Are natural ingredients and products actually safer?

With the modern zeitgeist being natural is better, is this necessarily always the case? Short answer – not always. Longer answer – no, maybe, case-by-case analysis…

It is evident that an increasing number of brands and raw material manufacturers are seeking ever-more ingredients of natural origin to put in their products. This is likely a reflection of the modern school of thought “natural is better”, at least when trying to explain consumer behaviours, with ingredients from Ayurvedic and Traditional Chinese Medicine carrying the most weight. There seems to be a belief that “naturals” are more healthy and safer than “synthetics”, but that is not always the case, and effective assessment of natural ingredients are further compounded by their very nature (further discussed in the article “Establishing safety of natural ingredients”).

Trends in natural beauty

Evidence suggests that the natural beauty market is expanding at a compound annual growth rate of 9.5%, which is almost twice the rate of the beauty market as a whole. Its market size is expected to double by 2025 to $25 billion. It is suggested that this is buoyed by rising demand for chemical-free products, including greater awareness of their harmful effects. After organic food, people are looking increasingly at organic beauty products. Indeed, a questionnaire-based study with respect to the use of topical herbal remedies and cosmetics showed that terms like “natural” and “herbal” were perceived to indicate benign properties without the risk of adverse effects (Corazza et al., 2009).

Public suspicion in synthetic chemicals could be further enforced by mistrust of large corporations; and example of which includes the Johnson & Johnson alleged talc (despite it being a natural ingredient) case where up to $120 million in damages was awarded to women who developed cancer, despite causation being inconclusive (American Cancer Society; Reuters). Specifically, a recent review of animal and human data indicated that the evidence does not support a causal association between perineal talc use and ovarian cancer (Goodman et al., 2020). Furthermore, the authors identified that some case-control studies reported weak positive associations, while other case-controlled and three large prospective cohort investigations found the association to be null. Additionally, animal experiments showed no marked association with cancer, in vitro and genotoxicity studies did not indicate a carcinogenic mechanism of action for talc, and mechanistic and transport investigations that did not support the retrograde transport of talc to the ovaries. As such, the authors concluded that an alternative hypothesis that talc does not produce ovarian cancer, and that bias and confounding contribute the reported positive associations in case-control studies, is better supported by the evidence across all scientific disciplines.

It is therefore evident that this increased trend in natural beauty could be a result of mistrust in synthetic chemicals, mistrust in the previous status quo, and the perception of risk by the general public (more on this later).

What does the data say?

For now, it would be pertinent to look at numbers to carry the point across that natural is not always safer. Below is a table of the lethal doses in humans of a number of different natural and synthetic substances.

Table 1: Comparision of human lethal dose between natural and synthetic substances

As is seen, the highest toxic substance to man is Botulinum toxin, which is not man-made but of natural origin. While the examples may be considered extreme (indeed there are many instances of natural products not posing acute risk to health as evidence by one example by the LD₅₀ >2000 mg/kg in rat for Lavender, Lemon eucalyptus, and Cassia oils (Jeong et al., 2010)), it nevertheless highlights the point; natural does not always equal safer. For instance, the rat LD₅₀ of MSG and glyphosate are also significantly higher than 2000 mg/kg (16600 and 10537 mg/kg respectively) (Sax, 1989; Walker and Lupien, 2000).

Is it really synthetic?

The difference between natural and synthetic substances should also be noted: natural chemicals are produced by nature without any human intervention. Synthetic chemicals are made by humans using methods different from those in nature, and these chemical structures may or may not be found in nature. This raises the interesting discussion of when is something truly man-made. It also points to the potential fallacy of conveniently binning something as either “natural” or “man-made” especially in the public’s conscience when natural = good, and man-made = bad. However, this discussion is perhaps one for the philosophers.

Risk perception

This topic is perhaps at the epicentre of why consumer behaviour indicates greater confidence in natural products and ingredients rather than synthetic, man-made ones. The public’s appetite for man-made chemicals has been decreased due to high profile cases such as the perceived estrogenic effects of sunscreens. An example of risk perception with media attention, consumer anxiety and a major impact on the market of sunscreens occurred in April 2001 in Europe. Briefly, the cause was the article by Schlumpf et al (2001), suggesting that several UV screens show estrogenic activity. They used an in vitro test with the MCF-7 breast cancer cell line and an in vivo rat uterotrophic assay (Schlumpf et al., 2001). What the authors identified was hazard, and hazard does not necessarily result in risk as risk is a function of exposure. The response from the media was significant, and likely drove consumer anxiety. But the response is understandable in light of growing concern regarding possible harmful effects of exposure to substances that are able of affecting the endocrine system. However, in the case of UV screens, this was not the case. In fact, their use was recommended by the SCCNFP (Opinion on the evaluation of potentially estrogenic effects of UV-filters, SCCNFP/0483/01). In that particular case, the activity found was very low (Schlumpf et al., 2001) in comparison to the exposure arising from estrogenic substances in food (flavonoids) and hormonal therapy (birth control pill, morning after pill, post-menopausal therapy).

