Each of us might recall moments when we realized that information we had read about medical treatment was no longer true. 

This has become most evident during all of the controversy over COVID-19, and methods of treatment and prevention, including masking, viral transmission and booster shots. Another is the use of daily aspirin as protection against the first heart attack or stroke. 

Surprisingly, shifting medical advice is not uncommon, and according to a recent New York Times article and Dr. Prasad’s book “Ending Medical Reversal,” it tends to fall into three categories:  emerging guidance, replacement advice and reversals. 

Emerging guidance occurs during times of crisis, like pandemics, and is destined to change quickly. In the past several months, guidance about the best way to treat COVID patients, masks to prevent transmission and the limits of vaccine protection have all shifted as the knowledge about the coronavirus and its variants have evolved. 

A primary example of medical reversal took place in 2002, when decades of advice about the heart benefits of menopause hormones seemed to change overnight. During that time doctors explained to women that the treatment would be good for the bones (decreasing the risk of osteoporosis), bad for the breasts (increasing the risk of breast cancer) and good for the heart (decreasing the risk of heart attacks).

On balance, it appeared that the benefits outweighed the risks. Many patients started the therapy. (When I practiced pharmacy,  Premarin, a conjugated estrogen, was one of the most prescribed drugs.)  But then a well-designed clinical trial showed that this strategy was flawed, along with the advice. Estrogen-replacement therapy was of no benefit to the heart. In fact, at least early in the course of therapy, the treatment might even carry some risk. This was a perfect example of a reversal. The current advice is not to use such drugs for chronic disease prevention.

The same is true for using megadoses of vitamins to lower cancer and heart risk.  For years, doctors believed that various vitamins could lower the risk for cancer and heart disease, but numbers of studies have shown just the opposite.  A study of beta carotene (a provitamin used by your body to make vitamin A) and vitamin A found that the supplements actually increased the risk of lung cancer in male patients. A study of vitamin E and selenium, thought to protect against prostate cancer, increased the risk for the disease.

Many cardiac surgeons elected to insert stents, tiny wire mesh tubes that prop open arteries in millions of otherwise stable patients with heart disease. Some were coated with a slow release medication to help prevent blood clots from forming in the stent.  A study found that the surgical procedure was no better than drug therapy for preventing heart attacks.

For years, doctors struggled to treat people (mostly women) who suffered osteoporotic fractures of the spine. These fractures can lead to chronic back pain. In the late 1990s, a couple of radiologists had a brilliant idea: Why not insert a needle into the fractured bone and inject medical-grade cement?  The theory was that the cement would plump up the bone, the nerves would get some extra breathing room as the fractured bone was lifted away, and the pain would dissipate. When these pioneers performed the procedure, vertebroplasty, on a few dozen patients, they were amazed with the results. Patients immediately felt better. Patients and doctors were convinced.

In 2009, two groups of brave investigators put vertebroplasty to the true test. They enrolled 200 patients. Half of the patients got vertebroplasty; the other half were taken to the procedure room and prepped for the procedure; the cement was opened, so patients could smell it; and salt water was injected. Both groups of patients, those that got vertebroplasty and those that had a sham procedure, had identical improvements. Vertebroplasty, as it turned out, is no better than a placebo.

Arthroscopy surgery had been used for years to partially remove torn meniscus tissue.  It was the most common orthopedic procedure in the United States, with about 700,000 performed each year. 

In 2013, a researcher in Finland compared the operation to a “sham” procedure and found there was no benefit.  Most doctors now recommend physical therapy for treatment.

The latest example of a medical reversal concerns using daily aspirin to lower the risk of heart attack or stroke. There is concern that such use can increase the risk for internal bleeding.  At the same time, the Preventive Services Task Force lowered the age of regular colonoscopy screening to 45, down from 50.

Final Thoughts

The reversal of established medical practice is common and occurs across all classes of medical practice. A review done a few years back examined 756 articles addressing a medical practice of that number, 146 were medical reversals.

Max Sherman is a medical writer and pharmacist retired from the medical device industry.  His new book “Science Snippets” is available from Amazon and other book sellers. It contains a number of previously published columns.  He can be reached by email at  maxsherman339@gmail.com.