Artificial Sweeteners: Are They a Health Risk?

Artificial sweeteners are in the spotlight. The World Health Organization (WHO) has issued guidelines warning against their use to control body weight or reduce the risk of non-communicable diseases. And a study conducted by ISGlobal suggests that artificial sweeteners do not increase the risk of cancer in general, but may pose risks for patients with certain health conditions.

[This article was written by Camille Lassale, Assistant Research Professor at ISGlobal, and Anna Palomar, Postdoctoral Researcher at ISGlobal.]

We now know that excessive sugar consumption has serious health consequences: it increases the risk of developing obesity, diabetes, heart disease and even cancer, for which obesity is a risk factor. This has led to an increase in the use of artificial sweeteners. These are additives that give foods a sweet taste with virtually no added calories, in small amounts to achieve the sweet taste of sugar.

Of the 19 artificial sweeteners authorized in Europe, aspartame, saccharin, acesulfame K, cyclamate and sucralose are the most common in Spain. They are found in beverages, desserts, chocolate and dairy products, and are hugely popular: it is estimated that 79% of adults in Spain consume artificial sweeteners on a daily basis, and around 9% of foods and beverages contain them.

But are they really harmless for health?

Are artificial sweeteners a proven cause of cancer?

The WHO released a guideline on May 15 that warns against the use of artificial sweeteners to control body weight or reduce the risk of noncommunicable diseases, saying long-term use is not effective and could pose health risks. In particular, the report suggests that continued use is not useful for reducing body fat and could increase the risk of type 2 diabetes and cardiovascular disease.

Some studies suggested that high intake of artificial sweeteners, particularly saccharin, may be associated with bladder cancer (although the quality of the evidence was rated very low)

This recommendation is based on a systematic review of the available evidence from observational and intervention studies on priority health outcomes: overweight and obesity, dental caries, type 2 diabetes, cardiovascular disease, cancer, chronic kidney disease, dietary patterns (including sweet preferences) and several cognitive parameters (plus asthma and allergies in children). WHO does not comment on the cancer findings in its guideline because the review found no overall association between artificial sweetener intake and cancer incidence or mortality. However, some studies suggested that high intake of artificial sweeteners, particularly saccharin, may be associated with bladder cancer (although the quality of the evidence was rated very low). Therefore, there is some controversy about the safety of artificial sweeteners in terms of cancer risk.

What the studies say about aspartame

Some studies in rats have suggested a possible link between two specific artificial sweeteners, cyclamate and saccharin, and bladder cancer. Other studies on another artificial sweetener, aspartame, showed an association between high intake and the development of tumors in multiple organs in rats and mice. Based on these findings, aspartame has been given priority for evaluation by the International Agency for Research on Cancer (IARC) to assess potential cancer risk.

A recent study conducted in France on a large population suggested that a high intake of aspartame may increase the risk of breast cancer and obesity-related cancers. Another study found that drinking artificially sweetened beverages was associated with an increased risk of dying from obesity-related cancers, but this may be influenced by body weight.

An ISGlobal study conducted in Spain

To fill the evidence gap and address this important health issue, we studied a group of people with colorectal, breast, prostate, stomach, or chronic lymphocytic leukemia and a control group (people without a cancer diagnosis). All of them were participating in the MCC-Spain study, conducted between September 2008 and December 2013 in 12 Spanish provinces. We asked them about their use of artificial sweeteners using a dietary questionnaire. We compared moderate and high consumers with those who did not use any, and we looked at both aspartame-containing products and other artificial sweeteners.

Overall, we found no association between the use of aspartame or other artificial sweeteners and cancer. However, among people with diabetes, high consumption of aspartame was associated with an increased risk of stomach cancer, but a decreased risk of breast cancer

Overall, we found no association between the use of aspartame or other artificial sweeteners and cancer. However, among people with diabetes, high consumption of aspartame was associated with an increased risk of stomach cancer, but a decreased risk of breast cancer. For other artificial sweeteners, high intake was associated with an increased risk of colon and stomach cancer. It is important to note that the number of cases in participants with diabetes was small, so these results should be interpreted with caution. In addition, because this study, published in the International Journal of Cancer, was based on observations rather than controlled experiments, there is a possibility that other factors may have influenced the results that were not taken into account.

In conclusion, our findings suggest that artificial sweeteners do not increase the risk of cancer in general, but may pose risks for patients with certain health conditions.