Are dietary supplements useful?

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How are dietary supplements different from drugs?

To answer the question “Are dietary supplements useful?”, you must first define what “useful” is. If the “benefit” is disease prevention or cure, that is, if we are asking if dietary supplements can cure, then there is no answer to that question.

You can understand this if you just look at the law "On the quality and safety of food products." This document defines the main requirement for dietary supplements in Russia. It sounds like this: "Food additives used in the manufacture of food products and biologically active additives should not harm human life and health." In other words, from a legal point of view, biologically active supplements are just food and they are subject to the same requirements as food products: you must not be poisoned by them. And it's all.

The next question is: what substances can we then say that they are useful, and how do we understand that they are useful?

Such substances are called medicines , and their legal status is defined by another law , "On the Circulation of Medicines", which says that they are used for the prevention, diagnosis and treatment of diseases. In other words, these substances should heal, help you cope with diseases, improve your condition. In the case of drugs, this is called efficacy, and it must be proven.

The proof of effectiveness involves solving the age-old dilemma: if something happened after that , does that mean it happened because of it ? Is there a causal relationship, for example, between a magical ritual (let's say you put a record book in the window and yelled: “Freebie, come!”) And the result (a good mark on the exam)? Or is it just a coincidence?

Many, for example, believe in the effectiveness of homeopathic remedies (which, by definition, cannot act on the body in any way), based simply on personal experience. Did it get better after taking the drug? It has become. So homeopathy works. But after all, we don’t have a time machine to go back and check: would it be better in the same situation just like that, without the drug?

Just single facts, personal experience, no matter how convincing, cannot be trusted: in this case, we have no way to check whether there is a causal relationship here. How to understand that the substance is really useful?

This requires a long set of procedures - preclinical and clinical trials - that the developers of any drug are required to carry out (if they want to receive registration and the right to manufacture and sell it).

How are drugs tested?

Testing a drug—or rather, a drug candidate—begins at the cell level: scientists check whether a substance has an effect on cell cultures, whether it can, for example, slow down the growth and reproduction of tumor cells grown in a Petri dish. This stage is called "in glass" - in vitro .

stage Now, with the advent of powerful computers, this stage is often preceded by the in silico - by computer simulation, scientists select a potential molecule of the active substance, and then check how it acts on the target - the molecule or molecular complex whose state needs to be changed.

Substances that have proven promising after experiments with cells are skipped to the next stage - preclinical studies, that is, animal experiments, or in vivo .

There are two tasks here. First, you need to make sure that the substance is safe, and determine, for example, the toxic dose. And second: check its effectiveness.

It is often not possible to simply take white mice and test them to see if a potential drug works. We must first find a model organism - that is, an animal that is able to suffer from the disease that we want to treat. To do this, it often takes a long time to breed a new line of animals, including genetically modified ones. Covid vaccine trials, for example, required genetically modified mice with human receptors in cells that human coronaviruses could land on.

In the middle of the twentieth century, at this stage - animal testing - drug testing often ended. Pharmaceutical companies could even send trial doses of drugs to doctors before registration, and then collect “impressions”. The thalidomide scandal forced a serious review of the procedure.

This tranquilizer began to be sold in the 1950s, and it was very popular as a harmless substance: in experiments on animals, it was not possible to reach a toxic dose, which means that patients were not threatened with an overdose. In particular, therefore, it was recommended to pregnant women as a remedy for insomnia and nausea. However, in the late 1950s, doctors began to record a sharp increase in the number of cases of birth defects in newborns - mainly underdevelopment of the limbs. It turned out that in most cases, mothers used thalidomide in early pregnancy. One of the two isomers of the thalidomide molecule was integrated into cellular DNA and interfered with the normal development of the fetus.

There were cases of children born whose development was affected by the fact that their mothers took thalidomide during pregnancy, were all over the world (with the exception of the countries of the socialist camp), and as a result of the investigation, it was decided to change the procedure for clinical trials and make evidence of effectiveness mandatory.

Today's requirements for clinical drug trials can be summed up in several adjectives: 1) double, 2) blind, 3) randomized, 4) placebo-controlled, 5) multicenter. The key word here is "placebo" , and that is the main way to distinguish "after" from "because of this".

And where is the guarantee that this is not a placebo?

A lot has been written about the placebo effect, let us recall the essence: even a simulation of treatment can affect a person's condition. If you give a patient a dummy pill that does not contain any active ingredient, he may still get better. That is, the very expectation of the effect of the drug can somehow affect the state of a person and his subjective assessment of his condition.

The idea behind placebo-controlled clinical trials is that a real drug, with an active ingredient, should work noticeably better than no treatment, but rather a placebo. Therefore, the standard procedure for clinical trials involves at least two groups of subjects: one receives a real drug, and the second a placebo.

