from the publishers of: Verywell, Real Simple, EatingWell, Shape, Parents, Health and Allrecipes
Of all the health-related things you worry about, blood sugar probably isn’t one of them. But groundbreaking studies are providing evidence that it should be. “Blood sugar is a primary determinant of your health,” says James O’Keefe, M.D., a professor of medicine at the University of Missouri–Kansas City. It affects the strength of your immune system, the quality of your sleep and even the rate at which your body ages. But what’s most surprising is that fit women are especially vulnerable to its dips.
Let’s back up: What is blood sugar exactly? Also known as glucose, it’s your body’s fuel, providing the main source of energy for your muscles, metabolism and brain. After you eat, glucose enters your bloodstream quickly, which causes a bump in your blood sugar level. Your pancreas then revs its production of insulin, a hormone that helps your cells absorb glucose and use it to function.
Blood sugar’s effects are so wide-ranging that scientists are only beginning to fully understand their scope. One study from Leiden University Medical Center in the Netherlands found that people with healthy blood sugar levels look younger than others. According to the study authors, regularly being exposed to high blood sugar may speed up the aging process. “Glucose causes collagen molecules to start cross-linking, making skin stiffer and more leathery,” explains Courtney Peterson, Ph.D., an associate professor at the University of Alabama at Birmingham. If glucose levels remain elevated, the excess sugar can trigger the production of harmful compounds that have been shown to damage cells throughout the body, Peterson adds.
In a study in the journal Neurology, people with healthy blood sugar levels performed better on a word-recall exercise than those with higher levels, and even had more gray matter in areas of the brain associated with memory. “There’s evidence that blood sugar spikes lead to blood sugar lows that limit the amount of glucose your brain receives, resulting in symptoms like brain fog and fatigue,” says James Gangwisch, Ph.D., an assistant professor in the Department of Psychiatry at Columbia University’s College of Physicians and Surgeons. In response, your body may produce higher levels of stress hormones like cortisol and adrenaline, which make it harder for you to sleep at night. That creates a vicious circle: The lack of zzz’s boosts your blood sugar, increases your appetite and prompts your body to produce more cortisol or adrenaline. Over time, these influences can cause damaging inflammation, weaken your immune system and encourage weight gain.
In addition, scientists have discovered that certain habitual factors, including when you eat your meals and how much you exercise, can also make your blood sugar level skyrocket. When that happens, “it’s like flooding an engine,” O’Keefe explains. “The amount of glucose in your system exceeds your body’s capability to deal with it.” His research has found that an elevated blood sugar level triggers a surge in free radicals, dangerous compounds that can cause inflammation throughout the body, damage the lining of blood vessels and cause blood clots. Even more, a steep rise in blood sugar prompts your pancreas to release large amounts of insulin, which sends your blood sugar and energy levels crashing and makes your body store fat, says Louis Aronne, M.D., a professor of metabolic research, the director of the Comprehensive Weight Control Center at Weill Cornell Medicine, and the author of the Change Your Biology Diet.
Ironically, the more you use your muscles, the more sensitive they are to insulin, says Loretta DiPietro, Ph.D., the chairwoman of the Department of Exercise and Nutrition Sciences at George Washington University. That means people who work out may actually experience greater blood sugar lows more frequently than those who don’t work out.
Certain types of foods—especially highly processed ones like white bread, pasta and cookies—can cause a huge spike in blood sugar. Conversely, when you eat meals consisting of healthy whole foods such as produce and lean meat, the rise in your blood sugar and insulin levels is small, steady and long lasting, which is the effect you want. You can also help keep blood sugar levels stable by staying hydrated, skipping artificial sugars and getting regular exercise. Even doing something as simple as going for a walk after lunch will help reduce blood-sugar spikes and improve your overall well-being.