Problematic Additives in Dietary Supplements

Which Additives in Supplements Are Problematic?

Artificial sweeteners, emulsifiers, and colourants are additives that may be found in dietary supplements. With daily supplement use, it pays to look at the ingredients list. Here is an overview of the current research on commonly used additives.

Why Are Artificial Sweeteners in Supplements Concerning?

Recent studies examine possible interactions between artificial sweeteners such as sucralose and the gut microbiota. The results are not conclusive, but especially with daily supplement use, the exposure adds up.

Sucralose (E955)

Sucralose is a chlorinated sugar that is approximately 600 times sweeter than sucrose. EFSA re-evaluated sucralose in 2026, confirmed the acceptable daily intake (ADI) of 15 mg per kg of body weight per day and assessed the currently permitted uses as safe.

What the research shows:

Sucralose is the subject of ongoing research. Some studies suggest interactions with the gut flora, but the results are not conclusive. A randomised study of 120 healthy adults (Suez et al., 2022) examined possible effects of sweeteners on the gut microbiota over two weeks, at amounts below the acceptable daily intake. A study in mice on acesulfame-K (Bian et al., 2017) found changes in the gut microbiota after four weeks that differed between male and female animals.

Important caveat: The evidence is not conclusive. Some studies find no negative effects. Research is still ongoing.

Aspartame (E951)

Aspartame has been extensively studied and classified as safe by EFSA and the FDA. EFSA confirmed the acceptable daily intake (ADI) of 40 mg per kg of body weight per day and estimates intake to be well below it. In 2023, JECFA, the joint WHO/FAO expert committee, saw no sufficient reason to change this daily intake.

Acesulfame-K (E950)

EFSA re-evaluated acesulfame-K in 2025 and set the acceptable daily intake (ADI) at 15 mg per kg of body weight per day (previously 9 mg). The highest estimated intake was generally below this level in all population groups.

Which Emulsifiers Should You Avoid?

Polysorbate 80 (E433) and carboxymethylcellulose (E466) are the most scrutinised emulsifiers, as animal studies show negative effects on the gut barrier. Emulsifiers improve texture and shelf life but may affect the gut barrier.

Polysorbate 80 (E433) and Carboxymethylcellulose (E466)

A widely noted study by Chassaing et al. (2015) in Nature showed that these emulsifiers can, in mice:

• Thin the intestinal mucus layer
• Increase intestinal permeability
• Cause changes in the microbiota

Limitations:

• Animal studies are not directly transferable to humans
• The mice received the emulsifiers in their drinking water (1.0%) for twelve weeks; how much emulsifier people actually consume is hardly recorded
• Individual responses vary greatly

Are Artificial Colourants in Supplements Harmful?

In the EU, foods containing any of the colours sunset yellow (E 110), quinoline yellow (E 104), carmoisine (E 122), allura red (E 129), tartrazine (E 102) or cochineal red A (E 124) must carry the statement “may have an adverse effect on activity and attention in children”.

What Does This Mean in Practice?

Don’t Panic

Most people consume these substances in small quantities without obvious problems. The dose makes the poison.

Apply the Precautionary Principle for Regular Use

If you take supplements daily, your exposure accumulates. In this case, it can make sense to choose products without these additives.

Pay Attention to the Ingredients List

Protein powders may contain:

• Sucralose as a sweetener
• Acesulfame-K in combination
• Lecithins as an emulsifier (harmless)
• Xanthan as a thickener (harmless)

Alternatives:

• Inulin (soluble fibre)
• Lucuma (natural sweetness from the fruit)
• Coconut blossom sugar (unrefined)
• Steviol glycosides (E 960, extracted from stevia leaves and purified)
• Unsweetened products
• Natural flavourings without sweeteners

Quality Indicators for Good Supplements

1. Short ingredients list: Less is often more
2. No artificial sweeteners: Or only natural alternatives
3. No unnecessary fillers: Maltodextrin, dextrose as bulking agents
4. Transparent sourcing: Information about raw material sources
5. Independent testing: Certifications such as Informed Sport

Conclusion

Research on additives is evolving. What is considered safe today may be assessed differently tomorrow. For daily supplement use, it makes sense to choose products with as few additives as possible. Not out of panic, but out of prudence.

bunaroba Protein Powder: no artificial sweeteners, 12 g of dietary fibre per 100 g.

Sources:

• Suez J, Cohen Y, Valdés-Mas R, Mor U, Dori-Bachash M, Federici S, et al. (2022). Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance. Cell, 185(18), 3307-3328.e19. DOI: 10.1016/j.cell.2022.07.016
• Chassaing B, Koren O, Goodrich JK, Poole AC, Srinivasan S, Ley RE, Gewirtz AT (2015). Dietary emulsifiers impact the mouse gut microbiota promoting colitis and metabolic syndrome. Nature, 519(7541), 92-96. DOI: 10.1038/nature14232
• Bian X, Chi L, Gao B, Tu P, Ru H, Lu K (2017). The artificial sweetener acesulfame potassium affects the gut microbiome and body weight gain in CD-1 mice. PLOS ONE, 12(6), e0178426. DOI: 10.1371/journal.pone.0178426
• EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) (2013). Scientific Opinion on the re-evaluation of aspartame (E 951) as a food additive. EFSA Journal, 11(12), 3496. DOI: 10.2903/j.efsa.2013.3496
• EFSA Panel on Food Additives and Flavourings (FAF) (2026). Re-evaluation of sucralose (E 955) as a food additive and evaluation of a new application on extension of use of sucralose (E 955) in fine bakery wares. EFSA Journal, 24(2), 9854. DOI: 10.2903/j.efsa.2026.9854
• EFSA Panel on Food Additives and Flavourings (FAF) (2025). Re-evaluation of acesulfame K (E 950) as food additive. EFSA Journal, 23(4), 9317. DOI: 10.2903/j.efsa.2025.9317
• Regulation (EC) No 1333/2008 of the European Parliament and of the Council of 16 December 2008 on food additives, Annex V. Official Journal of the European Union L 354, 31.12.2008, pp. 16-33.