Carbs:To Digest or Not Digest, that is the question?

What is so difficult in understanding the concept that rapidly digested carbs (>50% of our calories) spike glucose and insulin levels and drive fat storage, obesity and diabetes.

How does government reformulation policy that focuses on salt, sugar and fat come to be the Holy Grail for nutritional health transformation?  Don’t they know that salt is only bad if you have damaged kidneys in the first place, sugar bad but only part of the problem and fat is more a solution than a problem. Such lack of focus is irresponsible if not negligent.  In response, you can’t blame the food industry, making huge investments, even if they remove all three offending ingredients will most likely come up with products equally bad if not worse, as is the case with most gluten free baked goods, predominantly high glycemic starches made from processed corn, potato and rice, devoid of nutrients and fiber that are rapidly digested and spike postprandial glucose and insulin levels.

balance carb v fiber

Hyperinsulinemia from progressively rising refined carbohydrate consumption with decreasing fibre intake can best explain the diabetes epidemic and there are plausible mechanisms to explain why this should be so. I believe we can demonstrate that dietary measures that prevent (and cure) diabetes really ought to be adopted universally for healthy longevity and the best way to avoid putting on weight, diabetes, heart attacks, cancer and all sorts of other age related diseases.

The Trigger and the Antidote

Type 2 diabetes is defined by raised fasting glucose (sugar) levels. It develops over a long time and is preceded by a period of chronically high insulin levels, called ‘insulin resistance’ or ‘pre-diabetes’. Over time this “hyperinsulinemia” itself leads to the metabolic disorders that allow blood glucose to creep out of control and become clinically identifiable diabetes.  Here we summarize the mechanisms whereby high glycemic carbs over time lead to diabetes whereas dietary fiber is a powerful antidote to insulin resistance and diabetes.

diabetes the trigger

Chronically high carbohydrate consumption produces high levels of insulin which itself causes insulin resistance by depleting the levels of its own receptors.  The free glucose pool is only around 10 grams and just 50 grams of high glycemic carbohydrates increases insulin levels 10 fold, however, average daily consumption of carbs is 500 grams (USFDA). Most people are constantly exposed to postprandial hyperglycemia and hyperinsulinemia from ‘government recommended’ high carb diets.

24 hr insulin obese

Hyperinsulinemia (pre-diabetes) results from repetitive postprandial glucose and insulin spikes that lead to progressive weight gain and insulin resistance.

 

 

The Antidote:

Feed the neglected microbiome digestion resistant carbs (fiber) to increase production of Short Chain Fatty Acids that create anti-inflammatory signaling throughout the body and Glucagon Like Peptide 1 mediated organ protection.

Glucagon Like Peptide (GLP1) is a hormone produced by specialized intestinal lining cells of the hind gut.  These cells have receptors for short chain fatty acids (SCFA) which trigger the release of GLP1. SCFA are produced by bacterial fermentation of foods that escape digestion in the foregut.  GLP1 has powerful beneficial effects on glucose metabolism and many other aspects of health.

glp antidote

Many of the remedies for diabetes work by increasing GLP1. Gastric bypass surgery has a very high cure rate of diabetes where GLP1 levels are dramatically increased as a result of foods bypassing digestion to undergo fermentation in the hind gut. Similarly, the carbohydrate digestion blocking drug, Acarbose, as well as dietary fibers, oppose diabetes through increased GLP1 production.  Drug companies are developing GLP1 mimicking drugs, Exenatide and Liraglutide have been approved for treatment of diabetes and obesity as they are effective in curbing appetite.

Short Chain Fatty Acids (SCFA)

SCFA are the all-important products of gut bacteria fermentation of plant wall material (biomass), what we call fibre. Food labelling regulations have assigned dietary fibre an energy content of 2 kcals/gram and grazing animals obtain all of their energy from SCFA, SCFA’s Caproic Acid and Butyric Acid were named due to their high concentrations in goat and cow’s milk respectively. Early human ancestors, gorillas and chimpanzees would obtain 50-80% of their energy from SCFA and Paleolithic man would have probably consumed 10 times more fibre than we are accustomed to in recent times. Animals have co-evolved with symbiotic gut microbes over millennia and their mutual interdependency may extend much further than what we know so far about the beneficial effects of SCFA. SCFA receptors are present not only on intestinal cells but numerous other cell types and have important signaling functions throughout the body, most importantly on immune cells where they have powerful anti-inflammatory effects, for instance SCFA signaling transforms lymphocytes into Treg cells that secrete anti-inflammatory cytokines and control macrophage activation.

Summary

Multiple outcome studies have linked high glycemic carbohydrate consumption to diabetes, cardiovascular disease and all-cause mortality while high fiber consumption is associated with protection from all these things.  We now know that chronic carbohydrate consumption with high postprandial glucose spikes leads to hyperinsulinemia, diabetes and obesity.  High fiber consumption between 50-150 grams a day elevates short chain fatty acid levels, stimulates protective GLP1 hormone production, normalizes glucose metabolism, pancreatic cell survival, and anti-inflammatory effects throughout the body.  This can be achieved with a change in dietary philosophy and implementation of a low carb, high fiber diet.

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