Thursday, September 13, 2007

Carbohydrates Are Not The Villain

In my ongoing exploration of low-carb diets ...

I'm not convinced that "carbohydrates" are a problem - not for heart disease, not for diabetes, not for weight disorders.1 "Carbohydrates" is an all-encompassing word, as are "fat" and "protein". There are many different structures of carbohydrates, as there are fats and proteins, and every single structural difference equates to a difference in function. To tag "carbohydrates" a villain is not to appreciate its fundamental role in our existence.

Having to deal with my own IGT (Impaired Glucose Tolerance) has given me incentive to study further how foods affect metabolism. And I want to say right off ... what goes on in people's bodies when they eat is downright breathtaking.

I'm leaning towards the idea that eating a low-carbohydrate diet is merely treating a symptom of a more systemic metabolic disorder. One symptom of this metabolic disorder is high levels of blood glucose (and its attendant levels of hormones which result in weight disorders, dyslipidemia, etc.). A simplistic solution would be to limit consumption of carbohydrates, since they are a primary source of glucose in our blood, especially after we eat.

One drawback to this simple solution is that we eat fewer carbohydrate-rich foods. These foods offer nutritional benefits. Here are a few:
  • They provide nutrients in amounts that fat- and protein-rich foods struggle to provide.
  • They are foods we evolved to consume.
  • They are (in addition to fat- and protein-rich foods) pleasurable to eat. Pleasure, with its positive effects on the psyche and immune system, is as important as utility.
I find myself asking, why do we secrete amylase - an enzyme in our saliva that breaks down starches to sugars? (And why, as reported in the journal Nature Genetics this week, do humans have more copies of the gene AMY1 which codes for amylase than other primates? 2, 3 )

Why do we have taste buds for sweet foods - foods, such as sugar-laden ripe fruits, that are often carbohydrate-rich?

Why are our intestines lined with microorganisms that convert carbohydrates we eat into chemicals from which we derive benefit?

Low-carb Diets Are Not A Panacea

Another question I've been asking ... Why is glucose getting stuck in the blood? Why isn't it leaving the bloodstream and entering the cells where it can be used? It's natural for glucose to enter the bloodstream after a meal. It's unnatural for it to linger there.

If there was any one group of compounds (and I don't believe there is) that are responsible for weight disorders, heart disease, diabetes, etc., it would not be carbohydrates. It would be the chemical messengers (such as insulin, epinephrine, thyroxin, serotonin, growth hormone, adiponectin, leptin, etc.) that regulate glucose, fat, and protein metabolism.

Those chemical messengers are affected by a host of stimuli. Eating behaviors describe one group of stimuli. But eating behaviors are accompanied by sleeping behaviors, responses to stressful situations, physical activity, rest, environmental pressures, etc.

Regarding eating behaviors, I've incorporated methods to control my blood glucose (and its attendant levels of hormones which can result in weight disorders, dyslipidemia, etc.) that allow me to eat carbohydrate-rich foods without postprandial (after-eating) BG spikes. None of these methods are a secret, and if you've met with a nutritionist or Certified Diabetes Educator, or read this blog, you know them. If I can eek a few more minutes, I'll consolidate them.
1 This is not an endorsement of white flour, white sugar, high fructose corn syrup-containing products, and other highly refined foods.
2 Diet And The Evolution Of Human Amylase Gene Copy Number Variation
3 BBC summary of above study: Starch "Fuel Of Human Evolution"

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