Intensive sweeteners and health risks. A recent scientific study from the University of Calgary (Canada) highlights the possible negative impact of such substances on the microbiome and health during pregnancy and lactation, as well as on infants.
Non-nutritive sweeteners and bulk sweeteners, identities and differences
Non-nutritive sweeteners-or intensive sweeteners-attribute extraordinarily more sweet flavor to food products (30-8,000 times) than sucrose (sugar), but do not provide nutrition. Zero calories.
Almost all intensive sweeteners are chemically derived and are added to food products as sweetening additives. Saccharin, aspartame and acesulfame-K are the best known, as well as debated for the possible risks associated with their consumption.
Distinct from these are steviol glycolysides, which also qualify as intensive sweeteners(Non-Nutritive Sweeteners, NNS) and yet are derived from a plant, stevia(Stevia rebaudiana Bertoni). Which is itself the subject of biotech research, as noted.
Bulk sweeteners-such as sorbitol, mannitol, maltitol, isomalt, lactitol, xylitol, erythritol (polyols)-are themselves, like stevia, of plant origin. And yet they differ from non-nutritive sweeteners (NNS) in three respects:
– a sweetening power less than or equal to that of sugar (from which, moreover, they are favorably distinguished by a lower glycemic index),
– an energy value of 2.4 kcal/g (with the exception of erythritol, which is calorie-free),
– Substantial absence of doubt about their safety for human health (a common element with stevia. Subject to a laxative effect for polyols in case of excessive intake).
Intensive sweeteners and the microbiome. Health of pregnant women, mothers and and children
Scientific research published in Gut in February 2020 considers the potential negative impact of some non-nutritive sweeteners (aspartame and stevia) on the microbiome and health of pregnant or lactating women and their babies. (1) Researchers fed a high-fat, high-sugar diet(ad libitum) to 150 pregnant female rats and followed their delivery and offspring development over the next 18 weeks. The animals were divided into three groups, and the pregnant animals alone (then mothers, not also the young) were given-water, water and aspartame, water and stevia (Rebaudioside A, manufactured by Sigma-Aldrich), respectively.
Alteration of the gut microbiota was found in offspring as well as in mothers given non-nutritive sweeteners. And it is prominent in the aspartame group. Along with other phenomena:
– Obesity of pups of mothers subjected to aspartame (if even birth weight in the three groups was homogeneous), (2)
– greater weight of both groups of (obese) mothers subjected to aspartame and stevia, compared with the third group,
– diabetes risk. There is evidence of decreased insulin sensitivity in aspartame-consuming mothers and their offspring, with impaired glucose tolerance in male offspring. Glucose intolerance has also been reported in a previous study as an effect of saccharin consumption, (3)
The impact of the Calgary clinical trial.
The International Sweeteners Association (ISA) has taken the brunt of the study under review, however, trying to downplay the value of its findings. The use of acaloric sweeteners during pregnancy or lactation, ISA says, has so far been considered safe for the health of mothers and children (at least within the limits of the ADI, Acceptable Daily Intake). (4)
The last straw is for the chemical additives industry association and its large customers to go so far as to deny the clinical evidence offered by the University of Calgary. Reaffirming the dogma–clamorously disproved by gut tissue analysis–that non-nutritive sweeteners could not alter the microbiota because they would not reach the terminal part of the intestine.
Scientific studies ‘on order’, tentative conclusions
Robert Verkerk–founder , executive director and scientific director of Alliance for Natural Health International–has so far been the most critical voice against ISA chatter. (4) Emphasizing how the studies deduced by industry to obtain approvals for certain products turn out, in not a few cases, to be geared ‘to serve’ financiers.
The study ‘Relationship between Funding Source and Conclusion among Nutrition-Related Scientific Articles‘-coordinated by Prof. David Ludwig of Children’s Hospital Boston (USA)-had already revealed, in 2007, the bias in the results of hundreds of industry-funded nutrition studies. (5) And just in recent months, a wide range of scientific fraud ‘on order’ by the agrochemical industry has emerged.
It is too early to resign definitive conclusions about the impact of low-caloric or acaloric sweeteners on the microbiota, the health of pregnant and lactating women, and children. However, this clinical study highlights an emerging risk that food safety risk management authorities (European Commission and member states, in EU) need to address. The microbiome plays a key role in human health-including for the immune system, as noted -and the need to protect it is imperative.
Dario Dongo and Camilla Fincardi
Notes
(1) Jodi E, Nettleton, Nicole A. Cho, Teja Klancic, Alissa C Nicolucci, Jane Shearer, Stephanie L. Borgland, Leah A Johnston, Hena R. Ramay, Erin Noye Tuplin, Faye Chleilat, Carolyn Thomson, Shyamchand Mayengbam, Kathy D. McCoy, Raylene A. Reimer. (2020). Maternal low-dose aspartame and stevia consumption with an obesogenic diet alters metabolism, gut microbiota and mesolimbic reward system in rat dams and their offspring. Gut BMJ Journals, doi: http://dx.doi.org/10.1136/gutjnl-2018-317505
(2) The paradoxical effect of intensive sweeteners on obesity.
(3) Suez J, Korem T, Zeevi D, et al. (2014). Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature2014;514:181–6.doi:10.1038/nature13793
(4) Katy Askew,
Warning over exposure to low and no calorie sweeteners in pregnancy: ‘They may increase body weight and other cardiovascular risk factors’
, FoodNavigator.com, 24.2.20. See also ISA(International Sweeteners Association), press release 8.2.20,
(5) Lenard I. Lesser, Cara B. Ebbeling, Merril Goozner, David Wypij, David S. Ludwig. (2007). Relationship between Funding Source and Conclusion among Nutrition-Related Scientific Articles, PLoS Med 4(1). doi: https://doi.org/10.1371/journal.pmed.0040005
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Graduated in Law at the University of Bologna and in Italian-French law at the Université Paris Nanterre, she is currently enrolled in the Master in Law and Food Safety Consultant at the University of Bologna.
