Scares Du Jour
An unfortunate characteristic of the American health news scene has been the tendency of the media and the public to misinterpret and exaggerate preliminary reports of health risks.
These biased and frequently unfounded reports often ignite health scares that inflame public fears, waste scarce resources, and divert attention from real public health concerns to trivial or nonexistent ones. Perhaps a look at the past will teach us to cast a skeptical eye on the latest health scares being served up by fear-mongers.
15,000 Pounds of Cranberries a Day
Just a few weeks before Thanksgiving, 1959, consumers were horrified when then-Secretary of Health, Education and Welfare, Arthur Fleming, announced that a shipment of cranberries from Oregon had been found to be contaminated with a weed killer, aminotriazole. Since the pesticide had been shown to cause cancer in lab rats (when fed at extremely high doses), it had been restricted to post-harvest use.
The panic was immediate. State and city health officials in Ohio, California, and Illinois banned cranberry sales. Michigan, Kentucky, and Washington state called for voluntary suspensions.
But no one bothered to point out that a human would have to consume 15,000 pounds of berries every day for years in order to ingest a dose similar to that fed to the lab rats!
Fortunately, cooler heads prevailed in time for Americans to enjoy cranberry sauce with their Thanksgiving turkeys. Unfortunately, a precedent had been set by this widely publicized scare. The public developed an irrational fear of trace amounts of chemicals--regardless of lack of proof for any real human health risk.
How Sweet It’s Not
Ten years later, in 1969, another set of food-related chemicals, cyclamates, came under attack. Cyclamates are a group of synthetic, non-nutritive sweeteners widely used as sugar substitutes. In the late 1960s, FDA experiments showed that a byproduct of cyclamates, cyclohexamine, caused chromosome damage in male rats, and that some mice developed tumors if cyclamate was introduced into their bladders. Other studies were performed, including one showing that 8 of 240 rats fed cyclamate developed bladder tumors.
Even though the rats in this study were, again, consuming extremely high doses of cyclamates, the product was banned by the FDA. The ban was mandated by the Delaney amendment to the Food Drug and Cosmetic Act. That amendment allows no food additive that can cause cancer in animal tests (no matter what the dose ) to be added to human foods.
Later attempts to replicate studies showing cyclamate to be carcinogenic failed. Indeed, the National Research Council of the National Academy of Sciences, the World Health Organization, the National Cancer Institute, and the Food and Agriculture Organization of the United Nations have all declared that without such replication, cyclamate cannot be considered to be even a probable human carcinogen. But the ban has not been lifted in the United States.
Except for manufacturers of cyclamate-containing products, most people were not greatly affected by the ban. After all, consumers who wanted a sugar substitute could always turn to saccharin.
They could do so with confidence until about 1977. That year, the FDA moved to ban saccharin based, yet again, on high-dose rodent tests indicating that the product caused bladder cancer in rats and mice. In the case of saccharin, however, the public revolted. Millions of diabetics had depended on saccharin for years: They and other consumers pressured Congress to reverse the ban. Congress declared a moratorium on the ban, requiring instead that saccharin-containing products carry a warning label, which they do to this day.
Reassuringly, later studies have shown that while saccharin is weakly carcinogenic in male rats, it does not cause tumors in female rats or in any other species. Furthermore, human epidemiological studies have found no link between bladder cancer and saccharin use, and there has been no dramatic increase of bladder cancer in the United States.
Cancer Once Feared, Now Hormone Disruption
These historic health scares developed from a heightened awareness of, and fear of, cancer. While this factor still underlies scares we hear about today--it’s the rationale, for example, for dredging the Hudson River to supposedly alleviate contamination by polychlorinated biphenyls (PCBs)-- another basis for alarm is currently being touted.
The latest concern is that chemicals--particularly synthetic ones--are so-called “hormone disrupters.” These latest putative threats to human health supposedly interfere with the normal functioning of the human endocrine (hormonal) system. Speculated results of these interactions range from lowered sperm counts in men, to developmental delays in children, to reproductive failure in women. The evidence? Meager at best.
It is crucial for consumers to become critical analysts of health news. Important questions that must be asked of any reported scientific study include:
- Has the work been reviewed by peers of the investigators in a scientific journal?
- Have the results of the study been replicated by independent scientists?
- Is there a consensus among knowledgeable experts that the interpretation of the data is reasonable and in line with current scientific opinion?
There are many more questions that might be asked, but these few should give the wary consumer an idea as to whether the latest “scare du jour” is worth her concern. Let’s focus our attention on real health threats, learn from the past, and stop the scares!