Another big difference between prehistoric times and now is that sugar back then came solely from complex natural sources that had other nutritional qualities, such as fruit, honey, bark, and leaves. And because naturally sweet food is seasonal, ripening with the sun in the summer or growing almost exclusively in warm climates, it was relatively rare in past times.
The evolution of sugar
Over thousands of years our bodies used naturally sweet food safely and efficiently in this way. But then what happened? As our knowledge evolved, we grew adept at refining pure sugar from its food source. Sugar became its own food group — an empty calorie, devoid of protein, fat, or fiber — but still relatively rare.
As shipping and trade routes grew, sugar became widely available. New refining technology put granulated white sugar on every table, replacing the more nutritionally complex honey, molasses, barley and maple sugars. These had been generally added to food after preparation or to taste during baking and preserving, not pumped into the food itself.
Enter the modern era with its advanced food-processing techniques and competitive food companies, and presto! Refined sugar is everywhere and in everything.
Sugar is a food processor’s fantasy: it’s cheap, it adds bulk and texture, and it makes consumers prefer their product over a less-sweet alternative. So now consumers get sugar everywhere, from simple carbohydrates (so-called white food) to pure granulated sugar, and in other forms like dextrose, fruit juice concentrate, maltodextrin, and high–fructose corn syrup. These empty calories take the place of real nutrients — so while we eat and gain weight, we’re actually starving our cells.
The health effects of sugar
What happens to our metabolism, on all that sugar? Remember, we’re still primitive at a cellular level. What starts out initially as a survival tool quickly becomes a crutch if sugar is easy to procure. A sugar craving (which is really a craving for an energy and serotonin surge) becomes a habit.
We unwittingly reprogram our biochemistry to perpetuate these cravings. What’s more, this process is exacerbated by stress — because that’s when your body needs immediate energy and serotonin. We often put our bodies through the binge–crash cycle several times a day. Your fatigue tells you to have that extra cup of coffee or high–carb snack at mid-morning and again in the afternoon.
When you look at the huge increase in sugar in our diets this past century — particularly in processed foods — you see that it marches in step with the epidemic increase in metabolic diseases. According to the US Department of Agriculture, the average American is supplied with 140 pounds of caloric sweeteners per year. That’s 43 teaspoons for every man, woman and child every day! The USDA recommends an average of 10 teaspoons a day for a healthy adult (still too much for most women, in my book). The biggest sources are the corn sugar and corn syrup found in beverages like juice drinks and soda.
If we really listened to our bodies, we probably wouldn’t consume so much sugar. Our love affair with sugar has enjoyed a slow and subtle evolution — with daily nudges from the food industry. But our bodies simply aren’t equipped to handle such large amounts of sugar on a daily basis. Even in the short term, too much sugar can trigger headaches, tooth decay, and indigestion.
Over time, your body loses the ability to make enough sugar-digesting enzymes to meet the demand, and sugar sensitivity develops. Women tend to notice this more during perimenopause, when excess sugar and other simple carbohydrates trigger symptoms of hormonal imbalance.
Excess sugar consumption also upsets the balance of intestinal flora in your digestive tract and can cause symptoms of intestinal distress such as bloating, cramping, and gas (for more on this, see our Digestive Health section). Other symptoms of sugar sensitivity are headaches, insomnia, aggression, panic attacks, irritability, mood swings, and depression. Too much sugar can deplete levels of serotonin, the neurotransmitter whose deficiency is linked to depression. What’s worse, low levels of serotonin actually trigger more sugar cravings.