There was a time when all the products we used were natural. There was no special category for them, they were just products.

Everything we used came from plants, minerals or animal extracts. Whether for the simplest care or to treat the most complex illnesses, we used natural products. And also for making poisons.

Then, a few years ago in fact, humans invented chemical synthesis, more or less imitating the processes that take place in nature.

We got into a kind of fever for synthetics and left natural sources to one side a little bit, although we still draw inspiration from nature to design new molecules and new processes. The hardest drugs and the most potent poisons are still of natural origin. And substances of natural origin are still used in medicine to treat serious pathologies. So natural products are not lacking in efficacy.

Although I sincerely believe that, in the process of moving away from the use of natural resources for our daily care, we lost sight of their true properties, their efficacy and their danger.

Perhaps one of the few moments when we are brought back to reality is when a woman becomes pregnant and the gynaecologist tells her that she cannot take such simple things as an infusion of pennyroyal. Why can't she? Isn't everything natural safe? This is the moment when a lot of things break down.

In our efforts to promote the harmlessness of natural products, we are forgetting the real properties and efficacy of natural products.

In short: I detect a certain trivialisation of preparations and substances that were once part of our most powerful therapeutic arsenal.

To illustrate this idea, I am going to step out of my comfort zone a little and open the focus a little, I am going to reflect on 3 natural products that are very topical today: liquorice, essential oils and isoflavones, in their daily use.

Licorice

Hands up anyone who hasn't sucked on a liquorice stick. If anyone has raised their hand, they can stop reading, go to a herbalist's and try one. It is one of the most classic and well-known treats, thanks to its sweet and aromatic taste.

Liquorice extracts and products derived from liquorice are also very fashionable. They contain substances with anti-inflammatory activity, making them ideal preparations for formulating products for sensitive skin or skin sensitised by external agents. It has also been used since ancient times as a healing agent. In recent years, its properties as an anti-spotting agent have also been investigated, giving rise to various depigmenting active ingredients that are widely used in cosmetics.

If to this we add that it has a pleasant aroma and flavour, its popularity is increasing. Its use as a flavouring is becoming more and more widespread, and from the liquorice sticks I mentioned earlier, to popular black candies that I won't mention, rare is the person who hasn't tried it at least once.

But even though it is so widely used, the consumption of liquorice is not without its dangers.

There are many published case reports of side effects from excessive consumption of liquorice. Glycyrrhizin in liquorice appears to act directly on mineralocorticoid receptors in the kidney by inhibiting an enzyme, 11ß-hydroxysteroid dehydrogenase, responsible for sodium-potassium balance. The most important documented side effects are hypertension and hypokalaemia-induced side effects. This fact increases the toxicity of some drugs such as digitalis (yes, these are also extracted from plants) or thiazide diuretics. Also, oral use can alter the functioning of Cytochrome P450 and increase or decrease the potency of some drugs. Certain factors can increase people's sensitivity to liquorice, including older age and female sex.

And there is more. According to the available literature, extracts and salts derived from liquorice are not teratogenic, and have weak mutagenicity, genotoxicity, carcinogenicity and developmental toxicity effects. However, clinical studies have shown that the use of liquorice during pregnancy is accompanied by a reduction in gestational age, preterm birth and some change in hypothalamic-pituitary-adrenocortical axis function and cognitive dysfunction in the infants born. Therefore, its use during pregnancy, even topically, should be highly justified as skin absorption is modified, and especially should be used with caution in women with a family history of pre-eclampsia.

In short, the word "harmless" does not seem to be appropriate. But neither is "dangerous". We simply have to give it the value it has, enjoying liquorice in a conscious way, both for its beneficial properties and assuming its potential risks.

Essential oils

The truth is that a whole postgraduate course on essential oils could be planned and we would still leave a lot unsaid.

They are cocktails of volatile substances, small molecules, extracted by pressure or distilled from plant material. They have so many uses, so many virtues; and we often focus on their fragrance, but they go beyond smell. And here comes the main problem. Many people are trivialising the use of essential oils, focusing on the smell, without taking into account their chemical and therapeutic properties.

We are talking about complex mixtures of very small molecules, capable of crossing biological barriers, such as the skin or the placental barrier, and with high biological activity.

