Being in the nutrition world a common question I get asked is what’s better… sugar or artificial sweeteners. My answer? Sugar, like all things, in moderation. I’ll admit, I enjoy a diet soda from time to time, but other than that I do not like artificial sweeteners. In most cases, I can’t stand the taste of them. Even if you do like the flavor, you might not like what research has to say about the little pink, yellow, and blue packets.
A Bit About Sweeteners
Did you know that most of the artificial sweeteners we know today were discovered by scientists tasting their samples, often inadvertently? This includes Saccharin, the oldest artificial sweetener, which was discovered by Constantine Fahlberg at Johns Hopkins in 1879 while working on coal tar derivatives. Saccharin debuted as a specialty product for diabetics on medicine shelves. A sugar shortage during World War II and increasing desire for women to have a thin figure caused an increase in the use of artificial substitutes. At this time, the labels on diet soda bottles changed from “for use only in people who must limit sugar intake” to “for use in people who desire to limit sugar intake”. (1).
The most common, and well known, chemically created non-nutritive sweeteners (NNS) are Acesulfame K (brand name Sunett or SweetOne), Aspartame (Equal, Nutrasweet), Saccharin (Sweet n’Low), and Sucralose (Splenda). These sweeteners range from 200-600 times sweeter than sucrose, table sugar. Sucralose is actually derived from sucrose molecules, but is chemically altered with chlorine making it 600 times sweeter. In addition, there are polyols, or sugar alcohols, which are found naturally in fruits or can be manufactured and have some calories but are metabolized differently and do not effect blood sugar like sucrose. There are also natural, calorie free sweeteners stevia and nectresse. Stevia is extracted from the leaves of the Stevia Rebaudianae Bertoni plant and is 250 times sweeter than sugar (2). Nectresse, a new sweetener on the market, is made from Monk Fruit Extract blended with other natural sweeteners including erythritol, sugar and molasses (McNeil Nutritionals, 2012).
Safety of Artificial Sweeteners
All NNS must undergo review by the FDA and those on the market are “generally recognized as safe”. There are not currently any recommended dietary guidelines for sugar substitutes, but a related recommendation from the Dietary Guidelines for American’s is to control total energy intake and increase physical activity to manage body weight. The consumption of NNS in place of more calorie dense foods and beverages can help reduce energy intake. However, evidence supporting their effectiveness in weight management is limited. NNS are recommended for individuals with diabetes. NNS do not affect blood sugar and can be used to help moderate carbohydrate intake (2). The Academy of Nutrition and Dietetics has released their position stating:
“It is the position of the Academy of Nutrition and Dietetics that consumers can safely enjoy a range of nutritive and nonnutritive sweeteners when consumed within an eating plan that is guided by current federal nutrition recommendations, such as the Dietary Guidelines for Americans and the Dietary Reference Intakes, as well as individual health goals and personal preference (2).”
The Center for Science in the Public Interest (CSPI) has a nonprofit food safety watchdog group that produces the “Chemical Cuisine” guide to food additives. CSPI’s Chemical Cuisine gives the artificial sweeteners saccharin, aspartame, and acesulfame potassium “avoid” ratings due to rodent studies linking saccharin and aspartame to cancer in rodents and medicore quality tests of acesulfame potassium performed in the 1970’s. CSPI just recently downgraded sucralose, Splenda, from “safe” to “caution” pending a review of an unpublished study by an independent Italian laboratory that found that the sweetener caused leukemia in mice. The only previous long-term feeding studies in animals were conducted by the compound’s manufacturers. CSPI considers rebiana, a natural high-potency sweetener obtained from stevia, to be “safe,” though deserving of better testing (3).
The Bitter Truth about Artificial Sweeteners and Weight Control
Like most things, the idea of being able to have cloyingly sweet things for a fraction of the calories seems too good to be true. Unfortunately, as great as these sweeteners sound, they may not have the benefits one would hope for. Several large scale prospective cohort studies, including the San Antonio Heart Study, the Nurse’s Health Study, and the National Heart, Lung, and Blood Institute Growth and Health Study, all found positive correlations between artificial sweetener use and weight gain. These studies included both adults and children and looked at change in weight and body mass index (BMI) at intervals ranging from 1 year to 8 years. Investigators found that artificial sweetener use was associated with weight gain in both adults and children over time. Additionally, interventional studies have found that replacing sugar sweetened foods and beverages with those made artificial sweeteners as a method of weight loss alone does not result in weight reduction. Researchers actually found that when people knowingly consume diet beverages and foods, they had increased overall energy intake, suggesting overcompensation for expected calorie reduction (1).
Ever have sugar free desserts or candy and find yourself craving more?
It has been shown that sweet taste, whether natural or artificial, enhances the human appetite. There is increasing evidence that suggests that non-nutritive sweeteners do not satisfy the hunger for sweet foods as natural sweeteners do because they do not activate the food reward pathways in the same way. There are two parts to food reward pathway. The first part is the sensory portion, the satisfaction of the pleasant taste. The second part is post-ingestion which depends on the products created from the breakdown of food. Since artificial sweeteners do not provide any calories the second part of the food reward pathway is believed to be eliminated. Pilot studies have shown that sweetness not paired with caloric content offers partial, but not complete activation of the food reward pathways. This means that artificial sweeteners do not necessarily satisfy sweet cravings, leaving something to be desired and further fueling food seeking behaviors. The intense sweetness of the artificial sweeteners (200-600 times that of sugar) also trains the palate to prefer increasingly sweet things. More exposure to sweetness encourages sugar cravings and sugar dependence.
So while artificial sweeteners are considered “safe” for consumption by the FDA, they may not provide the benefits consumers are hoping for, and in turn actually do the opposite. A diet cola now and again may be harmless, but if you are trying to improve your overall intake by replacing sugar sweetened foods and drinks with alternatives made with sugar alternatives, you may want take a different approach to gain the most benefit.
(1) Yang, Qing. (2010). Gain weight by “going diet”? Artificial sweeteners and the neurobiology of sugar cravings. Yale Journal of Biology and Medicine. 83: 101-108.
(2) Fitch, C, Keim, KS. (2012). Position of the Academy of Nutrition and Dietetic: Use of Nutritive and Non-nutritive Sweeteners. Journal of the Academy of Nutrition and Dietetics. 112:739-758. doi: 10.1016/j.jand.2012.03.009
(3) Center for Science in the Public Interest. Chemical Cuisine Guide to Food Additives. https://www.cspinet.org/reports/chemcuisine.htm