Understanding Sugars & Health

Acceptance of sweetness is innate and universal among humans. Sweetness directs newborn mammals toward safe and nourishing foods and drinks, while bitterness signals potential harm. These early responses are modified by life experiences, producing adult taste preferences. Humans have sought sweet foods, drinks and sweeteners throughout history and sweetness continues as a strong force in food and drink selection.

SCIENTIFIC CONSENSUS STATEMENT ON MANAGING SWEETNESS
Oldways Managing Sweetness Conference, Brussels 2006

The role of carbohydrates and sugars in the diet is of much public and scientific interest, particularly whether they are related to health outcomes, such as heart disease, type 2 diabetes, dental caries and body weight. The 2010 U.S. Dietary Guidelines Advisory Committee found no detrimental effects of sugar as a source of carbohydrates calories on these or other health outcomes. The European Food Safety Authority determined that there is inconclusive evidence on the role of carbohydrates and weight gain and diet-related diseases.

Mental Performance and Behavior

Numerous studies with different populations show that sugar consumption does not affect hyperactivity, attention span, or cognitive performance in children. However, research does support a link between sugars consumption and mental performance. Studies show that under some circumstances, intake of sugars can boost performance on cognitive tasks. Of course, all calories count, and consuming more calories than you use will, over time, result in weight gain in most cases.

Athletic Performance

According to the American College of Sports Medicine, performance and endurance during prolonged physical activity is limited not only by dehydration, but also by declines in blood sugar levels and depletion of the muscle's carbohydrate (glycogen) stores. Consuming carbohydrates as simple sugars during prolonged physical activity can delay fatigue and improve performance by providing fuel directly to the brain and working muscles and sparing muscle and liver glycogen. Most commercial sports drinks contain a blend of carbohydrate sources such as the sugars sucrose, glucose, and fructose that provide the 13- to 19-grams of carbohydrates per 8 fluid ounces (240 ml) recommended by American College for Sports Medicine for optimal performance.

Diet Quality

In its examination of the data regarding sugars and micronutrient intakes for the 2002 Dietary Reference Intakes (DRI) report on carbohydrates in the diet, the U.S. Institute of Medicine found that very high and very low intakes of added sugars were associated with lower micronutrient intakes. The report suggested an intake level of 25% or less of calories (energy) from added sugars in the total diet based on data showing decreased intake of some micronutrients in some population groups exceeding this level.

Two recent reviews in the United States and England aimed to quantify associations between dietary added sugars (as a percentage of energy) and micronutrient intake. A 2010 review by Marriott and colleagues using data from the 2003 – 2006 National Health and Nutrition Examination Survey (NHANES) found mean added sugars intake and food sources of added sugars were comparable to the mid-1990s. However, the authors noted that while higher intake of added sugars was associated with more individuals not meeting average nutrient requirements, these high levels, "occur only among a small proportion of the population and cannot explain the existing problem of poor nutrient intake in the US population as a whole." A 2009 review by Gibson and Boyd using data from the National Diet and Nutrition Survey from 1688 British children aged 4-18 years found the "impact of added sugars on micronutrient intakes appears modest overall but may have relevance for children consuming inadequate amounts of nutrient-rich foods coupled with a diet high in added sugars (approximately 23%)."

Weight Management

Weight management is about energy balance - learning how to keep the number of calories consumed in foods and beverages in equilibrium with the number of calories the body burns each day for basic metabolism and to fuel physical activity.

A recent evidence-based review by the 2010 U.S. Dietary Guidelines Advisory Committee found some epidemiological evidence linking sweetened beverage consumption with weight gain. However, the Committee noted that these types of studies cannot determine if the weight gain was due to sugar per se or simply additional calories. On the other hand, the randomized control trials (RCT) reviewed found added sugars are not different from other calories in increasing energy intake or body weight. RCT studies are considered the "gold standard" in evaluating cause and effect relationships. The report further noted that "[t]he macronutrient distribution of a person's diet is not the driving force behind the current obesity epidemic," and that there "is no optimal proportion of dietary fat, carbohydrate, and protein to maintain a healthy body weight, to lose weight, or to avoid weight regain after weight loss. It is the total amount of calories eaten that is essential." In addition, the report states that if "total calorie content is held constant, there is little support for any effects on energy intake and body weight due to the calories consumed either as liquid or solid. Thus, Americans are advised to pay attention to the calorie content of the food or beverage consumed, regardless of whether it is a liquid or solid. Calories are the issue in either case."

