High blood sugar is also known as high blood glucose and hyperglycemia. Glucose is required by the body for energy and blood glucose levels are usually controlled by insulin, a hormone produced by the pancreas. However, when the body isn’t properly using insulin or is unable to make enough insulin, blood glucose levels can increase to dangerous levels (1).
High blood sugar is what occurs in diabetic people. Type 1 diabetics are unable to make insulin, while type 2 diabetics may have insulin resistance (their cells don’t respond properly to the insulin) or they may not be producing enough insulin (1).
What blood sugar levels are unhealthy?
There are different ways to measure blood glucose levels. A glucose test measures the levels of glucose in the blood at the specific time the blood sample was collected. If the sample is taken in a fasting stage (no food for the previous eight hours), healthy levels are < 100 mg/dL, while 100–125 mg/dL indicates prediabetes and ≥ 126 mg/dL indicates diabetes (2).
The hemoglobin (Hb) A1c test is another way to measure blood glucose levels. It provides an average blood glucose level for the preceding 2-3 months. This provides a better understanding of where your blood glucose levels are at over an extended period. HbA1c tests also have the distinct advantage of not requiring fasting. Normal HbA1c values are <5.7%, while 5.7–6.4% indicates prediabetes and ≥ 6.5% is supportive of a diabetes diagnosis (3).
Steps to lower high blood glucose
A combination of diet, exercise, and medication can lower blood glucose levels.
Let us first focus on the recommended dietary changes to help keep blood glucose at a healthy level (4).
- Limit sugar intake. Choose water to drink instead of juice or soda, and snack on a piece of fruit rather than a sweet treat.
- Limit carbohydrate intake. Carbs (e.g., pasta and bread) cause blood sugar to rise more than eating an equivalent amount of proteins or fats.
- Limit alcohol intake.
- Eat plenty of vegetables, fruits, and whole grains. Non-starchy vegetables (e.g., broccoli, carrots, spinach) keep you feeling full for longer, provide lots of nutrients, and have fewer calories and carbs. Fruits are also loaded with vitamins, minerals, and fiber, and can help satisfy that sweet tooth without added sugar. Whole grains are a great source of fiber and lots of other beneficial nutrients.
- Control your food portions, such as following the Plate Method.
Are there any “superfoods” for lowering and controlling blood sugar?
According to the American Diabetes Association, there are several “diabetes superstar foods” (5).
- Kidney, pinto, or black beans are high in fiber and full of important vitamins and minerals.
- Dark green leafy vegetables (e.g., spinach, collards, and kale) are low in calories and carbs, but high in lots of vitamins and minerals.
- Citrus fruits are excellent sources of vitamin C, folate, potassium, and fiber.
- Berries are tasty treats that can not only satisfy a sweet tooth craving, but also provide lots of antioxidants, vitamins, and fiber.
- Tomatoes provide lots of vitamin C, vitamin E, and potassium.
- Fatty fish (e.g., salmon) are an excellent source of healthy omega-3 fatty acids.
- Nuts are another excellent source of healthy fats, as well as magnesium and fiber.
- Whole grains (e.g., whole oats and quinoa) provide lots of fiber as well as vitamins and minerals.
- Milk and yogurt are good sources of calcium as well as vitamin D (in fortified products). Just make sure to choose options that are low in fat and added sugar.
Exercise is also important for controlling blood sugar
Regular physical exercise is essential for maintaining healthy blood sugar levels. When you are active, insulin is able to signal to your cells more efficiently to stimulate glucose uptake from the blood and lower your blood glucose levels (6).
And there is no need to sign up for a marathon (although no harm in that either!). Any exercise is better than nothing. Start small with a walk around the block and build from there. Go out dancing or swimming, even doing some housework can be exercise! The main aim is to consistently get some physical activity (20-25 minutes each day) to help control your blood sugar, weight, and improve your overall health.
An important thing to note is that very high blood sugar (above 240 mg/dL) can actually make physical exercise dangerous. People with values this high should check their urine for ketones before exercising, and consult with their health care professional about other ways to safely lower blood sugar (7).
Medication options for controlling blood glucose
There are different types of medications that are available to lower blood sugar levels. We won’t go into the details here, as this is something that you need to discuss with your health care professional, but they each work in different ways to maintain healthy blood sugar levels. For example, alpha-glucosidase inhibitors block the breakdown of dietary starches and slow the breakdown of some sugars to slow the rise in blood sugar that occurs after a meal, biguanides (e.g., metformin) decrease the amount of glucose produced by the liver, and meglitinides (e.g., Starlix) stimulate the pancreas to release more insulin (8).
1. Hyperglycemia: What Is High Blood Sugar? Endocrine Web. Updated June 2021.
2. Diabetes Tests, Diabetes. CDC. Reviewed August 2021.
3. Understanding A1C. American Diabetes Association.
4. Manage Blood Sugar, Diabetes. CDC. Reviewed April 2021.
5. What superstar foods are good for diabetes? American Diabetes Association.
6. It’s a great time to get moving. Fitness. American Diabetes Association.
7. Get Active. Diabetes. CDC. Reviewed May 2021.
8. Oral Medication. What are my options? American Diabetes Association.