Knowledge Comes and Knowledge Goes
A guest post by Arnon Krongrad, MD, urologist and coauthor of the selenium study cited below.
Once, the earth was flat and everybody knew it. Today, the earth is round and everybody knows it. Knowledge comes and knowledge goes.
So it is with health knowledge. Consider selenium, found in soil in inverse relationship to the incidence of skin cancer. Someone hypothesized that adding selenium to diet would reduce the incidence of skin cancer. Thus was hatched a multi-center, randomized, placebo-controlled trial that tested and found that selenium made no difference to the incidence of skin cancer.
As a secondary endpoint, the trial found that prostate cancer incidence was substantially lower in the selenium arm. There was a problem: This was a patterns-of-care study. This meant that, contrasted with designs of future studies of such drugs as finasteride, the selenium study did not require prostate biopsy: It was possible that selenium concealed – not prevented – prostate cancer.
No matter. In the wake of that study, selenium flew off the shelves. The people selling selenium knew what they wanted to know, regardless of primary data.
Then a new trial, SELECT, was instituted to better look at selenium and prostate cancer. This better study found that selenium makes no difference to prostate cancer incidence and it was summarily terminated. No matter: Various interests continued to promote selenium in prostate health, even in the face of overwhelming evidence that such promotion was contradicted by science.
Journalists still perpetuate the distribution of false knowledge in regards to selenium and prostate cancer. Witness a recent article from Staten Island Live. In misrepresenting current scientific knowledge about selenium and prostate cancer the article is broadly and consistently wrong. For example, it incorrectly identifies Bill Fair as the man behind the selenium story; years ago Dr. Fair did study zinc in relationship to infections, not selenium in relationship to cancer. The article omits the critical fact that SELECT negated the original hypothesis. How can false health knowledge be discarded if health reporters steadily ignore the facts?
Sometimes false knowledge lingers not from ignorance but elusive, other reasons. Consider antibiotics and chronic prostatitis, a condition associated with organ-specific pain and non-organ-specific complaints such as fatigue, irritable bowel, and social isolation. We know that antibiotics usually work no better than placebo, yet we prescribe antibiotics in wild excess. We know the knowledge is wrong but do not change our behavior to accommodate this.
Why are we fixed in old, false knowledge when we know it? As in the case of chronic prostatitis, one common problem may be the absence of effective alternatives. And so antibiotics, alpha-blockers, prostate massage, all minimally effective, are commonly prescribed. And when patients do not get better, they’re shuffled off to the next consultant as if modern-day lepers belonging to an international, itinerant colony. They disappear from view, which makes it easier to keep on keeping on with the old and ineffective.
At the nexus of old and new knowledge is scientific research. As we seek to unring the bells of selenium and antibiotics, we look at fish oil for prostate cancer prevention, laparoscopic surgery for chronic prostatitis treatment, and many other proposed new solutions. We start with the clues found in anecdote and, guided by hypothesis, grow them into case series and clinical trials and broad reproduction until maybe, one day, we arrive at knowledge that can endure for the ages, but not always.
Once, gastric ulcer was a surgical disease and everybody knew it. Today, gastric ulcer is an infectious disease and everybody knows it. Knowledge comes and knowledge goes. Health journalists should faithfully cover knowledge coming and knowledge going.
Publisher’s note: We don’t often turn over our blog to guest bloggers. But when someone makes a convincing case about a problem in the way health news and information is communicated, I will consider it. I don’t necessarily agree with Dr. Krongrad’s characterization of the article in question as “journalism.” It is, after all, written by another urologist who appears to be a columnist for a website. That doesn’t make it journalism. But that also doesn’t make it irrelevant. As more people turn to the Web for their health information, they come across many sources. And it behooves all of us to consider the source – whether it be Dr. Krongrad or Dr. Motta or me.