Artificial Sweeteners - Where is the research?

An article popped up today that inspired me to go on a dig into the latest research into artificial sweeteners and what we know about their effects on the body over time.

The VICE article focuses more on the strange history of how, then CEO of a pharmaceutical company, Donald Rumsfeld (yes, this Donald Rumsfeld), got the FDA to approve aspartame despite questionable safety. The long and short of it: it was a "controversial" approval.

Repeated, third-party assessed research has more recently been accumulating, drawing new scrutiny around the health and safety of aspartame. The investigators at VICE wrote:

The Center for Science in the Public Interest (CSPI) conducted a detailed investigation into the findings reported by the Ramazzini Institute, filing FOIA requests for further information. Lisa Lefferts, senior scientist at CSPI, said they found the criticisms to be entirely without merit, and characterized the findings this way: 'There is consistent evidence from well-designed, independent studies that aspartame causes cancer in animals and therefore, it may also cause cancers in humans. It is pretty compelling evidence and we recommend that consumers avoid it.'

The list of evidence further piles around the already concerning data-sets. VICE details additional researchers coming to similar conclusions:

Erik Millstone, professor of science policy research at the University of Sussex, who has been studying aspartame since 1984, says that the Ramazzini studies provide 'sufficient grounds to ban aspartame. We know it caused cancer in several varieties of several species of laboratory animals in dose-related ways, and at diverse sites.'

And most recently, in 2012, Harvard researches published their research, which VICE reported:

The researchers found a positive association between diet soda and total aspartame intake and risks for non-Hodgkin lymphomas and multiple myeloma in men and leukemia in both men and women

And this is focused primarily on direct-cause diseases, i.e. diseases caused by the substance, particularly cancers. There is a whole other slowly mounting body of evidence from research that there are significant and concerning indirect causes of disease from regular exposure to artificial sweeteners, e.g. aspartame that disrupt the digestive process, most notably by altering the gut microbiome.

Research into the widespread relationship between the state of a person's gut microbiome and other aspects of health is quickly becoming an exciting area of research because of not only the obvious connection between the gut and the wider digestive system but also because of the apparently powerful connections between the gut and the brain, the gut and the immune system, and the gut and the endocrine system.

Harvard Health Blog's contributing editor Eva Selhub MD writes about the increasing importance medical professionals should be putting on a healthy gut microbiome and the value of fermented and probiotic foods. Her main emphasis is on the importance of the gut in mental health, namely depression and anxiety, as her analysis of others' research points to the strong link between certain changes in diet to include probiotic foods and improvements in mental health.

Before we get too side-tracked, I want to quickly turn back to the case of aspartame and other artificial sweeteners and their apparently deleterious effects on the gut microbiome. These negative effects cause systemic and widespread harm throughout the body that create other patterns of disease. We can begin by looking at some of the research that VICE put together, showing the ironic links between drinking artificial sweeteners and "obseity, type 2 diabetes, and metabolic syndrome, and cardiovascular disease".

Following up on some more recent research, VICE pointed to research:

At the Weizmann Institute in Israel, researchers found that feeding mice artificial sweeteners caused glucose intolerance, one of the key markers in diagnosing diabetes. Through a series of experiments, the researchers concluded that the sweeteners were making changes to the bacteria in the gut (called the microbiota), inducing glucose intolerance. The researchers did a small follow-up study in humans and got the same result.

Their research and interviews stop there, but I dig some quick digging to find out what other research is saying.

From the international Physiology and Behavior Journal, Nettleton, Reimer, and Shearer write in their abstract:

Disruption in the gut microbiota is now recognized as an active contributor towards the development of obesity and insulin resistance. This review considers one class of dietary additives known to influence the gut microbiota that may predispose susceptible individuals to insulin resistance - the regular, long-term consumption of low-dose, low calorie sweeteners. While the data are controversial, mounting evidence suggests that low calorie sweeteners should not be dismissed as inert in the gut environment. Sucralose, aspartame and saccharin, all widely used to reduce energy content in foods and beverages to promote satiety and encourage weight loss, have been shown to disrupt the balance and diversity of gut microbiota.

(Nettleton Jodi E., Reimer Raylene A., Shearer Jane, Reshaping the gut microbiota: Impact of low calorie sweeteners and the link to insulin resistance?, Physiology & Behavior (2016), doi: 10.1016/j.physbeh.2016.04.029)

And they wrote in their conclusion:

Accumulating evidence suggests that low calorie sweetener consumption perturbs the gut microbiota and disrupts metabolic health in susceptible individuals. This concern was echoed by the US Scientific Report of the 2015 Dietary Guidelines Advisory Committee that provides the US Federal government with a foundation for developing national nutrition policy. These recommendations acknowledge a potential relationship between low calorie sweetened soft drinks and type 2 diabetes risk.

So while the scientific community and doctors may not have specific understandings of how much artificial sweeteners are a problem, or why exactly these artificial sweeteners are disrupting the gut, and therefore the rest of the body, it seems pretty clear that these compounds should be avoided as much as possible, and definitely are not safe for daily consumption. The consensus seems to be now one of warning consumers, similar to a warning a doctor would give about cigarettes, or alcohol.

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