Modern high carbohydrate diet; let's discuss the science behind.

Why not use this thread to discuss the science behind modern high carb diet. Talk about the pro and cons. I would like the thread to be very biochemical oriented (talk about the metabolism science behind) but still welcome personal experience.

It is evident that in this thread, it would not be considered offtopic talking about the opposite diets, the low carb diet and the ketogenic one, as the science behind is what I would like to discuss. It is also not offtopic to talk about human evolution that have made us high carb eaters. Sugar (sucrose) over consumption is, being a carb, included here. Discution on medical implications are also welcome.

Please remember that I am a big proponent for low carb and ketogenic diet but don't take it like I am imposing my ideas here! All of you high carb eater are welcome.

Iv spent all my life eating carbs weather its bread rice or pasta, iv recently been looking into different diets and only the other day come across the idea cslled the wheat belly. I have just done an intollerance test and wheat was a biggy for me, so i have cut it out now to see if it stops my eczema. a reply to: PeterMcFly

Carbs = bad
Fat = good

That's about as much sense as I can muster at 7,30am on a Monday morning.

First a little introduction, what happen when you eat a carbohydrate?

Forgetting a lot of details on digestion, basically the carb are converted into its basic constituants; monosaccharide (glucose, fructose and galactose principally). This digestion process, depending on the glycemic index of the food ingested, will release glucose in the blood stream in a faster or slower way.

Glucose, when released in the blood, once it's concentration past a specific threshold will induce production by the pancreas of insulin. Insulin is parts of the glucose blood level regulation control loop. It instruct to many cells in the body to absorb the excess glucose from the blood (excess glucose in blood is bad, but more on this later). These cells in the body will "eat" glucose and convert it into fat, some like the hepatocytes in the liver will store glucose as a multibranched polysaccharide of glucose called glycogen. Athlete are very aware about their glycogen store capacity.

When blood glucose level fall below another threshold level, another hormone is secreted by the blood glucose control loop, glucagon is released by the pancreas to signal the body that it is time to "fabricate" glucose from diverse storage mecanism and release it into the bloodstream, thus increasing glucose level.

Of course, while this happen, your body consume glucose as required, thus lowering naturally blood glucose level.

This is, grossly, the mecanism for the regulation of blood level glucose.

It is the right diet for some, for others it has disastrous health consequences. If you want to know if it is right for you, look to your ancestors and what they ate.

I cut out sugar and carbs 3 years ago. I have lost 5 stone in weight, no more acid, colds headaches etc. My diet is now mostly protein, green veg, salad and fat. I have to say I have never felt better!

What happen when constantly eating a high carb diet?

Basically the digestion of carb produce, amoung other monosaccharides, high level of glucose in the blood stream. This high level of glucose induce high production rate by your pancreas of the hormone insulin to down regulate glucose. It is widely speculated that this constant insulin production "wear" the pancreas and "desensitise" the receptors on cell to whom the insulin "speak".

Depending on wich one get "worn" the first, we see diabetes type 2 and then type 1!

originally posted by: PeterMcFly
What happen when constantly eating a high carb diet?

Basically the digestion of carb produce, amoung other monosaccharides, high level of glucose in the blood stream. This high level of glucose induce high production rate by your pancreas of the hormone insulin to down regulate glucose. It is widely speculated that this constant insulin production "wear" the pancreas and "desensitise" the receptors on cell to whom the insulin "speak".

Depending on wich one get "worn" the first, we see diabetes type 2 and then type 1!

I would say aside from a select few whose bodies have adapted I would say that is correct.

What happen when having constantly high blood glucose level?

Has said before, the pancreas and/or targetted cell receivers wornout. This result in increasing level of glucose in blood; the control loop is no longer able to maintain glucose level at the specified/required level (the consigne). The excess is the error of the control loop.

As glucose level increase, lots of very bad things start to happen.

First we see a dramatic increase of a mecanism called Advanced glycation end-product (AGE), this is nonenzymatic addition of glucose to a protein. Those product are real poison to the human body and inflict damage everywhere. It is postulated that theses product are one of the principal cause for many chronic pain and disease.

Also no need to mention that high glucose level is frequently associated with obesity.

Please allow me to continue my "monologue". I will gladly answer comments once I have finished trying putting back together this stuff from memory.

Dietary monosaccharide are not made equal when it come to prospensity at creation of AGE for a given concentration in blood.

Glucose is moderate at creation of AGE.

However, fructose is very highly active for the same concentration for the spontanious creation of AGE.

Galactose is considered negligible at creation of AGE in blood.

About fructose, after absorption, it enters the hepatic portal vein and is directed toward (principally) the liver where its absorbtion is rate limited. In other word it make the liver work hard.

It is inevitable that some will endup into the blood stream, producing high AGE production.

