Healthy foods and exercise keep glucose levels steady

DEAR DOCTOR » I’m trying to lower my blood glucose levels, but I have a sweet tooth. What raises blood glucose more — the sugar from fruit, or foods with refined sugar? Is a healthy diet the only way to keep blood glucose steady? DEAR READER » Managing your levels of blood glucose, which is the measurement of how much of a certain sugar is dissolved in the blood, is important to good health. Glucose, which comes from the foods we eat, is a major source of energy to cells throughout the body. However, blood glucose levels that remain consistently high can lead to a variety of health problems, including prediabetes, a condition that frequently leads to Type 2 diabetes.

Blood glucose starts its journey in the form of carbohydrates, which are the main nutrients in foods like bread, pasta, rice, fruits, vegetables, legumes, grains and some dairy products. When we eat these foods, the digestive process frees the sugars within the food and makes them easily available to the body.

Glucose, the smallest sugar molecule, moves from your small intestine into your blood. There, it is distributed throughout the body to provide energy to the cells. To get from the blood into the cells, glucose needs the help of insulin, a hormone produced by the pancreas, a long, flattened gland that sits behind the stomach.

As your question notes, not all foods release glucose in the same amounts or at the same rate. Foods like sugary breakfast cereals, pastries and candy are basically glucose bombs. But naturally sweet foods like apples, strawberries or yams, which contain carbohydrates but are also high in fiber, release glucose more slowly.

However, if you turn that apple into juice, you’ve just accelerated the rate at which your blood glucose will rise. But if the candy bar you’re eating contains a handful of nuts, the fiber they contain will slow the rate of glucose absorption.

It’s a little confusing, we know. Fortunately, a handy tool known as the “glycemic index” has taken much of the guesswork out of maintaining healthy blood glucose levels. The glycemic index, or GI, ranks each food relative to how it will affect your blood glucose.

Foods high on the GI release their sugars more rapidly, which can cause blood sugar to spike. Foods lower on the scale release their energy more gradually, and blood glucose levels remain steady.

Interestingly, research has shown that exercise affects blood glucose levels. When you increase your amount of activity, your body works harder and your muscles’ demand for glucose increases. The insulin your body produces becomes more effective as well. The key here, as with diet, is moderation.

A brisk walk, a dance class, an aerobic bout of house cleaning or yard work — any of these can add balance to the blood glucose equation. The good news is that even a little bit of regular exercise, say, 30 minutes three times a week, will also help your heart, lungs and even your mood. Eve Glazier, M.D., MBA, is an internist and assistant professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and primary care physician at UCLA Health. Send your questions to askthedoctors@ mednet.ucla.edu.