The Conflation Game.

Li-i-ife, is the name of the game, and I wanna play the game with you.....


People have been "grinding my gears" by conflating carbohydrates with sugars. All sugars are carbohydrates, but not all carbohydrates are sugars. See Carbs Carbs Carbs. to find out about the five basic different types of carbohydrates.

Krauss et al has been "at it" again. In Separate effects of reduced carbohydrate intake and weight loss on atherogenic dyslipidemia, at the bottom of Table 1 is "carbohydrate, 50% simple and 50% complex". The carbohydrates consisted of half simple (probably fructose, as that has the worst effect on particle size) and half starches (probably maltodextrin, as it rapidly hydrolyses into glucose).

The effect of such a sugary diet is as follows:-

The percentage of pattern B (small, dense) LDL particles increases significantly in proportion to the percentage of Dietary "carbohydrate". The implication of this study (also A very-low-fat diet is not associated with improved lipoprotein profiles in men with a predominance of large, low-density lipoproteins ) is that high-carb, low-fat diets are atherogenic.

I call "Shenanigans".

A high sugar diet is atherogenic, but carbohydrates from potatoes, rice, sweet potatoes/yams & beans (if not overcooked), actual whole grains (i.e not flour) & whole fruits aren't.

Carbs, Carbs, Carbs, Carbs and Carbs.

Carbohydrates seem to get the blame for everything nowadays. "Carbohydrates made me fat". "Carbohydrates burned-out my pancreas". "Carbohydrates raised my blood glucose". "Carbohydrates raised my blood triglycerides". "Carbohydrates stole mer jerb!". O.K, I made the last one up!
If carbohydrates are responsible for all of these bad things, then how come a diet of only potatoes had the opposite effect? See 20 Potatoes a day.

Also, Blue Zone populations eat a diet with a high percentage of total energy (%E) from carbohydrates. See Low serum insulin in traditional Pacific Islanders--the Kitava Study and The Kitava Study. The Kitavans eat ~70%E from carbohydrates, ~20%E from fats and ~10%E from proteins. They don't eat a significant amount of Western crap-in-a-bag/box/bottle.

Maybe it has something to do with the type of carbohydrates and with what they're eaten. In A very-low-fat diet is not associated with improved lipoprotein profiles in men with a predominance of large, low-density lipoproteins , (emphasis, mine) "The very-low-fat, high-carbohydrate experimental diet was designed to supply less than 10% of energy from fat (2.7% saturated, 3.7% monounsaturated, and 2.6% polyunsaturated), with 75% from carbohydrate (with equal amounts of naturally occurring and added simple and complex carbohydrate) and 15% from protein." Simple carbohydrates are sugars.

The experimental diet which did bad things contained 37.5%E from sugars. I declare shenanigans!

1. There are simple carbs, there are simple carbs and there are simple carbs. In the previous post, the graph of plasma triglycerides after an OGTT showed that 100g of glucose had no significant effect on plasma triglycerides over a 6 hour period. If it had been 100g of fructose, there would have been a significant increase in plasma triglycerides. Galactose is taken-up by the liver and has minimal effect on blood glucose, but I don't know its effect on plasma triglycerides.

2. There are complex carbs, there are complex carbs and there are complex carbs. Overcooked starch is high in amylopectin which is highly-branched, which means that it hydrolyses rapidly into glucose which gives it a very high glycaemic index. Raw & refrigerated potato starches have very low glycaemic indices, due to the presence of amylose, or other resistant starches. Rice contains a mixture of starches which varies with rice type, cooking time and subsequent refrigeration.

3. There are oligosachharides e.g. FOS.

4. There are polysaccharides e.g. inulin.

5. There is soluble fibre/fiber e.g. cellulose.

Although overeating sugars containing fructose & starches that rapidly hydrolyse into glucose makes the liver fatty, overeating fats also makes the liver fatty. See Pathogenesis of type 2 diabetes: tracing the reverse route from cure to cause.

It's the chronic over-consumption of crap-in-a-bag/box/bottle (high in sugars and/or starches and/or fats), not just carbohydrates, that causes over-fatness and other health problems.

Carbohydrates: Dogs' Doodads or Spawn of Satan?

Depending on which side of the fence you're on, Carbohydrates are either the Dogs' Doodads or the Spawn of Satan. As I get older, I prefer to sit on the fence. Let's start with the basics.


What are Carbohydrates?

Carbohydrates are so named because they have the generic formula (CH2O)n. C is carbon and H2O is water hence Carbo-Hydrate. There are several different types.

1) Sugars. There are monosaccharides, the most common being Glucose (a.k.a. Dextrose), Fructose and Galactose. There are disaccharides, the most common being Sucrose, Lactose and Maltose. Disaccharides are 2 monosaccharides linked by a glycosidic bond formed by a condensation reaction (removal of a water molecule, usually by an enzyme). Disaccharides have to be hydrolysed (have a water molecule added back in, usually by an enzyme) into monosaccharides before they can be absorbed in the gut.
Sugars are simple carbohydrates.

