Artificial sweeteners may not be as healthy as we think

How nutritionally rational is it when one eats all the calories one can ingest in a buffet lunch, but sheepishly requests for artificial sweetener from the waiter for one’s iced tea? Another version is to order “diet” instead of regular soft drinks.

Not very long ago, a local medical expert who was invited to give a lecture during a medical society meeting didn’t mince his words when he labeled it “gustatory hypocrisy” when someone in the audience pushed the contention that artificial sweeteners are safe and do not increase one’s risk of developing diabetes and other metabolic problems.

Several years ago, a noted international specialist called this in his published commentary a wolf in sheep’s clothing. That was how Dr. David Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia, described artificial sweeteners in his commentary that came out in the Medscape Internal Medicine publication.

Dr. Johnson is just one of many medical specialists who have expressed concern about the possible harmful effects of artificial sweeteners used in diet soft drinks and a variety of other food and drinks. They are recommended for better weight control and for patients with diabetes, since they’re supposed to be noncaloric and don’t contain any absorbable sugar.

However, based on some studies, they may not really be the healthier alternative many had hoped for. There are even studies suggesting that they may increase the risk of stroke, myocardial infarction (heart attack) and vascular death (related to narrowing of the arteries).

Diet soda consumption

Several years ago, Dr. Hannah Gardener, the lead investigator of a research paper from the University of Miami, Florida, reported during the annual congress of the American Stroke Association that people who had diet soda every day experienced a 61-percent higher risk of cardiovascular complications than those who reported not taking diet soda regularly.

Other studies have likewise linked diet soda consumption and the risk of developing metabolic syndrome and diabetes. Metabolic syndrome is composed of several risk factors including obesity, high blood pressure, cholesterol and blood-sugar problems. This syndrome has been associated with serious complications like heart attack, stroke and premature deaths.

One should interpret all these “observational” studies with caution, though. At most, they suggest an association but not a conclusive causal relationship, which more strictly designed, prospective clinical trials can provide.

In his commentary, Dr. Johnson cited a series of experiments from the Weizmann Institute of Science in Rehovot, Israel, that showed worsening of the metabolism, including blood-sugar control, in experimental animals.

He attributed these potentially harmful effects to the interaction with the microflora in the intestines. The hypothesis is that the intestinal microflora can convert the artificial sweeteners into fermented substances that may be harmful to the body’s metabolism. Pretreating the experimental animals with antibiotics that kill the intestinal microflora prevent this reaction.

The research group correlated these findings in humans, using a database with nutritional profiling in a large number of patients. They specifically looked at associations with blood sugar control and ingestion of noncaloric artificial sweeteners. They noted increases in prediabetes, reduced blood-sugar tolerance, impaired fasting blood sugar, and increased body weight and waist-to-hip ratios and hemoglobin A1c, which are indicators of diabetes.

Metabolic syndrome

“So, there was this central obesity pattern seen in metabolic syndrome. These changes were all related to this exposure to noncaloric artificial sweeteners, and there seemed to be a dose-related effect. In other words, those people who used more of these noncaloric artificial sweeteners had even more pronounced effects,” said Dr. Johnson.The researchers then evaluated seven healthy, lean participants and fed them the Food and Drug Administration-recommended acceptable daily intake of an artificial sweetener (saccharin). They looked at the blood-sugar effect as a response only to the saccharin ingestion, with standardized meals. Four out of the seven participants showed impaired glucose or carbohydrate tolerance (IGT), and Dr. Johnson described the blood-sugar response as “strikingly aberrant” compared to baseline values. IGT is an established precursor to diabetes.

Dr. Johnson implied we may be achieving the opposite as we try to attain an ideal reduction in the number of the diabetic population worldwide. “As we strive to try to improve these disease states (metabolic illnesses like diabetes), we actually may be making them worse,” said Dr. Johnson.

“To conclude, buyer beware to patients with diabetes or obesity. These artificial sweeteners certainly may be a part, if not the crux, of the problem, and patients should discuss using these sweeteners with their physician. Physicians who recommend these sweeteners need to take a step back and really reevaluate their recommendations, especially among their patients with diabetes and obesity. In fact, we may be dealing with a wolf in sheep’s clothing,” he warned.

Medical experts like Dr. Johnson, have also expressed, not only short-term, but long-term grave concerns about the potential harm of artificial sweeteners contained in diet sodas and other common drinks and foods.

Many doctors and patients alike have the impression that artificial sweeteners are an ideal alternative to sugar since they impart a sweet taste to drinks and foods with a negligible number of calories. The sweetening effect of artificial sweeteners is really much more than sugar, such that only 30 mg of aspartame would already have the sweet taste obtained with 5 grams (5,000 mg) of sugar.

Common practice

It’s therefore common practice that overweight individuals and diabetic patients replace sugar with these high-intensity sweeteners to avoid raising their blood sugar or gaining more calories that add to their weight. Ingesting these sweeteners intermittently or on a short-term basis does not appear to pose any serious harm, but based on the results of observational studies, long-term regular intake of drinks and food containing artificial sweeteners has been linked to cardiovascular events or complications including strokes. A few papers link them to other medical problems such as lymphomas but the link is still not strong enough. But as they say, if there’s smoke, there could be fire later on.

What is to be emphasized, though, is that these are just observational studies, which only show an association, but not a conclusive causal relationship between artificial sweeteners and strokes. Lawyers would probably label it as circumstantial evidence, which may not be strong enough to implicate artificial sweeteners.

Researchers should do well-designed prospective clinical trials either to determine or to rule out a causal relationship between artificial sweeteners and cardiovascular complications. But again, the big question is—who will fund this research?

With the strong lobby of industries raking in huge money from various drink and food products using artificial sweeteners, such a research is not likely to happen—not unless government regulators (the food and drug administration and other regulatory agencies) would show strong political will and require the manufacturers to conduct a clinical trial showing safety of long-term usage of these artificial sweeteners.

A few years ago, the Agence Nationale de Sécurité Sanitaire (Anses) in France convened a working group which evaluated all available scientific evidences to determine the benefits and nutritional risks of high-intensity sweeteners. The Anses study showed no conclusive risks of using high-intensity sweeteners, but it also reported that there was no remarkable health benefit from consuming them. More properly designed studies are still needed to see if artificial sweeteners are a boon or a bane.

Meanwhile, it would be wise to exercise moderation in drinking diet sodas and juices, or eating low-calorie cookies and food products that contain artificial sweeteners. We should disabuse our minds of the belief that they are part of a healthy diet. The good old natural way of limiting our caloric intake and exercising regularly remain the mainstay of a truly healthy lifestyle.