Every bottle on the pharmacy shelves makes a promise: “Energy and vitality.” “Immunity.” “Prostate comfort.” Pillboxes – or “nutritional supplements” – promise that they can reduce “oxidative damage” while increasing “sexual desire” and “fat burning.”
A few meters away, on the shelves of a supermarket, the same pattern is repeated: various combinations of multivitamins, minerals and herbal extracts are offered for “common well-being” or to help the consumer achieve “detoxification” or “extra vitality”. But the scientific community is skeptical of all these promises and warns that they are more marketing than actual effectiveness. These supplements do not cure or prevent disease… and they are not harmless.
Nutritionists warn about the limitations of these products, noting that except for those suffering from certain diagnosed nutritional deficiencies, nutritional supplements are not effective in treating conditions or preventing disease from occurring. In the worst cases, these mixtures can even pose certain risks to a person’s health if swallowed unsupervised or consumed in amounts higher than the maximum recommended amount.
In the eyes of the law, most of these supplements are classified as foodstuffs, not drugs. And foods intended to complement (not replace) a normal balanced diet, these supplements include vitamins, minerals (such as calcium or magnesium), and probiotics. They can also be amino acids, such as glutamine, or compounds derived from plants, such as caffeine or ginseng. Unlike medications, dietary supplements do not require a permit for sale and can be distributed wherever food is sold, from pharmacies to supermarkets. But dietitian and nutritionist Azahara Nieto warns that no matter how natural they are or appear, “they are not harmless.” Moreover, he emphasizes: “If your diet is complete, you do not need supplements.”
Experts point out that it does not make sense to resort to certain food supplements unless a nutritional deficiency is detected. “Aside from primary deficiencies, where a nutrient is absent from the diet, there are also secondary deficiencies in which a nutrient (despite being present in the diet) is not metabolized well for some reason. It doesn’t end [being absorbed] and it needs to be provided by other means,” explains dietitian Juan Revenga.
For example, obese people undergoing bariatric surgery need vitamin and mineral supplements. Vitamin B12 supplements are also recommended for people who follow a strict vegetarian lifestyle. Another supplement that may be needed is folic acid in women who want to become pregnant, according to Jordi Salas-Salvadó, professor of Nutrition at the Rovira i Virgili University of Tarragona. “Folic acid supplementation is recommended to prevent neural tube changes in the baby.” Neural tube defects can cause problems in the nervous system, such as spina bifida. According to scientists, iron supplementation to pregnant women also serves to prevent premature birth or low birth weight in people at risk of deficiency.
Weight of marketing
But in practice, the phenomenon of nutritional supplements goes beyond necessity. A survey published in the magazine Spanish Journal of Human Nutrition and Dietetics After surveying 2,630 Spaniards, it was found that 70% of the population studied had taken some form of supplement in the past year, such as food supplements, herbal extracts, products for athletes or weight loss pills. A health survey conducted in the United States found that more than half of Americans reported taking dietary supplements in the previous month. The majority claim that they take these drugs to improve their health, sports performance or to lose weight. “There is a lot of marketing and tendencies to promote poor management of daily nutrition with supplements. To compensate for this, we believe that supplementation compensates for the situation caused by our habits,” says Violeta Moizé, dietitian and nutritionist at the Barcelona Hospital Clinic.
However, no miracle can be found in these pills. “These are products that contain concentrated substances that we can find in food,” insists Revenga. This is especially true in Western countries where there is “animal food availability”; There is no food shortage. “These products are marketed because people want to be deceived. Those little boxes say ‘more energy, less fatigue, more vitality’ and that appeals to us. So-called miraculous properties are transferred to these products,” sighs the dietitian. But there are no magic recipes. “Vitamin D is related to the immune system, but taking more vitamin D will not make us more immune to Covid. We can only have an immune system within us [the boundaries of] it is our human nature; “We will not be superheroes,” he emphasizes.
According to scientific literature, beyond a few cases identified and investigated by healthcare professionals, the scope of dietary supplements is limited. Taking vitamin and mineral supplements for healthy people does not reduce the risk of disease, and weight loss supplements are not an effective method against obesity. Omega-3 fatty acids, which help reduce triglycerides, also do not have a clear and strong effect on preventing heart disease.
Last year, the U.S. Preventive Services Task Force (USPSTF) review of the role of nutritional supplements in disease prevention concluded: “Vitamin and mineral supplementation appears to provide little or no benefit in preventing cancer, cardiovascular disease, and death. With multivitamin use a small benefit in cancer incidence.”
