WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
By Dr. Mercola
Most people begin consuming diet products not because they love the taste or want to gain extra nutrition but because they believe doing so will help them lose weight. Those sweetened with aspartame make up a large part of the "diet" products market to this day, despite plentiful research showing they likely promote weight gain, not loss. Take the 2011 study by researchers at the University of Texas Health Science Center at San Antonio.
After following 474 diet soda drinkers for nearly 10 years, researchers found that the drinkers' waists grew 70 percent more than the waists of non-diet soda drinkers. Further, those who drank two or more diet sodas a day had a 500 percent greater increase in waist size.1,2 A similar study published in 2015 also revealed a "striking dose-response relationship" between diet soda consumption and waist circumference.
People who never drank diet soda increased their waist circumference by an average of 0.8 inches during the nine-year observation period, while daily diet soda drinkers gained an average of nearly 3.2 inches — quadruple that of those who abstained from diet soda altogether.3
Even occasional diet soda drinkers added an average of 1.83 inches to their waistline in that time period. The link between aspartame, the most used artificial sweetener worldwide, and weight gain, obesity and other health problems is so strong that some are now calling it one of the greatest consumer frauds of all time.4
Artificial Sweeteners Disrupt Your Metabolic Response
Part of the problem with artificial sweeteners is that the sweet taste they provide (in many cases even hundreds of times sweeter-tasting than sugar) does not match up with the energy (or calories) the food provides.
Your body, however, is designed to relate the two, and a recent study by Yale University School of Medicine researchers revealed that the mismatch that occurs when consuming artificially sweetened foods and beverages leads to disruptions to metabolism.5,6 In a Yale University press release, senior author and psychiatry professor Dana Small said:7
"[T]he assumption that more calories trigger greater metabolic and brain response is wrong. Calories are only half of the equation; sweet taste perception is the other half … Our bodies evolved to efficiently use the energy sources available in nature. Our modern food environment is characterized by energy sources our bodies have never seen before."
The study found that an artificially sweetened, lower-calorie drink that tastes sweet can trigger a greater metabolic response than a drink with a higher number of calories. Your body uses the drink's sweetness to help determine how it should be metabolized. When sweetness matches up with the calories, your brain's reward circuits are duly satisfied. However, when the sweet taste is not followed by the expected calories, your brain doesn't get the same satisfying message.8
This may explain why diet foods and drinks have been linked to increased appetite and cravings, as well as an increased risk of diabetes and other metabolic diseases.9,10 When you eat something sweet, your brain releases dopamine, which activates your brain's reward center. The appetite-regulating hormone leptin is also released, which eventually informs your brain that you are "full" once a certain amount of calories have been ingested.
However, when you consume something that tastes sweet but doesn't contain any calories, your brain's pleasure pathway still gets activated by the sweet taste, but there's nothing to deactivate it, since the calories never arrive. Artificial sweeteners basically trick your body into thinking that it's going to receive sugar (calories), but when the sugar doesn't come, your body continues to signal that it needs more, which results in carb cravings.
Diet Products May Promote Weight Gain
The research continues to pour in that consuming artificially sweetened products is counterproductive if you're looking to lose or maintain your weight.
A 2017 meta-analysis published in the Canadian Medical Journal found artificial sweeteners do not show a clear benefit for weight management and, instead, may be associated with increased body mass index (BMI) and cardiometabolic risk.11 A 2013 study likewise concluded that, like sugar-sweetened beverages, "artificially sweetened (diet) beverages are linked to obesity," and:12
" … [A]ccumulating evidence suggests that frequent consumers of these sugar substitutes may also be at increased risk of excessive weight gain, metabolic syndrome, Type 2 diabetes and cardiovascular disease.
This paper discusses these findings and considers the hypothesis that consuming sweet-tasting but noncaloric or reduced-calorie food and beverages interferes with learned responses that normally contribute to glucose and energy homeostasis. Because of this interference, frequent consumption of high-intensity sweeteners may have the counterintuitive effect of inducing metabolic derangements."
If you drink more than 21 artificially sweetened beverages a week, meanwhile, your risk of overweight and obesity is nearly double that of someone who does not.13 Aspartame consumption in particular has also been linked with an increased risk of abdominal obesity, which in turn is considered an important risk factor for cardiovascular diseases such as coronary heart disease and stroke.14 But when it comes to the overall health risks of artificial sweetener consumption, weight gain is only the beginning.
Serious Health Risks Linked to Artificial Sweeteners
The nonprofit consumer education group U.S. Right to Know (US RTK) released a fact sheet highlighting "decades of science" linking aspartame to serious health risks.15 "The U.S. Food and Drug Administration said aspartame is "safe for the general population under certain conditions." The agency first approved aspartame for some uses in 1981. Many scientists, then and now, have said the approval was based on suspect data and should be reconsidered," they say, adding:16
"Aspartame is a synthetic chemical composed of the amino acids phenylalanine and aspartic acid, with a methyl ester. When consumed, the methyl ester breaks down into methanol, which may be converted into formaldehyde."
Found in more than 6,000 products, from diet soda to sugar-free gum, children's medicines and no-sugar ketchup, some of the health risks linked to aspartame include:
Cancer
A study led by Dr. Morando Soffritti, a cancer researcher from Italy, found that even in low doses, animals were developing several different forms of cancer when fed aspartame.17
Sofritti is the head of the European Ramazzini Foundation of Oncology and Environmental Sciences, a well-respected, independent and nonprofit institution that has been dedicated to cancer prevention for more than 35 years. "An exceedingly high incidence of brain tumors" has also been identified in aspartame-fed rats, compared to rats fed no aspartame.18 Further, US RTK reported:19
"Harvard researchers in 2012 reported a positive association between aspartame intake and increased risk of Non-Hodgkin lymphoma and multiple myeloma in men, and for leukemia in men and women.20
In a 2014 commentary in American Journal of Industrial Medicine, the Maltoni Center researchers wrote that the studies submitted by G. D. Searle for market approval 'do not provide adequate scientific support for [aspartame's] safety. In contrast, recent results … provide consistent evidence of [aspartame's] carcinogenic potential.'"
