Sweeteners have been used to improve the taste and appeal of food and beverages for more than 75 years, but their health effects continue to be scrutinized. In 2012, the American Heart Association and American Diabetes Association issued a joint statement supporting the safety and use of nonnutritive sweeteners (NNS).1 Despite this, conflicting information in the media and scientific literature leads many consumers to struggle with the formation of a balanced, informed stance on these products.
Several important terms are used in discussions about artificial sweeteners.2-4 Nutritive sweeteners are substances such as honey, sucrose (table sugar), high-fructose corn syrup, agave, maple syrup, sugar alcohols and other sweetening agents that provide substantial calories. Nonnutritive sweeteners are sweeteners that contain few to zero calories.
The Food and Drug Administration (FDA) has declared aspartame, neotame, saccharin, sucralose and stevia "generally recognized as safe" (GRAS). GRAS status means that a general consensus has been reached among experts about the safety of these products.
Acceptable daily intake (ADI) is the amount of a food additive that can be safely consumed in one day. This number is based on current research and is calculated by the FDA.
Low-calorie food products must contain 120 calories or less per 100 grams, and calorie-free products must contain less than 5 calories per serving.
Nonnutritive sweeteners are prevalent in processed foods. Beyond the obvious sources of sweetener packets, NNS are often included in food and beverages that are ingested daily. Products marketed as sugar-free, diet or reduced-calorie are the most common products containing NNS. But many items sweetened with NNS do not bear obvious labeling, and reading ingredient lists is the only sure way to identify whether NNS are present. Commonly used products that have incorporated NNS in recent years include diet sodas and teas; reduced-calorie juices; sugar-free chewing gums; reduced-calorie yogurts and salad dressings, low-calorie puddings and gelatins; and reduced-calorie cookies and cakes.
The ingredients used in NNS vary widely, as do the methods by which they are processed and eliminated by the body. The following list summarizes the most relevant health information about commonly used NNS.5
• Acesulfame-K is a synthetic compound that is 200 times as sweet as sucrose. It is not metabolized, and it is excreted in urine.
• Aspartame is 160 to 220 times as sweet as sucrose and is composed of amino acids (L-aspartic acid and L-phenylalanine). It is metabolized as protein and its wastes are excreted in urine.
• Neotame is derived from aspartame and is a more chemically stable compound than its predecessor. Neotame is 7,000 to 13,000 times as sweet as sucrose and is not metabolized by the body. It is eliminated by the kidneys.
• Saccharin is a coal tar derivative that is 300 times as sweet as sucrose. It is not metabolized by the body, and it is eliminated by the kidneys.
• Sucralose is a synthetic derivative of sucrose that is 600 times as sweet as sucrose. It is not metabolized and is excreted in urine and feces.
• Stevia is made from dehydrated, purified leaves of the stevia plant and is 250 times as sweet as sucrose. It is metabolized by the liver and excreted in urine.
Many consumers are concerned about the safety of NNS. Because people with a propensity for cardiovascular or metabolic disease are more likely to consume these products to offset their risks, it is important to clarify for patients that an association with disease does not necessarily contraindicate use of these products. Table 1 provides a brief review of the safety concerns and available evidence.5,6
Some populations require special consideration.1,5-7 For example, patients with phenylkenonuria (PKU) must avoid aspartame because it contains L-phenylalanine. Pregnant women who ingest NNS may be at higher risk for preterm delivery, and some evidence suggests that saccharin is not fully cleared from the fetus when a pregnant woman ingests it.8 The American Medical Association recommends abstention from NNS during pregnancy.1-5,7 However, the current stance of the Academy of Nutrition and Dietetics is that NNS appear to be safe for use in breastfeeding women.5
In children, aspartame may affect appetite and nutrient intake, therefore limited use is recommended.5 At one point scientists thought that NNS might benefit patients with attention deficit disorder, but no clear evidence has proven this theory.
On the plus side, patients with diabetes can safely consume NNS-sweetened products while maintaining glycemic control.9
Acceptable Daily Intakes
The FDA has set conservative ADI estimates for NNS based on current evidence.1 Table 2 displays the ADIs for common sweeteners. Clearly, the ADI is large and not often exceeded. It would take fifteen 12-ounce servings of sucralose-infused beverages or 30 packets of sucralose per day for a 150-pound person to surpass this limit. In contrast, it would take 68 packets of aspartame or 14 12-ounce servings of this product to surpass the ADI.
