Do cosmetics trigger diabetes?

Sometimes it seems to me that the average Russian, and not only Russians, is not just afraid of chemistry. He feels some strange pleasure, enjoying his own indignation when reading the next news, telling about the next harmful effect of the next substance added to food, cosmetics, medicine - anywhere. The main thing is that it is added there artificially. It doesn’t matter how these “scientific” results were obtained, or whether they make sense at all. It is only important to make sure once again that the chemistry is harmful, we are being poisoned, and the authorities do not want to do anything about it.

Recently, there has been a wave of news reports in the media that cosmetics, artificial tanning and even perfume lead to diabetes. Of course, not all cosmetics, but only those that add harmful chemicals - phthalates. It’s not the first year that they have been suspected of various horrors, but they keep adding and adding. Business is business, it doesn’t care about the fate of ordinary people.

Is it so? Why doesn't anyone see the harm? It's very simple - it is much easier to declare harm than to provide reliable evidence. It is not the substance that is harmful, but its quantity. The dose of phthalates that enters us does not cause any harm, the substance is quickly metabolized, and the metabolic products are excreted from the body. These transformations have been studied in great detail. Phthalates can indeed enter the bloodstream directly from cosmetics in minute quantities, but even in this case they are harmless.

The primary source of the news was the work of scientists from Uppsala University (Sweden) published on April 12, 2012 on the website of the journal Diabetes Care . The stated purpose of the work was “to determine whether blood levels of phthalate metabolites are associated with diabetes.” The article presents the results of a blood test of more than a thousand 70-year-old city residents to determine the concentration of metabolic products of the suspected substance in their blood. It turns out that they are present in the blood of all subjects, but their concentration is higher in diabetics.

It concludes: “the findings support the current view that commonly used industrial substances (phthalates) may interfere with glucose metabolism.” The goal has certainly been achieved. But there is no need to rush to conclusions.

The main question that cannot be answered when studying the article is what is the amount of phthalates consumed by the people surveyed. Is it really believed that all 70-year-old residents of Uppsala apply the same creams equally often? I can admit that there is a certain average consumption of cosmetics by women, but what should we do with male representatives? I don’t know how it is in Uppsala, but in our area not all men, even over 70, use creams and perfumes. The researchers note, of course, that phthalates are everywhere and very difficult to quantify. So, it’s possible not to carry it out?

It turns out that the metabolism of a certain substance was studied without any idea of ​​its quantity. The effects (metabolites) have been measured, but there is not even a minimal understanding of the causes (phthalates). What conclusion can be drawn from this? With the same success, one can study the concentration of alcohol in the blood without finding out how much and what a person drank or did not drink, and draw conclusions on this basis about the activity of alcohol dehydrogenase (an enzyme that oxidizes ethanol in our body).

Okay, let's say the average amount of phthalates consumed does not depend on the individual. In this case, we are offered a hypothesis: an increased amount of metabolites of a substance leads to metabolic disorders. Returning to the example of alcohol metabolism, this is equivalent to the fact that the mere fact of drinking an unknown amount of alcohol causes a deficiency of alcohol dehydrogenase.

Where did the golden rule “correlation - not dependence” go? We discovered a connection, put forward a hypothesis, and then? What is the scientific value of a hypothesis that looks strange and has not been tested in any experiment?

I have my own hypothesis. Diabetes is a metabolic disorder. Scientists have discovered increased concentrations of certain substances in diabetics - products of phthalate metabolism. This means that in diabetic patients, not only the metabolism of glucose, but also of phthalates is disrupted. Metabolic disorders lead to metabolic disorders. Obviously and without unnecessary entities. It can be easily verified experimentally if desired. As with alcohol: there is not enough enzyme in the body - alcohol is excreted more slowly, and its concentration in the blood is higher.

Giving credit to the authors of the work, I note that their article modestly mentions that causation has not been proven. But who reads entire articles today? Many people don’t even finish reading the annotations...

Sergey Belkov

P. Monica Lind, Bjorn Zethelius, and Lars Lind, Circulating Levels of Phthalate Metabolites Are Associated With Prevalent Diabetes in the Elderly, Diabetes Care April 12, 2012, doi: 10.2337/dc11-2396