Heart Disease
A study of nearly 60,000 post-menopausal women who were followed for about 10 years found that drinking just two diet drinks a day can dramatically increase your risk of an early death from heart disease.21
The 2017 Canadian Medical Association Journal study also found artificial sweeteners are associated with a higher incidence of cardiovascular events and hypertension,22 as did a 2016 Physiology & Behavior study, which cited artificial sweeteners' link to cardiometabolic and other risks as "troubling."23
Dementia and Stroke
Drinking diet soda daily may increase your risk of stroke and dementia threefold.24 Even drinking artificially sweetened beverages one to six times a week was linked to a 2.6 times greater risk of stroke.25 For a bit of background, when aspartame is in liquid form, as it is in diet soda, it breaks down into methyl alcohol, or methanol, which is then converted into formaldehyde and represents the root of the problem with aspartame.
Research has even found that the administration of aspartame to rats resulted in detectable methanol even after 24 hours, which might be responsible for inducing oxidative stress in the brain.26 Chronic methanol exposure has been linked to memory loss and Alzheimer's disease in animal studies.27
In addition, US RTK points out, "While many studies, some of them industry sponsored, have reported no problems with aspartame, dozens of independent studies conducted over decades have linked aspartame to a long list of health problems … including … seizures … intestinal dysbiosis, mood disorders, headaches and migraines."28
Particularly in regard to its link to weight gain and its continued use in so-called "diet" products, Stacy Malkan, co-director of US RTK, has asked, "Is 'diet' soda a scam?"29 — and I believe that would be putting it mildly.
Changing Diet to Zero?
Even though diet soda still makes up 25 percent of the carbonated beverages sold in the U.S. (by volume), sales have dropped by 27 percent (or 834 million cases) since 2005.30 In an effort to revamp Diet Coke's increasingly negative reputation, Coca-Cola has rolled out artificially sweetened zero-calorie Coca-Cola Plus, which has added fiber, in Japan, while in the U.K. you'll find Coca-Cola Zero Sugar (formerly Coca-Cola Zero).
What's the difference between Coke Zero and Diet Coke? They both contain two artificial sweeteners (aspartame and acesulfame K) and virtually identical ingredients, except for citric acid (found only in Diet Coke) and sodium citrate (found only in Coca-Cola Zero Sugar). In short, they're virtually the same thing, packaged differently in an attempt to get away from the potentially huge legal liabilities of putting the word "diet" on a product that promotes weight gain and obesity.
As for Coca-Cola's attempts at an explanation, a spokeswoman again stayed away from diet claims, instead saying, "Both drinks are sugar-free and calorie-free. Coca-Cola Zero Sugar looks and tastes more like Coca-Cola Classic, while Diet Coke has a different blend of flavors which gives it a lighter taste."31
Splenda Using Shills to 'Debunk the Junk'
Artificial sweetener Splenda, the brand name for sucralose, is also getting in on the "zero" trend, now marketing Splenda Zero liquid sweetener as a "no calorie way to sweeten drinks 'til they're just right."32 Like aspartame, Splenda has also been linked to concerning health effects, like increased calorie consumption, an increased risk of cancer in mice33 and disrupted insulin response.
In the latter case, when study participants drank a Splenda-sweetened beverage, their insulin levels rose about 20 percent higher than when they consumed only water prior to taking a glucose-challenge test.34 An animal study also showed that 12 weeks of consuming Splenda led to significant alterations in the gut microflora of rats, including reductions in beneficial microflora.35 Yet, on the Splenda Living blog, you'll read no mention of these serious health risks but, instead, a claim of using science to "debunk the junk."36
They've even partnered with SciBabe, aka Yvette d'Entremont, a woman who's "long looked at the alternative medicine and pseudoscience movements with a skeptical eye."
In a seemingly independent blog post "debunking the junk about Splenda," which features a photo of her drinking a Splenda-sweetened coffee drink. In it, she touts the virtues of Splenda and how it played a part in the lifestyle changes she made to lose 90 pounds. Yet, if you look closely you'll see in the tiniest of disclaimers at the bottom: "The blog post is in partnership with SPLENDA® Brand Sweeteners."
Simple Tricks to Help You Ditch Artificial Sweeteners
If you're one of the nearly half of U.S. adults who consume artificial sweeteners, mostly in the form of diet soda, daily (even one-quarter of kids do so as well),37 it's important you're let in on the truth: If you consume a lot of artificial sweeteners, you're putting your health at risk. Instead, when you're tempted to reach for a diet soda or other artificially sweetened product, fight the urge with natural, good-for-you options.
Sour taste, such as that from fermented vegetables or water spruced up with lemon or lime juice, helps to reduce cravings for sweets. If that doesn't appeal to you, try a cup of organic black coffee, an opioid receptor that can bind to your opioid receptors, occupy them and essentially block your addiction to other opioid-releasing foods.38,39
I also recommend addressing your cravings on an emotional level. Turbo Tapping, which is a version of the Emotional Freedom Techniques (EFT), is specifically suited to help eliminate sweet cravings and it can be done virtually anywhere, anytime a craving strikes.