It shall be evident now that even small quantity of fructose in blood is as bad as high level of glucose in blood when considering AGE production.

a reply to: Lompyt

Even if you would not have intolerence, my point is that high carb diet is bad as explained before. Please consider a little reading about AGE mecanism.

a reply to: and14263

Carbs = bad Fat = good

That's what I think, but it would be nice to use the thread for a more indepth exploration of the cause.

a reply to: calstorm

It is the right diet for some, for others it has disastrous health consequences. If you want to know if it is right for you, look to your ancestors and what they ate.

Some people may have some kind of genetic mutation making the high fat diet dangerous as other have mutation making high carb dangerous for them. Discernement shall be used! This is why I am NEVER ok with the concept of those book that present a recipe for a "wonder" diet.

However, and this is a point I will eventually discuss, as you said the solution is to check our ancesters. Human have begun adapting to high carb diet since end of last glaciation, about 15kyears, this is too short for any significant adaptation (but little adaptation difference have developed). Before that for about 1millions year, human or proto-human was on a carnivor diet. One millions years is sufficient for some significant adaptation.

a reply to: blackrabbit1

I cut out sugar and carbs 3 years ago. I have lost 5 stone in weight, no more acid, colds headaches etc. My diet is now mostly protein, green veg, salad and fat. I have to say I have never felt better!

It does not surprise me, high carb diet is prospentious to weight taking.

However take note that too high protein in your diet strain your kidney especially if you don't drink enough water and produce nitrogenated compound in excess in your blood. Use moderation.

About the Warburg hypothesis, it say that cancer cell are cell having their mitochondria damaged. As mitochondria is an essential organel for the mechanism of programmed suicide, cancerous cell having a damaged mitochondria are immortal.

Also, if a cell have it's mitochondria damaged, it cannot use metabolic mode dependant on proper functionning of the mitochondria. Cancerous cell are under obligation to use metabolic mode based on anaerobic fermentation, i.e. use blood glucose in a low efficiency energy production way. But it crank up this mechanism in overdrive...

Basically, the Warburg hypothesis tell us that cancerous cell need glucose in blood to survive and multiplicate. If the glucose level in blood is low, they won't have a favorable environment to thrive.

But other non cancerous cell of the body that have normal functionning mitochondria are able to switch to others metabolic mode when glucose is sparse, like using fatty acid or ketones bodies.

Conclusion: low level of glucose mean no party time for cancerous cell, but business as usual for normal healthy cell!

When eating low carb and high fat (or fasting and burning own fat), digestion of fat produce fatty acid and ketogenic bodies in blood.

Most body tissue, except brain can use preferably fatty acid and ketone bodies as a fuel. The heart prefer 100% fatty acid or ketone bodies (cannot remember wich one) over glucose.

The brain cannot directly use fatty acid as fuel but will convert itself to up to 90% consumption of ketones bodies after a period of adaptation of a couples of days.

After brain adaptation to ketone bodies, it is possible to goes as low as under 1mmol/L of blood glucose level without suffering from hypoglycemia symptom. The needed glucose can be synthetised by the body from fat (lipid) or protein source by gluconeogenesis

The danger of low carb/ketogenis diet.

The main problem is that we are not born "naturally" in this metabolic mode. Adaptation is not alway easy or possible and may even be dangerous.

When in ketogenic mode, one of the main problem is the low pH produced (acidosis).

Also, even if it seem the glucose control loop is no longer required, insulin production capability is still required to limit (regulate) the production level of ketone bodies. If it is not possible to produce insulin like diabetes type 1, blood level of ketone bodies will past over 16mmol/L and produce a dangerous acidosis condition. That mean a big NO NO to diabetes type 1 sufferer. Also, strangly, there exist people that react to this diet like diabetes type 1 but they are not diabetics, they will start to produce excessive level of ketone bodies past 16mmol/L without a level of blood glucose increasing!

That yield that low carb dieters are at risk of all the danger of ketogenic diet as no one peoples are the same, some make ketones bodies very easily and other find it very difficult. Therefor It is recommended that even for a low carb diet, blood glucose level is monitored frequently, ketosis level is checked w/t ketostix in urine or better in blood, and urine pH is monitored.

Also please remember that low carb/ketogenic diet is deficient in many vitamin and mineral, so supplementation is mandatory. Also ketogenic mode require increased consumption of salt and very good hydratation. If you try to mix this with a low salt diet and consume not enough water, you will get into grave trouble!!!

Neurological effect of ketogenic diet:

It is established fact that ketogegic diet is neuroprotective and studied for a couple of neurological disease.

When every medication fail to control epilepsy, it have a good chance to work, see The Charlie Foundation.

It also allow for the tissue to be more resilient when lacking oxigenation.