This transcript has been edited for clarity.
Hello. I’m Dr. David Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia.
The use of sugary additives has been an insidious and “sweet infatuation” component of the Western diet for the past few decades. As an alternative, we often turn to artificial, non-caloric sweeteners. But does the use of these, paradoxically, also represent a negative trend?
What we know about traditional sugar-based sweeteners
Calorie drinks are loaded with sweeteners, especially high fructose corn syrup, a cheaper and sweeter ingredient than cane sugar.
In a previous article, I discussed some of the real concerns we have around the use of high fructose corn syrup. Animal models studying colon cancer suggest that there is an association with the acceleration of colorectal neoplasia and that fructose is actually incorporated into the cancer.
In a Gut study, researchers from the Nurses’ Health Study II (1991-2015) showed that the odds of developing early-onset colorectal cancer more than doubled among women who consumed two or more sugary drinks per day. These results have attracted a lot of attention, because these levels of sugary drink consumption are the norm for so many people. If this is a cause for concern it should be discussed with patients individually.
The influence of sugary drinks on inflammatory bowel disease (IBD) has also been a major focus of research. This is due to the concept that sugary drinks can have an inflammatory component. The inflammation also has an association with diverticulitis, the risk of which increases in those who consume sugary drinks.
We also now have a recent study looking at data from the UK Biobank, which includes information on over 500,000 participants. Using a validated dietary assessment tool, researchers found that consuming more than one unit of sugary drinks per day increases the likelihood of developing IBD (hazard ratio). [HR], 1.51; 95% CI, 1.11–2.05) compared with nonusers, although the trend was not statistically significant.
Comparison between nonconsumers and those consuming more than one unit per day revealed a twofold increased risk of Crohn’s disease (HR, 2.05; 95% CI, 1.22-3.46) that was significant and statistically insignificant higher risk of ulcerative colitis (HR, 1.31; 95% CI, 0.89-1.92).
Collectively, these results highlight the growing concern about the use of caloric sugar-sweetened beverages and the increased risk for a variety of conditions, including non-alcoholic fatty liver disease (where there is undoubtedly a association), colitis and colorectal neoplasia.
Effects of artificial sweeteners on the microbiome
Knowing this, should we switch our patients from caloric sugary drinks to non-caloric artificial sweeteners? The answer to this question may be no.
Dr. Eran Elinav and his group of brilliant researchers at the Weizmann Institute of Science in Israel have previously published data from controlled animal models showing that the use of artificial sweeteners led to a microbial change that actually predisposed obesity and diabetes.
In their most recent study, which was published in Cell, they now present data from a randomized controlled trial in humans with the four main non-caloric sweeteners: saccharin, sucralose, aspartame and stevia. The researchers administered two sachets, three times a day, containing these non-caloric sweeteners, glucose or no supplement to 120 healthy participants, and then monitored changes in their microbiomes.
After 2 weeks of exposure, the researchers observed changes in the microbiome in all participants consuming these agents compared to the control population. Saccharin and sucralose, in particular, caused a significant deterioration in glycemic indices.
The researchers then transplanted the feces of these individuals receiving artificial sweeteners into germ-free mice. The mice actually mirrored the glycemic response of individual human participants specific to whatever agent they had received.
This tells us that non-caloric sweeteners can, by themselves, cause harmful changes in the microbiome, and that there may be an individualized response based on microbiome changes in a particular patient.
Now, it remains to be seen whether this predisposes them to glycemic alteration in prospective studies. However, these data are quite impressive and certainly back up what has already been shown in animal models.
The current understanding
Caloric sugary drinks are probably not such a good thing to consume, and I routinely recommend them as part of my advice to avoid a Westernized diet. The Mediterranean diet really is the way to go.
When it comes to using artificial sweeteners, we’re still on the learning curve, but this evidence suggests they may not be the best either. Consider the paradox of this. We use them in patients who are potentially glycemic, predisposed to diabetes or obese, and who may have a contradictory response to consuming them.
When it comes to my patients and artificial sweeteners, I tell them to avoid them as best they can and to use moderation if they must use them. The best advice is to drink more water. I think it’s really a safe bet, at least for now.
In terms of manipulation and dietary advice, I don’t think we do a very good job. We are what we eat and drink and I certainly think we should be more proactive in our advice to patients.
We hope this has given you better advice when talking to your patients.
I’m Dr. David Johnson. Thank you for your attention.
David A. Johnson, MD, a regular Medscape contributor, is professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia, and past president of the American College of Gastroenterology. His main focus is the clinical practice of gastroenterology. He has published widely in the internal medicine/gastroenterology literature, with primary research interests in diseases of the esophagus and colon, and most recently in the effects of sleep and the microbiome on gastrointestinal health and disease.
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