Sugar and Diabetes

Sugar and Diabetes


Sugar is a simple carbohydrate that provides most of the energy the body needs to function. Dietary sugar comes in many forms and from many sources, including fruits, milk, other foods and some medications. After they are consumed, these sugars are converted into glucose (blood sugar), which a hormone called insulin allows the cells to use for fuel.

With diabetes, excess glucose builds up in the bloodstream. This hyperglycemia occurs because the body either can no longer make or properly use insulin.

Some research has suggested that heavy consumption of sugar may help cause type 2 diabetes. Yet organizations such as the American Diabetes Association state that eating sugar does not cause diabetes. Rather, a diet high in calories promotes obesity, a major risk factor for diabetes.

For many years, people with diabetes were urged to drastically reduce or eliminate sugar from their diet to ensure control of blood glucose levels. However, recent research has revealed that all carbohydrates affect blood glucose levels – a potato and a candy bar with the same amount of carbohydrates can cause a similar rise in glucose.

This finding does not mean sugar has the same effect on health as other foods. Sugary foods contain more carbohydrates per serving size and fewer vitamins and other nutrients than many other foods. They also usually lack fiber, which moderates levels of glucose and cholesterol. Some people also fault sugary foods for having a high glycemic index, but that system of ranking foods according to their effect on glucose is controversial.

People with diabetes can use artificial sweeteners (sugar substitutes) to sweeten their foods without causing hyperglycemia. Some of these sweeteners, however, do contain calories and carbohydrates that can raise glucose when consumed in large amounts.

Physicians often recommend that diabetic patients carry sugar or a sugary food with them and consume a specified amount to treat episodes of hypoglycemia (low blood glucose).

About sugar & diabetes

Sugar provides most of the energy the body needs to function. It is a simple carbohydrate made up of carbon, hydrogen and oxygen.

Dietary sugar comes in many forms and from many sources, including table sugar, candy, cakes, fruits, milk and other foods. Many processed items ranging from tomato sauce to salad dressings to frozen dinners have high amounts of sugar. Some medications, such as cough and cold remedies, also contain sugar.

After they are consumed, these sugars are converted into the simple sugar glucose (blood sugar). Insulin, a hormone, helps move glucose into the cells, where they are turned into energy to fuel the body’s activities.

Some sugar is vital to good health, but many people eat far more than they need. For example, glucose is normally the only source of energy for brain cells. Yet eating a lot of sugar triggers the pancreas to release insulin, which causes the level of glucose in the bloodstream to drop. This hypoglycemia then deprives the brain of fuel and can result in symptoms such as confusion.

In people with diabetes, severe acute episodes of insufficient glucose or excessive  glucose (hyperglycemia) can lead to a diabetic coma, and chronic hyperglycemia can cause complications ranging from heart disease to diabetic neuropathy. People with diabetes must monitor their intake of sugar to ensure they do not consume too many or too few carbohydrates. Patients may be advised by their physician to eat modest amounts of sugary foods at certain times, such as before, during or after exercise. 

Sugar in forms such as glucose tablets, nonfatty candies, nondiet soft drinks or cake icing is generally a part of a physician-recommended treatment plan for episodes of hypoglycemia. A typical protocol is to consume 10 to 15 grams of carbohydrates (e.g., six jellybeans or half a cup of fruit juice), wait 15 to 20 minutes, perform glucose monitoring again and repeat the treatment if necessary. Patients are advised to consult their physician about what source of sugar to carry, when to consume it and how much. Severe hypoglycemia may need to be treated with other methods, such as a glucagon injection or intravenous glucose at a hospital.

Most humans are born with a natural preference for sweet–tasting foods and substances such as sugar. It is believed that sweetness is a sensory cue in humans to obtain the energy needed to fuel metabolic needs and physical activity. Substances taste sweet to people based on how they interact with taste receptors in the mouth and throat. The preference for sugar varies among individuals.

Sugars belong to one of two classes:

  • Monosaccharides. Made up of one sugar molecule. They include:
    • Glucose (principal blood sugar)
    • Fructose (fruit sugar)
    • Galactose (milk sugar)

  • Disaccharides. Made up of two sugar molecules linked together. They include:
    • Sucrose (table sugar). Composed of glucose and fructose.
    • Maltose (appears when starch is broken down). Composed of two glucose molecules.
    • Lactose (sugar made by mammals and found in milk). Composed of galactose and glucose.

Starches are made up of many sugar molecules linked to form a complex carbohydrate. Examples include grains and potatoes. These foods do not taste sweet.