It is important at the same time that the tests are blind , and preferably double-blind - that is, neither the subjects themselves, nor those who give them drugs, nor those who monitor their condition, should know who got the placebo. In addition, the very distribution of participants into groups should be randomized - completely random, that is, which group a participant will fall into should be decided by lots, and not by a person. Blindness and randomness should eliminate bias on the part of experimenters so that they cannot improve (even unconsciously) the performance of those who received the drug.

Finally, it is considered important that the trials are multicenter - that is, they are carried out in different organizations, in different regions, and preferably in different countries. This makes it possible to take into account the influence of regional and ethnic characteristics.

Clinical trials are carried out in three phases: in the first phase, the drug is given to healthy volunteers to test its safety, since it is far from always possible to reliably judge safety based on the results of preclinical studies on animals.

If no serious side effects are found, they proceed to the second phase of trials to test the effectiveness - on a narrow group of volunteers. In the case of the Sputnik V coronavirus vaccine, for example, in Russia, the first and second phases were combined: the volunteers who were vaccinated were also tested for effectiveness, that is, the presence of antibodies was recorded using tests.

And the third phase is testing the drug on large groups of people, hundreds and thousands of people. In the case of vaccines, this can be several tens of thousands of people who receive a vaccine or a placebo, and then they are regularly tested - they check whether they caught the infection or not, and if they got sick, how long the illness lasted, how hard it was and how it ended.

Based on the test results, the results are statistically processed - for example, it is necessary to prove that the discrepancy between the placebo group and the group that received the experimental drug is statistically significant, that is, that it could not be just a product of fluctuations, random fluctuations.

It is far from always that, according to the results of trials, new drugs show a statistically significant effect. Let's say that some cold medicine shows that with it the illness lasts an average of two days less than without it - this is a statistically significant result, but hardly impressive.

Organizing this whole process requires many years of work and millions of dollars - with no guarantee that the costs will pay off. But such is the price for the right to say: "Yes, our product is useful, it is really able to alleviate the course of the disease, cure it or prevent it."

And what about dietary supplements?

Summarizing the above, the short answer to the question "Are dietary supplements helpful?" sounds like we don't know.

About dietary supplements, we can only say that they are safe. The list of documents that describe the rules and procedures for the verification of dietary supplements and the rules for their handling takes several lines, and the verification also requires complex equipment and procedures.

However, testing dietary supplements for safety is still immeasurably easier and cheaper than clinical trials, simply because this procedure does not require experimental animals and humans. The rules for quality control and safety of biologically active food supplements require only laboratory studies.

in Russia In total, more than 20 thousand names of dietary supplements are registered , and these are very heterogeneous substances. The only thing that can unite them is that they serve not as a substitute for food, but only as an addition to it.

There are dietary supplements that are designed to compensate for the deficiency of certain substances and compounds in your diet - they are called nutraceuticals. These are, for example, iodine preparations that should be taken in regions with a natural iodine deficiency. It can also be vitamins, minerals, dietary fiber, some fatty acids that are worth taking if for some reason your diet does not contain them.

Another class of dietary supplements is parapharmaceuticals: "almost drugs", a class that often includes many vitamins and substances that can prevent certain diseases - for example, osteoporosis in the case of calcium supplements.

These groups of substances are intended only to make up for the deficiency in the diet and thereby prevent its consequences. But in order to prevent or compensate for the deficit, you must first make sure that it really exists. If there are no deficiencies, taking such dietary supplements is useless, and even dangerous: despite the fact that dietary supplements are non-toxic, there are dangerous doses for many of them. For a number of vitamins, cases of hypervitaminosis with unpleasant symptoms are described: for example, busting with vitamin A can lead to defects in newborns if an overdose occurs during pregnancy.

Currently, there is no evidence that taking large doses of vitamins can affect the course of diseases, that is, large doses of vitamin C are unlikely to affect the treatment of colds. The idea that vitamins can work as a medicine was put forward by the Nobel laureate in chemistry Linus Pauling (based on his experience). He actively promoted this, and it is largely thanks to him that there is now a giant industry of vitamins and vitamin supplements in the world. But clinical trials didn't support Pauling's ideas.

A separate group of dietary supplements is eubiotics, or probiotics, that is, preparations containing microorganisms that should have a positive effect on the intestinal microflora. The idea of ​​these dietary supplements goes back to the work of another Nobel laureate, Ilya Mechnikov, who believed that the “right” bacteria in the intestines can, for example, slow down aging.

Clinical studies and reviews show that these drugs can shorten the treatment time for some types of diarrhea by several days.

Modern science is getting more and more facts that a lot of the state of the body, up to the tendency to depression, really depends on the intestinal microbiome. However, this "population" of the intestine is individual for each person, and there is no one universally beneficial bacterium. In addition, the composition of the microbiome itself is very difficult to study, since a significant proportion of it is made up of bacteria that are not cultivated. The procedure for correcting the microbiome is already being applied, but this is a medical procedure - it is called "fecal transplantation". In other words, a person immediately receives a whole microbiome from another, healthy person. And of course, it is not yet possible to buy a ready-made microbiome in a pharmacy.