stress leads to inflammation and disease
  • carnivores, fat

Naked Mole Rats Are as Unique as Humans

Naked mole rats and humans are odd compared to most mammals.  Those oddities may explain a lot about modern human diseases.  The biggest difference between humans and NMRs is the control of blood glucose.  It seems that NMRs control their metabolism by their eating.  In times of starvation, the NMRs eat less and their metabolic rate lowers.  At the cellular level, this must mean that fat stores are converted to blood glucose to modestly regulate blood sugar as it drops, but the lack of insulin does not permit control of high blood sugar.  Thus, a rise in blood sugar must lead to cessation of eating.  This would make sense, because NMRs husband their resources -- they typically encounter few, very large, starchy, underground tubers/roots, eat into them and continue to live off of them for their lifetimes.  They are underground farmers.  They do not wolf down their slow moving prey and hunt for more.

NMRs Know When to Stop

Individual cells of NMRs regulate their metabolism without apparent recourse to adjusting their surface glucose transporters, since their blood glucose levels are constant or unmanipulateably low.  There is no mechanism for blocking influx of glucose by insulin stimulation when intracellular glucose is too high.  It would be expected that intravenous injection of excess glucose could kill NMRs by producing excess intracellular glucose spilling excess high energy electrons of the electron transport chain into superoxide damage.  Of course low tissue oxygen levels would provide protection, since the rate of superoxide formation is proportional to oxygen concentration at the mitochondrial surface.

Humans Are Runners

Humans are adapted to running down prey during the heat of the day, which means that they produce high metabolic rates, high demands for cooling, high tissue oxygen levels and high glucose/fat utilization.  In a lengthy chase, glycogen is rapidly depleted and fat metabolism ensues.  Human brains are adapted for access to lots of oxygen and nutrients.  Human tissues are adapted to low serum glucose and high levels of oxygen.  Moderate levels of serum glucose lead to increased cellular metabolism via insulin production and increased glucose transport into cells.  Low serum glucose leads to lipid mobilization and liver gluconeogenesis.

Humans Kill for Fat

Physical activity regulates human cellular activity.  Depletion of celllular ATP leads to an increase in cell surface glucose transporters.  Inadequate serum glucose, low intracellular glucose (phosphates) and low ATP lead to lipid utilization.  Lipids are all metabolized in mitochondria and require oxygen as the last, low energy electron acceptor in the electron transport chain.  Brain evolution in humans was adapted to high metabolism and intelligence is associated with intense brain vascularization, oxygen supply and lipid utilization.  It could be argued that glycogen storage is a way for humans to handle excess blood sugar during sleep inactivity, since humans are adapted for handling fats and tolerating carbohydrates.

Sweet Tooth Is Deciduous

Why do humans have a sweet tooth?  A group of early humanoids stumbling onto a cache of cookies made by elves, would quickly eat themselves into a stupor as their blood was diverted from brain to belly, their blood sugar rocketed, insulin surged, glucose gushed into cells, cellular metabolism peaked, cellular ATP pegged over, and superoxide spilled high energy electrons out of the saturated mitochondrial ETC.  Cookies would be killers for humans, if superoxide production didn’t block insulin-based transport of glucose into most cells and channel the high blood glucose into fat deposition. 

Marauding Naked Mole Rats

Cookie-fed humans become fat, lethargic and start to look like potatoes with legs, i.e. NMRs.  Unfortunately, unlike NMRs, humans don’t have off switches for carb glutting.  Humans evolved to run on fats, and can exploit occasional carb caches, because of an adaptive sweet tooth, but lack of evolutionary experience with gigantic carb caches, e.g. agriculture and supermarket cereal aisles, left humans maladapted for high carb diets.  We can’t pull out the HFCS intravenous line and instead become couch potatoes waiting as potential victims for giant marauding NMRs (the healthcare industry).  Fortunately, NMRs can keep the potatoes fat and feed on them indefinitely.

15 comments:

Hans Schrauwen said...

Excellent,
please keep blogging.