For many years, people with diabetes were encouraged to avoid sugars as much as possible. At the time, experts believed that sugar was the main culprit in elevating blood glucose levels. However, recent research has shown that carbohydrates in general, not just sugar, affect blood glucose levels. Sugary foods remain a potential source of problems for people with diabetes, because foods that are high in sugar content are also high in carbohydrates and calories.

People with diabetes need to consider the following information regarding sugary foods in their diet:

  • Sugary foods tend to have higher carbohydrate counts than starchy foods. Candy, cakes and sodas can thus cause a greater and faster rise in blood glucose than potatoes or pastas. Also, sugary items such as pastries are usually made from refined sugar and white flour and can cause blood glucose levels to surge. In contrast, starchy foods made of slower–acting carbohydrates, such as a baked sweet potato, raise blood glucose levels more gradually.
  • Sugary foods tend to be less nutritious. Though some sugary foods – including fruits and milk – do contain vitamins and minerals, most are loaded with “empty calories” that provide energy but have little or no nutritional value. Even less-refined sugars such as honey, cane juice crystals and maple syrup do not contain meaningful amounts of nutrients.
  • Except for fruit, most sugary foods lack fiber, which helps moderate levels of glucose and cholesterol.
  • Sugary foods can promote tooth decay and gum disease. Dental conditions pose additional challenges to people with diabetes.

Diabetes mellitus is sometimes called sugar diabetes, but organizations such as the American Diabetes Association (ADA) state that, contrary to popular belief, sugar does not cause diabetes. The exact cause of diabetes is unknown. Type 1 diabetes is an autoimmune disorder in which the body mistakenly destroys the insulin-making cells of the pancreas. However, an excess of calories can cause obesity, a major risk factor for prediabetes, type 2 diabetes (by far the most common form of diabetes), gestational diabetes and double diabetes, which is the development of insulin resistance in someone with type 1 diabetes.

Furthermore, some research has suggested that excess consumption of sugar can damage the beta cells of the pancreas, foster insulin resistance and be a risk factor for diabetes. Research has also linked heavy consumption of sugar to other conditions including pancreatic cancer.

The glycemic index is a controversial measure of how fast a food affects blood glucose. Some studies have indicated that spikes in glucose caused by high-GI foods such as sugary pastries can contribute to obesity, diabetes and heart disease. Other studies, however, have questioned the value of this tool.

One belief that science has proven to be untrue is that some natural sweeteners, such as honey, have a nutritional advantage over others, such as table sugar. Honey has more calories and carbohydrates than granulated sugar, although it is also usually used in lower amounts.

The average American consumes almost 20 teaspoons of added sugars a day. Most of the added sugars in the typical American diet come from soft drinks, baked goods, sweetened fruit drinks, candy, breakfast cereals, table sugar (added to coffee, tea etc.) and dairy desserts.

The U.S. government’s latest Dietary Guidelines for Americans recommend choosing and preparing foods with little added sugars or other caloric sweeteners, as these added sugars provide calories with few vitamins and minerals. Though people with diabetes need to limit sugar much more than the average person, the ADA has a Diabetes Food Guide Pyramid that can be used for balancing meals and limiting added sugars. The Diabetes Food Guide Pyramid separates food groups by carbohydrate and protein content. For instance, potatoes, a starchy vegetable, can be found with the grains. The U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) also has guidelines for diabetes. Although these recommendations are close in numbers of servings per day, they are stricter on allowing sugary foods into the diet.

People with diabetes may not need to eliminate all sugary foods from their diets. Many experts suggest that the occasional ice cream sundae or candy bar is fine as long as it is substituted for an equivalent amount of starchy carbohydrate in the patient’s meal plan and is within a reasonable portion. Sharing desserts is one way to limit portions. However, medical professionals who treat people with diabetes often remind their patients that eating such “empty calories” wastes some of their daily carbohydrate allotment. It is better to consume carbohydrates in nutritious foods that provide the body with essential vitamins and minerals.

Alternatives to sugar

Artificial sweeteners, also called sugar substitutes, are compounds that serve as alternatives to sugar. They provide sweetness with fewer or no calories and have little or no effect on glucose (blood sugar) levels.

Sugar substitutes are much sweeter than sugar, oftentimes hundreds of times sweeter. As a result, they are used in smaller doses. Whereas a teaspoon of refined table sugar contains 16 calories, many sugar substitutes contain zero calories. However, patients should carefully read the label before buying a sugar substitute. Some of these products still contain small amounts of carbohydrates and proteins.  