Following its analysis, the USPSTF recommended against the use of beta-carotene or vitamin E to prevent cardiovascular disease or cancer and concluded that available evidence is insufficient to calculate the risk and benefit of taking other nutritional supplements to prevent these diseases. Commenting on these results, scientists at Northwestern University wrote an editorial in JAMA and cautioned: “The most common reason people report taking supplements is to improve or maintain overall health. However, whole fruits and vegetables may provide health benefits.” It contains a mixture of vitamins, phytochemicals, fiber, and other nutrients, possibly acting in synergy.Isolated micronutrients may behave differently in the body than when naturally packaged with other dietary components.
On the other hand, Revenga warns that since these products are considered food rather than medicine, “they do not have to prove what they say.” They also do not require a medical prescription. Anyone can consume them on their own… but these products are by no means risk-free.
Dangers of consuming excessive amounts of vitamins
First of all, one of the dangers is the control of quantities. “If you’re eating healthy and taking multivitamins, maybe you’re overdoing it,” says Revenga. The dietician states that there are maximum recommended daily intake amounts for all nutrients and that “toxic or harmful effects” may occur if these limits are exceeded.
“Many of these nutrients can limit the absorption of other nutrients,” he explains, or interfere with the activities of other organic functions. They can also cause negative side effects. “If you consume too much phosphorus, [your body’s] calcium absorption. If you take too much iodine, thyroid function may be impaired. “If you take too much vitamin D, you may get diarrhea.”
Along these lines, Salas-Salvadó warns that “absorption and bioavailability are not the same as when you get your nutrients from food.” He gives another example: “If we eat a varied diet with antioxidants such as vitamin A, E or selenium, we will consume different amounts of different antioxidants that are beneficial to health. But if you overdo it and take large amounts [of the vitamins]This may have oxidizing effects. “The important thing is to have a balanced diet and consume foods in normal physiological doses.”
Nutritionist Violeta Moizé also warns about the danger of “over-mineralisation”. “You can also saturate other channels because all these micronutrients are cofactors of reactions that occur in our body. They are needed in certain amounts to perform a function… [but]If you exceed the amount, you can fill it [your system].”
Experts point out the lack of studies on the safety of dietary supplements containing plant extracts. Revenga is critical of manufacturers advertising unproven benefits. “This is the exotic ingredient that serves the manufacturer at the sales level. “She puts glitter on,” she quips. In an article published in the International Journal of Environmental Research and Public Health, Polish researcher Regina Wierzejska points out that “recent years have witnessed the emergence of a large number of preparations containing plants never before used in Western medicine.” Its mechanisms of action have not been adequately investigated and defined; Labels often do not contain information about contraindications, which does not mean that they do not exist. Herbal ingredients, especially herbal mixtures, can have a negative effect on the drug’s mechanisms of action, both by accelerating excretion from the body and by producing dangerously high concentrations in the blood.
Added supplements
Another threat is the illegal addition of substances that the manufacturer does not identify on the box and the consumer unknowingly ingesting them. There are substances that can cause adverse effects or interact with other medications an individual is taking. The Spanish Agency for Food Safety and Nutrition (AESAN) closely monitors substances considered “pharmacologically active substances marketed as food supplements” and warns about their presence. This occurs above all with compounds that claim to increase sexual potency, promote muscle growth or accelerate weight loss.
In a study analyzing adulteration of dietary supplements to improve sexual function, the majority were found to contain phosphodiesterase inhibitors such as sildenafil (available in Viagra). In a few cases, these substances were even present in doses well above the maximum approved amount recommended in medicines. “This is an adulteration that is particularly dangerous for a person who is taking medication to control blood pressure, for example,” says Revenga. The same thing happens with “natural” weight loss products containing antidiabetic active ingredients, he adds. Last year, AESAN issued three warnings about the presence of active ingredients in food supplements similar to those used in the production of Viagra, as well as another warning about the presence of an anti-obesity drug in a supplement presented as a “natural product”.
“The word ‘natural’ is a key that opens many doors. A snake bite or a volcanic eruption is also natural,” jokes Revenga. Experts state that caution should be exercised when consuming these substances. Nutritionist Azahara Nieto advises that before making any decisions, people should “review their diet to see what they need and not self-diagnose or self-prescribe anything.” It is always best to consult your family doctor or other healthcare professional and be weary of miraculous promises.
“There’s a lot of marketing out there. Things are being advertised that are not supported by any evidence. [and there’s] There is no mention of any undesirable effects they may have,” confirms Salas-Salvadó. AESAN warns in its recommendations that “natural does not mean safe, it just makes sense to help with weight control.” [when accompanied by] A healthy lifestyle, sports performance requires adequate training and a healthy diet… and no nutritional supplements are of any help when it comes to sexual relations.”
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