2) Starches. These are chains of glucose molecules linked by glycosidic bonds. Starches have to be hydrolysed into glucose molecules before they can be absorbed. There are unbranched chains like amylose which is also known as resistant starch. There are branched chains like amylopectin and maltodextrin. Glycogen is a branched chain "animal starch" that is synthesised inside muscle and liver cells and which can be rapidly converted back into glucose inside cells.

3) Non-Starch Polysaccharides (NSPs). These are also known as fibre/fiber and there are 2 types: soluble (e.g. pectin, beta-glucan & cellulose) and insoluble (e.g. bran). These aren't absorbed, but gut bacteria can feed on soluble fibre/fiber. Starches and NSPs are complex carbohydrates.

For more information, see http://en.wikipedia.org/wiki/Carbohydrate

The amount of carbohydrate that someone needs varies from person to person and increases with the intensity and volume of exercise done. See Everyone is Different. What are the best carbs to eat? "Complex" ones from "wholegrain" cereals? Not necessarily.


Simple vs Complex

TV ads for breakfast cereals bang on about the wholegrain goodness of complex carbohydrates releasing energy slowly. The terms "Simple" and "Complex" actually refer purely to the chemical structure of a carbohydrate and have nothing to do with how quickly they turn into blood glucose in the body. The Glycaemic Index (GI) (or Glycemic Index if you're American) relates to how quickly carbohydrates turn into blood glucose in the body. See http://www.mendosa.com/gilists.htm for a list of 750 foods and their GI & GL (GL = Glycaemic Load = GI/100 x carb content per serving). Here are a few extracts. Note: a GI of 55 is low; a GL of 10 is low.

The last three items in the list are all simple carbohydrates. As you can see, some wholegrain complex carbohydrates turn into blood sugar faster than simple carbs. This is because the wholegrains have been ground into powder which is rapidly digested and absorbed, despite the presence of fibre/fiber.

As fructose has such a low GI, does this mean that we can eat as much of it as we like? No! When we eat fructose, it passes from the small intestine into the portal vein and goes straight to the liver. As liver cells contain an enzyme called fructokinase (which has a high affinity for fructose), all dietary fructose is absorbed by the liver where it tops-up liver glycogen. Liver glycogen is also topped-up by glucose (obtained from the digestion of starchy carbohydrates). Once liver glycogen stores are full, any further fructose is converted into fats, which are stored as ectopic liver fat and also exported as triglycerides. High serum triglycerides are heart-unhealthy. See Cholesterol And Coronary Heart Disease.

Why is GI important? When we eat carbohydrates, they raise blood glucose levels. Pancreatic beta cells secrete a hormone called insulin, which allows more glucose to pass into cells (by moving Glu-T4 transporters inside the cells). When more glucose enters cells, glucose levels in the blood fall. It's a negative feedback loop. For millions of years, we lived on a diet of natural, unrefined carbohydrates and so the secretion of insulin never had to change blood glucose levels very rapidly.

When unnatural, refined, high-GI carbs are eaten, blood glucose levels rise much faster. This results in over-secretion of insulin (hyperinsulinaemia). This shuttles too much glucose into cells and results in.......low blood glucose, followed by low blood insulin. Rapidly-falling and low blood insulin levels cause feelings of severe hunger and cravings to eat more carbs. It's a vicious circle. Hyperinsulinaemia also has other bad effects on the body. See http://www.mercola.com/2001/jul/14/insulin.htm to learn about Insulin and its Metabolic Effects.

GI has a weakness because adding fats and some proteins to high-GI foods lowers the GI but can increase the insulin response. Saturated fats, monounsaturates and omega-6 polyunsaturates raise the insulin response to carbs.

There is another index called the Insulin Index (II). See http://www.mendosa.com/insulin_index.htm.
The II contains a few surprises. Some proteins (e.g. the whey in milk & yoghurt) produce a large insulin response. Insulinogenic proteins are also glucogenic, so they don't cause low blood glucose.

On the other hand, refrigerating some foods lowers their GI & II by changing the starch in them into resistant starch, even if the food is subsequently re-heated. Rice & potatoes are two such foods.

As the terms "simple" and "complex" are meaningless in terms of carbohydrates' effects in the body, I prefer to use the terms "slow" and "fast". In a nutshell, slow carbs are good and fast carbs are bad. These terms can be applied to proteins, too. Egg is slow and whey is fast. Sticking to mostly slow foods keeps blood glucose and insulin levels stable, which results in better appetite control and better health, too.

It was soaring serum insulin levels that were sending me to sleep after carby meals years ago. Postprandial hyperinsulinaemia results in amino acids from digested foods being shuttled into cells. However, L-tryptophan isn't shuttled into cells, so the level of this amino acid in the blood rises relative to others. As L-tryptophan competes with other amino acids to cross the blood-brain barrier, now that the competition has been removed, more L-tryptophan enters the brain. It's converted into 5-hydroxytryptophan (5-HTP), then serotonin & melatonin. High melatonin levels in the brain cause sleepiness.

So remember, "Right carbs, right amounts, right times."