International Association for Evidence Based Psychotherapy

Doubts about artificial sweeteners – The ‘evidence-based’ minefield.

Seeing the news about artificial sweeteners and the various reactions to it, I’m struck how difficult it can be to assess the raw scientific data, the direct inferences drawn by researchers and then the more socio-economic-political positions of other users and commentators.

For many years I have been aware of an idea, little more than a proposition, that artificial sweeteners give a signal to the body that interferes with the metabolism of insulin.  In a sense, it didn’t matter whether or not this was scientifically proven*, it was a useful point to discuss if the agenda was to wean someone off a craving for sweetness that was harming their health.

However, a study on mice recently published in the journal Nature has found that ingredients such as saccharin and aspartame caused high blood sugar levels, a state that is a precursor for diabetes.  The effect appeared to be due to changes in the make-up of gut bacteria, which play an important role in metabolism. So that’s the data but then the interpretation of the data leads to headline warning that artificial sweeteners in diet products could raise the risk of diabetes.

Eran Segal, who led the work at the Weizmann Institute of Science in Israel, said “We were surprised by the results, given the massive consumption of artificial sweeteners”.  He’s not wrong.  Quite apart from Diet Coke there’s things like this cheesecake recipe 

that uses 6 tablespoons of sweetener.  Yes, tablespoons.

Not surprisingly, the conclusions have been challenged by nutrition experts.

The Times reports that Catherine Collins, principal dietitian at St George’s Hospital, London, said that because the diet of laboratory mice was so different from that of the average human, the results could not reliably be extrapolated.

The Times also reported that Sir Stephen O’Rahilly, of the University of Cambridge, said that recent randomised trials showed that children who were given artificially sweetened drinks rather than sugary ones were less likely to become overweight.  “This is the background against which the study needs to be viewed,” he said.

That’s one way to express the data but studies such as 

clearly show that it is sugar sweetened beverages (SSBs) that correlate with obesity to the extent that one can say that SSBs seriously contribute to obesity rather than being able to say that artificial sweeteners lead to weight loss, or that they are safe.

No article that mentions artificial sweeteners and ‘minefield’ in its title can ignore the Aspartame controversy. Suffice to say that FDA officials describe aspartame as “one of the most thoroughly tested and studied food additives the agency has ever approved” and its safety as “clear cut” (from http://en.wikipedia.org/wiki/Aspartame_controversy ).

So if we exit the minefield and want to take a thought with us from all this it might be: “If you are overweight, sugar is your enemy.”  (Sugar, fructose, or other carbohydrates that are easily broken down into sugars.)

*Btw, studies on humans have shown that artificial sweeteners DO have an effect on insulin – see http://www.medicalnewstoday.com/articles/261179.php or
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951976/