I love carbs, and I can’t say they haven’t served me well over the years. But are they shortening my life without my knowing it? I feel great, but could I feel greater with a different diet? Discussions of the ketogenic diet or any low-carbohydrate diet are compelling in theory. Avoiding carbohydrates would seem to increase your insulin sensitivity and fat-burning ability, provide greater satiety and avoid some of the carb-craving that goes along with a high-carbohydrate diet. But the vast majority of information and discussion around this topic focuses on diabetes or obesity. Both are problems that deserve our attention, to be sure. But I want to know whether regulating my carbohydrate intake can affect my energy levels, longevity, performance or risk for future disease.
I’m sold on the toxic effects of sugar, and there is little disagreement that other highly refined carbohydrates (hello Wonder Bread!) are not good for us. But what about whole grains and potatoes? What about fruit? Even a reduction in banana consumption would be a major dietary overhaul for me and my family!
I recently finished reading David Perlmutter’s book, Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar--Your Brain's Silent Killers. He makes the case that, in addition to diseases that we typically associate with carbohydrates, such as diabetes and obesity, carbs can increase your risk for heart disease, Alzheimer’s and other neurodegenerative diseases, mood disorders, attention-deficit hyperactivity disorder and even headaches. His prescription is a gluten-free diet that incorporates less than 60 grams of carbohydrate per day. My grandparents had Alzheimer’s, so ok, Dr. P, you’ve got my attention!
The first step is of course to measure just how much carbohydrate I am regularly consuming. I resorted to counting macronutrients, and kept it up for seven days, which was about as long as I could stand to do so. The result: I averaged 344 grams of carbohydrate per day (ranging from 287 to 431 grams), with carbs supplying, on average, 47% of my daily calories. This is a far cry from Dr. Perlmutter’s diet or anything approaching ketogenic or remotely considered ‘low carb.’ Truly, my average carbohydrate consumption is probably higher, as during the macro-counting week I was self-consciously avoiding the crushing of extra slices of bread, pizza or bowls of pasta.
But isn’t that ok for an endurance athlete? To get down to the brass tacks of whether gluten specifically and carbohydrates in general might be harmful to me, I asked myself, ‘what is the key event that I’m trying to avoid?’ The answer is insulin resistance, the precursor to the downstream effects whose end result is the aforementioned chronic diseases. Insulin metabolism is complex, and I won’t get into it here. It’s the hormone that causes sugar to move from the blood into cells. If our cells become resistant to our insulin, the levels of sugar in the blood rise and cause all sorts of damage to the organs they’re passing through.
My screening labs indicate that my body has no problem maintaining a normal blood sugar, on average. I have two questions though: (1) are my carbo-bombing ways causing large swings in blood sugar? (2) Is my pancreas working overtime to pump out insulin to keep my blood sugar in check? If the latter is true, I wouldn’t know any damage had been done until I became resistant to insulin.
To answer the first question, I got hold of a continuous glucose monitoring system (Dexcom G6). These are the approximately thumb-sized devices that you see stuck on to people’s arms. I naively supposed that the sticker was all there was to it. The adhesive is impressive (you can shower and swim with it). But it came as a rude surprise to me when, as I pressed the deploy button on the applicator, it sent a needle jabbing into my belly flesh where I had affixed the sticker. This gave me a renewed respect for those that have to monitor their blood glucose every day of their lives. As I began to peruse the data, the first thing I noticed was that the numbers were too high. Not in the diabetic range, but certainly higher than I would expect – in the pre-diabetic range. Cause for alarm? Maybe. It can take a day or so for the continuous glucose monitor to get used to your body. So I waited. No change. I decided to do a finger stick to compare. My finger stick was in the normal range, and came out more than twenty points below the fancy CGM! I put my faith in the finger stick value. After all, my hemoglobin A1C (a measure of blood glucose averages over 3 months) was normal last summer.
Disappointed with the CGM technology but relieved that I don’t have diabetes, I decided to move on to question number two – am I taxing my body by asking it to process all these carbohydrates? To answer this question, I want to know how much insulin is circulating in my blood. Time to head to the lab for a blood draw!
I’ll explore this subject some more in future posts. Until then, you are on notice, Mr. Carbohydrate – I’m watching you!