Prenatal exposure to nonnutritive sweeteners does not affect obesity risk in offspring

ISA statement in response to new publication by Azad et al.

Brussels, 6th May 2020: The International Sweeteners Association (ISA) responds to a new publication by Azad et al.1 Contrary to the claims by these authors, the collective scientific evidence shows that exposure to nonnutritive sweeteners, or low/no calorie sweeteners, during pregnancy does not stimulate weight gain in offspring.

In fact, a recent systematic review and meta-analysis of animal studies by Morahan et al.,2 which considered the totality of available studies investigating the metabolic and behavioural effects of maternal exposure to low/no calorie sweeteners during pregnancy and lactation, concluded that it does not increase body weight in offspring.

Importantly also, the new publication by Azad et al. has significant limitations for data evaluation. The study relies on outcomes from an observational study, which, by its nature, cannot prove a cause-and-effect relationship. Furthermore, the reported study in mice was insufficient in size for reliable assessment of body weight, a problem particularly notable when other much larger studies show no such effects.2 Finally, results from the cellular study (in vitro), the final type of study reported by Azad et al., is superseded by the larger in vivo studies, that show no ability of low/no calorie sweeteners to cause increased fat storage or weight gain.2

At a time when obesity and non-communicable diseases including diabetes and dental diseases remain major global health challenges, and in light of current public health recommendations to reduce overall sugar intake, low/no calorie sweeteners can be helpful in creating healthier food environments. They provide people with a wide choice of sweet-tasting options with low or no calories, and thus can be a useful tool, when used in place of sugar and as part of a balanced diet, in helping reduce overall sugar and calorie intake, as well as in managing blood glucose levels,3 including for pregnant women who may be at risk of gestational diabetes or excess body weight. Low/no calorie sweeteners are also not fermentable by oral bacteria, meaning that they do not contribute to tooth demineralisation, which is one of the reasons for tooth decay.3 This can be helpful during pregnancy which often puts a strain on the overall mouth health,4,5 and ensuring healthy teeth is all the more important.

  1. Azad MB et al. Nonnutritive sweetener consumption during pregnancy, adiposity, and adipocyte differentiation in offspring: evidence from humans, mice, and cells. Int J Obes (Lond). 2020 May 4. doi: 10.1038/s41366-020-0575-x.
  2. Morahan HL, Leenaars C.H.C, Boakes R.A., Rooney K.B. Metabolic and behavioural effects of prenatal exposure to non-nutritive sweeteners: A systematic review and meta-analysis of rodent models. Physiol Behav. 2020 Jan 1;213:112696. doi: 10.1016/j.physbeh.2019.112696. Epub 2019 Oct 21.
  3. EFSA Scientific opinion on the substantiation of health claims related to intense sweeteners. EFSA 2011 Journal 9(6): 2229, and 9(4): 2076.
  4. CDC Pregnancy and Oral Health:
  5. NHS Teeth and Gums in Pregnancy: