Do diet drinks cause cancer? Do diet drinks make you fat? Are diet drinks worse than the regular ones? And for those of us at Texas Children’s... should they be offered to children and adolescents?
Diet drinks have become extremely popular, and many theories have been tossed around recently regarding the "fake" sugar or artificial sweeteners they contain. How do you separate fact from fiction? It is often confusing for consumers. For example, saccharin, an artificial sweetener found in diet drinks, has been brought to the Food and Drug Administration (FDA) for safety concerns multiple times since it was discovered in 1879 and has been continually approved. So, if artificial sweeteners have been determined safe, then why are so many questioning it?
First, What Are Artificial Sweeteners?
Artificial sweeteners, also known as non-nutritive sweeteners, are added to foods to improve sweetness without the added calories. The reason they have no calories is because they cannot be absorbed in your body or are so sweet that very little has to be used. With obesity on the rise, many people have used artificial sweeteners as a weight loss tool. Since most people consume way more sugar in their diet than is needed anyway, this has been thought as an effective strategy to cut back on calories.
The FDA has approved 5 artificial sweeteners to be used in food and drink production. They include:
So, What‘s The Big Deal?
- Sucralose (Splenda)
- Aspartame (Equal, Nutrasweet)
- Saccharin (Sweet ‘N Low)
- Acesulfame potassium (Sunnett, Sweet One)
Studies in the past have questioned whether or not artificial sweeteners are safe to consume. This idea was sparked by a Canadian study, which showed that saccharin consumed in exceptionally large amounts caused bladder cancer in rats.  Since then, repeated studies conducted in humans have failed to show that artificial sweeteners cause cancer. Our bodies may work similarly to rats but the obvious truth is that humans are not rats! Moreover, it is often difficult to duplicate rat studies in humans, as it is unethical to dose humans as high as rats in these studies.
More recently, evidence has been uncertain on whether or not artificial sweeteners can lead to obesity. Even though these sweeteners cannot directly make you gain weight, some recent research suggests that they can enhance your cravings for sweet food. Artificial sweeteners can be up to 13,000 times sweeter than regular sugar.  So they may be "tricking" your taste buds and indirectly making you eat more! However, the science on this is inconclusive.
In 2008, Swithers and Davidson presented evidence that artificial sweeteners may cause weight gain.  Their evidence showed that rats given artificial sweetener ate more compared to rats given sugar. These results were interesting, but like the earlier cancer studies conducted on rats, similar studies on humans showed different results. One of these studies included 21 overweight adults assigned to consume 28% of their calories from real sugar and another 20 overweight adults assigned to consume the same amount of calories from aspartame, an artificial sweetener.  After 10 weeks, the group who consumed sugar had a significant increase in their calorie intake, body weight, fat mass and blood pressure. The group who consumed artificial sweetener did not show any significant changes in any category. Although this study does not directly associate artificial sweeteners with weight loss, it does show that artificial sweeteners may be a better choice than regular sugar. In another study, participants were given a snack containing real sugar, aspartame or stevia.  Results showed that overall daily calorie intake, including the snack, was smaller in the aspartame and stevia groups. So, calorie intake in the artificial sweetener groups did not increase later in the day to compensate for the lower calorie snack but actually remained smaller than the regular sugar group.
There is still a question as to whether artificial sweeteners increase your craving for sweet foods. A study released in 2011 looked at how the brain responds to the artificial sweeteners in diet soda and to the real sugar in regular sodas.  There were 2 groups of subjects with 1 group given a solution with real sugar and the other given a saccharin, or artificial sweetener, solution. Shorty after the solutions were given, the participants underwent MRI scans to check for differences in activation of the reward centers of the brain. The researchers found that real sugar activates the area of the brain that signals fullness and helps to satisfy the craving of sweet food. In people who regularly consume artificial sweeteners, there was less signaling of fullness and satisfaction from the brain causing people to crave more sweet foods.  These results were also interesting, but the American Heart Association brings up a good point in that there are many environmental and genetic factors that influence people’s preference for sweet taste.  Evidence shows that there may be a genetic component that dictates the differences in people for their cravings for sweet. Overall, there are too many factors involved to confidently say artificial sweeteners make you crave more sweet foods.
