Sugar: The Sweet Truth

  • Sugar is a general term for sweet, short-chain, soluble carbohydrates, many of which are used in food.
  • Sugars may be chemically divided into monosaccharides like glucose (dextrose), fructose, galactose, xylose and ribose or disaccharides like sucrose (common “granulated” table sugar), lactose (milk sugar), maltose, lactulose and trehalose, or the polysaccharides such as starch and cellulose.
  • The AHA 2009 statement on sugar recommends a limitation on the consumption of sugar and in particular specifies a limit on what is called “added sugar” to less than 10% of total calories.

Sugar (dextrose, fructose, glucose, sucrose), high-fructose corn syrup (HFCS), honey, brown sugar, corn sweetener, corn syrup, invert sugar, malt sugar, molasses or any syrup (brown rice syrup, agave or malt syrup) can all be considered “sugar.” If listed as one of the first three ingredients on an ingredient list, the food item is 
high in sugar and should be avoided.

Sugar: the new tobacco

A more recent 2014 recommendation on sugar restriction from the World Health Organization (WHO) makes the case for a much more aggressive stance. This group believes there are additional health benefits with stricter reduction of added sugars to below 5% of total energy intake per day. According to Dr. Francesco Branco, Head of Nutrition for Health and Development, World Health Organization (WHO) “Sugar might become the new tobacco in terms of risk.” Five per cent of total energy intake is equivalent to around 25 grams (around 6 teaspoons) of sugar per day for an “average” adult with a normal Body Mass Index (BMI). For a reference, one 12-ounce can of cola contains ≈8 teaspoons of added sugar, or about 130 calories which would put most Americans above the daily limit -before they ate any meal. Sugar sweetened beverages should be limited (no more than 36 ounces/week). The recent 2015 Dietary Guidelines for Americans however, is more forgiving and recommends that we restrict added sugars to less than 10% of total calories.

Our collective sweet tooth increased 30% between 1950 and 2000, according to the USDA. The average American now consumes about 3 pounds of sugar each week.  Reducing added sugars consumption is a good target for addressing then problems of overweight, obesity, and the epidemic of prediabetes and diabetes. Most American women should eat or drink no more than 100 calories per day from added sugars, and most American men should eat or drink no more than 150 calories per day from added sugars. High intakes of dietary sugars in the setting of a worldwide pandemic of obesity and cardiovascular disease have heightened concerns about the adverse effects of excessive consumption of sugars.

Added sugars

  • Added sugars (unlike naturally occurring sugars found in fruit and milk) are sugars and syrups that are added to foods or beverages when they are processed or prepared.
  • The major food and beverage sources of added sugars for Americans are regular soft drinks, energy drinks, and sports drinks, candy, cakes, cookies, pies and cobblers, sweet rolls, pastries, and donuts, fruit drinks, such as fruitades and fruit punch, dairy desserts, such as ice cream.
  • About one-third of added sugars come from regular consumption of soda and unbelievably more than 90% of American children aged 2 to 8 are getting more than half of their discretionary calories from added sugars.

Marketing shenanigans

There are many added sugars that appear on food label ingredients that may not be very obvious and include such aliases as: agave syrup, brown sugar, corn sweetener, corn syrup, dextrose, evaporated cane juice, fructose, fruit juice concentrates, glucose, high-fructose corn syrup (HFCS), honey, invert sugar, lactose, maltose, malt syrup, maple syrup, molasses, raw sugar, sucrose, sugar, and syrup.

Nearly 80 percent of the 600,000 consumer packaged foods in the United States have added caloric sweeteners.

Corn syrup is an example of an added –hidden sugar that is commonly found in processed foods such as: beverages, cereal and bakery products, dairy products, candy and other confectionery items. Be aware of the growing list of food items with added sugars that are typically not thought of as “sweet” and can easily escape our notice. Dairy items such as non fat (or low fat) yogurts and ice cream for instance may have a “health halo” effect since they are “low fat items” but in fact may have more calories as a result of added sugars -to improve taste and shelf-life. Breakfast cereals and granola with the words “healthy” and “whole grain”–may hide significant amounts of sugar. Some breakfast cereals have nearly 15 grams of added sugar in a “serving-size” that is one-half a measuring cup (and an average cereal bowel serving is at least 2 measuring cups).

