The Journal of the National Cancer Institute has just published "The U.S. Food and Drug Administration's Evidence-Based Review for Qualified Health Claims: Tomatoes, Lycopene, and Cancer" . FDA's Claudine J. Kavanaugh and colleagues found no credible evidence that lycopene, either in food or in a dietary supplement, was associated with reduced risk of cancer.

The articled prompted commentary from Sandra Szwarc at Junkfoodscience:

We've often reviewed the inferior evidence surrounding fruits and vegetables and their abilities to prevent major chronic diseases, including the 2004 comprehensive examination of the scientific literature done for the Produce for Better Health Foundation campaign, 5-A-Day, under the National Cancer Institute. That year, a study led by Walter Willet, M.D., DrPH, professor of epidemiology and nutrition at Harvard School of Public Health in Boston, MA, was also published. It had followed 71,910 women and 37,725 men for 15 years and found no relationship between fruits and vegetables and cancer, or any statistically significant associations with major chronic disease or cardiovascular disease.

But, time and again, the media makes little more than a whisper when studies are published questioning claims surrounding the "emerging" science of functional foods and supplements. For instance, how many heard about the May study in the journal Cancer Epidemiology, Biomarkers & Prevention on lycopene and prostate cancer? Researchers based at the National Cancer Institute and Fred Hutchinson Cancer Research Center had examined 692 cases of prostate cancer diagnosed among 28,000 men enrolled in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, an ongoing, randomized National Cancer Institute trial to evaluate cancer screening methods and to investigate early markers of cancer. They found no association between serum lycopene and total prostate cancers or aggressive prostate cancers.

No doubt it was a coincidence, but the recently-approved House ag appropriations bill contained language (Section 746) prohibiting FDA from authorizing qualified health claims for conventional foods. Including tomatoes.

USA Today turned 25 this week and ran a series of articles about changes in the world in the past quarter century. In their list of "25 Top Medical Events " was no mention of salt at all, not even recognition that during that time frame there's been a 50% increase in the number of infants born protected against the scourge of mental retardation. This achievement is due almost entirely to the massively successful global campaign to iodize salt.

One of the 25 was of some interest, however. Ranked 16th was the odyssey of hormone replacment therapy. USA Today says:

Hormones begone

Hormone therapy was once thought to be a fountain of youth for postmenopausal women, but a landmark study in 2002 found that estrogen plus progestin raises the risk of breast cancer, heart attacks, stroke and blood clots. Women stopped taking the hormones in droves, and today, they're prescribed only for relief of hot flashes and other symptoms.

As tragic as is the HRT story, it's important lesson is to teach us to demand high quality science on health outcomes before we launch a major population health recommendation. Before the government began to advise all Americans to reduce dietary salt, it should have looked at the health outcomes studied. Had it done so, we could have avoided the expensive delays -- and potential risks -- of having the "salt hypothesis" blow up in its face as HRT already has. Too bad.

The pernicious impact of advocates' use of junk science is to undermine public confidence in all science, argues an articulate letter in yesterday's Wall Street Journal. William Heller of Greenwood, Indiana, quotes an earlier WSJ op ed piece by Richard Grinker on claims that vaccinations cause autism. Grinker opines: "The antivaccine movement may be evidence that public confidence in science is eroding. . . ." Heller continues:

Proponents of the view that vaccines cause autism provide anecdotal trial "evidence" while the other side cites scientific study after scientific study that shows no such connection. A Gresham's Law effect of junk science and opinion debasing real science seems in evidence. The same factors are at work in the climate change debate. There are reams of scientific data that debunk the carbon dioxide theory of global warming, but the only data that seem to get media play is the junk science of the global warming alarmists.

Useful perspective. Bad science driving out good.