What About Kids?
It was no surprise that a study released in 2012 showed that artificial sweetener intake among children has doubled from the year 2000.  Although there has been an increase in consumption in children, there is little evidence on the effects of long-term consumption. Just like artificial sweetener use in adults, the jury is still out as to whether or not artificial sweeteners cause obesity in children. Currently there are several studies looking at artificial sweetener use in children and weight change.  These new studies will be crucial in in helping us understand the role of artificial sweeteners in children and adolescents, and as to whether they have played a role in the childhood obesity epidemic.
The position statement of the Academy of Nutrition and Dietetics does not distinguish between use of artificial sweeteners in adults and children and states:
”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.” 
The Bottom Line
Blog post co-written by Kelsey Clinch, dietetic intern
 National Cancer Institute. Artificial Sweeteners and Cancer. 5 August 2009. Retrieved from: http://www.cancer.gov/cancertopics/factsheet/Risk/artificial-sweeteners
 American Dietetic Association. The Truth about Artififcial Sweeteners or Sugar Substitutes: How Much is Too Much?. 2011. Retrieved from: http://www.adaevidencelibrary.com/files/docs/nnsresourcedraft3.pdf
 Swithers S and Davidson T. A Role for Sweet Taste: Calorie Predictive Relations in Energy Regulation by Rats. Behavioral Neurosciences. 2008; 122 (1): 161-173.
 Raben A, Vasilaras TH, Maller AC, and Astrup A. Sucrose Compared with Artificial Sweeteners: Different Effects on Ad Libitum Food Intake and Body Weight after 10 wk of Supplementation in Overweight Adults. Am J Clin Nutr.2001; 76: 721-729.
 Aston SD, Martin CK, Han H, Coulon S, Cefalu WT, Geiselman P, and Williamson DA. Effects of Stevia, Aspartame, and Sucrose on Food Intake, Satiety and Post-prandial Glucose and Insulin Levels. Appetite. 2010; 55: 37-43.
 Green E, Murphy C. Altered processing of sweet taste in the brain of diet soda drinkers. Physiology and Behavior. May 2012.
 National research center. Artificial Sweeteners: Are They Helping You Lose Weight or Gain it? 12 June 2012. Retrieved at: http://www.center4research.org/2012/06/artificial-sweeteners-are-they-h…
American Heart Association and American Diabetes Association. Nonnutritive Sweeteners: Current Use and Health Perspectives. Circulation. 2012; 126: 509-519.
 Sylvetsky A, Welsh J, Brown R, and Vos M. Low-Calorie Sweetener consumption is increasing in the United States. Am J Clin Nutr 2012; 96:640–6.
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 Blackburn GL, Kanders BS, Lavin PT, et al. The effect of aspartame as part of a multidisciplinary weight-control program on short- and long-term control of body weight. Am J Clin Nutr. 1997;65:409-418.
- There is no absolute answer to whether or not long term or high dose use of artificial sweeteners leads to obesity and no evidence that shows artificial sweeteners lead to cancer in humans.
- For people with diabetes and those who need to watch the amount of sugar they eat, the diet versions of food are probably better than their regular counterparts since studies in the past have concluded that artificial sweeteners have led to weight loss when replaced with regular sugars. 
- The verdict is still out as to whether or not artificial sweeteners cause people to crave sweets or gain weight.
- If you’re skeptical, avoid artificial sweeteners. Explore different ways to sweeten your drinks without adding calories. Add lemon, mint or even a splash of fruit juice to jazz up your water.
- The key word is moderation! Doing something in excess is usually not healthy so make sure you are not drinking too many diet drinks. Aim for no more than 1-2 servings per day.