Another example is that of aluminium in deodorant and its potential role in breast cancer. The synopsis was as follows; aluminium-based substances in deodorants form a temporary “plug” within the sweat ducts that stops the flow of sweat to the skin’s surface. This inhibited the elimination of toxins which could then accumulate in underarm lymph nodes and thought to be the origin of the onset of breast cancer. Firstly, the major premise for this had no scientific foundation, as the major function of sweating is not to eliminate toxins and waste products, but for thermoregulation and homeostasis. Furthermore, antiperspirants work by aluminium salts blocking sweat glands, not lymph nodes.  Although lymph nodes do remove toxins, they do not remove them by sweating.  Most carcinogens are removed through the liver or kidneys and excreted out (Darbre, 2005; Exley, 1998). It is also important to highlight that that breast cancer starts in the breast and spreads to the lymph nodes, and not as indicated by popular media at the time. Furthermore, no studies to date have confirmed any substantial adverse effects of aluminium that could contribute to increased breast cancer risks. A 2014 review concluded there was no clear evidence showing that the use of aluminium-containing underarm antiperspirants or cosmetics increases the risk of breast cancer (Willhite et al., 2014). The French Health Products Safety Agency (AFSSAPS, 2006) came to the same conclusion as the one reached by a group of experts in Europe (Namer et al., 2008), namely that in the absence of scientific evidence it seems not reasonable to conclude that at present a constituent in deodorants/antiperspirants could induce breast cancer.

As will be further explained the article “Establishing safety of natural ingredients”, safety of natural ingredients and products should be established on robust approaches, rather than on perceived risk by the public. The later plays a significant role in market trends and consumer behaviour, but at times can be at odds with scientific data and approaches. This is not uncommon, as several studies have shown that large differences exist between views of lay citizens and experts (Blok et al., 2008), or managers, toxicologists and the public (Mertz et al., 1998). These must be recognized and understood in order to facilitate communication and to really manage risks of different kinds (Reynolds, 2011). Risk perception by the consumer should not be underestimated as it can be the driving force behind media attention, political pressure, and market trends.

Conclusion

There is a trend for natural ingredients and products in cosmetics and this is likely driven by, amongst other factors, mistrust in synthetic chemicals, mistrust in the previous status quo, and the perception of risk by the general public. There are numerous examples of when natural substances have a higher potential for toxicity than synthetic, and vice versa. Instead of perceived safety being driven by perceived risk based on origin of the substance, safety should be established on robust scientific principles.

Owing to expertise in a number of relevant fields. kriTOX can help you define the best strategy for your products. Please click here should you need more information about cosmetic ingredient services.

Published by Boris Krivoshiev, PhD – Founder and Principal Toxicologist at kriTOX

References

AFSSAPS (2006) ‘Évaluation du risque lié à l’utilisation de l’aluminium dans les produits cosmétiques’, Agence française de sécurité sanitaire des produits de santé, Saint-Denis. Rapp.

American Cancer Society (no date) Talcum powder and cancer. Available at: https://www.cancer.org/cancer/cancer-causes/talcum-powder-and-cancer.html.

Blok, A., Jensen, M. and Kaltoft, P. (2008) ‘Social identities and risk: expert and lay imaginations on pesticide use’, Public understanding of science, 17(2), pp. 189–209.

Corazza, M. et al. (2009) ‘Use of topical herbal remedies and cosmetics: a questionnaire‐based investigation in dermatology out‐patients’, Journal of the European Academy of Dermatology and Venereology, 23(11), pp. 1298–1303.

Darbre, P. D. (2005) ‘Aluminium, antiperspirants and breast cancer’, Journal of inorganic biochemistry, 99(9), pp. 1912–1919.

Exley, C. (1998) ‘Does antiperspirant use increase the risk of aluminium-related disease, including Alzheimer’s disease?’, Molecular Medicine Today, 4(3), pp. 107–109.

Goodman, J. E. et al. (2020) ‘A critical review of talc and ovarian cancer’, Journal of Toxicology and Environmental Health, Part B, pp. 1–31.

Jeong, M.-H. et al. (2010) ‘Evaluation of acute toxicity of plant extracts, lavender, lemon eucalyptus and cassia essential oil’, The Korean Journal of Pesticide Science, 14(4), pp. 339–346.

Mertz, C. K., Slovic, P. and Purchase, I. F. H. (1998) ‘Judgments of chemical risks: comparisons among senior managers, toxicologists, and the public’, Risk Analysis, 18(4), pp. 391–404.

Namer, M. et al. (2008) ‘L’utilisation de déodorants/antitranspirants ne constitue pas un risque de cancer du sein’, Bulletin du cancer, 95(9), pp. 871–880.

Reuters (no date) ‘Johnson & Johnson ordered to pay $55 mln in talc-powder trial’. Available at: https://www.reuters.com/article/us-johnson-johnson-talc-verdict-idUSKCN0XT20L.

Reynolds, B. J. (2011) ‘When the facts are just not enough: Credibly communicating about risk is riskier when emotions run high and time is short’, Toxicology and applied pharmacology, 254(2), pp. 206–214.

Sax, N. I. (1989) ‘Dangerous properties of industrial materials’.

Schlumpf, M. et al. (2001) ‘In vitro and in vivo estrogenicity of UV screens.’, Environmental health perspectives, 109(3), pp. 239–244.

Walker, R. and Lupien, J. R. (2000) ‘The safety evaluation of monosodium glutamate’, The Journal of nutrition, 130(4), pp. 1049S-1052S.

Willhite, C. C. et al. (2014) ‘Systematic review of potential health risks posed by pharmaceutical, occupational and consumer exposures to metallic and nanoscale aluminum, aluminum oxides, aluminum hydroxide and its soluble salts’, Critical reviews in toxicology, 44(sup4), pp. 1–80.