Food additives that have never been added or used in foods, including new sweeteners, must be approved by the U.S. Food and Drug Administration (FDA) as safe – and categorized as Generally Recognized as Safe (GRAS) – before they can be marketed in the United States. Artificial sweeteners that have met the criteria will have GRAS on the food label.

Sweeteners are divided into two categories – nutritive and nonnutritive. In general, nutritive sweeteners contain carbohydrates, calories and nutrients and provide energy for the body. Nonnutritive sweeteners do not provide these elements. The following chart provides information on the two types of sweeteners:

Nutritive Sweeteners
Concentrated fruit juice.
Corn syrup.
Dextrose. Simple sugar found naturally in sweet fruits and honey.
Fructose. Simple sugar found naturally in sweet fruits and honey.
Lactose. Sugar found in milk and dairy products. 
Maple syrup.
Sugar alcohols, also called polyols. Alternative to table sugar derived from plant products such as fruits. Sugar alcohols are broken down by the body and provide about half the calories of sugar. Excess consumption may have a laxative effect.
Nonnutritive Sweeteners
Acesulfame potassium (acesulfame-K). This artificial sweetener tastes 200 times sweeter than sugar, and heating does not reduce its power to sweeten. Acesulfame-K has no calories.
Aspartame. A combination of two amino acids (phenylalanine and aspartic acid) combined with methanol that is about 200 times sweeter than sugar.
Saccharin. Between 300 and 700 times sweeter than sugar, with zero calories.
Sucralose. The only artificial sweetener made from sugar, sucralose is not metabolized by the body. Because it cannot be digested, it does not contribute any calories to a person’s diet. Sucralose is 600 times sweeter than sugar.

Nonnutritive artificial sweeteners generally do not affect blood glucose because they do not contain carbohydrates. However, some sugar substitutes do contain carbohydrates that can boost blood glucose levels. People with diabetes must examine food labels to determine the sugar and carbohydrate levels in foods with artificial sweeteners.

Experts advise people with diabetes not to drink soda, or to drink diet sodas, which have sugar substitutes.  Juices that are 100 percent fruit “juice” may be less harmful to blood glucose levels than fruit “drinks,” “punch,” “cocktail” or other variations. These beverages have more carbohydrates than real juice. Consumption of high-fructose corn syrup in soft drinks and many other foods has soared in recent decades and according to some researchers has contributed to the epidemic of obesity.

Patients also should be careful when shopping for “fat-free” or “low-fat” products, as these often contain higher sugar content or added carbohydrates.

Healthy sugar choices

People with and without diabetes can find a healthy way to satisfy their “sweet tooth” by eating fruits such as oranges, strawberries, blueberries, plums, melons and other produce. Not only are fruits low in fat and moderate in calories, but they also contain many nutrients.

Fresh fruits contain the most nutrients, but frozen, canned and dry fruits also contain vitamins, minerals and fiber. It is important to choose canned fruits that are packed in their own juice instead of high-fructose syrup.

Many fruits contain compounds called phytochemicals that may help prevent diseases such as cardiovascular disease, cancer and possibly diabetes. Fruits are also good sources of antioxidants, which are substances that slow down the damage to tissues and cells known as oxidation. Avocados and olives are rich in monounsaturated fats that in many studies have been found to benefit health.

Patients should consult with their physician and registered dietitian in deciding which fruits are best for their diet. Some fruits are not appropriate for people with diabetes.

Questions for your doctor regarding sugar

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about sugar:

  1. How much sugar is it OK for me to eat?
  2. What’s the best way for me to keep track of this?
  3. How do I adjust my diet if I have an occasional high-sugar, high-calorie treat such as a sundae?
  4. Does too much sugar lead to obesity? Can it raise my risk of insulin resistance, prediabetes, type 2 diabetes, gestational diabetes or double diabetes?
  5. Can the glycemic index be helpful to me, or does sugar have the same effect on my glucose as other carbohydrates?
  6. Will eating protein or fat with sugar reduce spikes in my glucose?
  7. Can artificial sweeteners help me eat right?
  8. Should I adjust insulin or other medication if I eat sugar?
  9. Should I eat a certain amount of sugar before, during or after exercise?
  10. Are juices that say “made from 100 percent fruit juice” lower in sugar?
  11. Is the sugar found in milk OK for me to drink?
  12. Can you refer me to a registered dietitian for help in meal planning?
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