It would be unwise to try to list their uses and virtues one by one (it would never end), nor to try to be exhaustive about risks and precautions. For anyone interested in learning more, I recommend Tisserand's books.

However, I will mention 3 important aspects, to be taken into account whenever we use essential oils:

1. All essential oils are potentially allergenic. Because of their complex composition, they are likely to cause allergies in people who are sensitive or previously sensitised to any component. Currently in cosmetics we have a list of 26 reportable allergens, but the list will soon grow and the reality is that any molecule of natural origin is likely to be allergenic.
2. Essential oils rich in furocoumarins (citrus, rue, verbena, angelica, ...) if applied before sun exposure, can cause phototoxicity or photoallergy. This is something to bear in mind when formulating products intended for use during the day without rinsing, and especially in photoprotectors.
3. They are generally not recommended for children or pregnant women (at least in the first trimester). And it never hurts to remember that Eucalyptol, Menthol and Camphor are contraindicated in children under 6 years of age due to the risk of bronchospasm, even without direct contact with the skin (in diffusers).

Does this mean that it is best to use perfumes? Well, if the only objective in the formulation is to give aroma, then yes, it is better to use a perfume, because that is what it is for.

If we formulate a product with essential oils, it should be to take advantage of their properties, to give added value to the formulation. And always taking into account all its biological activity and adding the precautions for use that apply to it. Not only to avoid the word Parfum in the list of ingredients.

In short, let's give essential oils the recognition and importance they deserve.

Isoflavonas

I am sure that when we hear the word isoflavones, images of nature, of care come to mind... They will be feminine images, since it has been said ad nauseam that they are beneficial for women's health.

On the other hand, if I say endocrine disruptor, the image changes, we imagine dead fish in rivers, health problems and other catastrophes.

But few people make the association that isoflavones, precisely because of the benefits associated with them, are true endocrine disruptors; although there is controversy among researchers about the degree of potency of this effect.

Isoflavones are compounds with a diphenolic structure similar to that of the oestrogen 17β oestradiol. Thanks to this structure, they have the ability to bind to the body's oestrogen receptors. The two main isoflavones are genistein and daidzein, and it is about them that the most literature and research can be found.

This ability has caused rivers of ink to flow about the benefits of a diet high in soya for Asian populations, such as lower rates of prostate and breast cancer. And also of the benefits of consuming and using soya products for menopausal women.

As I said, there is controversy among researchers, especially because some of the (more positive) studies have been funded by industries with conflicts of interest.

If we look at "visible" soya consumption (soya and derived foods), the levels of exposure to isoflavones present are not worrying.

What we do not see is the high "non-visible" consumption, introduced in processed foods as an additive, which increases these levels in a worrying way. And there are many cosmetic products on the market containing isolated isoflavones, mostly body products, i.e. with high exposure.

But even with such high rates of exposure, the main concern comes not from the general adult population, but in the infant and pre-pubertal population, as well as those with active oestrogen-dependent cancerous processes.

In these cases, the use of isoflavone-rich products, even topically, should be well justified and controlled. To our regret, it is not. The amount of soya derivatives present in baby foods (including infant formula) is, for want of a better word, worrying. And in many cases these are products labelled as natural, even vegan; and they are, natural and vegan, but that does not imply that they are safe.

This is perhaps the example I like the most, because it is the very property that brings the benefit that can be a potential risk. In other words, it perfectly illustrates the idea that natural products should be used consciously and without being misled by false notions of safety.

There are many reasons to choose the natural alternative over the synthetic one, we can talk about them another day; there is no need to resort to "good" / "bad" or "toxic" / "safe" antagonisms.

As Paracelsus, and so many others, said and we never tire of repeating: Everything is poison and nothing is poison, it is the dose that defines; and in the case of consumer products, it would be the exposure.

Many brands position themselves as better simply because of their natural and "non-toxic" ingredients. But with this positioning, they may trivialise the natural ingredients they contain and mislead vulnerable consumers.

So don't be swayed by siren songs. Choose natural because you believe in it, because you like it, because you trust its efficacy, but not because of a false sense of security, please!