Perhaps the most disputed topic surrounding NNS is whether these sweeteners may contribute to the obesity epidemic. NNS has been linked to obesity in correlational,6 prospective10 and experimental research.11,12 Yet, other research shows that these products are helpful for weight loss13 and weight maintenance.14
One theory for the epidemiologic and prospective evidence is that overweight patients and patients at risk for weight gain are more likely to consume these products in an attempt to control their weight. However, chronic NNS use is associated with altered cortical processing of sweets. Magnetic resonance imaging shows that glucose and NNS produce differential brain responses leading to reduced activation of reward pathways in the absence of glucose.15,16 Long-term users of NNS experience diminished responsiveness to sugar in the amygdala.17 The ramifications of this reduced responsiveness are unclear. However, reduction of this responsiveness was previously linked to obesity.18
Overall, it appears that NNS is associated with weight loss when it is intentionally used as a substitute for higher-calorie alternatives. However, some evidence suggests that certain factions of the population are more successful in this endeavor than others.1
NNS Intake Questionnaire
Using the youth risk behavior survey format19 as a guide, we developed a questionnaire to assess NNS intake. The questionnaire is included with the online posting of this article at www.advanceweb.com/NPPA. This survey was included in a larger study about NNS use, obesity and associated health behaviors. It could potentially be used to quantify and determine norms for NNS use in any patient population.
We scored the responses to each question from zero to six, with zero indicating no intake and six indicating four or more times a day. This resulted in a scoring scale of 0 to 24.
The online survey was answered by 113 college students aged 18 to 42, who were enrolled in an introductory nutrition class at the University of North Florida. Actual scores ranged from 0 to 15 with a mean score of 3.27. Standardizing the norms for different age ranges can help determine the relative ingestion of NNS in a person's diet. With repeated administration of this survey to heterogenous cohorts, a determination can be made about the parameters for designation as high, medium and low consumers of these products. Once these norms can be determined, patients can be classified accordingly.
These scores, when compared with the body mass index, can help a nurse practitioner determine whether NNS are being used appropriately as substitutes for sucrose. More specifically, patients with an elevated BMI who report regular, long-term use of NNS beyond a reasonable one to two servings per day would be candidates for referral to a nutritionist who could work with them to use NNS as substitutes for high-calorie foods instead of as additions to an already calorically excessive dietary pattern.
When used inappropriately, NNS may decondition a patient to sweets, leading to increased consumption of nutritive sweets in addition to nonnutritive ones.6 Much in the way an addict's brain becomes desensitized to the addict's drug of choice, leading to increased ingestion at higher doses, so too might the NNS user seek out higher and higher quantities of sweetness, leading to increased portion sizes and a higher caloric intake.
Implications for Practice
When used in conjunction with a healthy diet, NNS have the potential to improve health and enhance weight management. However, there may be mechanisms at work that counter this process, partially or completely compensating for the benefits of the sweetener. NNS appear to work best for weight loss and maintenance when used purposefully as a replacement for sweets.
However, if the person consumes these substances long term in addition to continuing to consume sugar, he or she may negate the positive health benefits and possibly cause reduced sensitivity to sweet tastes, leading to increased consumption of high-calorie sweetened foods.6 It is important to educate patients about this possibility so that they may remain vigilant as they incorporate NNS into their diets. Keeping a food journal and counting calories might help in preventing compensation.
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Although ADI values for NNS are quite high, it is not completely improbable that a small segment of the population may be consuming these products in those doses. A 24-hour diet recall, with special attention paid to the number of sweetener packets, NNS beverages and NNS foods, may be indicated. Since the patient may be unaccustomed to keeping track of these substances, he or she may need to bring a completed food diary to follow-up appointments for accurate assessment. As an alternative assessment technique, the NNS intake questionnaire can be utilized. The patient must also be educated about how to recognize which products contain NNS. In all cases, moderation is an important principle to encourage.
Finally, it is important to counsel pregnant patients and patients with PKU about the importance of abstaining from aspartame and saccharin. Parents should be encouraged to provide healthy diets for their children and limit the amount of NNS they consume.
The safety and efficacy of nonnutritive sweeteners are debated frequently. Due to recent statements by scientific bodies, conflicting evidence and mainstream media coverage, patients are likely to have questions about these products. Encouraging proper usage of NNS while instilling a healthy level of skepticism about their limitations may be necessary. All dietary counseling should include an emphasis on proper nutrition and adherence to federal safety recommendations. Being informed enables primary care providers to better help patients fight obesity, regulate blood sugar and maintain or regain optimal health.
