Sweet Danger

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By Mary Carpenter

THE SUGAR WARS are raging again—spurred by the explosive popularity of new weight-loss drugs that began with the diabetes drug Ozempic—with the familiar question: Can eating too much sugar cause diabetes? The short if complicated answer is no. But high levels of circulating glucose can damage nerves and blood vessels, creating risks for everyone that are similar to those of diabetes: cardiovascular disease including heart attack and stroke; diminished eyesight; damage to kidneys; and rarer, life-threatening problems, such as gangrene in feet and legs.

Circulating is the key word— independent of the amount of sugar consumed and linked to the effectiveness of insulin at moving glucose out of the bloodstream and into fat cells for storage and muscle cells to produce energy. Driven by insulin, healthy processing of glucose alleviates risk to vessels and nerves—and can improve with diet, exercise and most any kind of activity.

Type 2 diabetes develops in response to elevated circulating glucose levels, or hyperglycemia— with early detection of high blood sugar leading to a diagnosis of pre-diabetes that suggests higher risk for full-blown disease. Although most often associated with excess weight, too much sugar remaining in anyone’s bloodstream can create glucose levels too high for the body’s insulin to process—or for the fat cells to store—and over time lead to “insulin resistance” that in turn makes processing glucose more difficult.

(In type 1 diabetes, on the other hand, the pancreas stops producing insulin, causing patients to rely on infusions of artificial insulin. Although type 1 diabetes has similar risks to those associated with type 2, controlling glucose levels can be more difficult with type 1 because of challenges coordinating the amount and timing of infusions. And because it usually begins in childhood, type 1 has many more years for high circulating glucose to damage blood vessels and nerves.)

“Type 3 diabetes” is a label applied to Alzheimer’s disease (AD), with evidence that high blood glucose in the non-diabetic range can affect the brain, as suggested by the occurrence of blood vessel damage in retinal disease as an early indicator of AD. According to a recent Boston University School of Medicine review of more than 5,000 participants in the Framingham Heart Study, “people with normal cholesterol and glucose measurements in early through middle adulthood may be less likely to develop Alzheimer’s as older adults.”

Mild elevations of blood sugar over time can increase the production of inflammatory chemicals linked to dementia as well as to myriad other health problems. At the same time, excess circulating glucose decreases the elasticity of blood vessels and “causes them to narrow, impeding blood flow,” according to Medical News Today. “The reduced supply of blood and oxygen increases the risk of high blood pressure…a risk factor for heart disease.”

Age itself increases risk for type 2 diabetes: an aging pancreas pumps insulin less efficiently; and aging cells become more resistant to insulin. And notably, excess weight and obesity can increase insulin resistance when fat cells become too full to absorb more glucose. According to Honor Health, “More than 90% of people with type 2 diabetes are overweight [or obese].”

“It’s like trying to put furniture in a room that’s already packed” is how Cleveland Clinic endocrinologist Jay Waddadar explains the overloading of fat cells. As a result, “your pancreas produces more insulin to accomplish the job of moving glucose out of the blood…trying to push against the resistance created by the fat…your pancreas becomes overworked…wears out…starts producing less insulin [and] diabetes develops.”

“Reducing excess body weight can help people manage diabetes—and even reverse pre-diabetes and insulin resistance,” according to Medical News Today. And the new weight-loss drugs — developed in the wake of the success of Ozempic—lower blood sugar levels by boosting insulin secretion. In addition, these drugs suppress appetite, making it easier for people to cut back on specific foods, such as sugary treats.

Exercise can also help lower blood glucose because muscle cells have more insulin receptors to process glucose for energy than fat cells, according to Honor Health. Genetics plays a role in the development of type 2 diabetes, as does a diet with insufficient fiber, too much fat and too many simple carbohydrates, notably sugar.

While experts across the board advise consuming less sugary foods and drinks, much remains tentative and unclear about sugar risks and recommendations. Confusion about sugar most often concerns differences between “natural” and “added” sugars. The FDA recommendation that sugar should comprise no more than 10% of one’s daily diet refers not just to table sugar (sucrose) but also to coconut sugar, agave and corn syrup—along with fruit juice, honey and other naturally sugary foods. On the other hand, many dieticians, as well as the World Health Organization, suggest restrictions that exclude sugars in fresh fruits, vegetables and milk.

For me, such uncertainties about limiting sugars provide some leeway to continue allowing myself sugary treats, mainly sugar in afternoon tea and ice cream at night. But all the while I hear and read about how reducing or giving up sugar altogether can improve health—easing immediate problems such as arthritis, and preventing dreaded future conditions such as AD—I am collecting tips on sugar detox with the hope that I might try doing that, some day.

—Mary Carpenter regularly reports on topical subjects in health and medicine.