Give Me Some Sugar, Baby

…no, not that kind

I got invited to a fancy dinner party recently. As the hostess poured Chardonnay into my glass, she introduced me to the masked, wisp of a middle-aged woman standing next to me… who, I quickly learned, had an all-consuming interest in personal nutrition.

“It’s nice to meet you,” I said, extending my arm. In response, she pointed her elbow at me. I guess it’s still too soon after Covid to shake hands. So, I sorta’ awkwardly bumped her elbow with mine.

Before I could start my polite cocktail party banter, she pulled down her mask and started to tell me about her totally vegan, completely sugar-free lifestyle.

“I don’t eat any animals or sugar,” she said, “And neither does my husband.” (I learned later that he wasn’t totally onboard.)

“That’s why we’re so healthy,” she continued. “Everyone else we know is taking all sorts of medications. We’re not… and our blood pressure is normal!”

“That’s great!” I said with a smile.

She chattered on enthusiastically, explaining in great detail what food she bought, how she prepared it, and all of the healthy substitutes she’d concocted for those dishes that most people find irresistible. As she talked, I continued to smile and nod, but her voice faded in my mind as I began to daydream about that sugar thing. No sugar at all, I thought… wow.

Some of my other friends say that they don’t eat any sugar either. I guess it’s a thing now for my demographic. Then I wondered, is that even possible?

I guess when people say they’re avoiding “sugar,” they mean sucrose. You know, table sugar, the sugar that’s produced naturally by plants. Sucrose is a disaccharide (double sugar). It’s actually two monosaccharide (single sugar) molecules — a glucose, and a fructose — held together by their electrons. When you eat sucrose, the enzyme sucrase cleaves it into its two component molecules. Then, enzymes in your liver convert most of the fructose into glucose. (The rest is converted into triglycerides and lactate.) So, I guess it all boils down to glucose… that’s the culprit that my friends are trying to avoid.

The only other sugar (or dietary monosaccharide) that we eat regularly is galactose. When galactose binds to a glucose molecule, it forms the disaccharide lactose which is found primarily in milk and dairy products. If you’re not lactose intolerant, the enzyme lactase will split lactose back into its two original monosaccharides, galactose and glucose. However, your cells can’t use galactose directly, so it gets converted into glucose, too.

Wow, I thought, that’s a lot of glucose.

My new friend was still chatting. I was still nodding, smiling, and sipping wine. By this time, she had moved on to descriptions of her plant-based casseroles. I really tried to pay attention, but her voice faded into the background again, and I started to think about what would happen if she really was glucose free.

Our cells use just three kinds of macromolecules to get the energy we need to stay alive: lipids (fats), proteins, and carbohydrates. Lipids get broken down into fatty acids, proteins into amino acids, and carbohydrates get chopped up into sugar molecules… because carbohydrates are simply long strings of sugars, mostly glucose, and a small amount of fructose and galactose (which get converted into glucose). So, glucose is the final form in which carbohydrates get into our cells… I guess that means that if you’re avoiding sugar but eating carbohydrates, you’re not actually avoiding sugar. You’re just swallowing it in a different form. (I didn’t mention this to my new friend.)

So, could any of us just use fatty acids (from lipids) and amino acids (from proteins) for energy and stay absolutely sugar-free? Well, not really. Virtually all of our cells are designed to absorb and process glucose. Some cells — cardiac, muscle, fat, liver, and some kidney cells — can use fatty acids and amino acids under certain physiological conditions, for instance, if glucose levels are very low, but most cells rely primarily, If not exclusively on glucose.

Oh, I almost forgot. Your brain relies on glucose, too… unless you’re very hypoglycemic, starving, or in ketosis. When that happens, your brain will metabolize circulating ketones (produced by your liver) for energy, but it prefers glucose. In fact, your brain accounts for over half of your body’s glucose utilization, or 20% of your overall energy consumption.

And, there’s more. Metabolizing glucose produces compounds necessary for making new cells. So, it’s essential for cells that grow and divide quickly like white blood cells, stem cells, and epithelial cells (they make up one of the four basic tissue types in your body).

As a matter of fact, keeping your circulating glucose levels steady is so important that when you’re low, some cells (like fat cells and muscle cells) switch to burning fatty acids for fuel in order to maintain enough circulating glucose to meet the demands of cells that rely primarily, or exclusively on sugar, like your brain.

When you run low on circulating sugar, your liver will release glucose that it’s stored in the form of long molecular chains called glycogen. But, your liver can only do so much. Its reserves get depleted within 12-18 hours of fasting. So, if you continue to be hypoglycemic, your liver (and, to a lesser degree, some kidney cells) will start to synthesize new glucose molecules from amino acids. However, this process depletes your protein stores which can become life-threatening. So, it’s not a viable long-term solution.

I guess that no matter how hard she tries, my new friend can’t get away from sugar… and stay alive, that is.

My train of thought broke when I heard the word “dessert.” My friend’s soliloquy had transitioned from main courses to homemade sugar-free pastries.

“That’s interesting,” I said. “How did you say you sweeten your desserts?”

“I use figs,” she replied. “I never use refined sugar. Just figs.” She began explaining the rather laborious procedure she uses to create her sweet fig paste. Her voice faded again, and I drifted back into thought.

Figs produce sugar naturally. In fact, a partially dehydrated fig is about 64% sugar, and it’s the very same molecules you’d scoop out of your sugar bowl. Why would my friend waste so much time doing what the Domino® sugar company’s already done for her?

Maybe it’s the “refining” issue, I thought. No, that can’t be it. The refining process doesn’t change the sugar molecules. When sugar is refined from beets or cane, the plants are simply sliced up, soaked in water (sucrose and fructose dissolve in the water), the mixture is centrifuged to separate the plant material from the sugar water, the sugar is crystallized (just like when we made rock candy as kids), and the rest of the water is evaporated off. What’s left is dry sugar crystals. That’s basically what my friend was doing in her kitchen, except she wasn’t separating all the fig stuff from the sugar water.

“It’s the same molecule...,” I mumbled.

“What?” she asked.

“Oh, nothing,” I said, pleasantly. “I was just thinking out loud.”

Her narrative ended. She smiled, pulled up her mask, said “Nice to meet you,” and sauntered off to join another conversation.

“Nice to meet you, too,” I replied, as she turned away.

Wow, I thought, she eats a lot of fig sugar. Then I remembered that figs get pollinated by tiny fig wasps. It’s an interesting process. First, a fertile female crawls into an immature fig through that small opening in the tip, lays her eggs, and then dies inside the fig. During the process, she deposits pollen — acquired from the fig in which she originally hatched —  onto the tiny flowers inside her final resting place.

Her male offspring hatch first and develop inside the fig. Once mature, they locate their sisters’ eggs and mate with them before they’ve hatched. After mating, the males start to burrow their way out of the fig. Those that escape die soon after. Those that don’t make it out die inside the fig. When the inseminated females hatch, they crawl out of the fig through the tunnels excavated by the males. On their way, they pick up some pollen from the tiny, internal fig flowers. Once out, they'll fly off and begin the cycle again.

Interestingly, the fig produces an enzyme called ficain that partially dissolves some of the leftover wasp remains, including the original pollinating female. But, there’s still wasp stuff in there. So, I guess — strictly speaking — my new friend really isn’t a vegan. Of course, I’m not going to tell her.

I glanced down at my glass. I hate Chardonnay. I asked the hostess for bourbon.

The party got better after that.

***

A 1970 recording of “Give Me Some Sugar Baby” by Duke Turner, here, 3:19 mins.