Many research papers have associated artificial sweeteners with increased risk for cancer, weight gain and diabetes, but nobody yet has proven that artificial sweeteners cause these conditions. Researchers in Israel, Singapore and Italy used genetically modified bioluminescent bacteria from E. coli to show that taking artificial sweeteners causes toxic bacteria to overgrow in the colon and produce chemicals that are harmful to humans (Molecules, Sept 25, 2018;23(10):2454). This study supports an earlier study from the University of North Carolina and University of Georgia that showed that artificial sweeteners change colon bacteria to those that block the disease-preventing benefits of eating soluble fiber in fruits and vegetables (Molecules, Feb 9, 2018;23(2):367).
How Artificial Sweeteners May Affect Gut Bacteria
Many studies show that the bacteria in your colon have a strong role in controlling your immunity. The bad bacteria try to enter and damage the cells lining your colon, which turns on your immunity and can keep it active to cause inflammation and diseases. The good bacteria are happy to stay inside your colon where they eat the same food that you do. They convert the soluble fiber in fruits and vegetables into short chain fatty acids that lower high cholesterol and high blood pressure, make your cells more responsive to insulin to help prevent diabetes and reduce inflammation that can cause cancer and heart attacks. Artificial sweeteners appear to block the good bacteria that produce short-chain fatty acids, such as butyrates.
Other Concerns about Artificial Sweeteners
Artificial sweeteners appear to make you hungry so that you eat more food, which increases risk for weight gain and diabetes. In one study, researchers manipulated drinks without people knowing it. They controlled calories by adding tasteless maltodextrin, and the sweetness by adding the artificial sweetener sucralose. Those who consumed the artificially sweetened drinks:
• ate more food,
• had higher blood sugar levels and
• gained more weight than those who consumed a less sweet, higher calorie drink (Current Biology, August 11, 2017).
This study implies that a sweeter-tasting, lower-calorie drink is more likely to cause diabetes than a less-sweet drink with more calories.
For many years I have reported on studies associating artificial sweeteners with weight gain, diabetes, dementia, strokes, cancers and so forth. For example, see:
Artificial Sweeteners, Obesity and Diabetes
New Studies on Artificial Sweeteners
Artificial Sweeteners, Dementia and Strokes
New data showing the effects of artificial sweeteners on gut bacteria could provide the key to all of these negative associations.
Sugared Drinks Are Even More Harmful
Sugar in liquid form raises blood sugar more quickly than any other type of food. One can of sugar-sweetened soda contains 25 to 50 grams of sugar, the recommended upper limit for sugar for an entire day. Because of their high sugar content and lack of fiber, all fruit juices and fruit drinks are just as unhealthful as sodas. Sugared drinks have been associated with:
• weight gain (BMJ, 2015;351:h3576)
• increased risk for diabetes (Diabetes Care, 2009;32:688–694)
• Alzheimer’s disease in rats (J Nutr Health Aging, 2016;20:509–513)
• high blood pressure, high cholesterol, heart attacks, and strokes (Circulation, 2012;125:1735–1741; Am J Clin Nutr, 2009;89:1037–1042; J Gen Intern Med, 2012;27:1120–1126)
I believe that both sugar-sweetened drinks and artificially-sweetened drinks can be harmful to your health. Sugared drinks are useful during prolonged, vigorous exercise, but at all other times, I recommend that you use water to quench your thirst. Unsweetened coffee and tea appear to be safe also.