Anonymous said...

As always great post, and quite amusing.

StephenB said...

Nice. There seems to be a divergence of opinion about whether humans evolved for run-them-down-until-they-collapse-from-heat-exhaustion style of hunting or the lie-in-wait-and-sprint-after-them style. I'm biased towards the former explanation as I enjoy running, which of course doesn't make me correct.

Interesting comment about SOD. It sounds like a high fat diet reduces the need for SOD production.

drew said...

Art, as always your posts are fascinating. I would like to extend a warm holiday greeting to you and thank you for your great work...

Mary B. said...

I'm biased towards the former explanation as I enjoy running, which of course doesn't make me correct.
Interesting comment about SOD. It sounds like a high fat diet reduces the need for SOD production.

Nigel Kinbrum BSc(Hons)Eng said...

Sometimes, I wish that my house was edible. Happy Holiday!

Dr. Art Ayers said...

Nigel,
I haven't been very attentive to my blog. I thought that your reference to house-eating referred to the cancellation of the annual Gingerbread party that we have hosted for the last 25 years. We had to cancel this year, because my mother-in-law died last week, after ten years of decline with Alzheimer's. Many feel that their memories of her have now been returned to them. It was a time of sad celebration.

Season's Greetings to all!

Tanya said...

Sorry to hear of your loss, Dr. Ayers. May you find comfort in your memories. It has been a season of changed plans for a lot of us!

Nigel Kinbrum BSc(Hons)Eng said...

Sorry to hear about your MIL.

My comment about edible houses was in response to:-

"Mole Rats:
• live in the tubers that they eat -- sweet potatoes with legs"

Regards, Nige.

Dr. Art Ayers said...

Nigel,
I knew you would understand some of my thoughts and I just temporarily projected on to you my gingerbread concerns before I recalled the comments I had made about NMR habitations.

Thanks.

frost said...

I just found this link over at Mangan's and this seems to be as good a place as any to post it here.

http://mangans.blogspot.com/2009/12/cheap-longevity-trick.html

The real information is in this article:

http://www.lmreview.com/articles/Mitochondrial_part3.html

Any article that mentions mTOR gets my attention. ;-)

Heather Twist said...

I really am enjoying your blog. You have thought a lot about this stuff, for sure. But you don't mention anything about ferritin levels. For me, this is the one thing that ties together much of the conflicting health information. Some diets promote iron storage, others don't, and the difference is not necessarily the amount of iron in the diet. But a human being with high ferritin levels, does not process carbohydrates (on average) as well as one with low ferritin levels. Ferritin is the BIG inflammation culprit. Interestingly, the foods allowed during fasting times (seafood) don't seem to promote high ferritin levels, even though they are high in iron.

Dr. Art Ayers said...

Heather,
I have to admit that I haven't thought much about ferritin. I have it filed under iron storage. Ferritin should be nothing more than an indicator of the amount of stored iron. Free iron is a big deal and storage of iron away from pathogens is essential. Free iron is also very dangerous for oxidation of cellular materials. Iron is also a key component in the production of acid in the stomach and potentially in biofilms. Then of course there is oxygen transport and storage in muscle tissue, and iron in catalase, etc.

Clearly, I don't have a good conceptualization of iron in disease development. That is one of my areas of biochemical innocence. Please feel free to point me in the right direction.

Thank you for your comments.

garymar said...

I read about the naked mole rats when I was in school at Univ of Michigan, which had a colony for many years.

Their digestion is so poor that they eat each other's feces to extract more nutrients the second (and third?) time around.

Before the NMR were discovered, there was a conference on social species (early 60's?). Mostly they talked about ants, bees and termites. One researcher gave a talk about "what would a mammalian social animal look like?" And he described the main characteristics of such a species -- which just happened to match the characteristics of the naked mole rat, a social mammalian, when it was later discovered!

This just floored me -- that someone could think through a theory and describe a species utterly and completely before it was discovered.

diseases said...

ugly this is image :( Mole rats öööö not