Do Sweets Make Your Heart Race?

Simple sugars, such as those found in cookies, candies, cakes and soft drinks, have been implicated in the growing incidence of obesity and diabetes in the United States. At the time of publication, approximately 16 percent of the average American's daily calorie load comes from added sugars -- the sugars added by manufacturers to improve a food's marketability or by consumers to improve its flavor. In addition to their long-term health effects, sugars can cause more immediate problems, such as a racing heart.

According to Dr. Elson Haas, author of "Staying Healthy with Nutrition – The Complete Guide to Diet and Nutritional Medicine," dietary carbohydrates are broken down to simple sugars or monosaccharides – glucose, galactose and fructose – before they are absorbed from your gastrointestinal tract. Monosaccharides from sweet foods, which already contain a high percentage of simple sugars, are absorbed into your bloodstream more quickly than those from foods that contain complex carbohydrates, such as whole grains and vegetables.

Whenever you eat sweets, the sugar entering your circulation prompts a rapid and dramatic increase in your blood glucose level. This sudden glucose surge stimulates the release of large amounts of pancreatic insulin, a hormone that enhances the uptake of glucose by cells in your liver, muscles and fat tissue. As insulin drives your blood glucose downward, your pancreas and adrenal glands secrete "counter-regulatory" hormones, such as glucagon and epinephrine, to prevent your glucose level from falling too far. If your glucose falls rapidly or excessively – a condition called "reactive hypoglycemia" – you can develop unpleasant symptoms, such as a racing heart.

Hormonal swings are not the only consequence of widely fluctuating blood glucose levels. In fact, by stimulating your autonomic nervous system, the hormones themselves can trigger physiologic responses that indicate your blood glucose levels are unstable. Epinephrine and norepinephrine – hormones secreted by your adrenals in response to falling glucose concentrations – cause rapid heart rate, sweating, shakiness, anxiety and nausea. Diabetics who take their insulin and forget to eat will experience these same symptoms as their blood sugars fall too low.

Reactive hypoglycemia occurs in individuals who experience rapid, significant decreases in their blood glucose following a meal. This problem is much more likely to occur after you eat sweets, which prompts larger insulin "spikes" and a more dramatic outpouring of counter-regulatory hormones. Reactive hypoglycemia can be avoided by limiting your intake of sweets or by mixing sweets with other foods to slow their absorption into your bloodstream. If your symptoms persist despite these simple lifestyle changes, see your doctor.