DEAR DR. BLONZ: I drink milk daily -- sometimes nonfat, sometimes 1 percent or 2 percent. I was recently told that I am heading toward Type 2 diabetes, and when checking the contents on the milk cartons, I noticed that there were 14 grams of sugar per cup in the 1 percent milk and 15 grams in the nonfat milk. Does this mean "sugar" as in "sweet sugar"? How does this relate to diabetes? -- L.W., via email
DEAR L.W.: All sugars are carbohydrates, but not all carbohydrates should be thought of as sugars. Your question relates to the common confusion that "sugar" always refers to "table sugar," the white granular sweetener that's also called sucrose.
From the labeling standpoint, "sugars" refers to the sum of all the single and double sugars present in a particular food. Glucose, fructose and galactose are common single sugars, and a double sugar is when you have two single sugars bound together. For example: Sucrose is a double sugar made up of glucose and fructose, while lactose -- found in milk products -- is a double sugar made up of glucose and galactose. Other common sweeteners include corn syrup (all glucose), high-fructose corn syrup (corn syrup with some glucose enzymatically changed to fructose) and honey (a 50-50 mixture of unbound glucose and fructose).
Glucose is the main form by which carbohydrates travel through our bodies, and when carbohydrates are eaten, they tend to be converted to glucose, usually by the liver (assuming they weren't in the form of glucose to begin with). The blood sugar level, or blood glucose level, is the measure of glucose in our bloodstream. When in good health, the human body has a series of controls designed to keep blood sugar in a defined range.
Insulin, produced by the pancreas, is the hormone that keeps our blood sugar level from getting too high. A rise in blood sugar, such as that typically found after a meal or a sugary snack, triggers the release of insulin. This is the signal for glucose to be removed from the blood and turned into fat. Type 2 diabetes occurs when the pancreas is unable to produce sufficient insulin to do the job.
Different sugars and sweeteners affect this process to varying degrees and at various speeds. Getting back to your question: Lactose should not be considered a "sugary" sugar because it has much less of an impact on the speed at which it raises blood sugar, compared with an equal amount of sucrose.
Excess sweeteners do not cause diabetes, but sugars, carbohydrates, insulin and diabetes are closely connected. Thus, those at high risk for developing diabetes are advised to limit their intake of single and double sugars. Having soda and/or high carbohydrate snacks are particularly troublesome for these individuals, especially when consumed on an empty stomach. Excess body weight is a major factor increasing the risk of Type 2 diabetes because the body's sensitivity to insulin decreases as weight increases. The flip side is that those with extra weight who have been told they are at risk for Type 2 diabetes can see that risk decrease, or even disappear, with weight loss. For more information on diabetes, check the National Institutes of Health page: tinyurl.com/8kfow
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.