Retrospective #455: Are red grapes healthier than green grapes?

I’m not kidding. A friend, who is a recently diagnosed, insulin-dependent type 2 diabetic, asserted that he ate red grapes in preference to green grapes because they are healthier. When I strongly disagreed, he said, “Red grapes have resveratrol in the skins, and resveratrol has health benefits.” I don’t attribute this point of view to ignorance. He’s a bright, generally well-informed guy. I attribute it to a combo of denial and rationalization.

My friend is on insulin injections because he couldn’t tolerate Metformin or Januvia (a DPP-4) and a SGLT2 was counter-indicated. His fasting blood glucose (FBG) was so high (225mg/dl) his doctor knew she had to get his blood sugar under control as soon as possible, and she thought that injecting insulin was the only, if not the best, way to do it. With fasting blood sugars that high, I couldn’t disagree, but only because they were so out of control.

(In my own case, in 2002, after having been a diagnosed T2 for 16 years, and maxed out on a sulfonylurea (SU) and metformin and starting a 3^rd oral (a TZD), my FBGs were also out of control but just in the 150s. My doctor believed (at the time – it seems like ancient history) that T2D was caused by obesity (I weighed 375 pounds), so he suggested I try eating VERY Low Carb, or VLC (20g of carbs a day), to lose weight. He had just read about it in a New York Times Sunday Magazine cover story by Gary Taubes, “What If It's All Been a Big Fat Lie,”

So, I began the Very Low Carb (VLC) program “cold turkey” and within the first week I had several hypos. By phone my doctor ordered me to stop taking the TZD and then the very next day (after another hypo) to cut the SU and the metformin in half. Later that week, after another hypo, and he told me to cut them in half again. I later discontinued the SU altogether.)

So, as a newly diagnosed T2, my friend surely had a steep curve to learn about carbohydrates and his glucose metabolism. Type 2 diabetes is a dietary disease. His body’s ability to process glucose, the compound into which virtually all carbs break down, is impaired due to a condition called Insulin Resistance, developed over many years, decades even. As a result, his body doesn’t “take up” glucose easily.  He is thus Carbohydrate Intolerant – intolerant of all carbs, red and green grapes alike, and all other fruit and all starches too. They are all carbohydrates.

Fruits are just sugar and water. Your body doesn’t give a wit that they contain “natural sugars.” Your body processes “natural sugars” and “added sugars” the same way. Fruit sugars are mostly sucrose, a disaccharide made up of one molecule of glucose and one molecule of fructose, plus some free fructose and free glucose (monosaccharides). The fact that whole fruits have fiber or other micronutrients is just as irrelevant as the color and content of the skin of the grapes. They are inconsequential to you, compared to their glucose content.

To think otherwise is to deny the consequences to your health of ignoring the truth. You are Carbohydrate Intolerant. Red grapes have the same glucose content as green grapes, period. I’m sorry, but that’s the truth.

According to the USDA database, “grapes (red or green), European type, such as Thompson seedless, raw,” are 80% water and 18.1% carbohydrate, of which 15.48% are simple sugars. The remaining carbs are oligosaccharides (long chain “sugars” . There are also trace amounts of protein, fiber and ash. Each grape contains 3.5kcal, about 1g of carbs.

Now wine, that’s a different matter. LOL. Most carb counters say that a dry white table wine has fewer carbs than a dry red table wine (3 vs. 4). It depends, of course, on the specific wine, but according to the same USDA database, a typical 5 oz glass of Chardonnay (white wine) is said to contain 3.18g of carbs, and a 5oz glass of Cabernet Sauvignon (red wine) is said to have 3.82g of carbs (thus 3 vs. 4). But the total calories in each are the same (123 vs. 122kcal). The difference is that the white wine tested had a slightly higher alcohol (fermented sugar) content (15.7g vs. 15.4g).

And while pure ethyl alcohol (spirits) has more calories per gram than carbs (7 vs. 4), it does not raise blood sugar, as glucose does. A glass of wine, however, is a combination of alcohol and carbs and, in moderation, will raise your blood sugar somewhat. So, bottoms up, tipplers, but don’t eat grapes, red or green. You’re grape intolerant!