This transcript has been edited for clarity.
Hello. I am Dr. David Johnson, Professor of Medicine and Chief of Gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia.
The use of sugar additives has been an insidious and “sickeningly sweet” component of the Western diet in recent decades. As an alternative, we often turn to non-caloric artificial 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 component that is both cheaper and sweeter than cane sugar.
In a previous article, I discussed some of the real concerns we have about using high fructose corn syrup. Animal models examining colon cancer suggest that there is an association with accelerated colorectal neoplasia and that fructose actually incorporates into cancer.
In a study by Gut, researchers from the Nurses’ Health Study II (1991-2015) showed that the risks of developing early colorectal cancer more than doubled in women who consumed two or more sugary drinks per day. These results have drawn a lot of attention because these levels of sugary drink consumption are the norm for so many people. Whether this is a cause for concern should be discussed with patients on an individual basis.
The influence of sugary drinks on inflammatory bowel disease (IBD) has also been the subject of significant research. This is due to the concept that sugary drinks may have an inflammatory component. Inflammation is also associated with diverticulitis, the risk of which is increased in those who consume sugary drinks.
We also now have a recent study analyzing 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 sugar-sweetened beverages per day increases the likelihood of developing IBD (relative risk [HR], 1.51; 95% CI, 1.11-2.05) compared to non-consumers, although the trend was not statistically significant.
The comparison between non-drinkers and those consuming more than one unit per day revealed a two-fold increased risk of Crohn’s disease (RR, 2.05; 95% CI, 1.22-3.46) which was significant, and a higher but statistically non-significant risk of ulcerative colitis ( RR, 1.31; 95% CI, 0.89-1.92).
Together, these results highlight the growing concern about the use of calorie-sweetened beverages and the increased risk of various conditions, including non-alcoholic fatty liver disease (where there is a clear association), colitis and colorectal neoplasia.
Effects of artificial sweeteners on the microbiome
Knowing this, should we switch our patients from calorie-sweetened beverages to calorie-free 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 previously published data from controlled animal models showing that the use of artificial sweeteners leads to a microbial change that actually predisposes to obesity. and diabetes.
In their most recent study, published in Cell, they now present data from a randomized controlled trial in humans using the four major noncaloric sweeteners: saccharin, sucralose, aspartame and stevia. Investigators administered two sachets, three times a day, containing these noncaloric sweeteners, glucose or no supplement to 120 healthy participants, 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 alteration in glycemic indices.
The investigators then transposed the feces of those individuals receiving artificial sweeteners into germ-free mice. The mice actually mirrored the glycemic response of individual human participants specific to the agent they had received.
This tells us that noncaloric sweeteners can, by themselves, cause harmful changes to the microbiome, and that there may be an individualized response based on changes in the microbiome in a particular patient.
Whether this predisposes them to glycemic alteration in prospective studies remains to be seen. Nevertheless, these data are quite impressive and certainly confirm what has already been shown in animal models.
The current understanding
Calorie sugary drinks are probably not such a good thing to consume, and I regularly advise against them as part of my advice to avoid a westernized diet. The Mediterranean diet is truly 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 thing either. Think of the paradox in there. We use them in patients who are potentially glycemic, predisposed to diabetes or obese, and who may have a contradictory response when 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 absolutely must use them. The best advice is to drink more water. I think it’s definitely a safe option, at least at present.
When it comes to dietary manipulation and advice, I don’t think we’re doing a very good job. We are what we eat – and drink – and I certainly think we should be more proactive in advising patients.
I hope this has provided you with better guidance when talking to your patients in the future.
I am Dr. David Johnson. Thanks for listening.
David A. Johnson, MD, a regular contributor to Medscape, is professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Va., and past president of the American College of Gastroenterology. Its main focus is the clinical practice of gastroenterology. He has published extensively in the internal medicine/gastroenterology literature, with primary research interests in diseases of the esophagus and colon, and more recently in the effects of sleep and the microbiome on health and gastrointestinal diseases.
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