Worth reading

The Flip-Flop Files

When the National Academy of Sciences (NAS) recently concluded that one’s sense of thirst — not a set number of glasses of water — should determine the amount of liquid to drink each day, this respected scientific group overturned yet another widely held piece of health advice.

Add that to a growing list of recommendations that recently have been tweaked, changed or outright discarded. In addition to ensuring full employment for health journalists, this trend has left many consumers baffled, annoyed and discouraged.

From the finding that hormone replacement therapy doesn’t help prevent heart disease in post-menopausal women to the news that we need more of certain kinds of fat in our diets, new and contrary findings are reported regularly. And consumers who thought the conclusions of medical research were ironclad often have their confidence shaken.

“We just have to accept the fact that something that is considered correct now, in a year or two there may be findings that show up to say this really isn’t necessary,” said Munsey Wheby, president of the American College of Physicians and professor of medicine at the University of Virginia School of Medicine. “I’m sure the public feels, ‘Can’t scientists just get a set of information and stick to it?’ But I don’t know of any way around it.”

Blame can be assigned many places. Researchers and institutions often over-promote the importance of their work. Journalists, suspecting that editors and audiences don’t like shades of gray, tweak findings into black or white. Consumers baffled by all the hype in the health care marketplace demand simple, unambivalent advice to act on.

Even physicians can be frustrated by the flip-flops. After giving a lecture on new guidelines for vitamin supplements during pregnancy a number of years ago, Wheby fielded a question from a physician in the audience. “Why do they keep changing these things?” the doctor asked.

As experts note, medical research and practice have never been static.

“People want science to be definitive, but anyone who has explored science knows that it is an evolving process,” said Neal Kohatsu, president-elect of the American College of Preventive Medicine and an associate professor of epidemiology at the University of Iowa’s College of Public Health. “Rarely is there a single definitive study. It’s a matter of looking at patterns over time and seeing the results come up by different investigators.”

I have ranted concerning this general issue in the past. Science demands that we test and revise hypotheses. As a physician we must search for the best data and make decisions based on those data, understanding that we may change as new data appear.

Read the long article for an update on a wide variety of interesting dietary, exercise, and even some medication issues.

This should scare you

Around the Globe, Drug-Resistant TB Is Rampant. TB was once known as the white plague or consumption. Literature abounds with characters who died of this scourge.

During my medical career, we have had great drugs to treat TB. Most patients have a quick and successful cure. However, due to a variety of factors, we now must once again worry about TB.

“The true burden is unknown,” said Dr. Mohamed Abdel Aziz, the organization’s tuberculosis expert and leader of the study. “The more we survey, the more multi-drug-resistant TB we find.”

Despite 10 years of effort, the organization has examined only about one-fifth of the world’s cases. Some countries have been reluctant to participate, and setting up regional laboratories, a worldwide effort led by the Prince Leopold Institute of Tropical Medicine in Belgium, is expensive and time-consuming.

In South Africa, only 1.6 percent of the cases are drug-resistant, said Abigail B. Wright, another author of the study, but the country’s overall tuberculosis rate is so high that that translates into 6,000 cases. In India, which has a major TB problem, a survey limited to Tamil Nadu state found a 3 percent resistance rate.

The report highlights the need for new tuberculosis drugs, said a spokeswoman for the Global Alliance for TB Drug Development.

“The last new drug was introduced in 1963,” said the spokeswoman, Gwynne Oosterbaan. Because tuberculosis is a bacterium, virtually all antibiotics attack it. But drug companies rarely test their new antibiotics against it because they might be pressured to limit the drugs’ use to that disease, costing them billions.

Tuberculosis is common in very poor countries with many AIDS cases, because weakened immune systems allow the bacteria to grow. But drug-resistant cases are more common in moderately poor countries where patients receive inadequate treatment.

Many cases were found in Kazakhstan, Uzbekistan, Estonia, Latvia, Lithuania and parts of Russia, as well as in two Chinese provinces, South Africa and Ecuador. On a smaller scale, a high rate of cases per capita was also found in Israel, presumably through immigration from countries of the former Soviet bloc, the report said.

The situation in former Soviet Union countries is particularly bad because of the abrupt collapse of the bloc’s economy in the 1990’s, said Dr. Peter Cegielski, leader of the international multi-drug-resistant TB team at the Centers for Disease Control and Prevention in Atlanta who conducts studies in Russia.

Shortages forced many patients to cut back to one or two drugs “and that’s what leads to resistance,” Dr. Cegielski said. Also, a number of prisoners with TB were released in amnesties, spreading the disease. In addition, said Dr. John Jereb, a C.D.C. epidemiologist, Soviet bloc countries used unusual treatments.

In the West and in poor countries following World Health Organization recommendations, all patients are supposed to get a cocktail of four “first-line” drugs: streptomycin, isoniazid, rifampicin and ethambutol. The standard therapy, “directly observed treatment, short-course,” or D.O.T.S., requires that a family member, a nurse, or even a traditional healer watch each pill swallowed every day for six months.

The first-line drugs are cheap and have few side effects. Resistance develops when patients skip pills. But researchers also suspect resistance is high anywhere that the same drugs are sold over the counter, as they are in Southeast Asia.

One of my colleagues studies this problem. Most strains are susceptible to more expensive medications. Someone must find the money to treat these patients properly. We in the US do a particularly good job at treating TB through our public health departments. For this disease we have model programs.

As this epidemic spreads, it may well once again become a major health problem. Some would argue that it already is.