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Risks of supplement use

There are thousands of nutrition supplements on the market and there are many claims that make these supplements sound attractive to athletes interested in performance, recovery, weight management, muscle building etc. These potential benefits of supplements receive a lot of attention, but although supplements may, in some cases, provide an edge, there are also risks associated with the use of nutrition supplements. These risks receive much less attention.

Cost benefit analysis

It is recommended to do a careful risk-benefit or cost-benefit analysis before using a nutrition supplement. This means: understanding the potential benefits and the evidence that the supplement may indeed (or may not) have the claimed effects. This article will not focus on the potential benefits of supplements. That side of the equation has been discussed in previous blogs and will also be discussed in future blogs. This article will discuss the cost and risks of supplements. With cost we do not only mean financial costs but also the fact that a supplement could have negative effects on performance or on health. A risk could also mean that the supplement does not contain what it should contain. Perhaps there is less of the effective ingredient or there is too much of the active ingredient. It is also possible that there are substances in the supplement that were not listed in the label and it is even possible that some of these substances could result in a positive doping test. For elite athletes the risk of an adverse analytical finding could be devastating and potentially career ending and therefore we will discuss this risk in more detail in the next blog, including ways to mitigate this risk.

Regulation of supplements

Nutrition supplements may contain one or more, or a combination of vitamins, minerals, amino acids, fatty acids, enzymes, probiotics and other bioactive substances. Each country has its own regulatory requirements for registration and marketing approval for supplements. In some countries ,supplements are regarded as foods and in other countries as therapeutical agents (a little like over the counter drugs). The European Union (EU) and the Food and Drugs Administration (FDA) in the USA classifies these products as Food Supplements and they are regulated as food.

Too many supplements to control

In some countries, a supplement company will have to show that the supplements are produced according to certain standards, but once a supplement is on the market they are less likely to be checked again. In other countries, no control is carried out before a product is marketed but a product may be checked once it is sold. The challenge is that in most countries there are thousands of supplements on the market (the USA alone is reported to have 28,000 registered supplements), so it becomes impossible to check all supplements.

In the EU a supplement needs to be approved before it goes to market. It is checked on 3 main areas.

  • Safety of the product – A committee does an assessment on the basis of the available scientific evidence and makes a judgement if the food poses a safety risk to human health.

  • Product Label – The product label should not mislead the consumer. The companies need to ensure proper labelling of the product. Special attention needs to be given when the food is intended to replace another food and there is a significant change in the nutritional value.

  • Intention of use – When the food is intended to replace another food, it should not differ from that food in such a way that its normal consumption would be nutritionally disadvantageous for the consumer.

Different countries, different rules

In other parts of the world the requirements may be less stringent. For example, the US Food and Drug Administration (FDA) does not have the authority to review dietary supplement products for safety and effectiveness before they are marketed.

But even within the EU, the assessment is only based on the listed ingredients and there is no check of the actual contents of all supplements on the martket. So, a supplement can be contaminated or adulterated and it could contain substances. It is up to the consumer to prove that a supplement is contaminated or does not contain what it says on the label and if the consumer wins this case, the company may be fined.

Online channels make unsafe supplements available in most places

Because most supplements can be purchased online, even in countries where legislation is tighter it is possible to get nutrition supplements from countries where there is little or no regulation. So, this is a worrying situation and not easy to find practical solutions. On the one hand parts of governments want to protect the consumers, but on the other hand there is a huge industry pushing the sales of these supplements.

A summary of the risks

In summary, (adapted from UK Anti-Doping guidelines) supplements can present a high risk for several reasons:

  • Some supplements contain banned substances (read more here)

  • Some supplements can be contaminated during the manufacturing process

  • Some supplements will list ingredients on the label differently to how they would appear on the Prohibited List

  • Risk of counterfeit (fake) supplements, especially when purchased online

  • Risk of purchasing a supplement that contains more or less of an ingredient, or even none of the ingredient listed on the label (Read blog on CBD products)

What can athletes do to reduce the risk?

Although there are risks associated with supplements, it is important that athletes do two things:

  1. Make an informed decision about whether or not a supplement would really be necessary or would really help. This should be a decision based on available evidence.

  2. Limit the risk of using a supplement that is not produced to the standards you would expect. There are some general guidelines about which supplements and which companies are higher or lower risk and there are quality assurance programs that significantly reduce the risk of contamination and/or poor quality control.


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If you want to know more about supplements, the benefits and the risks. Click here.

Sports nutrition

General sports nutrition topics can be found here.

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