As the Winter Olympics get underway, Olympic athletes have medals on their minds. It’s not unusual for athletes to turn to nutritional supplements in hope of gaining a competitive edge, but some supplements — even seemingly natural ones — have the potential to threaten heart health, the European Society of Cardiology warns.

The group’s position statement describes the cardiovascular effects of several supplements — doping substances; medications, both prescribed or over-the-counter; legal performance-enhancing supplements; and experimental drugs.

Taking multiple supplements every day and ignoring recommended doses is common practice, but interactions between substances can be dangerous and result in abnormal heart rhythms, high blood pressure, heart attack, even death.

“Doping substances” in this case refer to the use of a substance or method that may be dangerous to an athlete’s health, often with the ability to enhance their performance. The use of anabolic androgenic steroids is an example of a doping substance. An athlete who uses steroids is six to 20 times more likely to die, with about 30 percent of those deaths attributed to cardiovascular disease.

While the World Anti-Doping Agency has a list of prohibited drugs, nutritional supplements are not included because many of them are neither regulated nor licensed. Depending on the sport and level of competition, about 40 to 100 percent of athletes use legal substances such as caffeine, creatine, energy drinks/gels/bars, beetroot juice and proteins. While these supplements may be deemed legal and safe, abuse of them can be risky and even deadly.

Taking multiple supplements every day and ignoring the recommended doses is common practice among some athletes. However, interactions between substances can be very dangerous and result in cardiovascular effects such as abnormal heart rhythms, high blood pressure, heart attack, even sudden cardiac death.

In addition, supplement use can expose athletes to the chance of taking prohibited substances since dietary supplements are not subject to the safety standards of pharmaceutical products, and the ingredients in them are not always known.

Even riskier to athletes’ health is the use of experimental drugs and methods meant to increase strength, decrease pain and repair tissue damage, all of which may result in long-term adverse health consequences.

“Athletes who use supplements often have no knowledge regarding their effects on sports performance and overall health,” the group’s position statement points out. “It is reported that most athletes get nutritional advice from coaches, fellow athletes, family members and friends, suggesting that more wide-reaching educational interventions, at an early age, are necessary.”

For athletes — and anyone seriously considering using dietary supplements — that means turning to doctors and nutrition professionals such as registered dietitian nutritionists for the best information about dietary supplements. It also means only using products from manufacturers who are well-established in the supplement field and known for their quality standards.

The statement is published in the European Journal of Preventive Cardiology.