People are usually sensitive to drugs’ adverse reactions rather than to their effectiveness. This is why many people turn to dietary supplements instead of medicines. Let’s take statin as an example. A statin is often used to lower the cholesterol level in the blood. According to a 2021 U.S. study, 80.9 percent of the respondents said they did not take a statin because they worried about side effects even though doctors prescribed a statin for them. A whopping 72.3 percent said they would choose folk medicines or health-functional foods instead of prescription drugs. However, they need to think again. On Nov. 6, the Journal of the American College of Cardiology published a study, saying six widely used dietary supplements, promoted for reducing LDL or “bad” cholesterol, were not effective.

The researchers analyzed health data for 199 adults between ages 40-75 years and compared the effectiveness of a low-dose statin and placebo to that of six supplements – fish oil, cinnamon, garlic, turmeric, plant sterols, and red yeast rice. Among the six, garlic, plant sterols, and red yeast rice are classified by the Korean Ministry of Food and Drug Safety as health-functional foods that help lower cholesterol. However, none of the six dietary supplements showed meaningful effectiveness to lower cholesterol in the U.S. study. The only one that showed the effect was the low-dose statin (rosuvastatin 5mg).

In terms of adverse reactions, the study results were different from what the general public expected. Although the study was conducted only for 28 days, there was little difference between the drug and the six supplements in side effects related to liver function, kidney function, and blood sugar level. Statin is not without side effects but they are very rare. Other studies showed similar results. In a study that involved people who stopped taking a statin because they thought the drug would cause adverse reactions, researchers gave statin to one group and a placebo to the other. The study found that there was little difference in side effect symptoms. Researchers have concluded that 90 percent of statin’s adverse reactions were caused by the “nocebo effect,” incurred by negative expectations about the drug’s side effects.

As adverse reactions are more newsworthy than efficacy, the mass media mainly cover adverse reactions. As a result, more people worry about side effects. This is where the vicious circle is created. With growing fear, many experience symptoms that feel like adverse reactions that are not treatment-related adverse reactions. Drugmakers could feel unfair about this. They may complain that if their products were health-functional foods rather than prescription drugs, they would not have received such negative expectations.

If the blade is dull, the risk of cutting is low. But such a knife is useless. The same goes for medicines and health-functional foods. Even if it's safe, if it doesn't work, it's harmful. People should not avoid prescription drugs and rely on alternative therapies that do not work. This may worsen the disease. That is the danger we must avoid.

Jeong Jae-hoon is a food writer and pharmacist. He covers a variety of subjects, including trends in food, wellness, and medications. This column was originally published in Korean in Joongang Ilbo on Nov. 9. – Ed.