Liquid sugar

Coca-Cola markets Vitaminwater as a healthful alternative to soda by labeling its several flavors with such health buzz words as “defense,” “rescue,” “energy,” and “endurance.” The company claims that its drinks reduce the risk of chronic disease, reduce the risk of eye disease, promote healthy joints, and support optimal immune function -but did you know about he 33 grams of added sugar in each bottle? PEPSICO markets Naked Juice products were falsely and misleadingly labeled as 100% Juice 100% fruit “ALL NATURAL” suggesting that the beverages’ vitamin content is due to the nutritious fruits and juices, rather than the added synthetic compounds such as calcium pantothenate (synthetically produced from formaldehyde).

Sucrose (sugar), the most well known sweetener, is made by crystallizing sugar cane or beet juice. Sucrose is made up of the same two simple sugars, glucose and fructose, joined together to form a single molecule containing one glucose molecule and one fructose molecule, an exact one-to-one ratio. All added sugars whether natural or not are chemically very similar and contain nearly equal amounts of glucose and fructose. 1 teaspoon full of table sugar is about 4 grams of sugar. Table sugar (sucrose) consists of a disaccharide (or 2 sugars bound together) that is, 50% glucose and 50% fructose.

Agave (derived from the same plant used to make tequila) is about 1.5 times sweeter and is marketed as a sugar with less effect on raising blood sugar. Agave has more fructose than table sugar (sucrose) and since fructose has a lower glycemic index will not raise blood sugar as much as table sugars. This fact is often used as a marketing ploy but there are important metabolic concerns with too much fructose and this does has important health consequences. The bottom line is that we need to reduce all sugar in our diet.

Fructose is not glucose

High-fructose corn syrup (HFCS) is different from corn syrup since it is manufactured into a sweeter and less expensive product thanks to government farm bill corn subsidies. As a result of an enzymatic process HFCS is made from corn glucose and consists of 42-55% fructose. The proportion of fructose to glucose in both HFCS 42 and HFCS 55 is similar to that of sucrose. Compared with sucrose, high fructose corn syrup (HFCS) is widely available, and is much more inexpensive thanks to US government subsidies; it is not surprising that it is ubiquitous in foods in the US, Canada, Japan (use is limited in Europe). The food industry favors this sugar in non fat items especially for palatability and ability to improve shelf life. Current United States annual HFCS consumption is 63 pounds per person.

Increases in fructose consumption have paralleled the increasing prevalence of obesity, and high-fructose diets are thought to promote weight gain and insulin resistance.

Fructose and glucose both have 4 calories per gram but the metabolic fate of fructose is metabolically different from that of glucose. Not only do we often unwittingly consume too much fructose its real danger related to its unique metabolism.

Excess dietary fructose can encourage eating too much since the natural hormones insulin and leptin, important in appetite control, are blunted by fructose when compared to glucose. Specific brain regions that can increase appetite and reward processing are stimulated by fructose unlike glucose which is more likely to increase fullness (satiety). Some researchers believe that fructose consumption is less likely to be associated with “feeling full” and may promote “over-consumption” and unwittingly increase an individual’s caloric consumption. (Effects of Fructose vs Glucose on Regional Cerebral Blood Flow in Brain Regions Involved With Appetite and Reward Pathways Page, KA et al JAMA. 2013;309(1):63-70).

Fructose unlike equal caloric amounts of glucose can increase the risk of fatty liver disease (fructose turns on what we call de novo lipogenesis). Fatty liver disease or so-called non-alcoholic liver disease (also known as, NAFLD) represents a worldwide health concern and is a leading cause for cirrhosis -even more than alcohol. Increased liver fat tends to develop in people who are overweight or obese or have diabetes, high cholesterol or high triglycerides. NAFLD affects up to 25% of people in the United States and is now believed top be an independent risk for diabetes and cardiovascular disease. Elevated uric acid, blood pressure and increased prediabetes (metabolic syndrome) and type 2 diabetes are additional downstream effects of excessive fructose consumption that are all directly linked to an increased risk of cardiovascular disease.

Summary

Some sugar is fine but collectively we consume too much sugar and often it is unwittingly consumed as hidden or added sugars (high fructose corn syrup). The health consequences are staggering and have contributed to the epidemics of overweight and obesity, diabetes and cardiovascular disease. Be mindful especially when it comes to processed foods: read labels and take charge of your health.


World Cancer Research Fund/American Institute for Cancer Research: Food Nutrition and Physical Activity and Prevention of Cancer: A Global Perspective. 2007, Washington, DC