People’s Pharmacy: Tonic water led to liver problems

Q. One summer, my go-to beverage was diet tonic water. I’d drink it all day (no alcohol). Toward the end of the summer, a routine blood test showed my liver values to be off the charts, although I felt fine.

While discussing this with my doctor, I remembered that years earlier, a similar erratic blood test had prompted another doc to ask what I had eaten or drunk the night before my blood was drawn. When I answered, “gin and tonic,” she had said, “that’s OK then.”

This time around, I quit tonic water for life. After a month, my liver values were going down. After three months, they were still elevated, though. My doc asked me whether I had any other peculiar eating habits.

I did. I had gotten in the habit of chomping cinnamon sticks all day. He did some research, and I quit cinnamon. After another month, my liver was normal. Conclusion: Apparently some people have a genetic pre-disposition to not be able to tolerate quinine. Cinnamon may also have an adverse effect on the liver for people like me.

A. Thanks for the reminder that even natural substances can have side effects. Quinine is known to cause dangerous blood disorders in some people. A study of adverse effects of this compound found that some sensitive individuals experienced liver toxicity after exposure to quinine-containing beverages such as tonic water (American Journal of Hematology, May 2016).

Cinnamon is a bit more complicated. Several animal studies showed that it can help protect against liver damage due to acetaminophen toxicity. At high doses, however, cinnamon also may harm the liver (Regulatory Toxicology and Pharmacology, June 2018).

Q. My wife has terrible motion sickness. She can’t sit in the back seat of a car. When she needs to travel, she takes ginger root before she leaves home. She has not experienced any side effects and it is inexpensive. Perhaps this approach might work for others who are susceptible to this problem.

A. Your suggestion may help people headed out on their summer vacations. Ginger has a reputation for preventing motion sickness, though scientists are still trying to figure out the exact mechanism (Journal of Ethnopharmacology, May 23, 2022). In mice, ginger compounds improve balance and coordination by reducing the release of histamine and acetylcholine in the vestibular system responsible for balance and motion sickness.

We included other testimonials on ginger for travelers along with numerous other treatments for common problems in our book “The People’s Pharmacy Quick & Handy Home Remedies.” If your library does not have a copy, you can find it in the books section under the store tab at www.PeoplesPharmacy.com.

Q. My retina specialist wants me to take PreserVision for macular degeneration. A daily dose has 80 milligrams of zinc. I also take a multivitamin containing 20 milligrams of zinc.

Credible sources state that 40 milligrams/day is the safe upper limit for zinc intake. Should I be concerned?

A. You are correct that the tolerable upper limit established by the Food and Nutrition Board is 40 milligrams for adults. Daily doses above 50 milligrams can interfere with copper absorption. This can impair immune response and lower HDL cholesterol.

We suggest that you check with your eye doctor about whether you might switch to a lower dose. The standard AREDS (Age-Related Eye Disease Studies) formulas contain 80 milligrams of zinc per day.

In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email them via their website: www.PeoplesPharmacy.com. Their newest book is “Top Screwups Doctors Make and How to Avoid Them.”