When my vegetarian friends get together for lunch after our Tai Chi class, we eat really healthy low carb foods: tofu, bean sprouts, bok choy, mushrooms. and lots of salad.
Yet, blood glucose readings for hubby, after two hours always show high numbers, and we are at a total loss to understand why .
However, after reading Diabetic Solution, by Dr. Richard Bernstein this puzzle has been solved.
"Many years ago a patient asked me why her blood sugar went from 90 mg/dl up to 300 mg/dl every afternoon after she went swimming. I asked what she ate before the swim. "Nothing, just a freebie", she replied. As it turned out, the freebie" was lettuce. When I asked her just how much lettuce she was eating before her swims, she replied "A head."
A head of lettuce contains about 10 grams of carbohydrate, which can raise a type 1 adults blood sugar about 50 mg/dl at most. So what accounts for the other 160 mg/dl rise in her blood sugar?
The explanation lies in what I call the Chinese restaurant effect. Often Chinese restaurant meals contain large amounts of protein or slow-acting, low carbohydrate foods, such as bean sprouts, bok choy, mushrooms, bamboo shoots, and water chestnuts, that can make you feel full.
How can these low-carbohydrate foods affect blood sugar so dramatically?
The upper part of the small intestine contains cells that release hormones into the bloodstream whenever they are stretched as after a large meal. These hormones signal the pancreas to produce some insulin in order to prevent the blood sugar rise that might otherwise follow the digestion of a meal. Large meals will cause greater stretching of the intestinal cells, which in turn will secrete proportionately larger amounts of these hormones.
Since a very small amount of insulin released by the pancreas can cause a large drop in blood sugar, the pancreas simultaneously produces the less potent hormone glucagon to offset the potential excess effect of the insulin.
If you are diabetic and deficient in producing insulin, you might not be able to release insulin, but you will release glucagon, which will cause gluconeogeneses and glycogenolysis and thereby raise your blood sugar. Thus, if you eat enough to feel stuffed, your blood sugar can go up by a large amount, even if you eat something indigestible, such as sawdust. Even a small amount of an indigestible substance will cause a blood sugar increase in type 1 diabetics if not covered by an insulin injection.
Complicating matters further, pancreatic beta cells also make a hormone called amylin. Amylin inhibits the effectiveness of glucagonand works on the brain to cause satiety. It also slows stomach-emptying to discourage overeating. With few or no betta cells. Diabetics don't make enough amylin, and consequently they tend to remain hungry after eating and show an exaggerated Chinese restaurant effect."