1. Gardner C, et al. Nonnutritive sweeteners: current use and health perspectives. A scientific statement from the American Heart Association and the American Diabetes Association. Circulation. 2012;126(4):509-519.
2. Food and Drug Administration. Definitions of Nutrient Content Claims. http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/GuidanceDocuments/FoodLabelingNutrition/FoodLabelingGuide/ucm064911.htm
3. Food and Drug Administration. Generally Recognized as Safe. http://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/default.htm
4. United States Department of Agriculture. Nutritive and Nonnutritive Sweetener Resources. http://fnic.nal.usda.gov/food-composition/nutritive-and-nonnutritive-sweetener-resources
5. Fitch C, Keim KS. Position of the Academy of Nutrition and Dietetics: Use of nutritive and nonnutritive sweeteners. J Acad Nutr Dietetics. 2012;112(5):739-758.
6. Yang Q. Gain weight by "going diet?" Artificial sweeteners and the neurobiology of sugar cravings. Yale J Biol Med. 2010;83(2):101-108.
7. Schwide-Slavin C, Swift C, Ross T. Nonnutritive sweeteners: Where are we today? Diabetes Spectrum. 2012;25:104-110.
8. Academy of Nutrition and Dietetics. GDM: Use of Non-nutritive sweeteners. http://andevidencelibrary.com/template.cfm?key=2168&auth=1
9. Franz MJ, et al. The evidence for medical nutrition therapy for type 1 and type 2 diabetes in adults. J Am Dietetic Assoc. 2010;110:1852-1889.
10. Fowler SP, et al. Fueling the obesity epidemic? Artificially sweetened beverage use and long-term weight gain. Obesity. 2008;16(8):1894-1900.
11. Martinez C, et al. Effects on body mass of laboratory rats after ingestion of drinking water with sucrose, fructose, aspartame, and sucralose additives. Open Obesity Journal. 2010;2:116-124.
12. Swithers SE, et al. High-intensity sweeteners and energy balance. Physiol Behav. 2010;100(1):55-62.
13. Hendriksen M, et al. Impact of substituting added sugar in carbonated soft drinks by intense sweeteners in young adults in the Netherlands: example of a benefit-risk approach. Eur J Nutr. 2011;50(1):41-51.
14. Phelan S, et al. Use of artificial sweeteners and fat-modified foods in weight loss maintainers and always-normal weight individuals. Int J Obesity. 2009;33(10):1183-1190.
15. Haase L, et al. Cortical activation in response to pure taste stimuli during the physiological states of hunger and satiety. NeuroImage. 2009;44(3):1008-1021.
16. Smeets PA, et al. Functional magnetic resonance imaging of human hypothalamic responses to sweet taste and calories. Am J Clin Nutr. 2005;82(5):1011-1016.
17. Rudenga KJ, Small DM. Amygdala response to sucrose consumption is inversely related to artificial sweetener use. Appetite. 2011;58(2):504-507.
18. Stice E, et al. Relation of reward from food intake and anticipated food intake to obesity: a functional magnetic resonance imaging study. J Abnorm Psychology. 2008;117(4):924-935.
19. Centers for Disease Control. Methodology of the youth risk behavior surveillance system-2013. MMWR Recomm Rep. 2013;62(RR-1):1-25.
Katharine Wright recently graduated from the family nurse practitioner program at the University of North Florida in Jacksonville. Jan Meires is an associate professor in the School of Nursing at the University of North Florida. The authors have completed disclosure statements and report no relationships related to this article.
Close-Up on Monk Fruit
One of the more intriguing sweeteners to enter the market in recent years is derived from monk fruit. The monk fruit is a small, sweet melon native to China and Southeast Asia. Legend has it that Buddhist monks cultivated the lemon-sized fruit in the 13th century. In China, monk fruit is known as luo han guo and is often used in herbal medicine.
Monk fruit contains antioxidants and vitamins, but it has gained more attention for its inherent low-calorie sweetness. Food and beverage manufacturers have been incorporating monk fruit into products such as VitaTops and Kashi cereals, and it is also available for consumers to use as a sugar substitute in beverages and recipes.
Nurse practitioners can request product samples of Monk Fruit In The Raw at http://professional.intheraw.com/. General information about the monk fruit is available at www.monkfruit.org.