It's essential to keep your blood sugar from spiking (rising suddenly), whether you're healthy or you're among the 122 million Americans who have diabetes or prediabetes. But with all the conflicting advice in circulation, it can be hard to figure out what foods and habits you need to avoid.
On the internet you'll find many reports of factors that purportedly increase blood sugar. Here are a few claims that you should know about because they just don't hold up.
Stress from sunburn pain. Stress hormone levels have the side effect of raising blood sugar, and sunburn slightly raises levels of stress hormones. "But when we think about what induces stress, the big ones are heart attack, overwhelming infection such as COVID-19, or third-degree burns -- not sunburn. You should avoid sunburn because it's bad for your skin, not because it's going to raise your stress levels and increase blood sugar," says Dr. David M. Nathan, director of the Diabetes Center and Clinical Research Center at Massachusetts General Hospital and professor of medicine at Harvard Medical School.
Dehydration that increases the concentration of blood sugar. "You'd have to be so dehydrated that you need to be hospitalized in order for dehydration to raise blood sugar," Dr. Nathan explains.
Nasal steroid sprays. Corticosteroid pills can make your blood sugar rise. But there's no need to worry about corticosteroid nasal sprays for allergies, such as fluticasone propionate (Flonase). "There's no effect on blood sugar," Dr. Nathan notes. "The mucous membranes don't absorb enough steroids."
The following claims about blood sugar spikers are speculative and not proven.
Caffeinated coffee. Caffeine increases stress hormone levels a little. "But any effect of caffeine on blood sugar is quite small. The real risk from coffee is putting too much sugar in it, which will raise blood sugar," Dr. Nathan points out.
Artificial sweeteners. The Internet contains claims that the consumption of artificial sweeteners is associated with increased blood sugar. What we do know: "If you drink sugary soda, it will spike your blood sugar like a rocket. In contrast, if you drink a sugarless soda with artificial sweeteners, it doesn't cause your blood sugar to spike," Dr. Nathan says. There is some inconclusive evidence that drinking a lot of sodas with artificial sweeteners can slightly raise your baseline level of blood sugar, which is different from causing spikes in blood sugar.
Gum disease. Gingivitis, the early stage of gum disease, is a complication of diabetes. But whether the presence of gingivitis worsens diabetes is unknown. "It could cause a stress reaction, but that would have only a minor effect on blood sugar," Dr. Nathan notes.
Claims that may hold up
Some internet claims about factors that raise blood sugar do have something to them.
Skipping breakfast. "People who skip breakfast and collapse all of their calories into one or two meals are more likely to gain weight. And consuming large amounts of calories in one sitting is more likely to spike your blood sugar than spreading out your daily calories," Dr. Nathan says. "Weight gain is the single greatest risk factor for developing diabetes."
Losing sleep. Being sleep-deprived for a few nights can affect blood sugar levels slightly, but Dr. Nathan says by itself short-term sleep deprivation won't cause diabetes or make it worse. Chronically poor sleep quality is a diabetes risk factor.
The "dawn phenomenon." A variety of hormones increase during the night and keep the hormone insulin from shepherding blood sugar into cells, which increases blood sugar levels by the time you get up in the morning This happens to all of us, but it's considered a problem only in people with type 1 (autoimmune) diabetes.
We know for sure that a number of factors raise blood sugar over time, increasing diabetes risk. It's these major triggers, such as overeating, a sedentary lifestyle, and obesity, you should keep in mind, notes Dr. Nathan, not factors with little or no risk. "It's easier to switch to a caffeine-free coffee than manage your lifestyle," he says. "But don't focus on minutiae. Focus on the main reasons that so many people are overweight or obese — overeating and not enough activity — that have resulted in overweight, obesity, and the diabetes pandemic."