Artificial sweeteners: Do they really control blood sugar levels, raise the risk of heart attack and stroke in diabetics?

WHAT ARE ARTIFICIAL SWEETENERS?

Artificial sweeteners, also called non-nutritive sweeteners (NNS, because these have no nutritional potential) are prepared chemically. They are 30-1,300 times sweeter than the natural sugar called sucrose. These are used in preparation of sweetened beverages, juices, dairy products, desserts, processed foods, jams and so on. There are several artificial sweeteners that contain aspartame, saccharine, sucralose, neotame, cyclamate, acesulfame-k, stevia, erythritol and so on. The first five of these have been generally recognised as safe (GRAS) by the Food and Drug Administration (FDA), USA. Stevia, a plant based sweetener that has been used in Japan since the 1970s, has not yet been approved by the FDA. These have been promoted as diabetes and tooth-friendly and ideal for inducing weight loss.

DEVELOPMENT OF ARTIFICIAL SWEETENERS WAS ALWAYS PROBLEMATIC

The story of saccharine is widely known as it was used in both World Wars for sugar rationing. In laboratory animals, it was found to induce bladder cancer. This doubt was later cleared with further studies. Aspartame is toxic to patients who suffer from a rare disorder called phenylketonuria. It has been blamed for brain tumours and chronic fatigue syndrome without any concrete proof. The fear of cancer with the use of these alternatives still lingered in people’s minds.

ARE ARTIFICIAL SWEETENERS BENEFICIAL FOR WEIGHT LOSS OR DIABETES?

All individuals using artificial sweeteners aim to cut down calories, expect weight loss and anticipate a decrease, or at least no increase, in blood sugar. They believe these will lead to a general improvement in health due to the absence of sugar in the diet. However, some studies now show that the use of these agents leads to obesity, hypertension, Type 2 diabetes and even stroke upon long-term use, contrary to expectations. But others continue to vouch for their effectiveness. In a recent review, authors of a major study say: “The available evidence suggests that NNS beverages sweetened with single or blends of NNS have no acute metabolic and endocrine effects, similar to water.” To sum up, they are supporting the use of these agents in beverages.

However, authors of a major review published in 2019 cautioned that the quality of most studies on artificial sweeteners was not of high standard. After considering data from all studies, they concluded that “No evidence was seen for health benefits from non-sugar sweeteners and potential harms could not be excluded”. A WHO review (2022) also concluded that long-term weight loss has not been proven with the use of artificial sweeteners. Beverages/cola companies have opposed this notion.

NEW SIGNALS OF CANCER AND HEART DISEASE

However, new studies should raise fresh concerns. In a recent large French study (NutriNet-Sante, published in 2022), people taking artificial sweeteners were studied for up to nearly eight years. In this study, the overall risk of cancers (breast cancer and obesity-associated cancers) increased, correlating to the amount of intake of these sweeteners. This was particularly shown for aspartame and acesulfame-k, which have been used in a wide variety of popular foods and beverages worldwide. In this study, most people consumed sweetened beverages or tabletop sweeteners. An interesting point to investigate now is whether weight gain associated with artificial sweeteners lead to observed increase in cancer risk. Possible cellular mechanisms for induction of cancer include inflammation and DNA damage.

A more damaging study (published in a top journal, ‘Nature Medicine’ a few days ago) shows that an artificial sweetener, erythritol (sold singly or combined with other artificial sweeteners such as stevia), can induce thrombosis (clotting), thus having potential to cause heart attack or stroke over three years. More concerning, once taken, erythritol can stay in the body for several days. This study was very well conducted and consisted of population-based and lab-based data. Increase in heart disease and stroke risk by artificial sweeteners (aspartame, acesulfame, sucralose) has been shown by a large (103 388 participants) French study published in 2022. Concerned by findings of these recent studies, many experts have suggested that FDA and other regulatory agencies should revise their guidelines as to which artificial sweeteners should be considered as generally safe/unsafe.

TIME FOR NEW ADVISORY

My advisory about artificial sweeteners has changed too. In view of these recent data, I often worry about uninformed individuals who continue to take sweetened beverages in excess. I also wonder if some of these artificial sweeteners are being mixed in laddoos and mithais targetted for people with diabetes during festivals, especially Diwali. I am also worried if these artificial sweeteners have been injected in the particularly sweet fruits I recently bought. But I am clearer in my mind as to my advice. I agree with French researchers of the two large studies, who wrote, “Our results indicate that these food additives, consumed daily by millions of people and present in thousands of foods and beverages, should not be considered a healthy and safe alternative to sugar.” No artificial sweeteners from now on, and that includes diet colas, I tell my patients. I allow well-controlled patients with diabetes to take less than 5 gram sugar (about one teaspoonful) in tea/coffee instead. Finally, I have made a mental note to carefully read the front of package labels of all sweet foods I am buying, including the luxury I sometimes indulge in, chocolates.

(Dr Misra is Padma Shree Awardee and author of the book, ‘Diabetes with Delight.’)