Tonic or bitter lemon drinks carry the label “containing quinine“. Few consumers will know the reason for this: Even though drinking beverages containing quinine is unproblematic for the majority of the population, consuming larger quantities can be hazardous to the health of individuals. “Pregnant women in particular should refrain from consumption as a precaution,” says Professor Dr. Dr. Andreas Hensel.
Danger in case of hypersensitivity to quinine
People who are advised against quinine by their doctor because of a certain medical condition or hypersensitivity to cinchona alkaloids should also avoid drinks containing quinine.
To better inform consumers about possible risks, the BfR (German Federal Institute for Risk Assessment) recommends that the current labeling be expanded to include specific instructions for pregnant women and certain other risk groups.
Use of quinine
Quinine is a bitter-tasting crystalline powder extracted from the bark of the cinchona tree, Cinchona pubescens. In medicine, the alkaloid is used to treat malaria and nighttime calf cramps.
However, quinine is also used as a flavoring agent, especially in beverages such as tonics (tonic water) and bitter lemonade (bitter lemon). In Germany, non-alcoholic soft drinks may contain a maximum of 85 milligrams of quinine per liter (mg/L).
Risk to pregnant women and unborn babies
Consumed in larger quantities, quinine can be problematic for health. The BfR sees potential risks for pregnant women in particular: scientific literature reports “withdrawal symptoms” in a newborn whose mother had drunk more than a liter of tonic water daily during pregnancy.
24 hours after birth, the infant was found to be trembling nervously. Quinine was detected in his urine. Two months later, these symptoms could no longer be observed.
Quinine is also considered to promote labor and, in this context, was also previously abused in high doses as a means of abortion.
Warning about quinine
Because of their slightly bitter taste, quinine-containing drinks are popular thirst quenchers, which are drunk in larger quantities especially in the summer months – also by pregnant women. What’s more, recommendations can be found on the Internet expressly advising pregnant women to drink quinine-based beverages to counteract cramps in the calves at night or morning sickness.
The BfR’s advice to pregnant women, on the other hand, to refrain from drinking beverages containing quinine as a precautionary measure is made along the lines of the use of quinine as a drug – here, pregnancy is considered a contraindication.
Other risk groups
People who are advised against taking quinine by their physician due to certain medical conditions such as tinnitus, pre-damage to the optic nerve, certain forms of hemolytic anemia, or hypersensitivity to cinchona alkaloids should also avoid foods containing quinine.
Anyone with cardiac arrhythmias or taking medications that interact with quinine, such as anticoagulant drugs, should drink soft drinks containing quinine only after consulting a physician. These recommendations bring health protection in the food sector in line with risk prevention measures in the pharmaceutical sector, BfR said.
Better labeling called for
Already today, beverages containing quinine must be labeled. However, the BfR believes that more extensive information for risk groups is just as necessary as comprehensive information for consumers about any undesirable effects of quinine.
Quinine: intolerance and side effects
The signs of quinine intolerance, which can occur even after consumption of small amounts of quinine if hypersensitivity is present, are not well enough known in the general population, according to the BfR.
Adverse effects resulting from quinine ingestion are mainly tinnitus, visual disturbances, confusion or skin bleeding and bruising. In these cases, quinine should no longer be consumed and a physician should be consulted.