However, because sugars provide calories and it's possible to consume excess calories from any source, it's important that consumers learn to manage their sugar calories (as well as those from fat [9 calories/gram] and protein [4 calories per gram]) in the context of an overall sensible, balanced diet that meets their nutrition and hydration needs while remaining within daily calorie limits and keeping in mind that all calories count, including those in caloric beverages. For most individuals, choosing portion sizes that are right for them, as well as including foods and beverages sweetened with low-and no-calorie sweeteners, can help them satisfy their desire for sweet tastes while keeping calorie levels in line with their individual needs.

Diabetes

Diabetes is a metabolic disorder that occurs when the body cannot regulate blood glucose levels properly. In type 1 diabetes the pancreas does not make insulin, the hormone needed to help the body use glucose for energy. In type 2 diabetes, the body does not make enough insulin or cannot respond normally to the insulin that is made. The causes of diabetes continue to be a mystery, although both genetics and environmental factors seem to play a role. Obesity and lack of exercise are important in susceptibility to type 2 diabetes. Interestingly, sugars are not "off limits" for people with diabetes. Current American Diabetes Association (ADA) nutritional recommendations do not provide specific guidelines for intake of sugars, except to note that sugars and other carbohydrates can be substituted for one another on a gram-for-gram basis. The ADA also recommends limits on dietary fat and dietary saturated fat for diabetics.

Dental Health

Sugars and cooked starches (e.g.: bread, pasta, crackers, and chips) are fermentable carbohydrates that contribute to the risk for dental caries (tooth decay). Tooth decay can develop when fermentable carbohydrates are exposed to bacteria on the teeth, with the bacteria producing acids which gradually break down the hard structure of the tooth. The degree of risk for tooth decay is related to several factors such as exposure time of oral bacteria to fermentable carbohydrates, poor dental hygiene practices, the strength of the tooth enamel, the presence of deep pits and fissures, the flow and composition of the saliva, and the type and amount of bacteria in the mouth.

However, risk can be decreased through the proper use of fluoride, along with good oral hygiene that includes regular dental checkups.

Dental erosion is the loss of minerals from the tooth's enamel due to frequent exposure of the tooth to acids. It is unrelated to the bacterial action that occurs due to the action of oral bacteria. Dental erosion generally occurs from exposure of the tooth surface to acids, including acids found in various foods and beverages, stomach acids (Gastroesophageal Reflux Disease -GERD), and even chlorine from water. Any food or beverage that is high in food acids can contribute to dental erosion if it is consumed too frequently, or if a person allows the acidic food or beverage to remain in his or her mouth for relatively long periods of time. Although many sparkling beverages are acidic in nature, they are similar in acid content to many fruit juices, including orange, apple, and grape juice.

Summary

As the main energy source for the body, carbohydrates are an important part of a healthful diet. Currently, experts agree that carbohydrates and sugars in foods and beverages can be enjoyed as part of a sensible, balanced diet and active lifestyle.

For more information on sugar metabolism, see "IFIC Review: The Science of Sugars".

References

Scientific Consensus Statement on Managing Sweetness (Oldways)

Scientific Opinion on Dietary Reference Values for carbohydrates and dietary fibre (EFSA)

2010 Dietary Guidelines Advisory Committee Report, Part D. Section 5: Carbohydrates

Intake of added sugars and selected nutrients in the United States, National Health and Nutrition Examination Survey (NHANES) 2003-2006. Marriott BP, Olsho L, Hadden L, Connor P.Crit Rev Food Sci Nutr. 2010;50(3):228-258.

Dietary Reference Intakes Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. (2005) Institue of Medicine, Food and Nutrition Board (FNB)

Associations between added sugars and micronutrient intakes and status: further analysis of data from the National Diet and Nutrition Survey of Young People aged 4 to 18 years. Gibson S, Boyd A. Br J Nutr. 2009 Jan;101(1):100-7. Epub 2008 Jul 8.