Risk In the news – Artificial Sweetener A Cancer Risk?
Last week we looked at risk and how risk impacts our lives and our decisions. This week, we’re going to look at risk, and data to understand how risk plays a role in our lives.
While it's easy to get caught up in clickbait headlines about the latest scientific breakthroughs, that can fill us with fear and anxiety, it's essential to take a step back and explore the information critically and directly from the source. In this post, we'll dig into the facts surrounding that latest paper that's led to sensational headlines around the risks associated with artificial sweeteners.
What does the news say?
You may have seen the headlines: “Artificial sweeteners cause cancer in mice. Here’s worrying data from humans.”, “Hard to swallow. Popular fizzy drinks could increase your risk of deadly cancers, study finds”, “Are artificial sweeteners a safe alternative?”, “These Popular Drinks May Increase Cancer Risk, New Study Suggests”, “Artificial Sweeteners Are Associated With Increased Cancer Risk, Finds Large-Scale Cohort Study”, “Artificial sweeteners linked with a 13% higher risk of cancer”.
These are a few, of the many, headlines making their way through our newsfeeds over the past couple of weeks. But, do most of these articles explain the scientific nuance?
We found that the reporting quality varied dramatically depending on the news source. While some sources explained the research and the risks fully, other sources provided little useful information other than reinforcing the headlines that artificial sweeteners cause cancer.
Most concerning, it appears that the articles shared more frequently contained less scientific rigor and more on adverse health outcomes.
So, what are the facts?
We've looked at the study and found that, frustratingly, many news headlines and stories did not fully represent the science or the researchers' conclusions. Unfortunately, this isn't uncommon in the world of science journalism.
What makes this case particularly poignant is that the limitations of the study are specifically called out by the study's authors yet were not discussed in many of the journalism and blog posts around this topic. The study's shortcomings are significant in understanding the actual rise in cancer risk associated with the consumption of artificial sweeteners.
Author identified study drawbacks:
- The study was not designed to determine if artificial sweeteners cause cancer, therefore it cannot conclude that artificial sweeteners cause cancer.
- The study lacked diverse participants.
- The data suggests some of the outcomes could be the result of participants' weight-related health disturbances.
What do the drawbacks mean?
The author-identified shortcomings help put research into context and provide insights into future research directions.
Study design: casual links cannot be established
When beginning to design a study, all outcomes good, bad, and neutral are equally possible. The goal of a study design is to eliminate factors that can impact the study’s results. While researchers can adjust for factors that may unduly sway outcomes, there are many factors that cannot be entirely ruled out and adjusted for in the data model. Meaning, the link between an ingredient and cancer could be completely unrelated and happenstance (e.g., correlation vs. causation).
Due to this drawback, this study shows the correlation between artificial sweeteners in this particular data set but does not determine causation. Determining causation would require a different type of study using a different research model. In this study, it’s especially poignant because other similar studies haven’t replicated this result, as noted by the authors.
Impact of participant diversity
The study participants are integral to the study’s design and results. Participants in this study were more likely to be females with higher education and socio-professional levels. They tended to be younger, smokers, less physically active, and have prevalent diabetes. Additionally, they had a lower intake of fiber, fruits and vegetables, wholegrain foods, and alcohol. They tended to consume more sodium, total sugar, dairy products, sugary foods and drinks, and unsweetened non-alcoholic beverages.
When participants are overrepresented from one sex, sex-related biological, physiological, and behavioral differences between female and male participants can impact the outcomes. When participants are more likely to be less healthy overall (e.g., smokers, less active, overweight) and from one specific socio-economic class it can greatly impact the study’s outcomes. Due to this drawback, the study cannot provide precise cross-population outcomes due to the limited scope of participant data.
Weight-related health disturbances
It’s well documented that individuals with obesity and with worse overall health, in general, are at a higher risk for metabolic disturbances, cancers, and other health conditions.
Due to this drawback, the participants may already be at a greater risk for cancers due to their overall health.
What else do I need to know about the study?
A major problem with epidemiological studies like this study is that it requires participants to recall and record information that people can easily forget or misremember.
While it may be the best way we currently have to collect this sort of data, there are limitations when we rely on participant recall that needs to be taken into consideration. Especially as it relates to exposure and potential adverse health outcomes caused by exposure.
The findings many news articles miss
While many news articles focused on sensationalized finds, they did not include information that showed no trend of adverse health impacts noted in the study itself. Nor did they discuss the known adverse health impacts of obesity which can be caused by excess calories consumed via sugary foods and beverages.
Readers need to see the full story and that requires sharing all the relevant results, not only the eye-catching results but also the results that show no adverse effect.
What does this mean for the scientific community as a whole?
We think it's important to call out the facts and help demystify the science and, in some cases, calm fears. We need to do our best to continue highlighting study shortcomings, vetting our research through the lens of the public and the press, and be willing to work with journalists and even bloggers to make certain they get our research right.